I mentioned in my post about the Theory of Everything that I wrote another book before Tools of Control, which I never published on the history of the universe and the development of Earth, life, and humans. I cover a good deal of ground in it, including the development of physical laws after the Big Bang, galaxy formation, matter, language, race, tool use, early religious behaviors, and written language. I didn’t have special knowledge on these topics when I started the book, but I learned and researched more and more as I wrote. I wrote most of it from the ages of 15 to 17, but I just recently updated it. I started writing Tools of Control when I realized I needed to narrow my focus because there were and still are so many ongoing human rights and environmental abuses due to man-made institutions with incredibly concentrated power and influence, and I felt my focus on all of history and physics was too broad. But I think it’s important to understand our roots from the very beginning to add even more context to our lives and the problems we have. I think this information should be freely available and it might be of interest to regular readers of this blog, so I thought I would publish it. This another free work. If you have the means and would like to donate, please do. Donations can be made to AGoldstein221@gmail.com.
The Birth of the Universe and the Development of Life
“A day without yesterday…”
About 13.7 billion years ago, the universe was small enough to hold in your hand. In fact, if there was there physical space to occupy surrounding it, the universe would be too small to see without a microscope. This microscopic ‘singularity’ didn’t exist within a larger black space as some conceive when told this theory.1 Rather, physical space in its entirety existed all within this blip due to the gravitational attraction of the matter in this microscopic singularity, which was so high that it attracted and drew in all of physical space.
The curvature of space-time in the singularity is currently unknown. Since there was hardly any space at this time, it makes it very difficult to define its curvature. Some physicists, such as Stephen Hawking, say it was infinite. There certainly weren’t any planets or stars present at this time and space wasn’t dark, empty or expansive. The whole universe was just one tremendously dense and most likely hot singularity consisting of extremely condensed, lifeless, subatomic particles so small that they would not be visible with any of our current technology. Because we don’t know what these particles physically were, cosmologists just call them inflatons because they eventually caused “inflation.” Although we know the gravitational attraction of the matter in the singularity was strong enough to draw in all of space itself, there could have been something alien outside of the universe that wasn’t affected by the force of gravity or any natural laws, but any speculation about such things is outside of the realm of science. For most people, imagining the singularity in either case is difficult because people often wonder, how can space abruptly end or be infinite? Both concepts seem utterly implausible to most people, but one of them has to true. Many people have difficulty believing time just “began” as well and even some of the same people have trouble with the alternative possibility that time has always existed. But since science cannot currently explain what the happened before the Big Bang, scientists believe time, as we know it, began once the Big Bang occurred.
There was likely no darkness at this time and in a very real way everything was whole. Because this mixture was so highly compact and dense, the sub-atomic particles of the mixture had virtually no room to move around, even though they were far smaller than anything we can imagine. Heat is just a measurement of how fast particles are moving. Because there was so little space for these particles to move around and they were moving tremendously fast, there was likely constant bumping and friction among these particles and this created even unfathomably high temperatures. As most know, heat causes expansion. This level of heat caused expansion on an unfathomable scale.
How long the universe remained in its singularity state before expanding and how or why it came into existence (or what surrounded the edges of space – if anything – a question that bothers people the most) is unknown. What is known about the singularity state is very limited and mostly speculative. The laws of physics that governed this singularity are also unknown because none that apply to our universe had any relevance to this singularity. But immediately after expansion, the laws of physics we are familiar with applied. First, there was gravity, followed by the nuclear strong force. Then, the nuclear weak force came into existence, followed finally by the electromagnetic force. Gravity, of course, is the force responsible for the attraction between planets and their orbits. The strong force keeps quarks, the smallest known particles in existence, together inside protons and neutrons and it also keeps baryons such as protons and neutrons together, thereby forming atomic nuclei. The electromagnetic force is responsible for keeping negatively charged electrons in orbit around nuclei. This force is caused by the exchange of photons and virtual photons, and the weak force is responsible for the emission of beta particles.
What is very strange is that cosmologists believe the forces all had the same amount of strength (they were “unified”) during the Planck epoch, a period that lasted for an incomprehensibly small fraction of a second after expansion. One Planck time (5.39121 × 10−44 of one second, that is 0. followed by 44 zeroes and then 539121) after expansion began, the Planck Epoch was over and the forces were no longer unified. After the Planck epoch, the strength of gravity was no longer equal to the strength of these other forces and it weakened dramatically and continued to do so. This was between 10-43 and 10-36 seconds after the Big Bang and it is sometimes called the Grand Unification epoch, which is a somewhat misleading name considering not all the forces were unified, as cosmologists believe they were in the Planck Epoch. Once the universe began expanding, these particles were given space, they immediately began cooling down (but were still tremendously hot), the pressure began to decrease and space became increasing large. Despite the growing volume of space, during the Planck epoch the mass of the part of the universe that we can now see was equal to a grain of sand a millimeter across. (Barbara Ryden, 2006.i)
2.1 The Inflationary Epoch and Other Early Stages of the Universe
10-36 seconds after the Big Bang just before inflation the strong force become stronger than the electroweak force, (the unified forces of electromagnetism and the weak force). This was caused by the temperature, which was 1028 Kelvin or “K.” (Kelvin is measure of temperature, in which zero is absolute zero, the temperature at which particles stop moving and can get no colder. Absolute zero is equal to -459.67° Fahrenheit.) Exotic particles such as W, Z and Higgs bosons may have begun to form at this time, but the universe mostly contained quark-gluon plasma. W and Z bosons are fundamental particles (meaning they contain no known smaller particles) that mediate the weak force. The Higgs Boson is also a fundamental particle that hasn’t yet been observed. Massive vector bosons along with photons (massless light energy particles) are what carry the weak nuclear force or weak interaction.
10-35 seconds after the Big Bang, the particle field “froze out,” and inflation began. Inflation was a period during which the rate of expansion increased exponentially and the total density of the universe approached critical density. (Critical density will be explained shortly.) The intensity of the curvature of the universe might have also changed. If the curvature was negative it would have become more negative during inflation. If it was positive before inflation it would have become more positive during inflation. But if curvature was zero before inflation it would have remained zero. Before inflation kinetic energy (the energy of motion) was more “important” than potential or stored energy and the universe was radiation dominant. But during inflation potential energy rose and became dominant. Inflation ended when the kinetic energy in the universe overcame potential energy and radiation once again became dominant over the universe. (70,000 years later, the universe became matter dominant and eventually dark energy dominant as it is today.) Inflation increased the volume of the universe by a factor of at least 1060 or possibly as much as 1078. A particle the size of a nucleus may have grown into the size of a solar system during inflation. (Stephen Hawking, 1988ii)
During inflation virtual quarks and hyperons (baryons containing a strange quark) may have begun to form, but would have only lasted for fractions of a second. (These terms will be discussed in greater depth shortly.) The universe’s temperature decreased greatly as metric space expanded so rapidly during inflation. Inflation may have ended 10-32 seconds after the Big Bang when the potential energy was transferred back into matter, thereby reheating it. Quarks, electrons and neutrinos then began to form.
Between 10-12 seconds and 10-6 seconds after the Big Bang, the temperature dropped to 1015 K (100 times hotter than the core of our Sun) causing the electroweak force to split into electromagnetism and the weak force. At this time, none of the forces were unified and they will remain that way forever unless the Big Crunch occurs. Hadrons (subatomic particles made of quarks) may have begun to form at this point, but the universe was likely still too hot.
Before the universe reached one second old, the temperature cooled to 1012 K, making the further development of hadrons (such as protons, neutrons, anti-protons, and anti-neutrons) impossible. If there had been the same number of anti-particles as particles, they would have annihilated each other leaving the universe virtually empty. (A particle’s anti-particle has the same mass, spin and helicity, but an opposite charge. A particle and its anti-particle [ex: quark and anti-quark] can annihilate each other if they touch.) All quarks were now gone having combined into hadrons. Some quarks combined with anti-quarks to form mesons, which are unstable hadrons that don’t last long. When the meson is annihilated electrons are released. Electrons can also be created by photon collisions, which also create positrons or anti-electrons.
Around this time neutrinos began decoupling from electrons, neutrons, protons and other matter, (meaning they ceased to interact with these particles.) When this occurred the ratio of neutrons to protons became “frozen.” The random movement of the neutrinos forms the cosmic neutrino background (CNB) which can provide information about the Big Bang, as the cosmic microwave background (CMB) does. (However, the CNB hasn’t yet been observed.) The CNB and CMB are similar because the energy density of a neutrino is close, but not exactly the same as the energy density of a photon. (The CMB consists of photons.) But there was no CMB until photons decoupled from electrons and protons, which occurred 380,000 years later. We don’t know what the CNB looks like, but if we did it would give us an idea of what our universe looked like just one second after expansion. It is theoretically possible to get such a picture. If we can get an atom at rest to absorb a neutrino we would know what direction the neutrinos are coming from and this would allow us to detect the neutrinos and paint the picture.
One second after the Big Bang, the universe contained mostly electrons, neutrinos, their anti-particles and photons. Approximately 3 seconds after the Big Bang, the temperature of the universe fell to the point at which anti-leptons and leptons eliminated each other in annihilation reactions, leaving a small number of leptons. In less than one minute after the Big Bang the universe was a million billion miles across, (Bryson, 2003iii) a little more than the distance light travels in 170 years. (Readers familiar with relativity who know “nothing” can travel faster than the speed of light may be confused by this fact. Relativity states no information or object can travel faster than the speed of light, but it doesn’t say anything about the speed at which metric space can expand. The galaxies stay in the same place relative to each other, but the space between them increases, so they are not moving. Space is just growing between them at a much faster rate than light can travel.) At this time nucleosynthesis began to occur, the process whereby hadrons (such as protons and neutrons) combine to form atomic nuclei, but the temperature was still so intense they almost immediately broke apart.
Three minutes after the Big Bang, nucleosynthesis began to stick. The temperature was low enough for the strong force to keep the neutrons and protons bonded. The rate at which neutrons fuse with neutrons and protons fuse with protons is much slower than the rate at which protons fuse with neutrons and neutrons fuse with protons, so fusion of the latter kind was much more common during the era of nucleosynthesis. Most of the protons and neutrons present fused into deuterium nuclei, an unstable isotope of hydrogen nuclei with one proton and one neutron. Some of the deuterium nuclei then fused with other deuterium nuclei to form helium-4, a very stable isotope of helium.
Ten minutes after the Big Bang, nuclear fusion almost completely ceased, and in less than one hour, nuclear fusion ceased because the density of the universe had decreased considerably (due to the vast expansion of the universe) to the point at which this was no longer possible. Overall, nucleosynthesis was inefficient. 75% of the baryons2 in the universe remained unfused protons (hydrogen-1 nuclei) and almost 25% of the baryons bonded to make helium-4 nuclei. (A very small fraction bonded to make deuterium, lithium and beryllium, and there were also a few free electrons present.) There was only a trace of deuterium because it is a very unstable isotope of hydrogen. Hydrogen-1 is much more stable, as is helium. So the deuterium either broke apart or combined with other deuterium to form helium. All of the deuterium would have been fused into helium-4 if the universe had expanded more slowly and remained hotter and denser. If this had been the case, life probably wouldn’t have had a chance to begin. Once the universe was a few hours old it contained no free neutrons.
2.3 Recombination, the Cosmic Microwave Radiation Background and the Dark Ages
Arguably, more occurred within those first few hours after the Big Bang and especially during that first second after the Big Bang than during most of the rest of time. The universe never stopped expanding, of course, but after those few hours there was little activity for a long stretch of time. Matter domination occurred within 70,000 years. 240,000 years after the Big Bang finally complete hydrogen and helium atoms had begun to form. This occurred when the hydrogen nuclei and helium nuclei began to capture those free electrons to become complete atoms. Half of the electrons were already captured by nuclei by this time. The other half were interacting with or “bouncing off” photons and protons in the “photon-baryon fluid.” In scientific terminology, they were “scattering.” This increase in the number of electrons being captured was only possible because of the vast decrease in the average temperature of the universe, which was now 3000 K. Other previously ionized baryonic matter (an ion is simply an atom that has lost or gained one of more of its electrons, making it negatively or positively charged) had already gained electrons and become neutral. In the case of hydrogen nuclei. it is positive without an electron. When it captures an electron, it becomes neutral. This process was well under-way 310,000 years after the Big Bang. Most of the electrons had paired with baryonic nuclei by this time, but to this day a small number of free electrons still remain unpaired.
When these electrons began pairing with hydrogen and helium nuclei (and lithium nuclei), they released the photons they were previously interacting with and they were shot off into space in random directions. This process is known as decoupling as mentioned This decoupling resulted in a random, isotropic distribution of the photons in space, which became known as the cosmic microwave background (or CMB) as these photons have redshifted (meaning their wavelengths have increased) to microwave radiation over billions of years. The temperature of the CMB varies by only 30 microkelvin, (Ryden, 2006iv) which provides strong proof that the universe didn’t begin in one particular place in space and is expanding.
The “last scattering” is when very near all of the photons had decoupled (they stopped interacting with baryons and electrons. This occurred 350,000 after the Big Bang. Before decoupling occurred when the photons were still interacting with protons and electrons in the photon-baryon fluid, the universe was opaque. There was visible light, but it was foggy or scattered. The photons couldn’t travel very far and they emitted random energies. Even if we had a very powerful telescope, we couldn’t observe this epoch because these photons hardly traveled at all, much less 13.7 billion light-years. But when the photons decoupled, the universe became “transparent.” Neutral atoms scatter photons at very specific frequencies. We could observe the universe at this time if we knew what these frequencies were and we had the technology to build telescopes that could observe these very specific frequencies. Therefore, we could theoretically observe the universe after the last scattering (or maybe even ten or twenty thousand years before) but as these photons slowly started to redshift, they eventually became not visible to the human eye. This period is known as the Dark Ages, which ended once star formation occurred. But the way we define the Dark Ages doesn’t make very much sense. We call the epoch the Dark ages, but throughout the epoch there was optical light; it was just decreasing. At the time of the last scattering a small amount of photons had already red-shifted to infared radiation.
When the temperature of the universe was 1500 K, only a small amount of optical light remained. At 700 K there was almost no optical light. Almost all of the photons had red-shifted. The Dark Ages were merely a gradual process of dimming, but it’s not as if someone flipped a light switch and the universe became pitch-black. (It was more like a dimmer switch that lasted thousands of years.) We can observe part of the “Dark Ages”, if not most of it. But we can’t observe the photons before they were scattered either through telescopes, so it doesn’t make much sense to call it the “Dark Ages.” The terminology used in the field of cosmology can sometimes be misleading. As far as we are concerned, the universe has always been “dark” (or unobservable) up until star formation. Now that the hydrogen nuclei (protons) had electrons and no photons, they collapsed under their own weight (with the presence of dark matter) and began nuclear fusion. This is how the first stars were born.
2.4 Interpreting the Improbability of Abiogenesis and the Scarcity of Life
We are fortunate the universe turned out this way. If the strength of the four fundamental forces had varied even slightly the universe would have become a very different place. If the strength of gravity, for example, decreased more rapidly with distance, planets would not orbit the stars in stable ellipses. There wouldn’t be enough gravitational attraction to keep them in orbit, so they would fly away. If gravity was weaker (at all distances) than it is today, matter would have been torn apart by the subatomic particle because of the high rate of expansion of space. (This scenario is called The Big Rip.) However, if the strength of gravity increased by more than it does when the proximity between two objects decreases, the planets would not have stable elliptical orbits either. They would spiral in towards the stars before life had a chance to get started. If gravity was slightly stronger overall (at all distances) than it is today the universe would be crushed into a singularity again. Variations in the strong force would have also resulted in the absence of life. If the strong force wasn’t as strong, making electrical repulsion (electromagnetism) the strongest force, particles would never fuse no matter how close together or fast their movement. Because nuclear fusion would be impossible, stars wouldn’t be able to form and it goes without saying we would cease to exist. If the strong force was even less strong, it wouldn’t be able hold quarks together and atomic nuclei couldn’t form. The whole universe would just be a “soup” of scattered, microscopic sub-atomic particles.
In fact, everything in the universe was “just right,” and if the events that led up to the formation of our planet were just slightly different, life, as we know it, would not exist. This may be easy to say in retrospect though. It is all relative. If the goal of the creation of the universe was to have life on every planet then the outcome could be considered an apparent, near total failure. Because of how implausible our mere existence seems to be, some interpret the creation of life as an ‘unwanted’ event or at least an unplanned one (for someone or something). But it is important to keep in mind that while life may seem tremendously scarce (though this may not be the case) and we may occupy an enormous, seemingly desolate space, this may be the only way life can exist. Of course, life could have never existed within the singularity and if the universe was much smaller than it is today (and it could be if the force of gravity was stronger) life likely would have been destroyed over and over because the larger the universe is, the smaller we are as target for meteorites and other objects in space that can destroy our planet. The most violent collisions of material flying through space occur very far away because the universe is a “mercifully large” place. If life were abundant on all planets, one could argue this would make life on Earth less important and so unique. The fact that space is so large and expansive is also comforting in some ways. It may make us feel small, but this is good during certain times in our lives. When we become distressed about the events in our lives, if we think about the immensity that surrounds us on Earth and around it, then what goes wrong in our lives can seem trivial because there is so much more out there that seems, in context, much more meaningful. This perspective can also have the opposite effect, however, if we trivialize our lives, successes and happiness in the same way. When we succeed and feel elated, it makes sense to focus on those endeavors and feelings. But when we feel distraught about a failure, it can be helpful to attain a broader, more universal perspective to prevent us from exaggerating our problems or failures.
There is reason to believe we are wanted or that our existence is at least planned by something or someone, despite life’s apparent scarcity. As I have said, the universe has to be large for life to exist, and if the universe was, in fact, designed and there is reason for the laws of nature then it does seem likely they were created for life because without them the universe would be a completely uninhabitable place. The universe would be total chaos and the existence of carbon based life forms would be impossible. I already explained that small variations in the strength of gravity, the strong force or the electromagnetic force would result in a completely uninhabitable universe. The fundamental laws also permit generations of life to live for a long time, so long as we do our part to terraform other planets and not destroy each other. But if the universe was designed could it have been designed better? If life is the purpose of the universe why should it be so scarce? It may make us feel important, but it also makes some feel alone. The components of the singularity and their quantity are the two variables that affected the evolution of the forces and thus the fate of the universe and life the most. There are many more combinations of different components and mass that would have resulted in a lifeless universe than there are that would have resulted in a life-bearing universe. Because of this fact one could conclude that we must be intended, but this conclusion assumes that all potential initial conditions we can think of were equally likely to occur. Because we don’t know what preceded the Big Bang, we can’t make this assumption. Those fewer combinations of components and mass that make life possible could have been the most likely or the only possibilities if what preceded the Big Bang made this so. One could assume a creator made it this way, but we can’t be sure what (if anything) preceded the Big Bang.
Beginning the universe as a singularity is a chaotic and unpredictable way to start one, but perhaps it is the only way to make one. Theoretically, if we had the ability to begin a universe, even if we knew how the physical forces would become consistent almost immediately after and how they would evolve before this time, it would still be difficult to predict how the universe would develop and whether or not there would be suitable conditions for life to evolve with no experience making universes. If we were created and our creator is flawless and all-knowing as some believe, perhaps he/she/it could have created a universe without any experience designing other universes. But if our creator is flawless and we are intended why should he/she/it create a universe in which life is scarce? Again, this is all speculative. Whatever preceded the Big Bang could have existed in various forms for much longer than our universe is old, but we do know with almost complete certainty there were no Big Crunches and only one Big Bang (at least in this universe) because the microwave cosmic radiation background wouldn’t be isotropic if this wasn’t the case.
2.5 The Physical Forces
The entire history of our universe has been governed by the aforementioned physical forces as well as other laws of nature. There have been no inconsistencies or violations of these forces or laws, (except in the first fractions of the second after the Big Bang). One law that is vital for the development of life is the Second Law of Thermodynamics. Entropy only increases in a closed system because of the Second law of Thermodynamics. Life would have never evolved without the law making it essential in our universe. All of the laws and forces are essential. The strong force and electromagnetic force are responsible for quarks combining into baryons and baryons combining into atoms and atoms combining into heavy nuclei. Gravity affects these particles over much larger distances. It brings them together from billions of miles apart and causes orbits from these distances as well. Gravity is not only responsible for holding matter together, causing the formation of planets and galaxies, but it is also responsible for the position of planets in solar systems. All of the planets in our solar system revolve around the sun in the center because it has the greatest mass, which gives it the greatest gravitational pull. Most solar systems are created with one or two stars in the center, around which the planets revolve. This is the only way a solar system can be created if it is going to sustain life. Life needs light, warmth and energy, all of which stars provide. Stars always have the greatest mass of all celestial objects in solar systems because of gravity and the way they come into being Plant life also relies on the pressure of gravity to know which direction is up and thus which way to grow. Because of gravity on Earth, seeds that are buried upside down will still grow the correct way.
These physical forces provide consistency and the universe needs to be consistent to foster and sustain life, but because there are no violations of these forces a comet flying through space directed towards us can’t disobey any of the physical forces to avoid us. Does that mean we are not the purpose of this universe? Not necessarily because if the universe had no laws and almost had a consciousness (or a God that could intervene at anytime) that was sympathetic to life it would be inevitably unfair to someone because what is fair is subjective. Cosmogony is Gods only place for intervention in a consistent, “law-abiding” universe. God can have no intervention for it would be impossible to create a world that is fair for everyone and every being. Surely, many people would complain and too many people would feel victimized and left out. People already feel that way now. Similarly, governments can never be fair. Democratic governments in developed countries all have the same supposed goal of establishing order and justice for all citizens, but because what is fair is subjective this is impossible, and it would remain so even if those in power actually had this intention.
If God could intervene it would not only be inevitably unfair to certain people, but it would take away what little control we have over our identities. If God could get us out of our ruts for us, we may not learn anything or develop and we would expect all of our problems, no matter how trivial, would be solved by God. But there are massive inequities on Earth and if there was a God, surely God could rectify some of this without making us complacent. Although if our universe was inconsistent (benevolent or not) and there was observable proof it was, people would likely become deranged because we all need a stable, unchanging reality, even if this means that some will suffer. If our universe was inconsistent but benevolent, what guarantee would we have that it would continue to act in a way that suits life? For all we know it could turn intentionally malicious and its sole purpose could be to cause human suffering. (Many religious texts explain God does just that when he is disappointed in humanity, and this one of the many reasons organized religion can be so dangerous.) That is why it is good that our universe is consistent and indifferent to our presence. There’s nothing positive about life’s inequities but we can change them on our own. Life began in tremendously harsh, unforgiving circumstances, but it evolved and thrived despite this and changed the environment to better suit all life-forms. If it had all been done for us, what would have been point? For this reason perhaps it is good that life is so apparently scarce and it might even be nice to find out we were never wanted at all. Then, we really beat the odds.
2.6 Predicting the Future of the Universe and Life’s Fate
Although the laws of nature don’t change and the universe is consistent in this way, the matter in the universe does change, of course, and these changes can affect the expansion of space, the curvature of space and the future of the universe. As mentioned, small fluctuations in the strength of gravity over small and large distances would have disastrous consequences for humans. If gravity was weaker overall the “Big Rip” would occur. If gravity was stronger the “Big Crunch” would occur. One of these scenarios may actually occur in the very distant future, but if one does occur it won’t be due to gravity getting weaker or stronger. Gravity like the other forces will always be constant, (unless the Big Crunch occurs and like in those first fractions of a second after the Big Bang, the strength of the laws would vary greatly at the very end of the universe). But the expansion of the universe can accelerate and slow due to the amount of matter and energy in the universe. The more matter there is in the universe, the greater the universe’s gravitational attraction and the slower it expands. The more dark energy in the universe, the faster it expands. The strength of gravity doesn’t change, but the forces that repel gravity (dark energy) and push against it can overwhelm it or be overwhelmed by it.
After inflation the universe’s expansion slowed because the amount of matter in the universe increased as particles began to coalesce. If the universe began to expand at the same rate it did during inflation or faster right now, then the Big Rip would eventually occur. The universe needs to have just the right amount of matter and energy to hold together. With too much dark energy and too little matter the rate of expansion will be too great and everything will tear apart (or drift very far apart) and with too much matter and too little dark energy, the universe’s expansion can come to a halt, causing gravity to bring the universe back into its singularity state. Matter and energy affect the curvature of the universe and this affects its fate. The universe’s curvature is hard to imagine because we can’t really describe three-dimensional curvature. (It’s like trying to describe what a 4-dimensional square looks like.)
If the Big Crunch occurs and the universe is crunched back into a singularity, the whole process may begin all over again, (i.e. another Big Bang followed by another Big Crunch). Some Hindus believe there have been many Big Crunches or universe “deaths” and Big Bangs or “rebirths.” This belief has its origins in old Hindu scripture that existed before the science was known to support it. However, we know that there has only been one Big Bang because if there had been more than one the events in the previous universe would affect the current one. The universe would not appear homogeneous. There would be hotspots in the microwave radiation background. The lengths of its “splotches” wouldn’t be consistent. The fact that the background radiation is homogeneous (or looks the same in all directions) means the Big Bang didn’t occur in one particular place because there was no space before the Big Bang. If the Big Crunch does occur, it is possible it would not collapse into a singularity like the Big Bang singularity, but rather become a “black hole” singularity.
The Big Crunch can only occur in the future if the average density of the matter in the universe is high enough to cause the curvature of the universe to be “positive”, resembling a sphere, in which case the universe would be “closed.” (This terminology can be confusing because a sphere’s surface is two dimensional. A sphere as a whole is three dimensional, but space is curved and it has three dimensions and a forth including time. If the universe was closed, it would be a curved, three-dimensional sphere, and we don’t know what that looks like. Of course, a sphere’s surface is curved, but its surface is only two-dimensional. The third dimension or “Z” axis would also be curved if our universe was closed. To get a better idea of what this might look like, first picture our solar system. You have likely seen models in which gravity is represented on a graphical plane (or a “gravitational field”). Our sun in the center, bends the plane downwards the most because it has the most mass, which is why the planets orbit the sun. They orbit inside the “bend.” Similarly, if the universe has enough mass (gravitational attraction) it will bend the universal “plane” so much that the plane will collapse in on itself and connect with itself on all sides, resembling a sphere. Gravity can crush the sphere into a singularity, but this doesn’t have to happen. As mentioned, closed universes don’t have to collapse in on themselves into singularities. If there is enough dark energy closed universes will expand forever. (Dark energy accelerates expansion because it has a strong negative pressure. This negative pressure repulses gravity and overwhelms its own gravitational attraction from its mass. Although it has never been observed and we don’t know what it consists of, it is thought to make up 70% of the known universe.)
The density parameter or omega (Ω) is the average density of the universe divided by the critical energy density. Critical density (which is approximately one hydrogen atom per 200 liters or around 7 cubic feet) is the density at which the curvature of the universe is 0 (meaning it is flat) and the Ω = 1. (Ω is the curvature plus 1.) If Ω > 1 the universe would be closed, and if this were to happen Ω would always be greater than one and the universe would be forever closed.. If Ω = 1, it will equal one forever and the universe will be forever flat. The density parameter (Ω) is dependent on the density of matter, which is dependent on how much matter is in the universe, (or Ωm) and how close it is together. There are also two other factors, which affect how close matter is together. These two factors are dark energy (or ΩΛ) and relativistic particles, (or Ωrel) such as neutrinos and photons. Ωm + ΩΛ + Ωrel = the density parameter (Ω.) According to the MAXIMA (Millimeter Anisotropy eXperiment IMaging Array) and COBE’s (Cosmic Background Explorer) CMB data, the dark energy value is currently 0.73 +/- 0.04, the amount of matter in the universe is 0.27 +/- 0.04 and the amount of relativistic particles is very small around 8.24 x 10-5). If these figures are added (and the plus or minus numbers are negated) the sum is slightly greater than one. But because there could be a margin of error of 0.04 on the value of the dark energy and the amount of matter, their findings don’t really make any definite predictions either way. However, the experimental value for Omega from the Wilkinson Microwave Anisotropy Probe or WMAP data is 1.02+/-0.02. This probe’s findings rule out the possibility of a negatively curved universe while other findings say the opposite.
If Ω < 1 the curvature of the universe is negative and space is “open” (shaped like an infinite saddle) and it will expand forever, but if Ω is much less than one, expansion will accelerate and the Big Rip might occur. If Omega is very near one, expansion will decelerate. This saddle universe is even harder to picture than a spherical or “closed” universe. We can all picture an infinite saddle shape, but the third dimension of an ordinary saddle is not curved. If Ω < 1, it will always be less than one.
Like open universes, flat universes also expand forever, but their expansion accelerates more slowly. Therefore, if our universe is either flat or open, it will keep on expanding. Either way life cannot live on forever. There are two ways life could be extinguished in an open or flat universe. If phantom dark energy exists, it will accelerate expansion to the point at which everything will eventually rip apart by the sub-atomic particle. If no such thing exists, we will die from “Heat Death” or “The Big Freeze.” Heat Death and the Big Freeze are very similar, (even though their names make them sound like opposites.) Heat Death means the universe’s average temperature will become very close or equal to absolute zero. The Big Freeze only differs from Heat Death in that the average temperature of the universe would just become too cold to sustain life, (which is a given in the Big Freeze) but it would never decline to a temperature near absolute zero. How this would happen is very simple. In both scenarios heat sources (stars) will get too far from any areas that have life and the universe won’t be able to sustain life. The universe will become cold, dark, desolate and empty. But when exactly will this occur?
If our universe is open, star formation will cease sometime between 1012 and 1014 (1 trillion to 100 trillion) years from now. (Because the universe would expand more slowly if flat, the following events listed would likely occur much further in the future if the universe is, in fact, flat. These dates are also subject to change as more information is discovered.) Once low-mass, cool Red Dwarf starts have exhausted their fuel, only white dwarfs, brown dwarfs and neutron stars would remain at this time. These are all compact stellar remnants. Brown dwarfs are “substars” too small to maintain nuclear fusion. White dwarfs are dense, low-mass, compact stars composed of electron-degenerate matter. Red dwarfs are also small and cool stars. And neutron stars are compact stars as well composed mostly of neutrons.) Although these stars are nothing like our sun in its present form, if we haven’t destroyed each other and improved space technology greatly by this time, this shouldn’t be the end of life.
1015 years from now we will face another obstacle: planets will begin to detach from their orbits due to gravitational radiation. This still might not be the end of life if we have the technology to build artificial planets at this time, which we could set in orbit around heat sources. Planets that are currently closer to their stars will take the longest to detach from their orbits. 1020 years from now, brown dwarfs and stellar remnants will be expelled from galaxies. If we have the technology to harness the energy of heat sources using solar power satellites (in the formation of a Dyson Sphere) which could send the energy to a habitable planet and provide heat and light, this could keep us alive. It also theoretically possible we could make artificial stars by somehow collecting and storing large amounts of hydrogen and putting immense pressure on it until it undergoes nuclear fusion. If we had any of these technologies, we could live for trillions of years implementing them, but the universe around us would remain extremely cold.
1065 years from now it is predicted solid matter will rearrange its atomic particles because of a process known as quantum tunneling. This will happen because of the low temperature, which will be near absolute zero and it will make all matter (excluding matter located near heat sources) behave as a liquid. The frozen particles in solids would experience no friction, so they would move freely and take on the shape of a sphere due to gravity. Assuming we are able to make habitable artificial planets, stars or Dyson spheres, this shouldn’t affect us. But if proton decay is real, we could die off well before this time. It is not known whether protons do, in fact, decay and if they do, how long this takes. (However, some theorize protons have a half-life of 1036 years. If this is true humanity will die long before 1036 years from now.) 101500 years from now all matter will decay into iron-56, (a common isotope of iron) due to the temperature, unless we are able to construct heat sources. Iron stars will exist at this time, but they won’t provide much energy. Many of these stars will eventually collapse into neutron stars. This happens to stars with iron cores today, but no stars are made solely of iron. Some large stars that continue to fuse their atoms into heavier and heavier elements eventually arrive at iron. Fusion of iron requires more energy than it creates (as opposed to the twenty-five lighter elements that precede it on the table of elements) and if the mass of the core is greater than the Chandrasekhar limit, (1.38 solar masses) the star will collapse into a neutron star. Once the iron stars collapse into neutron stars we could use the energy from neutron stars again to sustain life, but how long we could keep doing this, if at all, is open to question. It is not likely we could live near a neutron star or on a planet in its orbit because neutron stars emit a great deal of X-ray radiation and their temperatures aren’t very consistent, but again, we could harness their energy using solar power satellites.
It is not clear when exactly life will become extinct. There are many variables, such as whether proton decay is real or not and whether we will even have the technology to create artificial planets and stars. With politics the way it is, it is not clear if we will even survive each other. It is posited that all matter will eventually collapse into black holes. But this is predicted to happen so absurdly far in the future that it is not even worth considering. Matter is expected to collapse into black holes between 10(10^26) and 10(10^76) years from now. There is no way to grasp how far in the future that is, but to give you an idea, if the low estimate was typed on standard, 8 ½ by 11 paper (single spaced) it would take up 30,193,236,714,975,845,410,628 pages. (There would be 3312 zeroes on each page.) The high estimate would cover 3,019,323,671,497,584,541,062,801,932,367,149,
758,454,106,280,193,236,714,975,845,410,628,019,323 pages. For all intents and purposes, that is eternity. But I don’t think it is remotely possible that we will live that long.
The universe will present us with many obstacles in the very distant future, but most of them are theoretically possible to overcome. But regardless of whether these obstacles are possible to overcome or not, the question remains: why should we be confronted by them? Why should the universe expand and become so cold? Why should there ever be an end to life? If our existence was planned, are these obstacles just a result of poor planning or are they necessary for reasons we may not understand? Or are we just an unlikely result of natural events planned by no one? These are important questions for their answers would tell us if we are truly wanted. The universe has to be consistent for mankind to maintain its sanity, so perhaps if the universe was designed by a creator he/she/it/they did their best to calculate what amount of matter and energy in the singularity would result in laws that would favor of the creation of life, but couldn’t come up with an equation that would permit life to live forever. Maybe our creator(s) is (or are) flawed. If we are wanted and even the purpose of this place, how could the almighty universe not fulfill its purpose? The universe without life seems so empty and lonely. However, from a point of view that isn’t human, it may not seem this way. From a non-human perspective a universe without matter is empty and lonely. And in comparison to the mass of all of the matter in the universe, the eradication of life seems incredibly insignificant. As you know, sub–atomic particles attract to form larger and larger masses and this tendency (due mainly to the strong force), along with gravity’s desire to bring all matter together into a singularity again (so no particle is isolated) gives one the impression that the universe was the least desolate and lonely as a singularity when life could have never existed. (But one could also consider this the most lonely time because essentially nothing existed. Although since we don’t know what the singularity looked like it’s hard to say for sure.) As human beings, most of us can’t help but see the universe as lonely without life. What is the universe in all of its grandeur without a mind to perceive it? Matter has no emotion; only humans feel loneliness.
2.7 Star and Galaxy Formation
The first stars to form called population III stars or extremely metal poor stars were massive and relatively short-lived with lives lasting less than one million years. They were massive hydrogen stars, which fused hydrogen into helium and helium into much heavier elements near the end of their lifetimes. (90% of their lifetimes were probably devoted exclusively to hydrogen fusion) (Ian Dell Antonio) Population III stars created the first 26 elements in the periodic table. (Cosmologists aren’t certain they created the 26th element, Iron, but it is possible.) These stars probably formed sometime between 100 and 400 million years after the Big Bang. They most likely exploded in supernovae at the end of their lifetimes, but because they have not been observed, this is not proven. It is thought to be true because before a star explodes it will usually create many, much heavier elements in its core. Before stars explode they lose significant amounts of energy because hydrogen fusion is the most energetic type of nuclear fusion. This is why hydrogen fusion lasts for so long and the fusion of the rest of the elements takes a very short period of time. When stars do explode, they release a tremendous amount of energy.
After population III stars died, galaxy formation began. With galaxies came Population II stars, which had slightly more metals. Galaxies formed around 1 billion years after the Big Bang when there were pockets of high density gas due to gravitational attraction (mainly from dark matter), as well as neutral atoms, ions, and electrons assembled in protogalactic clouds. Stars formed in these clouds in smaller pockets of high-density gas called protostellar clouds, and the planets followed, (starting out as orbiting debris) accruing around the stars over a few million years and thereby creating the individual solar systems in the galaxy. Galaxies were formed when a protogalactic cloud would collapse under its own gravity into a flat, galactic disk and because of angular momentum the debris around it would continually orbit around the center. The hydrogen and helium gas would move to the center of the disk forming many protostellar clouds, (which soon turn into halo stars) but star formation is, of course, not limited to the center of galaxies. (Our solar system for example exists on the outskirts of our Milky Way galaxy.) Star formation occurs in these gas clouds because of the gases density and the pressure being exerted on it. The gas particles are so close together and moving so fast there is no time for electrical repulsion to act, so a thermonuclear reaction (nuclear fusion of hydrogen) takes place creating the star. Nuclear fusion is a self-sustaining process in stars that occurs a countless number of times throughout their lifetimes. Stars can consists of any of the first 26 elements. Once most of the hydrogen in a star has been fused into helium, helium fusion begins to take place, which creates beryllium. Beryllium can be fused to create carbon and carbon can be fused to create even heavier elements and so on. (Hydrogen fusion occurs when two hydrogen nuclei fuse to make deuterium nucleus. The deuterium fuses with a proton to make a helium-3 nucleus. Then, two helium nuclei created by such a process fuse to become helium-4, releasing their two protons.) Stars stay together because the pressure hydrogen fusion exerts outwards is at an equilibrium with the pressure gravity exerts on them inwards. But once their hydrogen has been fused into helium and heavier elements, they begin to collapse. Once this happens a star can have many different futures depending on its mass and composition.
2.8 The Formation of Our Galaxy, Solar System and Planet Earth
The Milky Way’s protogalactic disk is thought to have been formed between 6.5 and 10.1 billion years ago. Our solar system formed around 4.6 billion years ago. Around this time a great swirl of gas and dust (called the Solar Nebula) accumulated in the area in which we now live. An large percentage of this mass went to create the sun. The sun is a Population I star, meaning it is metal-rich. Shortly after the sun had formed, two microscopic grains orbiting around it came close enough to create electrostatic forces. This was the very beginning of our planet. In our solar system our planet and sun developed at a perfect distance from each other and the sun was giving off just enough heat for that distance to allow for the formation of life. In fact, if the sun was just 5% nearer from Earth, it would be inhabitable. (Bill Bryson, 2003v) Over the span of about two hundred million years, neighboring dust grains floating nearby collided with our microscopic planet until it was large enough to be called a planetesimal. This process is called accretion. These dust particles were minerals made of iron, magnesium, silicon and oxygen. Around our sun the other terrestrial planets (Mercury, Venus, and Mars) were being created in a similar manner. A terrestrial planet is one composed primarily of silicate rocks or metal that can be stood on. The Jovian planets (Jupiter, Saturn, Uranus, and Neptune) are composed primarily of gas and are not habitable. The Jovian planets are like failed stars, which never became dense enough to undergo nuclear fusion. All over our undeveloped universe planets and stars were created in the same manner, but our planet was slightly different than all the others, even during its creation.
During and long after our planet’s formation, our planet was constantly subject to bombarding debris still flying through space from the force of the Big Bang. The most devastating (but ultimately the most rewarding) of these collisions occurred 4.4 billion years ago. At this time the Earth had completed its formation. The object that collided with Earth was a planet named Theia. It was as large as mars, and it hit with such force that it knocked an enormous mass of our planet into space. (It is theorized that the planet contained water and possibly life. Water molecules have been found in a thin layer above the surface of the moon and Soviet Luna 24 and India’s ISRO Chandrayaan have both found water on the moon). Within a year the cloud of dust that encircled our planet from the collision transformed into a spherical rock that is now known as our moon, “Luna.” The impact of this planet colliding with Earth also caused great heat on Earth and the temperature of the Earth’s center was already very high. The Earth could not withstand the temperatures the additional force created and it began to melt. All of the heavier elements and molten material sank to the center while the lighter elements floated to the surface, creating the hard crust. The crust consists of multiple layers that are harder deeper down in the Earth. This way the surface can be habitable and still withstand the great heat of the core. This was one of many unlikely occurrences that made Earth more habitable for life. (It was unlikely because this is not the typical way a planet’s moons are made.) Without the moon the Earth would have virtually no land. All intelligent life would have developed in the oceans.
The moon is extremely necessary for life because it also acts as a climate regulator. Its gravitational pull keeps the Earth’s tilt consistent at 23 degrees. Without it the Earth would wobble and the ice caps would get more and more sun exposure. The polar ice caps would then melt and flood the globe. This will happen far in the future because the moon is slowly pulling away from the Earth, at a rate of 1 and ½ inches per year. As it pulls away the days get longer and the years become shorter. 900 million years ago there were 481 days in a year and 18.2 hours in one day, (Blake Barronvi). The moon also sometimes acts as a physical obstacle for bombarding meteorites, which could strike Earth if the moon wasn’t present, and its gravitational pull that creates waves was responsible for formation of life in the froth of the tide. The waves also assisted marine animals and bacteria to come to the land and become amphibious. The moon even gave us a goal we could reach. It was the first planet we were able to travel to, which was a remarkable feat. It may act as a stepping stone to other planets in our future, especially if we can access and use lunar water.
- 2.9 The Development and Evolution of Life
- About 3.9 billion years ago, the crust of the Earth had completely solidified and become hard. At the time the Earth was a chaotic place, constantly being bombarded with meteorites, comets and lightning storms. The atmosphere contained almost no oxygen (around 1%, and most of it was bound by hydrogen in water vapor molecules). The primary atmospheric gases were methane, ammonia, carbon dioxide, water vapor and nitrogen. These environmental elements were all necessary for the creation of life. The bombarding comets were bringing water and some carbon compounds and the low amount of oxygen in the atmosphere was also necessary. Some very interesting chemicals were abundant in the oceans. There were RNA molecules in the froth of the ocean that began to replicate themselves, but scientists aren’t exactly sure how they formed. This very first form of life arose around 3.85 billion years ago or possibly earlier. (Earth had oceans 4.3 to 4.4 billion years ago, so self-replicating molecules could have been present at this time, but killed off a number of times by the unstable environment until 3.85 BYA.) When these molecules learned how to replicate this was the catalyst of all life, which seems very hard to imagine. What was so special about these chemicals in the ocean that brought forth the beginning of life? What separated this first form of life from rocks, gases or any non-living material except their ability to replicate themselves? Is this what defines life?
- Life is defined by its organization. It is able to convert a chemical or photo energy source into energy for itself using redox reactions (redox is short for reduction/oxidation meaning a loss or gain of elections) and create heat (and often adenosine triphosphate or ATP) as a byproduct. This energy is used to drive organisms. Two common energy sources for organisms are lipids and sugars, which can be broken down into simple sugars like glucose. These simple sugars drive the organism and ATP and carbon dioxide are released as byproducts from the oxidation of glucose. But the first organisms did not generate ATP or gain energy in such a way. Certain chemicals can do this, which we don’t consider living because they don’t reproduce. So this alone doesn’t define life. If a chain of molecules can gain material faster than it loses material through the excretion of waste products, it could survive destruction. The development of such molecules probably took a long time, which is why early life took so long to evolve. And if this chain of molecules becomes enclosed in a lipid membrane that gets large enough, physical forces can split it in two. (A lipid can also insert itself into another lipid, splitting it in two.)
- Amphiphilic long chain molecules can spontaneously form lipid bilayers, which are the central components to the membrane. Lipids are attracted to fat (or lipophilic) and a hydrophile is a molecule that bonds with water. A hydrophobe is a molecule that repels water. Amphiphilic molecules have both hydrophilic, hydrophobic, and lipophilic properties. They consist of polar heads and non-polar tails like soap. The polar end attracts water and the tail end repels water. This drove them together and when they grouped together, they formed an enclosed shell, or a membrane, which contained these molecules. The tails are pointed towards the inside of the membrane, thereby repelling the water and keeping it out of the interior of the membrane, while the heads face the outside, making contact with the water. When amino acid solutions are heated, cell membranes can also form spontaneously from protein-like molecules (or proteinoids), but protenoids differ from protein spheres because they don’t have bilayers.
The development of complex molecules, which could eventually self-replicate began with monomers. Monomers, such as amino acids and nucleotides, which were also present in abundance became covalently chemically bonded (due to their similar electronegativities) to form polymers, or simple, self-replicating RNA (Ribonucleic acid) molecules called ribozymes. Ribozymes are enzymes. They serve the same purpose as DNA enzymes. They break down and reform phosphodiester bonds in the RNA molecule, thereby creating two RNA molecules. They also have other functions as DNA enzymes do. Once these ribozymes became enclosed in a lipid membrane they were pre-cells. RNA is a fragile molecule that can be broken apart by hydrolysis or simply a chemical reaction with water, so becoming enclosed in a membrane was crucial.
It is unknown whether a metabolic cycle preceded RNA or self-replicating RNA was preceded by different organic molecules or RNA molecules had a completely different origin. The predominantly accepted theory that states that a metabolic cycle preceded RNA is known as the Iron-sulfur World Theory. The theory that states RNA was the first self-replicating molecule is known as the RNA World Hypothesis. A similar, alternative theory states that there were different nucleic-acid precursors to RNA such as TNA, PNA, or GNA, but there is no strong proof of this because these nucleic acids don’t currently exist in nature and have only been artificially produced in the lab. “T” stands for threose. “P” stands for peptide and “G” stands for glycerol. They are similar to RNA and DNA, but they differ in their backbone. PNA could have been a precursor to RNA because it is more stable than RNA and it does not contain ribose or phosphate groups, which might have difficult to synthesize in certain prebiotic conditions. PNA may have also spontaneously polymerized at 100 degrees Celsius. TNA could have also been a precursor to RNA because it is easier to assemble and threose might have been easier to come by than ribose. It has only 4 carbon atoms while DNA’s deoxyribose and RNA’s ribose have 5. GNA’s glycerol has only 3 carbon atoms. It too is much more stable than RNA and even DNA and it takes a high temperature to melt a double stranded molecule of GNA. TNA segments, or oligonucleotides, can base-pair with themselves and with other RNA and DNA segments.
If a metabolic cycle was a precursor to RNA rather than alternative nucleic acids, it would have developed differently. In that case, iron sulfide and nickel sulfide present in the boiling oceans of Earth, along with hydrogen sulfide gas and carbon monoxide would have created acetic acid through metallic ion catalysis. Then, the addition of carbon would have made pyruvic acid, which with the addition of ammonia would form amino acids. These amino acids would then have become peptides and proteins. If RNA molecules did, in fact, have such an origin, they would not have developed in froth of the tide. They would have developed inside or near hydrothermal vents, which were coated with metal sulfide. If they developed near hydrothermal vents, they would have developed on mineral surfaces, such as iron pyrites.
Pre-cells eventually developed RNA genomes and became true cells. From there self-replicating asexually reproducing DNA cells evolved. Once this occurred, cells could change and adapt at a much faster rate. RNA could also mutate once the RNA genome developed, but not as often. Large amounts of information storage in RNA are a problem due to its fragility. However, DNA cells could become more numerous and use different energy sources to drive their internal redox reactions. They could store information and pass on traits allowing for the rate of evolution to increase.
It is difficult to determine when life began and it would be even if we knew exactly when RNA and DNA developed because there is no universally accepted definition of life. Is reproduction life’s one defining characteristic? Some scientists don’t think so. Fatty acid vesicles can be made to grow and divide in certain chemical and physical conditions, but they aren’t considered living. This will happen when a vesicle incorporates a fatty acid in the form of micelles. This process makes the vesicle grow and forces the extrusion of large vesicles through small pores thus allowing for the creation of multiple generations of vesicles. (Jack Szostak) Some scientists who don’t think reproduction defines life don’t even consider RNA molecules that could self-replicate and grow as living. These scientists claim that life began when DNA evolved from RNA because all current organisms have DNA and it is what allows modern evolution to take place. (As mentioned, RNA can mutate and “evolve” as well, but complex life never would have evolved if it wasn’t for the development of DNA.)
Our knowledge of this time period and of abiogenesis is very limited. Unfortunately, so far, science has gotten us frustratingly close to the answers of the big questions, but hasn’t really answered them. We know almost exactly how life evolved after it began, but we don’t know what or how life began exactly. We have theories as mentioned, but none are proven. We also know exactly what happened up to an extremely tiny fraction of a second after the Big Bang, but we don’t know what the conditions of the singularity were, where it came from, what its purpose is or what is outside of the universe, if anything.
The first DNA carrying organisms were prokaryotes, the first form of life on the planet according to those few scientists who don’t consider RNA living. These organisms were unicellular and without a nucleus. They were able to duplicate their single chromosome and attach it to the cell membrane and divide it in two, creating another prokaryote. This is one of the several types of asexual reproduction called binary fission. Asexual vegetative reproduction or budding is a much different process, as is asexual spore formation, both of which developed much later on. These particular prokaryotes were chemoautotrophs, just as the very first forms of life were. An autotroph is an organism that transforms simple, inorganic molecules into complex, organic (or carbon-based) ones using light as its energy source or inorganic chemical reactions like oxidation, which chemoautotrophs use as their energy source. Most plants are photoautotrophs (or photolithotrophic autotrophs to be specific). The majority of photoautotrophs are phytoplankton, which include photosynthetic prokaryotes, algae, and other photosynthetic organisms. They also obtain their own energy to drive their internal reactions from an inorganic source, but not from inorganic chemicals. They receive energy from sunlight and they evolved long after the first forms of life.
At the time life was born, it seems there was little that distinguished life from non-living things. All the things we associate with life like consciousness, thought and feeling were obviously irrelevant to this form of life. All this form of life did was reproduce. So how could we come from such unfathomably humble beginnings? How could such complex beings who are assured their existence and consciousness are significant form from just a few interesting chemicals and a unique atmosphere? And how could the most complex development occur at such a fast rate when the more primitive organisms took billions of years to evolve into something that could at least have thought? The answer to that particular question could be related to the development of society. We have arguably changed our world more in the past 100 years than we really ever have. The more we know and complex our systems are, the faster we can advance in good ways and bad.
2.10 Defining Death and Interpreting the Lifetimes of Organisms
As the first molecules split and life was born, death was born as well. The atoms that you consist of essentially lose interest in you at a certain point. They have no consciousness, yet it seems they almost want to move onto better things. So they begin to silently disassemble and cling to other lifeless particles to make up dirt or rock or almost anything you see on Earth. We say everything has a lifetime: people, inanimate objects, planets, stars, galaxies and so on, but only something that is living can die. We’re so focused on consciousness and life and death that we say all of these things “die” when they don’t.
We could define death as a permanent loss of consciousness, which is something non-living things obviously do not have, but plants don’t have consciousness, nor do many other types of life. When an organism dies, it loses its homeostasis; it can no longer maintain its internal biological functions. But this doesn’t happen to anything that is not living when we say it has died. (Although if someone says an inanimate object is broken, this is usually why.) Stars, for example, outside of academia are said to be dead when nuclear fusion ceases. But just because nuclear fusion ceases does not mean there is no activity inside the star. (In White Dwarfs, for example, the electrons in the star travel at the Heisenberg speed, which contributes to the Electron degeneracy pressure. This pressure keeps the star from collapsing as long as its mass is below the Chandrasekhar Limit.) And a star can have many different futures when nuclear fusion ceases (depending mainly on the star’s mass) unlike the bodies of organisms, which will reliably decompose in the same way. Using White Dwarfs as an example again, if their mass is above the Chandrasekhar Limit the star will collapse into a black hole or a neutron star. White dwarfs, neutron stars, and other dense stars and black holes (often referred to as compact stars) will exist almost forever, (assuming proton decay is not real) and they are never referred to as “dead stars,” so there is an inconsistency in the terminology some people use. A supernova is the only stellar future that could be considered star death because the star explodes and its gases are scattered. But the gas usually accumulates to become another star (eventually.) The process of star “death” and the death of an organism are dissimilar in many ways, of course. The human body doesn’t decompose and become another human. (However, a few of your atoms may have belonged to someone who is now dead.)
When we die, our amino acids are converted into acetic acids by acetogens. Then our acetic acids are converted to methane. These processes release oxygen, nitrogen, methane gas, carbon dioxide and hydrogen. In this way our deaths are somewhat similar to supernovae in that we are recycled just as everything else is, but these processes are only possible because of detritus feeders, which eat away at our flesh. The most basic components of matter that make up organisms and stars never die (unless proton decay is real). Therefore, only our consciousness dies (unless there is an afterlife). Most of us need to feel we have eternal souls and that we are significant because we are self-aware, which by itself makes us significant, and virtually no one can cope with the inevitable extinction of their own consciousness, but it doesn’t make sense to dwell on death. Death is and always has been an integral part of life, so we should be grateful that these microscopic particles keep their interest in us for as long as they do and enjoy what we get of life, whether there is an afterlife or not. Saying everything has a lifetime can make us focus too much on death. It is nice to know some things like the particles we are made of never die because they were never living.
The average human body (around 154 lbs) is made up of 7,000,000,000,000,000,000,000,000,000 atoms. (That will give you an idea of how many make up the universe.) Ironically, some of the simplest organisms on Earth have much longer life spans than the most complex forms of life on Earth like humans do. A good example of such an organism is a plant that has been around for billions of years. It is called lichen.
Lichens can grow just about anywhere, ranging from your backyard to the most unforgiving terrain in the Polar ice caps or the Sahara. They often grow where there is little competition, either in the hottest parts of the desert or on the highest, most frigid peaks of mountains. They have little control over their hydration and can survive long periods without water. When they become desiccated they enter a certain metabolic suspension called cryptobiosis, during which their metabolic functions cease until they are hydrated and environmental conditions are normalized. Cryptobiosis also helps them survive freezing temperatures and low oxygen levels. Lichens grow mostly on bare rock and wood and for a long period we had no idea how they received sustenance.
Lichen is a cross between green algae and fungi. The fungus creates acid, which seeps through the rock on which it grows, releasing minerals that the alga converts into food for itself and for the fungi. What’s so interesting about lichen is that the atoms that it consists of are much more devoted to its existence than those that make up humans. Lichens can live for a few thousand years and undergo little change in their lifetime. They just get slightly bigger every century. How could atoms lose interest in us, the most complex beings on Earth, but be so committed to lichens, a form of life that will never have a single thought? Is the fact that they are simpler an attraction for atoms? Perhaps they are less work? Not for an atom. The answer lies in life’s tenacity and desire to live, but also in its lack of ambition.
2.11 Life’s Motivation
The very first organisms on Earth were self-replicating. All textbooks on the origins of life will explain that, but few discuss their reason for doing so. They didn’t need motivation. They, of course, never made a decision to reproduce. But life was very tenacious. When it was eliminated, it would reappear over and over again. If the first forms of life were capable of having desires it seems as if all they “wanted” to do was thrive and multiply, under any circumstances their environment produced. It was a rare occurrence that a cluster of stardust flying through space at unimaginable speeds would coalesce and end up in a location that would provide a perfect combination of light, heat, and the right elements and gases necessary to sustain just the smallest, most simple form of life, and these molecules were not about to give up and die out. Almost all forms of life are very resilient and persistent. Even microscopic forms of life like viruses that adapt to survive the drugs being used to eradicate them are resilient. But again, viruses and other forms of life don’t decide how to change themselves. Of course, they are incapable of doing this. The only reason they survive is because nature produces many mutations and variations, and the early Earth’s atmosphere was high in radiation and the oceans were filled with chemicals, some of which were likely mutagens. (Self-replicating organisms make almost an exact copy of themselves and very rarely undergo spontaneous mutations.) Some mutations happen to be beneficial and others are harmful. Therefore, if an organism is born with a beneficial mutation or it undergoes an induced, beneficial mutation during its lifetime and this mutation passes on, those without mutation will die, and those with it will be the only ones left to reproduce and pass on the mutation.
DNA mutation, to be more specific, is a change in genetic code or a change in the sequence of base pairs of nucleotides, the building blocks of nucleic acids made up of hydrogen, oxygen, nitrogen, carbon, and phosphorus atoms. These nucleotides are represented by letters, A, T, G and C. Adenine (A) forms a base pair with thymine (T), and guanine (G) forms a base pair with cytosine (C). DNA has the shape of a double helix. When the double helix is split during reproduction into single helices, nucleotides are attached to both now separate helices to make two double helices. When this occurs occasionally the wrong pair is made. Adenine can pair with guanine or cytosine can pair with thymine and so on. Sometimes the mispair is rejected by the enzyme which codes it, but other times it will stay. It can have a beneficial effect and spread or kill the organism or have no effect at all. This type of mutation is called spontaneous (point) mutation and it occurs during DNA replication only. (Spontaneous mutations can occasionally result from mutagens.) There are other ways for DNA mutation to occur through deletion of one or more nucleotides or insertion of one or more extra nucleotides and there is a multitude of reasons mutations can occur, such as ultraviolet light, ionizing radiation, viruses, chemicals, and more. These induced mutations can be deletions or insertions of nucleotides as well as mispairs of nucleotides. Induced mutations do not occur during DNA replication, unlike spontaneous mutations. RNA mutates in much the same way as DNA does, but the major difference is RNA has no thymine nucleotide. In its place is the nucleotide uracil, which uses less energy to reproduce than thymine. Deoxyribose is only different from ribose because it has one less oxygen atom. (“Deoxy” means less oxygen.) DNA mutation or evolution is a natural process. It happens without organisms ever knowing or making a decision about it like our heart beats.
Mutation is the reason why life can evolve to so many different circumstances. It is part of the reason life is so resilient, but we humans do make the decision to keep living and to reproduce and without that, humans wouldn’t continue to exist. The desire to live is instinctual. Most organisms struggle and do whatever it takes to survive everyday without hesitation. Why? Most likely they see no other option, unlike humans. Other life forms have more limited or no self-awareness. They lack a complex, developed conception of themselves or their situation or how it relates to the situations of others. Giving up and dying is hardly ever an option to other life forms. Some animals do things to perpetuate their species that will cause their own death, but it’s not because they want to die nor do they not want to die. (Honey bees are a good example.) There is arguably no decision being made. Their actions are purely instinctual.
Humans, on the other hand, do face the decision of whether or not to get up in morning and, of course, many do intentionally kill themselves for reasons that have nothing to do with the perpetuation of the human species. It may be counter-intuitive to see this as a attribute of sophistication, but it’s not giving up that makes us sophisticated. Rather, it is the ability to reach that state due to the recognition of complex processes and our place in them. Primates (excluding humans) have never been seen intentionally jumping off trees in order to kill themselves. A rare witnessed exception occurred in Gombe Stream National Park in Tanzia when an eight-year-old chimp became disconsolate when his mother died. He knew how to find food, but he refused to leave his mother’s corpse and he died within a month. This is the only case known of chimp suicide. There could certainly be others, but primates don’t usually have such an overly emotional response to the death of a family member. The only other animal that may have the ability to decide to kill itself is the domesticated dog. Dogs have relatively large brains; they have been domesticated for tens of thousands of years; their food is often provided and they have had heavy exposure to human suffering. Therefore, they are more self-aware than they would be without human intervention, and it is possible a dog could decide to stop eating to starve to death. Being dependent on humans for food, they can lack the skills to get food themselves as well. Other sophisticated animals when facing certain death could give up sooner than others, but they wouldn’t give up for emotional or existential reasons. Of course, we can’t witness all animal behavior, so suicide could be more common than we believe among certain other lifeforms, but it is does seem to be far more common in humans at the very least.
The earliest forms of life evolved extremely slowly. This may have been due to the still undeveloped environment around them that was destroying them again and again due to bombarding meteorites, large (over 1000 feet tall) tidal waves created by the close proximity of the moon, the noxious atmosphere and intense radiation. There was also much competition among prokaryotes and other microscopic life for resources. Natural selection favored organisms that were most proficient at reproduction. To come as far as we have, it stands to reason that our oldest human ancestors must have been advanced from the beginning and extremely proficient at reproduction. But it’s also possible molecules we descended from were only adequate and all achievements and clear progression from all other animals came much later. What’s strange is that no other animal has come as far as we have. No animal is even close today, so what made us excel? (The sad answer may be our violent inclinations. Neanderthals who were very similar and could have become as sophisticated instead became extinct likely because our ancestors killed them off. We excelled largely because we took over the planet.)
3.5 billion years ago, the bacteria that dwelled in the oceans developed a primitive form of photosynthesis that did not generate oxygen, but ATP. Humans develop ATP too, as do all organisms. This bacterium was the first photoautotroph. 500 million years later Cyanobacteria evolved. Cyanobacteria used water as a reductant and produced oxygen as a waste product. This was a very important because it oxidized the iron in the water and put oxygen into the atmosphere. Without this output of oxygen in the air, land dwelling animals would have never evolved. However, oxygen was poisonous to much of the anaerobic bacteria that lived at that time, so this likely killed off large numbers of bacteria as a result. (This is called the “Oxygen Catastrophe.”) Around 2.2 billion years eukaryotes evolved from prokaryotes. They were more complex, unicellular forms of life than prokaryotes. They had a membrane bound nucleus that stored DNA arranged in chromosomes.
5.12 The Development of the Sexes and their Effect on Identity
About 1.2 billion years ago, life finally made an enormous change that would transform identity forever. The bacteria that inhabited Earth changed its method of reproduction. During asexual reproduction, a single celled organism would use its genetic material to make a virtually exact replica of itself, and this way of reproducing left very little room for evolution to take its course. This may be why life took so long to evolve. When these single cells learned to combine their genetic material through sexual reproduction the rate of evolution increased greatly. As explained, genetic variation in offspring can produce good genetic mutations that provide certain organisms with upper hands in their specific environments. The organisms without the mutation will die out, but the organisms with it will thrive and multiply, thereby spreading the mutation. Therefore, sexual reproduction speeds the rate of evolution, but we are not certain why these organisms first began to reproduce sexually. Harsh environments force organisms to make mutations and if the conditions in an environment are extreme enough, they can cause asexual organisms to begin to reproduce sexually. So was the development of sex and the sexes just an adaptation to speed the rate of evolution? If it was, does this mean love has developed from an attraction between two sexes only created and attracted to each other to speed the rate of evolution?
Love, we all trust, is a genuine emotion, but knowing the reason for the development of the two sexes, and that an organism can reproduce by itself may cause you to rethink some of your philosophies about needing another in a spiritual sense. We don’t asexually reproduce, but if our ancestors did and they didn’t need a partner, what makes the need we have for a partner meaningful? Hermaphroditic organisms don’t asexually produce, but some species that are hermaphroditic can self-fertilize because they have both male and female sex gametes or sex cells.
Self-fertilization (or autogamy) has been known to occur among certain plants, fungi, protozoa, and some invertebrates. Many humans are born hermaphrodites or “intersex”; 1 in 4500 to be exact. These infants usually undergo sex assignment surgery to make them male or female. How could the male and female roles mean anything if an organism (humans especially) can be both male and female? Furthermore, some organisms can even change sexes during their lifetime (Clownfish and a group of reef fish called Wrasses are examples) and sex determination is random and can be controlled by something as trivial and meaningless as surrounding temperature. (The sex of alligators and certain other reptiles is determined by the temperature at which the egg is incubated.) In tropical clown fish, the dominant individual of a community (comprised of both sexes) is always female. If she dies the dominant male will change its sex and become female.
Our understanding of male and female characteristics is fundamentally based on the differences we notice among the human sexes and many people assume these differences exist among all plant and animal life. Most adult human males are larger and stronger because they were the hunter/gatherers. And human females are smaller and less physically strong because their natural role has always been to nurture and care for their offspring. However, these roles apply mostly to mammalian animals. These roles are reversed among some species of which the females are much larger and stronger than the males. This is called reverse sexual dimorphism. (Other examples of this, besides clownfish, include falconiformes and owls.) Sexual dimorphism is the study to determine the purpose of the apparent differences between males and females. It focuses on species which have very different looking and acting males and females. In some extreme cases, the male of a species is a parasite that attaches itself to the much larger female and lives there permanently, such as the Triplewart seadevil and the Zeus water bug.
There are no major differences between the sexes that apply to all life forms. There are major differences that apply to the majority of male and female organisms, but not all. Most people think every female organism creates the zygote, but this is not the case. Female seahorses, for example, do contain the eggs, but they deposit their eggs with their ovipositor into the male’s brood pouch and the males gives birth to the offspring. So the male’s gamete isn’t fused or fertilized by the female in every species of animal. There are male carriers of offspring. (Seahorses are thought to be the only genus with male carriers of offspring, but it is possible there are a few others. There may be at least a few other species with male carriers of offspring.) There is no consistent definition of male and female that would apply to all forms of life. Even the size of male and female gametes can be exactly the same. Most male organisms, including humans, produce spermatozoa and most female organisms produce ova, (eggs.) The ovum (or egg) is larger than the sperm. But stated, it isn’t always this way. Isogamy is a type of sexual reproduction in which both sexes produce gametes of the same size. Organisms that reproduce this way are nearly identical in appearance and they cannot be classified as either male or female.
Because the vast majority of female organisms give birth to their offspring, one might think that the emotional connection female organisms have to their offspring should be stronger and thus male organisms would always assume the role of being the hunter, and female organisms would always be the caretakers of the children. Because these roles are common among mammals, is there some underlying sense for these roles? Most likely, the only reason it isn’t this way with every species is because some species aren’t capable of having such an emotional attachment. However, even though male seahorses birth their young they show very little emotional attachment to their children. In fact, when they are born they have to fend for themselves. This isn’t because seahorses are incapable of having emotion. In fact, they tend to be very emotional organisms, which is apparent when they blush and change color due other emotions. They are also monogamous organisms that mate for life. Therefore, because birthing young doesn’t make male seahorses possess more female-like qualities, perhaps the emotional attachment women have for their children has little to do with the fact that they do birth their young and more to do with the fact that males and females produce different steroid hormones. Males produce androgens and females produce estrogens. However, female seahorses do possess some more typical male qualities in that they travel 100 times further than the males who stay with other males in a one-square meter habitat (or home.)
The development of the sexes has had a lasting effect on human identity. Our gender inevitably affects who we become. Of course, we can’t choose our gender, making it one of the many aspects of identity that we can’t control. Gender roles also greatly affect our identities, and when humans began having sex for pleasure, this had a large effect on our identities. It is unlikely life and human identity would have ever become as complex as they have if the sexes hadn’t developed.
5.13 The Cambrian Explosion
The evolution of sexual reproduction was a crucial step for life, but at the time the two providers of the gametes weren’t much different. They were extremely simple organisms. There was no third date before sex. They only needed each other for one reason: reproduction. And since these organisms had no thought, it is safe to say this wasn’t the most passionate affair. Since organisms were now reproducing with a mate, an explosion in the rate of evolution occurred, appropriately called the Cambrian Explosion, which lasted until 500 MYA, (million years ago). The cause of Cambrian Explosion is not agreed upon by scientists. According to many scientists like Nicholas J Butterfeildvii multicellular life appeared around 1-1.2 billion years ago (when sex evolved), but they were still very simple organisms. However, according to others like Richard K. Grosberg1 and Richard R. Strathmann the first multicellular life appeared much longer ago. In their essay entitled The Evolution of Multicellulartiy: A Minor or Major Transition published in 2007: “The first evidence of this transition comes from fossils of prokaryotic filamentous and mat-forming Cyanobacteria-like organisms, dating back 3 to 3.5 billion years (Knoll 2003, Schopf 1993), with signs of cell differentiation more than 2 billion years ago (Tomitani et al. 2006). Multicellular eukaryotes may have existed 1 billion years ago (Knoll et al. 2006), but a major burst of metazoan diversification occurred about 600–700 Mya, at a time of dramatic increases in atmospheric and oceanic oxygen (Carroll 2001, King 2004, Knoll 2003, Maynard Smith & Szathmary ´ 1995, Pfeiffer et al. 2001).”
The first complex, multi-cellular life form (animals or heterotrophs, organisms that primarily consume organic compounds) with partially differentiated tissues may have been a sponge-like creature, which evolved around 600 MYA. However, there is evidence to support that animals emerged much earlier. A decline in diversity of Proterozoic fossil stromatolites is attributed to the emergence and diversity of animals by some scientists like K. J. McNamara and S. M. Awramik. These scientists posit multicellular life could have emerged as early as 1.2 to 1 BYA. Organisms that became acritarchs (small, organic fossils) dominated the oceans before the Cambrian Explosion and provide further evidence. Around 1 billion years ago, they developed many more spines to defend against predation, and other small organisms developed similar defenses against predation at this time like hard surfaces and ability to move. (Bengston, 2002)
All animals are multicellular, heterotrophic eukaryotes, but not all heterotrophs are animals. Heterotrophs are organisms that can’t create their own carbon, so they have to ingest organic compounds. (Organic molecules can, of course, exist independently of living things, so not all heterotrophs eat living organisms.) Surprisingly, there are organisms called photoheterotrophs, as well chemoheterotrophs. Chemoheterotrophs obtain carbon from organic molecules, but receive energy from the oxidation of inorganic compounds. Photoheterotrophs receive energy from the sun like plants, but they need more carbon than the carbon dioxide in the atmosphere can provide so they also receive it from organic molecules. Photoheterotrophs are like a mixture between a plant and an animal. (Most photoheterotrophs are bacteria, but some are carnivorous plants such as the well-known venus fly trap.) Nature creates many “in-betweens.” During the Cambrian explosion the output of oxygen from cyanobacteria and other photosynthetic organisms that produced oxygen as a waste product was building up in the atmosphere, causing an ozone layer to develop. (Ozone is a triatomic molecule consisting of 3 oxygen atoms).
Ediacaran biota was likely the next large, multicellular organism to evolve. They appeared around 580 MYA. Cnidarians (which evolved around this time) may have been the first animals with the ability to move. They had muscles and nerves and they likely used them together to move. Flat worms were the first animals to have brains and acorn worms had hearts, which also functioned as kidneys, as well as structures that resembled gills for breathing. Acorn worms may have been the first organisms to develop an even more significant adaptation around 540 MYA: the evolution of the proto-eye; the development of physical awareness in the form of sight, from which all modern eyes originated.
5.14 The Development of Vision
The first evolutionary step towards vision was the development of “eye-spots” or photoreceptors. A photoreceptor is a cell consisting of a light sensitive protein called opsin and a chromophore or pigment. When a photon reaches a chromophore, a chemical reaction takes place, turning its energy into electrical energy. (This energy is transmitted to the nervous system in more advanced, modern animals. Some of these first organisms with eyes might not have had brains, in which the case the information gained from the eyespot would have been transmitted directly to their muscles.) Eyespots can distinguish light from darkness, but they have no sense of its color or direction. Eyespots likely assisted in the function of circadian rhythms and photosynthesis. Plants and bacteria that sustained themselves through photosynthesis could move towards the light with eyespots. These photoreceptors or eye-spots, which were flat, eventually depressed into a cup, enabling organisms to differentiate between the directions of light. Different angles of light would activate photoreceptors in different places. Ancient snails had depressed photoreceptors. These depressed photoreceptors became almost entirely enclosed chambers with pinholes that let in light. With this development organisms had a much better sense of the direction of in-coming light and even some idea of the shapes of objects which reflected light. The deep pit of proto-eyes where the photoreceptors lay was filled with water until a transparent humors developed. Lenses eventually developed over the humors and then corneas and irises developed in front of the lense. Then, aqueous humors developed in front of all three. After this occurred, a nontransparent ring developed around eyes to mask visual imperfections.
Organisms could see in color when photoreceptor cells developed multiple pigments. The reason why our vision is limited to a narrow range of the electromagnetic spectrum is because these first organisms that developed photosensitivity were, of course, under water and the only wavelengths of light that can pass through water are the ones visible to us today. (There is another narrow range of the spectrum that can pass through water that humans can’t see.) If the first organisms had developed on land (which is likely impossible) we would see a completely different range of the electromagnetic spectrum and probably a much wider one. (Some birds can see ultraviolet light.) This whole process of gaining vision from eye-spots to color vision took only a few million years. When organisms could first see they took the first step towards self-awareness. Eyes were one of the most important physical developments organisms ever made, and self-awareness was the one of most important psychological developments. When we developed eyes, we could finally see our world for most of what it was and we could see others, which gave us an idea of how we might look. This most likely had a major effect on our identities.
5.15 The Evolution of Vertebrates and the Transition from Water to Land
Once we could see, evolution sped up greatly and the Cambrian Explosion began. Our newly developed vision may, in fact, have been the cause of it. Our ancestors around this time were strange-looking, jawless, filter-feeding fish. But eventually, they developed jaws and teeth, and the function of their gills changed from filtering food to respiration. Gills were used for respiration before jaws developed. Jaws started to form as the bones of the first gill arch in fish became more developed and enlarged. Gill bones are positioned in a way that resembles a “less than” symbol used in mathematics (<) but the angle is usually more curved. The upper and lower gill bones make up the top and bottom of the shape, respectively. Once the first gill bones had enlarged, they were the upper and lower jaws. (You can see the shape resembles an open mouth.) The oldest vertebrate fossils that have been found are 530 million years old, so vertebrates emerged around this time, but possibly earlier. (Nature Journal, November 1999.) These fossils are ostracoderms belonging to the genus Haikouichthys and Myllokunmingia. Both of these genera of fish were jawless and they both had defined skulls. Acanthodians were likely the first vertebrate fish with jaws. They appeared around 450 MYA in the late Ordovician period. The Placoderms could have been human ancestors, but there is not very strong evidence to support this. They were jawed fish with armored heads and upper bodies.
Around 530 MYA, the first foot-prints were made on land, meaning that animal exploration of land may have predated the plant migration to land, but they were not footprints of human ancestors – (MacNaughton, R.B.) These organisms could have been euthycarcinoids, a group of arthropods, but it is not known for certain. They likely had exoskeletons that helped keep in water, so they wouldn’t desiccate on land. Human ancestors did not get out of the water until much later. Sarcopterygii, a class of lobe-finned fishes, (which were likely human ancestors) developed limb-like fins around 375 MYA. These fins were likely used to push through shallow, swamp-like areas that were lush with plant life. The first tetrapods evolved from these fish. (Tetrapods are vertebrates with 4 legs.) 475-440 million years ago, primitive plants that evolved from green algae living on the outskirts of ocean began to migrate on land. (Dr. Paul F. Ciesielski) They were “amphibious,” non-vascular, bryophyte (non-vascular) type plants, which eventually became vascular plants. Non-vascular plants have no roots, stems, or leaves that transport water. Fungi migrated on land around the same time plants did.
Insects without wings developed on land sometime between 400-363 MYA. Sharks were the most deadly predator at the time. They ruled the oceans for nearly 100 million years. They were (and are) very adaptive and have survived five mass extinctions. Forests of vegetation covered the land at this time, which included non-flowering, seed-bearing plants that developed around 375 MYA. (Paul F. Ciesielski) The first known amphibious animal to have recognizable limbs was the Acanthostega, which evolved around 315 MYA. The Acanthostega wasn’t the best-suited amphibian for taking trips on land. Its limbs were weak and it didn’t have wrists, so it couldn’t support its weight very well. But it did have lungs as well as gills, so it could breathe out of water. It would hunt in shallow waters and occasionally breathe air but it would never venture on land.
Reptiles evolved from the amphibians 300 MYA. Hylonomus was the first known reptile. It looked like a modern lizard and was about 8 inches long. By 300 million BP (before present) various forms of life had thrived on land. Insects had developed wings and reptiles were able to reproduce on land because of the development of the amniotic (hard-shelled) egg. This allowed reptiles to create larger offspring that had a better chance of survival on land because there were fewer predators there than in the sea. The first mammal-like reptiles (or synapsids) evolved around 256 MYA. They are called the pelycosaurs. The therapsids, direct ancestors of mammals, evolved from them. They developed secondary palates which allowed them to eat and breathe at the same time. At this time, life on Earth was evolving and flourishing until 251.4 MYA when the Permian-Triassic extinction wiped out over 95% of all life. The cause of the extinction is thought to be a discharge of frozen methane hydrate from the ocean beds resulting in an increase in ocean temperature and carbon-12, causing a greenhouse effect. The Lystrosaurus was one of the few herbivores that survived the extinction.
2.16 The Evolution of Early Human Ancestors
One group of therapsids called the cynodonts, became the eucynodonts, which evolved into the first mammals. These animals all had increasingly mammal-like features. The cynodonts and eucynodonts both evolved around 220 MYA. (The cynodonts are a suborder, which includes eucynodonts). The first mammals likely had a constant body temperature, milk glands and a neocortex region in their brains, which are among the defining characteristics of mammals. They likely appeared in the early Jurassic period, which occurred 199.6 to 145.5 MYA, and they were small and shrew-like in appearance. The climate was still fairly dry at this time from the previous extinction and the most well-suited organism for the environment was the Archosaur. The first dinosaurs evolved from a group of Archosaurs in the late Triassic Period (around 200 MYA). (Benton, M.J.) They had much longer life spans than we do, but even though dinosaurs roamed for a relatively long time (about 170 million years) and individually had long lives, they didn’t survive one extinction since it took such a great deal of resources to sustain them. Scientists believe their life spans ranged from 75 to 300 years. They had such long life expectancies because of their body size and type of metabolism.
At this time sea-dwelling animals began to adapt much more quickly and avoiding predators and finding sustenance became greater struggles. This was likely related to the appearance of dinosaurs. The first placental mammals (a placental organism is one that doesn’t lay eggs, but rather develops offspring internally in the placenta and gives birth to live young) evolved from a small, mouse-like mammal known as Eomaia scansoria around 125 MYA. The first known marsupial, Sinodelphys, appeared around this time as well. The first placental mammals looked like small house mice that could climb shrubs. Their similarity in appearance to house mice was no coincidence because mice and humans actually share a recent (100 million-year-old) ancestor.
Dinosaurs (except for avian dinosaurs, which evolved into modern day birds) became extinct around 65.5 million years ago, along with 75% of all species and how it happened is still disputed. The most credible theory involves a drastic climate change due to an asteroid 6 miles in diameter that struck the Earth at this time. This was named the “KT impact.” (KT is short for Cretaceous–Tertiary.) The dinosaurs couldn’t or wouldn’t have been able to handle such a harsh change because it took so much to sustain them. When dinosaurs became extinct all other forms of life that survived increased in size and thrived because they no longer had to compete with predator dinosaurs. (J. David Archibald, 2011viii) The same would occur if humans died out today. In fact, there were “guinea pigs the size of rhinos” and rhinos that were two stories tall. (Richard Dawkins, 1986.) While dinosaurs were still roaming the Earth, angiosperms (flowering plants) developed around 130 MYA, (but possibly earlier.) This development excelled the rate of plant evolution and co-evolution because plants could now spread pollen, and some insects and birds, which were naturally attracted to the pollen assisted in this process.
When the dinosaurs became extinct, our mice-like, mammal ancestors had evolved and taken to the trees. These tree-dwelling, insect eaters were called Euarchonta and they would eventually evolve into treeshrews, flying lemurs and primates. Plesiadapiformes, which evolved from Euarchonta were proto-primates. One species of Plesiadapiformes might have been the ancestor of all primates. (Richard Dawkins.) (Primate means “first in rank” in Latin.) However, some scientists dispute this. 40 MYA primates divided into 2 suborders. The suborder that led to humans is called Haplorrhini or “dry nosed” primates. 30 MYA Haplorrhini then split into 2 infraorders. Catarrhini was the infraorder that led to humans. 25 MYA Catarrhini then split into two superfamilies, Old World monkeys and apes or Hominoidea. Apes were slightly more intelligent than their ancestors. As they evolved, their motor skills improved, as did their ability to communicate. An example of an early genus belonging to the Hominoidea superfamily was the proconsul. They had slightly larger brains than their ancestors and no tails.
15 MYA great apes or Hominidae became genetically distinct from lesser apes or gibbons. By this time there were many different families, genera and species of apes. 13 MYA the great apes then split into the Homininae subfamily and the Ponginae subfamily. (Orangutans are part of the latter subfamily.) One genus of the Homininae subfamily, Pierolapithecus, was very human-like. These primates had unique adaptations to make climbing easier, such as shoulder blades positioned on their backs and flexible wrists. 10 MYA Homininae then split into the Hominini tribe and Gorllini tribe, ancestors of gorillas. The Hominini tribe includes chimpanzees, humans and our ancestors. The latest common ancestor of humans and chimpanzees called Sahelanthropus tchadensis split into different subtribes 7 MYA. Hominina is the human subtribe and Panina is the chimpanzee subtribe.
The earliest known human relative belonging to the Hominina subtribe is Orrorin tugenensis, which evolved from Sahelanthropus tchadensis as the chimpanzees did 6 MYA. Chimpanzees share 98.4% of our DNA, but the 1.6% difference accounts for their inability to speak. They share many social characteristics with humans: chimpanzees make friends ,they are able to gain and lose each other’s trust, they can influence one another and communicate by using facial expressions and body language, and they even have a basic form of spirituality. (James Harrod) It is likely early chimps and human ancestors, such as Orrorin tugenensis living at this time had most, if not all of these characteristics. These early human ancestors had a limited sense of self-awareness. They were developing somewhat more complex identities. Some of them were very social and others were socially isolated, afraid to face the world. We were clearly making huge strides.
Ardipithecus Ramidus likely evolved from Orrorin tugenensis around 4.2 MYA. Ardipithecus Ramidus was likely one of the first species to occasionally walk upright, (this is apparent from the position of its skull, which rested on top of its spinal column rather than in front of it) but the first genus to become completely bipedal was Australopithecus. (Bipedalism is walking using your two rear limbs only.) Australopithecus was another new genus of the Hominina subtribe. They first appeared around 4.2 million years ago. (Seth Borenstein.) Since they no longer needed their hands to walk, they could use their hands for other useful things, such as tool making and hunting. This was another large step forward. Australopithecines lost most of their body hair around 2 MYA, around the same time they became fully bipedal. Another genus evolved from the Australopithecines around 2.7 MYA called Paranthropus. They didn’t adapt well to changes in their environment and their diet was limited to shrubs and other plants. They had much larger brains than the Australopithecines, but their brains were only 40% the size of the brains of members of the next genus, Homo, the human genus.
The Dawn of Man: Self-awareness, Tool use, Language, Money, and Art
Because self-awareness is one of the most defining characteristics of mankind, was the first species (Habilis) of the Homo (human) genus the first to achieve this characteristic? Because we have called these ancestors “human” it would make sense, but even if this was the case this is not the reason we have called them human. We don’t know when exactly humans first became self-aware, but we do know when humans began using tools and they had to have some self-awareness at this time. Tool use is often considered another defining characteristic of mankind. Tool use demonstrates an understanding or at least a recognition of the relationship between the physical self and its environment. All animals manipulate their environment in order to survive, but only in ways that are biologically programmed. Human tool use is much different. We constantly refine our tools and find new applications for resources in an attempt to change our relationship with our environment in different ways. The change in perception that made us able to see multiple applications for things that we would otherwise treat with indifference stimulated human brain growth and catalyzed technology.
The oldest stone tools that have been found are 2.6 million years old, (Semaw S., et al. 2003ix) but we most likely began to utilize everyday objects in our environment like wood and bone as far back as 4 MYA, well before we became Homines, (plural form of Homo) so tool use was not exclusive to ancestors who we call human. Orangutans and chimpanzees used stone tools as well. Humans of the Homo habilis or “handy man” species who evolved 2.2 MYA weren’t as handy as their name lets on. Initially, they didn’t use stone tools for defense or hunting, but rather for scavenging. They mostly used lithic flakes, which are sharp flakes of stone removed from the core of a stone by striking it with another stone called a hammerstone or an antler for scraping meat of the bones of carrion (dead animals), but they eventually used them for hunting and protection. The fact that we named the first species of the human genus “handy man” reflects the widespread impression that tool use is considered synonymous with mankind.
The actions of most other animals are predictable because all of their actions are driven by the instinct to survive. Because their actions are predictable, there is very little that separates them from each other in terms of their identity. They have very little control over their identity because they most have limited or sense of self-awareness and they have almost no time to contemplate anything besides survival and their daily routine. Some animals think about mating and protecting their families, and if an animal is trying to attract a female (almost all male animals do the “courting”) he has to have some sense of himself and his appearance, but he will only do things to attract the female that are biologically programmed and instinctual. And if no female is attracted to him he may feel rejected, but the animal won’t become introspective and question the nature or purpose of his existence. Animals don’t seem to be capable of this or they at least cannot express it. Other animals (with the possible exception of chimpanzees) don’t single themselves out or feel self-pity as humans do. For this reason (and others) they don’t usually act in rash, unpredictable ways.
Tool use made the lives of the Homo habilis species easier. There was a slight change in focus when this occurred. Because survival was easier, their actions were less driven by the instinct to survive and more by the pursuit of pleasure. Tools, especially ones that could not only be used for killing animals for food, but for killing their own species if confrontation arose induced a feeling of power, self-importance, and even omnipotence. When such tools were invented, the priorities of humans likely shifted. The concept of ownership broadened, as did human ambitions When this occurred human actions became less predictable and superior tools gave those with them greater control over their fate and identities. Some animals are naturally aggressive and greedy, but this wasn’t exactly an increase in greed, as much as it was an increase in our understanding that much more was possible than we once thought.
The more we became aware of own existence, the more we thought about the end of existence. As stated, animals don’t question their daily routine. They very rarely just give up and die, and it’s not because they are positive; they just don’t seem to know there is any other option. They just know innately to survive and it takes a great deal for them to stop trying and die. They adapt. They never feel victimized, and it’s not because they value life. They know what death is, but they probably aren’t capable of considering their own death. This would require self-awareness and it would bring up all sorts of philosophical and spiritual questions that they are far from capable of asking. They see the effects of death, but they don’t wonder if something comes after death. All they know is when certain circumstances arise that cause the death of someone they know, they have lost that animal.
Why Homo habilis and older human ancestors first began using stone tools is often a matter of debate. It is a possibility the very first tools were mistakes. Perhaps it was carelessness or just plain luck that made these early humans first recognize the many applications ordinary objects have in their environment, but this is unlikely. There may have been isolated incidents in which this occurred, but the ability to invent tools generally requires a mind with at least a limited sense of self. It requires a mind that feels there is something missing. It requires a mind that figures it could use help. It requires a mind to think outside of its daily routine. As soon as an animal sees there is more to the world than its routine, there is no limit to the number of questions and inventions that can arise. You could say tool use and self-awareness was mankind’s way of breaking out of the animal state of mind. Tool use is a very important landmark.
Another tool of equal importance that had (and has) a wide range of applications was discovered by Homo Erectus around 1.5 MYA. (James, Steven R, 1989x) This was the tool of fire.
Homo Erectus evolved around 2 MYA while Homo Habilis was still present. They learned how to control fire in Kenya and it served many purposes. It gave humans an even greater upper-hand in the animal kingdom. It increased social activity in the night and may have changed our circadian rhythms. It gave us the benefit of cooked proteins which are safer to eat than raw meat (fire also kills toxins in parts of plants we couldn’t normally eat raw) and it made us marvel at the power and mysteriousness of what we didn’t know. Our ancestors who discovered fire may have seen stars as fires in the sky as their descendents did much later. Fire (and our ability to control it) may have resulted in a greater sense of our surroundings than stone and wood tool use did. Fire likely gave us a greater respect for our surroundings as we were learning to control it. Fire may have also helped us to achieve a universal perspective because of its similarity in appearance to stars.
3.1 The Development of Verbal Language
The next step in human progression was communication. Because of our ancestors’ discovery of tool use and their increasingly self-aware minds, they likely began to feel the need to express themselves in more depth ways than they had. Our ancestors were beginning to wonder about questions that define the self-aware mind, but they must have been very murky and unclear. The questions themselves weren’t fully formed because they had no language and these ideas likely came and went in their minds very quickly. Communication is, of course, a means of self-expression. Expressing the self in ways that others can observe and appreciate shows a higher level of awareness of the relationship between the self and other human beings. A mind that can communicate is even more self-aware. It recognizes the importance of its own thoughts and the need to verbalize them. Giving thoughts words opens the possibility of recordation of thought. This idea is monumental, but it came much later.
Verbal communication is one of the most prominent and vital developments we have made in all of human history. It began as another “tool” for survival, but it developed into a very emotional need. All other animals lack the ability to speak a language and it is one of the many things that make humans so unique. Other animals can make noises and cries and use body language to communicate how they feel, but this is very different than the ability to speak a language. It’s not that all other animals are not intelligent enough to communicate. Many mammals do have the necessary components for speech, but either their function or shape differs from the human speech components, which renders them either unable to create a distinct range of sounds and/or unable to process and understand these sounds. Many animals (such as primates) have the same vocal components as humans, but they are not shaped or positioned in the same way as they are in humans. Apes also have speech regions in their brains that are similar to humans, but their larynx is positioned too high for speech and the structure of their vocal tract is much different, as is the shape of their hyoid bone. These differences make them unable to create a range of distinct sounds, but they are able to understand speech and respond in alternative ways because of these speech regions in their brains. This is why they can learn sign language (and it might even be possible to teach them how to write a language.) Dolphins can also communicate in limited ways by calling each other by name. (Stephanie L. King, 2013xi) (However, the sounds they make are not generated by their vocal chords, but rather their nasal air sacs) Dolphins can also communicate to each other how to do certain tasks.
The way we speak is by forcing the air in our lungs to flow up the vocal tract, oscillate the vocal chords and alter the sounds that are generated by positioning our tongues in different ways and changing the shapes we make with our mouths. Before the sounds leave our mouths they pass through bandpass filters called formants, which affect the frequency of the sound, but they do not affect the pitch. The pitch is determined by how much the vocal chords vibrate. The vocal folds of the larynx are adducted (closed) during speech and open during inhalation. The vocal tracts of Homo habilis became more L-shaped as they evolved. This allowed them to make a wider range of sounds. They also had brains that were close to the size of modern humans. But it was not their larger brains that enabled them to communicate; it was the way their brains worked and processed information. To understand speech, process it and create a response, the brain needs two vital regions: the Wernicke’s area and Broca’s area. The Wenicke’s area is connected to the Broca’s area by a neural pathway shaped like a loop called the arcuate fasciculus. The arcuate fasciculus in the chimp brain is smaller and the connections it makes to the Wernicke’s area and Broca’s area are more superficial. (Rilling, J.K, 2008xii) This may account for the fact that chimps can’t learn nearly as many words as humans.
The inferior parietal lobule is a convergence zone, which relays information from the Wernicke’s area to the Broca’s area. The inferior parietal lobule consists of two regions (or gyri) known as the Supramarginal gyrus and the Angular gyrus. This lobule was one of the last structures in the brain to mature during human evolution. However, some other primate brains do have this structure in a simpler, more primitive form, and apes have the same overall anatomy present in the human Wernicke’s area and Broca’s area. So language did not develop because of completely new structures in the brain; rather, it developed due to small adaptations in existing areas of the brain (among other reasons.) (Bruno Dubuc – McGill College) Having this lobule isn’t a prerequisite for understanding and developing language (even though it assists children in language acquisition.) Before it evolved language could have been under the control of the limbic system. (Bruno Dubuc)
When a person wants to repeat a spoken word, the word is first perceived by the primary auditory cortex. From there it is passed onto Wernicke’s area. Then, it is relayed to the Broca’s area and finally brought to motor cortex. Reading a word and pronouncing it is a slightly different process, which starts in the primary visual cortex. The information observed by the cortex then goes to the angular gyrus, the Wernickes area, the Brocas area and ends at the motor cortex. The development of language did not require an angular gyrus either since this region (as well as the primary visual cortex) is only involved in processing written language.
Among the necessary vocal components an animal must have in order to be able to create a range of sounds is the L-shaped vocal tract. A hypoglossal canal of human proportions may also be necessary, but this is disputed. A low larynx is also thought to be a necessary adaptation. And a hyoid bone of similar proportions to the human hyoid bone is also a necessity for speech, but since the hyoid bone isn’t attached to the skeleton it is a difficult bone to find. Only one Neanderthal hyoid bone has been found, (B. Arensburg et. Al 1989xiii) which makes it very difficult to pinpoint when language developed. (This hyoid bone had human-like proportions, so the Neanderthals certainly had the ability to speak, but whether they had a language or not is not known for certain.) It is not clear when we made most of these adaptational changes, but it is important to understand that these adaptations came as a result of attempts to communicate. They never would have developed if we hadn’t seen the need or tried to communicate. (Johansson, Sverker, 2005xiv) There is simply no form without function.
Many people have trouble imagining how humans created so many common functional languages from just grunts and hand signals, especially when we were very limited by our vocal equipment for a long time in terms of the range of sounds we could make. But it’s important to remember that our languages developed over thousands of years. Creating a language with none in place would be impossible to do in fortnight, but over thousands of years, the task is much easier.
As we all know, when we teach parrots to talk they don’t actually understand what they are saying but are merely copying it. Birds have complex vocal components that are positioned in a very human-like manner. These vocal components and their positions allow parrots and other birds to make sounds that are very similar to human words. But the only reason parrots can learn these words is the presence of humans. (Parrots aren’t the only animals capable of mimicking sound. Elephants have been known to imitate traffic noises – Joyce Poole, 2005xv) When we were developing language we didn’t have trainers we could mimic. We had to start with no foundation. No other organism on Earth has our remarkable ability to communicate verbally through language, and express emotions in the same manner as we do. And it is truly incredible that we can express so much just by exhaling and manipulating sound waves generated by the oscillations of our vocal chords. At the same time, communication makes our lives much more complex. Languages give us words to attach to our thoughts and they do a great deal to increase self-awareness, making many of the “big questions” and unknowns of the universe palpable and clear to anyone who can understand the language in which they are conveyed. Before the development of a language (but after the invention of tools) we were merely curious. We could wonder why things are the way they are, but such thoughts were likely fleeting since we couldn’t fully understand them. There were no formal words attached to our thoughts. We knew there was more to life than our survival, such as the pursuit of pleasure, but we not have wondered whether or not there was more still. We were too content to contemplate the nature of things. But as language began developing, these unknowns and questions were given words and possibly communicated, and so subsequent feelings of confusion and great curiosity followed. As positive as it can be to more fully understand or at least question our place in the universe, it can and has also caused much uncertainty, fear, depression, and feelings of purposelessness.
Before we had a language when we may have been self-aware but were merely curious about our relationships with our environment and other animals, our ancestors likely didn’t suffer because of their inability to communicate questions about these relationships. If you were to tell a person living in the 21st century that he or she had to go the rest of life without verbalizing another thought or emotion, that person might lose his or her mind, but that is only because language has already been developed. We have words to express even the most complex thoughts. To our ancestors with little to no language, it might have been much less frustrating because they could communicate just fine with the primitive methods of communication they had. Everything they felt and experienced may have been simple enough to be expressed with grunts and body language. It seems any more in-depth methods of communication were simply unnecessary. Communication covered the basics: the signs and signals necessary for survival. So these unknowns, these questions we still struggle with today, were likely much less troubling when we didn’t have a language and they only gradually became more troubling as language developed and became more complex.
No one knows exactly how we developed our array of complex languages. We know how most of the current languages developed, but little is known about the first languages because written language was developed after verbal language. There are about 14,000 known languages, but as of 2015 only 7,102 of them are living human languages (Ethnologue: 18th Editionxvi). There is no way to prove how the first language developed, but we do have a rough idea how it may have happened. As early humans began to associate noises with certain objects according to their appearance by pointing to objects and experimenting with their vocal chords, they were developing the basic components necessary to make and comprehend words. The noise that came most naturally to them when they saw an object was used. There is much conflict over whether or not our ancestors used similar words to describe the same objects. To say that they did implies that certain sounds have inherent meaning and that the naming of objects wasn’t (and isn’t) completely arbitrary. This belief stems from a branch of linguistics called sound symbolism or phonosemantics and it is related to synesthesia, which is an automatic sensory or cognitive reaction to the stimulus of another sense or cognitive pathway. Sound symbolism is very apparent in the English language and other languages, such as Japanese. Words like “meow” and “whack,” for example, are “sound-imitating” words. Less obvious examples include words that have the same meaning and also start with the same letter or a similar sound, such as words like “beaten”, “banged”, “battered”, and “bashed.” There are many other examples, but there are also many counter-examples, which challenge the argument. Modern languages have been modified so much that they have likely lost many words that were good examples of sound symbolism. If many of our ancestors (who lived in different places) naturally associated some of the same words with the same objects, this would have made the development of a communal language slightly easier and intuitive.
Neuroscientists Vilayanur Ramachandran and Edward Hubbard were among the first to provide a neurological basis for sound symbolism. They did so by conducting an experiment first created by a German psychologist named Wolfgang Köhler in 1929. In the experiment participants were asked to pair two nonsense words (“bouba” and “kiki”) with two separate shapes. (See figure one. In the original experiment conducted by Köhler the two words were “baluba” and “takete.”) The first shape resembled a glob of viscous liquid and the other was a jagged shape, resembling a cartoon depiction of a star. In the original experiment the majority of the participants paired baluba with the more rounded, liquid-like shape and takete with the jagged, angular shape. The words in the experiment were slightly revised to bouba and kiki in 2001 when Ramachandran and Hubbard conducted the experiment, but the results were the same. 95-98% of the people tested chose bouba for the more rounded shape and kiki for the angular shape. The two experiments had the same results because baluba and bouba both sound very similar, as do kiki and takete. Baluba and bouba convey roundness because the mouth makes a more rounded shape when pronouncing the words (and the rounded shape looks more like the letter “o.”) Kiki and takete convey jaggedness because the mouth makes a more angular shape when pronouncing the words. The tongue is also positioned near the roof the mouth, making an angle relative to the roof of the mouth. Kiki starts with the sharp consonant “k,” opens up with the “i” vowel, and repeats, imitating several angles or jagged shapes. Many people also feel these words convey more tension and friction than baluba or bouba, making the jagged shape a more natural choice.
The neurological basis for sound symbolism likely has to do with synesthetic cross modal abstraction, which is the recognition of properties that certain sounds and images or objects share. This is likely due to “cross-talk” or cross-activation between different brain regions that are near each other. In 2006 Daphne Maurer did performed the experiment with children and found that even children under two and half years old consistently make the same choice as adults. This provides some proof that when our ancestors began associating sounds with objects, their choices of sounds weren’t completely arbitrary. People often argue against sound symbolism because languages are quite different from each other. But as mentioned, the major reason languages can be very different from one another is that they have had so much time to evolve.
Languages that are a part of language families, which are groups of languages that have a common ancestor language called a proto-language are very similar. For example, the proto-language of the Romance languages (Latin, Austrian, Catalan, French, Galician, Italian, Occitan, Portuguese and Spanish to name a few) is called Proto-Romance, a language almost identical to classical Latin. Proto-languages developed into different languages because dialects emerged from these languages as their speakers migrated and these dialects eventually became distinct enough to be called different languages.
There are many words with the same meaning and similar spelling in languages that were derived from Latin. One could argue that this is only because they had the same origin. But these languages have had thousands of years to develop and they likely changed most often because contributors felt modifications would better suit their corresponding meanings. This provides some further evidence for sound symbolism. If we knew the words used in very first languages we would know for certain whether our ancestors named objects and actions arbitrarily or not, but there are very few traces of the first languages because written language was developed after verbal language.
If our ancestors did associate similar sounds with the same objects and actions when language first developed, this would have made communication possible between groups of people who lived close together. What makes this very likely (besides synesthetic cross modal abstraction) is the fact that we could only produce a narrow range of sound anyway due to our still relatively undeveloped vocal equipment, so the chances humans from different regions would associate the same sounds with the same objects were greater than if our ancestors always had the vocal equipment of modern humans. As our ancestors began to migrate 60,000 years ago, dialects developed, and words became more divergent, they discovered new things to associate with sounds. Different wildlife and scenery never before seen by humans had be named. This too contributed to the growing diversity and differences among languages.
Before words were associated with objects, it is widely believed hand gestures and body language (gesticulation) were used. Hand gestures are essential for verbal communication and without them language may never have developed. Hand gestures come naturally to humans and before babies can speak they use hand gestures to communicate what they want. When most people imagine some of the first words and hand gestures used, the ones most essential for survival, they normally think of “yes” and “no.” Why the nod and shake of the head is associated with “yes” and “no” respectively is controversial. Some linguists believe it is partially innate. As babies when we don’t want to be fed we will move our heads from side to side, almost pushing away. But when we do want to be fed we will nod our heads forward, advancing toward the food. (Charles Darwin, 1872xvii) However, some believe the nod and the shake of the head are not innate gesture because in some countries (China, Korea and Japan) nodding is just a form of bowing and in others the meaning of the gesture is reversed, (such as in Bulgaria and Sri Lanka). If they are innate gestures perhaps our ancestors imitated their infants until they became widespread. But it is currently unknown when the gestures became widely used.
The “thumbs up” is also a gesture for “okay” or “yes.” We know the origin of this gesture and it is likely younger than the nod and the shake of the head. The “thumbs up” gesture dates back to the time of the Roman Empire. When the Romans were feeling merciful they would conceal their thumbs in their closed fists, possibly to symbolize a sword being sheathed. But when they wanted someone killed they would protract their thumb, “unsheathing the sword” and making a stabbing gesture. So through the years this gestures meaning has changed slightly to mean “okay” or “go for it.” But this is usually considered the Western definition, (even though some Eastern countries use the gesture in the same way.) In some countries (such as Iraq and Iran) the gesture is considered very offensive.
Almost all of the gestures that we use today were created when modern verbal languages had already been developed. Most people can interact today using verbal language, so these gestures simply lend a visual aid to the message we are trying to communicate. Therefore, the gestures used when there was little to no verbal language may have been vastly different than the ones we use today. The first gestures used were probably not ones that indicated “yes” or “no.” These words may seem vital and basic to a person who already has a language, but gestures used before there was language more likely had relevance to hunting or danger. “Yes” and “no” are somewhat more complex concepts to understand. Our ancestors likely used pointing, yelling, or running to indicate danger (and to escape). The “come here” gesture and the hand wave as an acknowledgment of another person’s presence are likely very old gestures as well. Gestures to indicate dominance or anger were likely common too. But there came a time when a more in depth method of communication was needed or otherwise language would have never developed.
The concept of written language is more abstract than a verbal or gesticulatory one. Letters, of course, are symbolic representations of sound. The letters on this page are an example of a written linear language, which means that these sounds are represented by a series of lines rather than true symbols. The Ancient Egyptians were responsible for the creation of one of the first alphabets, Sanskrit. But before the alphabet was created, their written language consisted of a series of symbols called hieroglyphics. It was much more intuitive than an alphabet. They used representations of sound that resembled their definitions unlike our modern linear languages with the exception of Mandarin. Egyptian hieroglyphics were more like a series of drawings than a written language, but they were a stepping stone for linear language.
The development of speech and languages took a great deal of time. Because the development of verbal language left no physical traces we can only roughly estimate when the first verbal language developed, so there are great discrepancies among historians’ estimates of the date of its conception. Currently, the only means by which historians can estimate an upper limit (maximum potential age) of the age of language is by dating fossils of the first human ancestors genetically from chimpanzees, Orrorin tugenensis. These ancestors had the necessary vocal components to speak and communicate, but it is not known whether or not they did. Using the age of these ancestors gives us an upper limit of 6 million years. Experimental psychologist and linguist, Steven Pinker, is among the few that believe verbal language is millions of years old.
A lower limit (minimum potential age) of the age of language is thought 600,000 years. Homo neanderthalensis (Neanderthals) emerged around 600,000 BP with human shaped hyoid bones. Homo erectus also had human sized brains, so the lower limit could be the time of their emergence. We very likely had a relatively complex language before we began to migrate 60,000 years ago. It is very unlikely we could have communicated the need to migrate without a language. (Other animals can migrate without communicating in complex ways, but they usually come back to their place of origin. Human migration came with permanent settlement of generations.) It also unlikely the Cultural Revolution could have occurred without the presence of human language. The Cultural Revolution was a sudden emergence around 40,000-200,000 years ago of artwork, creativity and primitive signs of spirituality. Therefore, the first verbal language(s) developed at least more 40,000 years ago and most likely more than 200,000 years ago. Of course, language didn’t come all at once. Early forms of communication likely took tens of thousands of years at least to evolve into what we would now recognize as fully formed languages.
3.2 From “Humanlike” to Truly Human
Homo rudolfensis was the second species of the Homo Genus to evolve. Archaeologists have only found one skull of this species so far, so some believe it may be a misidentified Homo habilis skull. If it is not misidentified, it is unknown whether it is our direct ancestor or if Homo habilis is our direct ancestor. The single Homo rudolfensis skull was found Kenya and is 1.9 million years old. The next Homo species to evolve was either Homo georgicus or Homo ergaster, which means “workman.” They both evolved around 1.8 MYA. Homo ergaster was present until about 1.4 MYA. Ergaster bones have been found in South Africa, Ethiopia, Kenya and Tanzania. Ergaster began using tools 1.6 MYA. They made use of tools such as handaxes and cleavers, which are similar to hand-axes, but they have wide, sharp cutting edges, whereas handaxes are more blunt. These tools were used primarily for destruction.
The next species of the Homo genus to evolve was Homo erectus, which means “upright man”. They evolved around the same time as ergaster and georgicus in Africa and Eurasia, but they lived at least 400,000 years longer than ergaster according the fossil record. They were around the same size as modern humans at an average of 5ft and 10 inches tall, but much stronger. (Bill Bryson, 2005xviii) They also had a larger cranial capacity than Homo habilis and used more sophisticated stone tools. While they did not have the right vocal equipment to produce a wide range of sound, they could have had a “pre-language” or used gesticulation as a way of communicating. (Merritt Ruhlen, 2006xix)
Homo heidelbergensis was likely the next Homo species to evolve. The morphology of this species’ middle and outer ear allowed them to hear sounds with frequencies of up to 4415 hertz and as low as 770 hertz, which is around the auditory capacity of modern human ears. (I. Martinez, M. Rosa, et al, 2012xx) This indicates they at least had the ability to hear a wide range of sounds. Frequencies higher than 4 kHz can be generated by humans when they speak, although we usually produce sound waves with frequencies of 2-4 kHz. Homo heidelbergensis bones have been found China, France, South, Africa, Germany, Ethiopia and Spain. However, the Dali fossil found in Germany could be a Homo erectus fossil, but if it is a heidelbergensis fossil this would greatly impact the time at which we believe they died out. The majority of archaeologists believe they lived between 600,000 and 400,000 years ago.
The Neanderthals likely evolved from H. heidelbergensis. Proto-Neanderthal characteristics appeared in Europe sometime between 600,000 and 350,000 years ago, (James L. Bischoff, 2003xxi) but full Neanderthal characteristics didn’t appear until 130,000 years ago. Neanderthals lived in Europe and western and central Asia. They were much stronger than the average human, but had comparable height. (BBC) They also had larger cranial capacities than modern humans, which may mean they had larger brains. As already mentioned, Neanderthals had hyoid bones similar to our own, which are essential to speak a language. The hyoid bone is attached to the musculature of the larynx and tongue and its shape affects their movements. However, linguists don’t all agree Neanderthals did have complete proto-languages. They also had hypoglossal canals that were around the same size as human canals. (Richard F. Kay) But hypoglassal canal size is likely irrelevant to the ability to produce a range of sounds. (David DeGustaif, 1999xxii) Most Neanderthals also lacked a mental protuberance. (Jeffrey Schwartz) The mentalis muscle controls the movements of the lower lip and could effect the pronunciation of some words. Because of their absence of a mental protuberance they would have had less motor control over their lips, making speech more difficult. However, Neanderthals did have a gene called FOXP2 (forkhead box P2), which plays a role in the development of language and grammar competence. (Nicholas Wade, 2002xxiii)
3.3 Human Migration and Race Formation
Homo sapiens, (modern humans) were the next to evolve. Neanderthals were still present when our species evolved and whether there was interbreeding is still debated. We likely killed off the Neanderthals. The first Homo Sapiens were born in Ethiopia near the Omo River around 200,000 years ago. (Tim White, 2003xxiv) Some scientists believe there were multiple populations of humans that made separate migrations from different places in Africa, but it is more likely that human migration began with one group of humans situated in Ethiopia. (Dr Andrea Manica, 2007xxv) This is called the single-origin-hypothesis. This hypothesis states that a small group (around 150 people) crossed the Red Sea and the descendants from this group populated the world over tens of thousands of years. At the time, the Red Sea was narrower and more shallow than it is today, making the journey much more feasible. We likely made the first migration because of climate changes and our diet. Climate changes may have made food scarcer on land and forced humans to adapt a diet more dependent on shellfish and move to further coastal regions where shellfish was more abundant. (Curtis Marean, 2007xxvi) When we made these migrations we replaced the other Homo species that lived in other parts of the world. Most human migrations and race formation occurred within the past 60,000 years. There were Homo sapien migrations well before this date (specifically from 170k to 130k years BP), but these migrations were limited to Africa.
When we left Africa 60,000 years BP, we migrated to Yemen and Omen and then stuck to the shoreline of India all the way through Burma, Thailand, and Indonesia and then eventually reached Australia Once Australia broke off from the other continents the settlers there became known as the Tasmanian Aborigines. Others split once they reached Yemen and Omen and went through Saudi Arabia up to the Middle East and then split in Iraq, some going to Europe and some others to Asia. Many groups split in Asia and Russia. Some groups settled in different parts of Asia and Russia while others went to inhabit the Americas. Some settled in what is now America, 35-25K years BP. These were the first Native Americans. Some went further and settled in South America 15-12k BP and some settlers who came later settled in what is now Canada 9-7k years BP. These migrations took thousands of years and were only possible because the continents were, at the time, much closer to each other and touching in certain places. Now that the continents have shifted due to tectonic plate movement, migrations on foot to continents across the globe are, of course, no longer possible. As Homo sapiens made these migrations, modern day race was formed. Those who stayed in Africa made the most noticeable and distinct adaptation, the darkening of the skin.
Skin pigmentation is impacted by the Mc1r gene, which gives instructions on the production of the Melanocortin 1 receptor in melanocytes. These receptors determine which type of melanin is produced by melanocytes in our bodies. When the receptor is activated it causes chemical reactions that make melanocytes produces eumelanin, which produces a brown or black pigment to the skin and protects the skin from UV radiation. When the receptor is not activated or blocked, melanocytes produce phaeomelanin, which produces a red or yellow pigment to the skin and does not provide protection from UV light. The inhabitants of Africa needed eumelanin made by the gene to survive or many would die from high exposures to the U.V. light and heat because pheomelanin can become carcinogenic when exposed to excessive U.V. Light.
Mutations to the Mc1r gene can cause MC1r receptors to be inactive or blocked or receptors. Different mutations can cause the receptors to be continually signaled without stimulation. The mc1r gene is changed by cleavage or splitting products of another gene called proopiomelanocortin, which are split by enzymes called prohormone convertases. The MC1r gene mutation that results in continual production of eumelanin spread in Africa because others died without it, whereas it was not needed in regions of the world where there is less intense UV radiation, so it did not spread there as much. This was just a small, natural adaptation to protect the skin, yet many humans have used it as an excuse to commit countless senseless acts of violence and destruction against people with darker skin.
White skin is actually more “abnormal” than dark skin. If all humans were black, cases of melanoma would decline sharply. All humans did have much darker skin in Ethiopia, and those who stayed or migrated or to regions near or on the equator (where U.V. levels are high) have dark skin today. Light skin is actually a relatively new adaptation, which occurred sometime between 6 and 12 thousand years ago, (Ann Gibbons, 2007) whereas our human ancestors had dark skin for 1.2 million years. (Alan R. Rogers, 2004xxvii). The enslavement of Africans had nothing to do with skin color, but rather with the profitability of the slave trade and the sense of superiority many Europeans and Americas had due to their advanced technology.
All race formation occurred when Homo sapiens migrated to areas unlike the one in which their ancestors were first born. Races of people share the same morphological attributes because we have all adapted to our unlike climates. Of course, all animals adapt in the same way we do, but the word race is only used for organisms with varying physical traits that can interbreed and produce fertile offspring. Some other forms of life aside from humans have been categorized by different races as well. The Key lime and Mexican lime, for example, are the same species, but they belong to different races since the skin of the Mexican lime is thicker and darker. There are also multiple races of Western honey bees and chimpanzees.
Instead of dividing humans by different species names or races, some have suggested we should separate humans by subspecies. However, some consider race to be synonymous with subspecies. (Alan R. Templeton, 1998.xxviii) But there are many subspecies of animals, which we don’t call different races like the organisms mentioned above. We are another example. Our full biological trinomial is Homo sapiens sapiens. All modern humans are a subspecies of Homo Sapiens. Homo sapiens idaltu is the other (extinct) subspecies of Homo sapiens. It would very confusing to call idaltu a Homo sapien race because it was so different than modern human races.
Another reason we don’t call human races different sub-species may be because it sounds more divisive than race does. This may be one of the biggest reasons because it has little to do with its definition. Subspecies doesn’t have a precise definition and the word race is also used ambiguously and in far too many contexts. Because there is no consensus on the definitions of either word it makes sense that we would use the least divisive word. Only slight morphological differences in other animals can warrant the naming of a new subspecies. If this was applied to humans, there might be hundreds of subspecies of humans. (The higher taxonomic rank of species is also ill-defined due to the fact that some organisms that are classified as different species can interbreed if they weren’t geographically isolated.) Race, as I have said, is not always used consistently either. Most commonly people who live in different geographical regions and are genetically and morphologically distinct in some consistent way are said to belong to different races. But it is also used to describe different cultural, religious, social, ethnic and linguistic groups.
Genetic variation in isolated regions is relatively lower, and people of different races aren’t incredibly genetically different. There is far more genetic variation among individuals that is not categorized by race. (Alan R. Templeton, 1998xxix) (The reason for this is that some genes result in superficially imperceptible traits, while some others result in very perceptible morphological traits.) In fact, 85% of genetic variation occurs within populations and only 15% occurs between populations. For this reason some biologists, such as Richard Lewontin, suggest humans shouldn’t be separated by race or subspecies. Our genetic similarities between populations are probably due to mass transportation. People don’t usually stay isolated within their country or continent their whole lives, so genes mix with interracial breeding. This is very much the case in America because so many people have come very recently from all over the globe and mixed genes. To say that there is an “American race” would be silly. To separate humans by race (by name, not literally) may be just as senseless.
The fact that race likely isn’t a valid term for groups distinguished by race makes racial discrimination all the more absurd. We make adaptational changes all the time, but we only single each other out when these changes are palpable, physical attributes like skin color, eye shape, facial structure, and so on. Most of the people who discriminate against races don’t even know the root of race or that race may not be a valid distinction from a biological standpoint. All Homo sapiens looked similar when they all lived in Ethiopia and if we all lived in one decent sized country, the same would occur over hundreds of thousands of years of interbreeding and adaptation.
3.4 The Development of Currency and Government and their Effect on Identity
Before our ancestors made the first major migrations out of Africa and the “races” developed, an invention that has permanently changed our culture and the way we live as human beings nearly as much as the development of speech was created around 100,000 years ago. This was the invention of currency. We know when money was invented because there are physical artifacts left as proof, whereas language’s date of conception is much harder to prove because it left no physical traces and there is not total consensus on what qualifies as a language. We still don’t know which invention came first, but language was probably being refined and becoming more complex around the time of its formation.
The earliest forms of money were called proto-money and they came in two forms: shell necklaces made of the pea-sized snail, Nassarius Kraussianus, and red ochre, a pigment made from naturally colored clay. (Nassarius Kraussianus shells were found in Blombos Cave in South Africa had red ochre on them, which shows that they both had great significance in early human cultures.) It is not known for certain whether shell necklaces were used as currency but they certainly had cultural significance and symbolic meaning. They could have been indicative of power or wealth or used as apotropaic symbols. (Christopher Henshilwood, 2004xxx) The oldest shell necklaces found are 100,000 years old. (Marian Vanhaeren, 2006xxxi) They were found at Skhul cave in Israel and Oued Djebbana, Algeria, which have never been remotely close to an ocean. This means they were either transported far distances by one person, or traded a number of times by people who lived in different regions.
Families or larger groups of humans might have occasionally traded shells or ochre for food with another family or group if there was a great lack of it, but our ancestors couldn’t stop hunting or gathering food if they had a large number of shells or ochre. Some families or groups from distant regions might not see their worth. What is worthless to one may be priceless to another. Trading likely went on between parties that were already familiar with each other. Shell money is still used in the Papa New Guinea and East New Britain Islands, but it requires more work to make. The shells have to be chipped down into circles and threaded for necklaces.
Sea shells are a form of commodity money. Commodity money can really be anything that two people consider tradeable. Foods are the most common commodity. The value and importance of particular commodities is determined by the people making the trade (as well as by the availability of the commodity) and no form of government has to be in place to determine these values. In a resource based economy, resources are the only kind of “currency.” Decorative forms of commodity money differ from vital human commodities like food and water. As mentioned, not everyone would value a shell necklace, but everyone must eat and drink. As marketplaces became larger, people desired forms of currency universally valued and accepted for trade like gold, silver, and fiat currency. But in a resource based economy, fiat money can be completely unnecessary.
In the past, the importance and value of certain commodities has fluctuated greatly for reasons beyond supply and need. Cocoa beans were among the most valuable products available in Mexico during the 15th century and considered to be a status symbol. (Peniche Rivero, Piedad,1990xxxii.) While supply and demand are the variables that most affect the value of products, the cultural significance of commodities also often affects their perceived value. Tens of thousands of years ago, anything that was rare and/or had spiritual significance could be used to trade goods.
Paper money was representative of gold in the United States until 1971 when the system collapsed. At the time, the Federal Reserve had printed more money than they had gold, and the government had used this money to pay nations, but the money was worthless without the gold and in 1976 most nations switched to fiat currency because of this. Fiat money is modern paper money. (The S’ung dynasty in China was the first to use paper money in 1023.) Fiat money only has value because of the government that prints it. Without a government fiat money has no value. It is like a ticket of credit. If the government prints too much currency, it loses its value as the rate of inflation increases because even fiat money is affected by supply and demand. Conversely, if governments don’t print enough money, it will be worth too much and if the cost of products don’t increase immediately, many people will go bankrupt. Recently, there have been vast increases in the rate of inflation in the United States, but wages have not been increased accordingly. From 1913-1955 the city average consumer price index for all urban consumers was relatively stable, experiencing small increases and some decreases. However, from 1955 the CPI steadily rose. Then, in 1973 the rate of inflation began to skyrocket. From 1970 to 2014 the CPI increased more than 6 times over, yet wages have not causing economic instability, a growing gap between the rich and poor, and wider poverty. (Malik Crawford, et al, 2004xxxiii) The Federal Reserve system, which is the central banking system that prints all US money is shrouded in secrecy. Their distribution of money is often criticized because their actions are so secretive. It operates on a system of credit wherein the US government and taxpayers are perpetually borrowing printed money and in-debt to the wealthiest private bankers in the world.
Modern currency printers spend a great deal of time attempting to make modern money very difficult to replicate or steal. But this is becoming harder and harder as methods of production of fake currency become more developed. Currency printers might eventually decide to eschew all physical money and instead keep track of the net-worth of individuals simply through computer databases. But this won’t make it impossible to steal. There will just be different kinds of people stealing it. The number of computer savvy hackers stealing money would likely increase.
Money does not ensure the weak can survive. Barter of resources is more than sufficient. Paper that represents value is as silly as politicians “representing” people. These systems of representation do not work as they extremely prone to corruption and inequity. Money had changed many people’s perception of our purpose as human beings, what is needed to survive, and our identities irrevocably for the worse. Greed is the cause of the much of suffering and violence in the world and money helps perpetuate our economic systems wherein the greediest get to keep their riches and power at the expense of working people.
3.5 The Development of Artistic Expression and its Purpose and Effect on Identity
Around 30,000 BCE as money and language were developing, paintings and carvings were becoming a common sight in caves as humans left their marks for future generations. These art forms represented further breakthroughs in consciousness. Art had been developing for some time at this point. As mentioned painted seashell necklaces have been found that are over 100,000 years old. But art was becoming much more sophisticated at this time. The first cave cart archaeologists have found is in Australian caves that is 40,000 years old. Aborigines rubbed their hands across ductile limestone in these caves, which had acid seeping through them, making their walls malleable. Most archaeologists assume these manipulations in the stone demonstrate an early human understanding of symbolism and fascination with nature.
Art is as much a form of self-expression as language. However, language is generally direct and concise while art is a somewhat more abstract and symbolic way of conveying feeling and thoughts. Even though forms of language had already been developed before the invention of cave art it is very likely that our ancestors still had thoughts they couldn’t express very well or at all, as modern humans still do. Unknowns about our world were still likely confusing at best, so art was the only way of expressing such thoughts. Some archaeologists don’t think that this was the purpose of cave art since the subject matter of most cave art was not anything philosophically related and superficially it didn’t show much depth. But this is very subjective. It is likely that cave art wasn’t a means of expressing specific unknowns or questions, but rather was a way for our ancestors to express themselves and how they felt about what they did not know and what they were faced with in their everyday lives.
Cave paintings were made with colored ochers and Earthy iron ores that could be ground into different pigments. Iron ores and some clays contain iron oxide. Different ores contain different kinds of iron oxide, which have different pigments. Ochers, especially of red pigment, were used long before the invention of cave art during certain rituals like funerals and for making jewelry as mentioned. Carvings or petroglyphs were also common in caves and were sometimes accompanied with ocher paintings. Our ancestors employed many different techniques to paint with ochers. To create a negative image some of them would take the ground pigment in their mouths and spit it out on the stone around their hand. They also used brushes, pads and reed blowpipes. (Stokstad, 2007xxxiv) Some prominent examples include the cave paintings at Chauvet and Lascaux, especially the “Hall of Bulls.”
Our ancestors began sculpting around the same time they began to paint caves. Of course, stone tools carved from rock were far from new, so sculpture wasn’t a much different concept, but artistic sculptures were done for a very different reason. They also utilized many different mediums, beside stone, to sculpt figures. Figurines of people and animals were made of clay, bone, stone and ivory. (Stokstad,2007xxxv) They have been found mostly in Europe and Asia. A notable example of an early sculpture was the “Lion-Human” figure made around 30,000-26,000 BCE. Combining human characteristics with (other) animal characteristics (known as anthropomorphism) requires self-awareness and a mind capable of “religious” or supernatural thinking and questioning. Many mythological deities of early religions were, in fact, anthropomorphic. Many sculptures of women were also made around this time, such as the Woman of Willendorf, the Woman from Ostrava petrkovice and Venus of Dolní Věstonice. Women and animals were commonly depicted in cave art. The depiction of women, especially well-endowed women, demonstrated a greater fixation on females and feminine attributes. Our ancestors were likely having sex for pleasure and may have valued women more than ever. Relationships likely became increasingly complex and meaningful due to the development of language and humankind’s interest in symbolism and creative expression. Many of the women were also depicted pregnant, such as the Woman of Willendorf, which perhaps demonstrated greater appreciation and contemplation about conception.
Animals depicted in most ancient cave art were shown being hunted, fleeing more dangerous predators, or chasing after humans. Depicting animals likely had a different purpose than depicting women in art, but both types of art may have been made for almost the same reasons. The hunt was our means of gaining sustenance and surviving. On the surface, we were just showing our experiences, but by doing this we were also making deep philosophical statements. We were showing what we did not understand. By depicting our hunt we were communicating to others that our lives were difficult, that we wondered about life and death and that we were risking life and limb doing what we were doing just to survive. All other animals were doing the same, but we had the ability to express it and we might have begun to question our will. Hunting tools did help, but hunting was still no easy task, and the importance of relationships may have offset the selfish effects tools had. Death was likely much more difficult to deal with and death was occasionally depicted in cave art. Sex and relationships drove us to maintain our will, which is why they were depicted with these animals in cave art and as sculptures.
Cave art shows a greater self-awareness than both tool use and language because it is such an abstract form of self-expression that exhibits knowledge of all kinds of relationships the self shares. This higher level of self-awareness led to more complex identity formation. Art is often very emotionally charged and cave art was no exception. It may have served as an alternative to expressing emotions verbally because our ancestors’ abilities to do this were still limited. They likely wanted future generations to know what they had experienced as well. This recognition of their history, their ancestor’s history, and future generations was very significant. If we hadn’t already begun to question the meaning of our existence, our daily routine or even our will to live, we were nearing the point at which we could. Tool use made us see there was more life than once thought.
Organisms that know nothing outside of their daily routines and are not conscious enough to question don’t have to face the uncertainty that more aware beings have to face. We are conscious enough to question, but we are far from knowing everything. Many of us can contend with unknowns and be sane and comfortable in a world with few answers, but unknowns can still be troubling for many people. Some people have made peace with these unknowns. Some scientists, for example, revel in unknowns and hope that theories that act as the foundation of science are wrong so they can rework them. They enjoy the journey; the answers are just as important, but they don’t lament if they don’t find them right away. However, not everyone has science or that access to information. To our ancestors who did not yet have science, these uncertainties may have become overwhelming.
As our knowledge and awareness of the world has expanded, more and more of these unknowns have become apparent and troubling. Over tens of thousands of years of progression, our emotional needs have become more broad and complex. Our perspective of time and space has improved immensely making some of us feel small and insignificant in a world larger than we could ever imagine. Without science our ancestors coped by forming their own mystical answers and religious behaviors, as well as forging deeper bonds with other people.
3.6 Religious Behavior
Because relationships were more important to people after the birth of art and language, the death of someone close to one of ancestors was all the more devastating, so eventually people began to wonder about death and whether or not it is really the end of existence. Relationships may have given us motivation, but the deaths of those who were close to us would make us extremely unmotivated. The instinct to survive might just fade away. If an animal’s family dies and that animal is capable of emotion of course he/she will feel sad, but he/she won’t feel wronged or cheated. This is solely a human attribute, as is suicide. (I mentioned this earlier.) If things became too difficult we might have begun to feel as if we were cheated or wronged, mainly because of our self-awareness, but by whom? This is where a higher power comes into play. We began to single ourselves out because of our higher self-awareness, as if we were the only ones suffering, and we denied that we deserved what was happening to us. Because a primitive sense of morality was developing, we began to wonder why bad things happen to good people.
Some historians claim religious behavior (like shamanism and ancestral worship, not organized religion) developed around the time of language formation. The archaeological evidence for this weak, but it is possible. Our ancestors began intentionally burying their dead well before painting on cave walls, but intentional burial should not always be considered a form of religious behavior. Intentional burials and even burial ceremonies aren’t always performed by people who believe in an afterlife. We could have began intentionally burying our dead because of a stronger emotional attachment to the people in our lives. If we just left corpses of our friends and family to rot, animals would pick them apart until there was nothing left but bones scattered and strewn about. Intentional burial shows respect above all else.
Cave art, on the other hand, is strong evidence of the presence of religious thoughts and ceremonies. We might have even had “semi-organized” religions when we began painting and expressing ourselves creatively. It is possible cave art served as a foundation for developed religious and philosophical thought. If there were “organized” religions when we began painting caves, they were rather isolated and their group of followers would have been small. We didn’t live in communities at this time so any specific religious ideas or beliefs would have been limited to members of the same family or group. Groups or “bands” likely consisted of about 10 to 100 humans. Religious thought is far older than the invention of religion.
Neanderthals may have intentionally buried their dead before Homo sapiens did. There are many examples of Neanderthal burial in Shanidar in Iraq where Neanderthal bodies were buried with flowers. (whether or not this was intentional is controversial), Kebara Cave in Israel and Krapina in Croatia. (Paul Bennett, 2002xxxvi) The oldest fossil belonging to Homo genus intentionally buried is probably the Tabun C1 Neanderthal, which could be as old as 120,000 years. (Grün and Stringer, 2000xxxvii) In Atapuerca Spain, the oldest example of intentional human deposition was found in the dark recesses of a cave named Sima de los Huesos. (Bermúdez de Castro & Nicolás, 1997xxxviii) In this cave over 32 Homo heidelbergensis skeletons were found that could be 300,000 years old. The bodies were likely deposited in the cave intentionally in lieu of burying them. This is not quite the same as burial, but it was likely done for similar reasons.
3.7 The Neolithic Revolution and Organized Religion
As stated, true organized religion is a much more recent invention than religious thought or behavior. Organized religion developed sometime after the invention of cave painting (30,000 BP) and before the Neolithic/agricultural Revolution, which took place sometime between 10,000 and 7000 BP. (Barker 2009xxxix) The Neolithic revolution occurred when we learned how to grow plants and domesticate animals, and communities were built. Because humans lived closer together than they did before this time, this allowed religious ideas to spread. Between these two dates, organized religion was most likely in its infancy. Religious thoughts and ideas were very likely discussed and expressed broadly during this time, but specific religious concepts remained isolated because “bands” of humans were too small in number for these ideas to spread.
When cave art became widespread, those who hadn’t thought of expressing themselves in such a way were now aware of the possibility, and the cave paintings must have sparked much contemplation and encouraged dialogue. This is when language became much more than a simple survival tool. Explanations needed to made so we could feel that there was order and fewer unknowns than we thought there were. These unknowns didn’t consist exclusively of the “big questions.” Unknowns at that time included all physical processes because there was no science. As discussions about these unknowns began, our ancestors likely began to feel overwhelmed by them. Thoughts about death, a possible after-life and (as mentioned) feelings of being wronged or cheated can all lead to the idea of a higher power. When we began to wonder about the nature of things or why things happen, the simplest way to answer these questions was to claim that everything is caused by a higher power for divine reasons. It took us much time to realize that complex physical, chemical and electromagnetic laws that we could discover with much study control how and why just about everything occurs. Assuming ambiguous higher powers were responsible for all physical processes made life less difficult for humans. But this eventually catalyzed the development of strict and zealous religious rules and rituals like human and animal sacrifice, as well as the invention of various Gods and constant worship and prayer to them. Once these religious rules and ideas about certain gods became widespread, true organized religion was born.
Religion developed very naturally and the reasons why it developed are easy to understand. But geneticist Dean Hamer believes religion is hardwired into the human condition, or in other words, that there is a gene that makes us think there should be a higher power called the VMAT2, or the “God gene.” His theories have not been academically published and aren’t credible, but they are worth mentioning to make a point about the misinterpretation of science and scientific cynicism. The VMAT2 (vesicular monoamine transporter 2) is an important gene that transports essential neurotransmitters into synaptic vesicles, which store neurotransmitters in the receiving neuron. The longer the neurotransmitters stay in synapses, the gaps between the neurons that releases neurotransmitters and the neurons that receives them, the more intense the effects of the neurotransmitters will be.
Hamer came to this conclusion by testing participants in his study for their “level of spirituality” or their place on the “self-transcendence scale” and studying their DNA to determine if there were any correlations between their level of spirituality and variations in the VMAT2 gene. What he discovered is that one change in the position of a nucleic acid base (cytosine) in the gene results in a higher level of self-transcendence. But to say that one gene or even thousands of genes are responsible for human spirituality is likely fallacious and it ignores the history of human spirituality. More spiritual people may feel “self-transcendence” more often than non-spiritual people, but that doesn’t mean self-transcendence necessarily had anything to do with the development of religion, nor does it mean that people with this particular variation in the VMAT2 gene will be more spiritual. And even if it did, a state of self-transcendence can be brought on by a variety of stimuli. The neurotransmitters which result in feelings of self-transcendence are often secondary to the stimuli, not the cause. Hallucinogens, which affect these same neurotransmitters much more may have played a role in the development of religion. However, religion likely would have developed regardless.
Hallucinogenic drug use is a spiritual practice in many religions, such as certain indigenous religions, which often partake in rituals involving peyote, San Pedro, the Peruvian Torch cactus, hallucinogenic mushrooms, DMT, or ayahuasca. Some of these religions have practiced these rituals for thousands of years. Major distortions in perception caused by drugs could only be explained by our ancestors as the intervention of super-natural forces. Many cultures describe hallucinogenic experiences as profound and religious and still claim certain hallucinogens are gifts from God. Some of these cultures also claim hallucinogenic plants provide feelings of self-transcendence and a spiritual connection to the Earth and the rest of universe. The psychoactive properties of the mescal bean (a toxic seed of the Sophora secundiflora tree) were discovered before 10,000 BP and peyote was discovered soon after. A similar ceremony was conducted during the ingestion of both substances by Native Americans.
3.8 Human Cultures, Advances in Technology, and the Expansion of Governments
For those who experienced and embraced the Neolithic Revolution, hunting and gathering was no longer necessary. More and more of our ancestors began to understand how plants reproduce and how to grow them from seed. This encouraged people to make shelters (the first houses were made of mudbricks or stone) and build farms so they could reside in one place permanently or for long periods of time. It made sense for people to live closer together. Survival was easier in large groups as long as no one tried to steal anything because it made the “marketplace” larger.
While communities developed after the Neolithic Revolution were most likely peaceful for a long period of time, there was eventually battle for fertile land. A notable example of land that was constantly fought over is the Fertile Crescent, which is a region in the Middle East shaped like a crescent, which includes the Levant, Ancient Mesopotamia, and Ancient Egypt. Halafian culture developed there in 5500 BC. There was ready access to water and the ground was rich in nutrients. Mesopotamia was conquered by many different cultures at different periods in time. The discovery of agriculture helped catalyze government. Survival was much easier after the development of agriculture and the domestication of animals. This again made humans more selfish, as the first stone tools, and since money was becoming more valuable, this increased greed even more. Because land was now a commodity and people were living closer together, conflict over land ownership was to be expected.
Families were still largely economically independent until the Bronze Age. They may have relied on other humans in their tribe to provide things which they could not, but they did not need a hierarchy in place to survive. There was also a high degree of social sophistication and cooperation among humans in tribes in the absence of hierarchies and government. Structures such as burial mounds, hedges and elaborate tombs are evidence of this (these are also very impressive examples of our ever-increasing interest in life, death and the afterlife), because they took a considerable amount of time and effort to build, and they were most likely built without any hierarchies or government in place.
Circular stone huts were built near the Euphrates River 8200-8000 BP. The design of houses improved sometime between 7700 and 5000 BCE to rectangular mudbrick ones found in the Abu Hureyra mound in Syria. (Frank P. King, 2008xl) Domestication of goats, sheep, and cattle also increased at this time. Human skulls were often plastered to make masks with facial features and either buried under homes or placed on the walls of homes. (Sloan, 2014xli) Many were also buried independently of homes. Plastered skulls have been found in Ain Ghazal, a region of Jordan, as well as Syria, Israel, and Turkey. Some skulls were also painted and decorated with shells or stones to represent eyes. Humans were clearly more fascinated with death at this time, but the exact purpose of such rituals is not known for certain. They may have been religious in nature and had something to do with beliefs about an afterlife.
The oldest pottery vessels were found in China and they are about 20,000 years old. (Wu X et al 2012xlii) But the invention of the potter’s wheel around 6500 BCE made pottery vessel production much easier, as did the invention of the kiln in 600xliii0 BCE. Europe was slower to adapt to new technologies at the beginning of the Neolithic Revolution. They gained information about Neolithic traditions mostly from the Middle East. The first farming societies arose in Europe around 7000 BCE. Copper was first discovered in the Middle East around 9000 BCE. (Marianne Stanczak, 2005xliv) But copper was not smelted until 4500 BCE. (Smelting is a process of chemical extraction, which usually involves heating ores or rocks in order to extract their metals.) The people of Israel, Egypt and Jordan were probably the first to begin smelting copper. (Marianne Stanczak, 2005) Europe took longer to smelt copper, but Artisans from Hacilar, present day Turkey, did make smelted lead beads and copper pins, which were not smelted around 7000 BCE. (Frank P. King, 2008xlv) Europe was also slower to make the transition into the Bronze Age than the Middle East, although they did make the transition sooner than China and Korea.
3.9 The Development of Written Language
Eventually languages became complex enough to be represented in alternative ways. Because art had developed into something that was visually quite impressive and thought-provoking, written language was an easy transition. It began as a set of simple symbols or pictographs that represented objects and actions, which were similar to what was being painted and sculpted. But it eventually developed into a large set of symbols that first represented words, then syllables, and then letters. When written language developed, events could be recorded less abstractly by writing about them rather than by painting or sculpting them.
Some linguists believe the first written language was Egyptian Hieroglyphic script, but in truth the first form of writing using ideographic and/or mnemonic symbols came much earlier. Jiahu script may have been the first, which developed around 8600 BCE. (Dr. Garman Harbottle, 2003xlvi) It consisted of only 16 markings on tortoise shells. These were found in Jiahu or what is now Henan, China and belonged to the Peiligang culture. (A lunar calendar was also carved around 6500 B.C. found between the Congo and the Uganda, but this was just a series of drawings, not a written language.) Vinča signs emerged around the same time as Jiahu script in the 7th millennium BCE as very simple symbols but evolved considerably over thousands of years, which is evident in the Tărtăria tablets of the 5th millennium. Some historians deny this was a form of writing because no one can decipher the clay tablets or vessels of writing, but this doesn’t necessarily mean they weren’t a written language. Ancient symbols that have the appearance of written language are almost never just artistic expressions with no linguistic meaning. These tablets were found in south-eastern Europe (Tărtăria, Romania) and if they are a language they may be an old European script. (Merlini, Marco, 2009)xlvii) The Indus Script may have been another early written language, but this is debated as no one has been able to decipher this script either. Artifacts with Indus script have been found as old as 3500 years.
The Sumerian Cuneiform script is the first known and undisputed, complex written language with many symbols. It has about 1,000 symbols or about 1,500 if variants are included. It was invented sometime between 3400 and 3000 BCE and began as a mostly logographic language, which is a language which uses symbols to represent words, but developed into a primarily syllabic one, a language that uses syllables to make words. Cuneiform was adapted for writing many other languages besides Sumerian, such as Akkadian, Eblaite, Elamite, Hittite, Luwian, Hattic, Hurrian, and Urartian languages. Egyptian Hieroglyphic script was invented around the same time in 3200 BCE, but proto-hieroglyphics were present 100 years earlier. Contrary to common belief, hieroglyphs aren’t just logographs. There were glyphs that were logographs, which stood for morphemes, the smallest units of language that have meaning, such prefixes, affixes or words. But there were also two other kinds of glyphs: phonograms or phonetic complement glyphs, which were parts of a word or single-consonant characters (there were no vowels unlike in cuneiform), and ideograms or determinatives, which helped determine the meaning of the other two kinds of glyphs. With the invention of cuneiform and hieroglyphs, history could now be recorded. Currently, we can only understand hieroglyphics that were written after 2600 BCE. An alphabet was developed in Egypt in 2000 BCE from the alphabetic principles of hieroglyphics, and this enables us to understand the language. Written language was an immense step forward.
1 There are theories that claim there was space around the singularity, at least in other dimensions or universes, as well as other Big Bangs occurring all the time in these different dimensions or universes, but they are still very speculative.
2 Baryons are hadrons that contain 3 quarks, such as protons and neutrons. Some scientists believe there are baryons with 1 quark and others with 4, but this is not widely accepted.
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