Natural History

 

It is not from space that I must seek my dignity, but from the government of my thought. I shall have no more if I possess worlds. By space the universe encompasses and swallows me up like an atom; by thought I comprehend the world.

                                                                                                                Blaise Pascal, Pensees

 

 

I discover myself, I among others, and in the objective spirit I recognize the object of history as the arena of my action, spiritual history as the content of my consciousness, history as a whole as my nature. I merge myself with my development, as humanity merges with its history.

 

Raymond Aron,  An Introduction to the Philosophy of History

 

Natural history is taught in the fields of biology and geology as a study of plants, animals, and the earth, but here we view it as a story of the universe. For us, it starts with the origin of time when no clock could measure anything. There were no objects in the world, only a great light in an explosion of energy and a sound that human ears will never hear. This history is about the sequential appearance of particles, atoms, constellations, molecules, the earth, cells, and organisms.

According to astrophysicists, “particles” were produced by the Big Bang in an unimaginable explosion of energy and light. There was nothing, no "thing" at the beginning of this history. But “things” start to appear as particles and transform into atoms and molecules, each thing developing more complex parts through antecedent parts, combining, recombining, and synthesizing in constellations, until finally going into the formation of stars, planets, the earth, and life on the seas; then the primitive cell, the organism, the ape, and humankind.

Let us look at this story synoptically without treating all the details and theoretical issues. Our purpose is to lay the basis for a new perspective on the history of humankind.

 

The History of Particle Formation 

Astrophysicists believe the Big Bang started some 13.8 billion years ago with incredibly high temperatures. This explosion produced particle formations that became the foundation for all changes that followed.

According to the best knowledge available, radiation from the Bang was so hot that there was only pure energy. The simplest particles—protons and electrons— could not take shape until things cooled down. At one-hundredth of a second after the explosion, the temperature was a hundred thousand million Kelvin, so hot that ordinary components of matter could not combine.

These particles were seeds of the cosmos, bearers of light for the coming universe, spreading like waves in an ocean, etching an underlying fabric of light for all time. Among the early particles to appear was the negatively charged electron. It now flows through wires in electric currents and is part of most of the atoms and molecules in the universe today. Another early particle was the positively charged positron that is found only in high-energy laboratories and in powerful astronomical phenomena, like cosmic rays and supernovas, but at the beginning of the universe they were equal in number to the electrons. There were also roughly similar numbers of neutrinos with no mass or charge at all. The whole universe was filled with light, particles of negligible mass and zero electrical charge known as photons. Indeed, an unbelievable abundance of light filled the entire small universe.

 After a tenth of a second following the initial explosion, the temperature dropped to about thirty thousand million degrees of Centigrade. After a full second, it dropped to ten thousand million degrees, and after about fourteen seconds, to three thousand million degrees, cool enough for photons and neutrinos to re-create the electrons and positrons more slowly than they would be annihilated. The energy released in this annihilation of matter slowed the rate at which the universe cooled, but the temperature continued to drop to about one thousand million degrees by the end of the first three minutes. It was then cool enough for protons and neutrons to begin to form into complex nuclei, starting with the nucleus of heavy hydrogen, which consists of one proton and one neutron. The density was high enough that these light nuclei assembled themselves into the most stable light nucleus, helium, consisting of two protons and two neutrons. [1]


The universe had to become cool enough to form the first atoms of hydrogen and helium. The atom gases then formed clumps under the influence of gravitation, ultimately condensing to form galaxies and stars of the universe. Great galaxies in the sky began rushing away at a rate approaching the speed of light. The galaxy in which we live and have our being is the Milky Way. It is a flat disk of stars with a diameter of 80,000 light years and a thickness of 6,000 light years. It is surrounded by a spherical halo of stars, with a diameter of almost 100,000 light years.[2]

We imagine the beginning of this universe as external to us, but of course particles and elements are in us. They are evolving along with us. The history of nature looks like a process of synthesis and transformation. Each stage carries key elements born in previous stages. Natural history in this sense is an activity of destructive creation going through heavy/light concentrations of energy, becoming the foundation for life.

 

The History of Particles and Atoms

Atoms are constructed of two types of elementary particles: electrons and quarks. Electrons occupy a space that surrounds an atom's nucleus. Quarks make up protons and neutrons, which, in turn, make up an atom's nucleus. Each proton and each neutron contains three quarks. A quark is a fast-moving point of energy.

 In addition to electrons and quarks, physicists have identified a number of other subatomic particles. Quantum physics describes the subatomic world as one that cannot be depicted in diagrams -- particles are not dots in space but are more like "dancing points of energy."[3]

This first "species"—called the particle—is followed by a sequence of changes: 1) quarks appeared at about 10-11 second; 2)  hadrons (protons, neutrons, and mesons) appeared at 10-10 second;  3)  leptons (electrons, neutrinos, and muons) were formed;  4) atoms evolved as the universe continued to cool, allowing the surviving particles to become electromagnetically linked. At the one- million year mark, huge atomic systems developed and then began to contract and form galaxies.[4]

There are 103 different types of atoms (called elements) found on the earth and they combine to produce many millions of different compounds. Compounds are the raw materials from which all earth things are formed. If split up, their distinctive properties are lost, leaving a collection of protons, neutrons, and electrons. Two types of opposite charges form atoms: positive and negative. Opposite charges are attracted to one another, and those with the same charges are repelled from one another. These electric charges of attraction and repulsion play a part in the formation of atoms as they interact with one another. [5]

While protons are in the nucleus of the atom and have a positive charge, they are surrounded by negatively charged electrons that spin about the nucleus like satellites in orbit. Neutrons are also in the nucleus, but do not carry a charge.

In sum, at the time of the Big Bang, an explosive fireball produced sub-atomic particles that were unable to fuse due to the phenomenal amount of energy that kept them from combining, but during the next few minutes, the rapid expansion of energy reduced its density enough to let protons (the nuclei of hydrogen atoms) fuse together with neutrinos into more complex clusters, such as the nuclei of helium. Further fusions began to create the nuclei of lithium, a third atomic element. At that point, the temperature fell too quickly to allow any further "nucleosynthesis" to occur.

It took at least l00,000 years before things calmed down enough for electrons to be captured by the nuclei to form hydrogen, helium, and a few lithium atoms. A few thousand million years later, as the first stars formed, cooling and gravitation permitted the remaining atomic elements to form.

All things, including atomic structures, evolved in a time sequence. All known chemical elements are derived from hydrogen. Although the elements number more than one hundred, their structure and properties have a common ancestor in the hydrogen atom.[6]

Atomic formations create the basis for the molecular and cellular foundations of life on earth. The process involves a continuous synthesis of past elements, transcending old elemental patterns to produce new self-organizing forms of sustained energy, more capable of survival and setting the foundation for biological life.

The History of Stars: Astrophysics

The first stars were clouds of gas that slowly condensed under the pull of gravitation. Gradually, the increasing energy generated by radiation pressure forced all the atoms of the gas together to ignite the fires of nuclear fusion.

Stars are massive "fusion reactors" in which the nuclei of light atoms—such as hydrogen and helium—become synthesized to form larger nuclei, accompanied by the release of energy that shines as starlight. This great fusion within the stars generated the heavier atoms—such as carbon, oxygen, and nitrogen—which are essential to life on earth.

The stars themselves exploded as novae over time and provided the energy to create some of the larger atoms. The more spectacular explosions, known as “supernovae,” created the larger atoms while the smaller explosions, called simply “novae,” scattered the new atoms. They were released as seeds on "particle winds" across the universe. Thus, from the raw material of hydrogen, helium, and lithium, all the elements of the periodic table were constructed by the gradual combination of the nuclei of simpler atoms.

Today hydrogen accounts for about 92.7 percent of all the atoms in the universe. Helium takes up another 7.2 percent, leaving a tiny 0.1 percent for all other atoms, including most of the ones inside human beings. It is possible that many larger atoms may be added to the cosmic periodic table after another 20 billion years. According to some scientists, the heavier atoms of the table will become much more abundant, and may turn up within a wide variety of living things more complex than humans.[7]

The first significant discovery about the directional movement of star clusters took place in 1929 when Edwin Hubble announced that he had perceived red shifts of galaxies increasing in proportion to their distance from us. By this means he could predict the flow of matter in this exploding universe. By 1931, Hubble was able to verify the proportionality between velocity and distance for galaxies ranging up to 20,000 kilometers per second. The conclusion that astrophysicists began to draw from a half century of observation was that the galaxies are receding from us and that the universe is continuously expanding.[8]

The field of particle physics has been growing rapidly for more than a decade, with new theories of cosmic strings, cosmic inflation, and particles of invisible “dark matter” that appear to be left over from the Big Bang. A Center for Particle Astrophysics has been funded by the National Science Foundation to coordinate new projects to fathom how particle dynamics could have shaped the universe. The Center is beginning to focus on the problem of dark matter, which may comprise at least up to 90 percent of the mass in the universe and which is detectable only by its gravitational effects on galaxies.[9]

One of the most remarkable developments in cosmology in the past decade is the discovery of clusters and voids on scales of a hundred million light-years. Radio observations of the red-shifted 21-cm hydrogen line from thousands of galaxies show structures whose sizes are comparable to the largest scales that have been studied. With new instrumentation being developed, it will be possible to extend these measurements to even larger scales. Some astrophysicists propose that there are actually a number of “universes” instead of a single universe.[10]

The outer universe is a multiverse, according to these astrophysicists, containing stars brighter than our sun. There are variable stars that pulsate regularly, including supernovae, pulsars, and X-ray stars. One finds clouds of luminous gas that permeate the spaces around bright blue stars, faint red stars in the hundreds of thousands come together in globular clusters. Galaxies whose sizes far exceed the Milky Way populate the universe in every direction in distances unreachable by telescopes. Here and there galaxies emit their energies, not in visible light, but as X-rays and infrared radiation. Quasars are interspersed in clusters of galaxies, some seeming to eject mass at velocities beyond the speed of light.[11] 

These phenomena of the universe differ immensely in scale from one to the other in size, luminosity, variability, energy of emitted particles and waves. Such differences must be taken into account in the study of evolving solar systems. These physical forms laid the foundation for all biological and social life to form their own level of development.[12]

Atoms synthesized in the interiors of stars are returned to interstellar gas. “Red giants”—giant stars that are in a late phase of their development—find their outer atmospheres blowing away into space. Supernovae violently eject much of their stellar mass into space at calculable rates. It is a natural sequence of chemical change in which the atoms returned are those most readily made in the thermonuclear reactions in stellar interiors. There is a definite sequence of changes here that suggests an evolutionary process. Carl Sagan describes it as follows:

Hydrogen fuses into helium, helium into carbon, carbon into oxygen and thereafter, in massive stars, by the successive addition of further helium nuclei, neon, magnesium, silicon, sulfur, and so on are built—additions by stages, two protons and two neutrons per stage, all the way to iron. Direct fusion of silicon also generates iron, a pair of silicon atoms, each with twenty-eight protons and neutrons, joining, at a temperature of billions of degrees, to make an atom of iron with fifty-six protons and neutrons.[13]

This early stage of the universe was a continuous process of transformation. It included processes such as "breakdown," "integration" and "differentiation,"  "division," "fusion," "linkage," and "synthesis," all of which lay a foundation for human life.

Carl Sagan says we are all made of "starstuff." All these chemicals continue to make up human bodies: the nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were all created in the interiors of collapsing stars.

The atoms and galaxies created a new level of transformation. Hydrogen, helium, and galactic systems created the ground for multivalent possibilities in the development of galaxies. When stars implode, neutrinos blast out, and vast remnants are sent streaming away at high velocities to become mixed with the swirling gases and stars of each galaxy. In the galaxy of the Milky Way, four and a half billion years ago, two high-density arms moved at twenty miles per second, creating millions of star bursts, each new star carrying its own self-organizing destiny.

Can we explain each new phase-level as self-organizing? Sagan argues that the universe is created from the “inside out.”  Evolution began as an unfolding from within, a process of inner-outer development. It is misleading, he says, to describe the expansion of the universe as a distending bubble viewed from the outside. By definition, nothing we can ever know is "outside" or if there is really an outside. It is better to think of these origins from the inside, perhaps with grid lines, adhering to this moving fabric of space and expanding uniformly in all directions.

A History with Links

The discipline of astrophysics connects with neighboring disciplines—like physics, chemistry, and biology—to explain succeeding steps in the creation of the earth and the emergence of life. Cosmic rays affect biological mutation and bear directly on the origin of species. They can change the nucleotides or tie the nucleic acids up in knots. Mutations can be caused by radioactivity from the sun's ultraviolet light and by chemicals in the immediate environment. If the mutation rate is too high or too low, it can seriously affect the direction of animal evolution. Thus, there is a high interdependence among the sciences in explaining all life on earth. But there is also reason to believe that other disciplines, far removed from science, may also be involved in exploring this history.

The sun is interpreted in science, myth, and poetry as the source of all life on earth. Scientists see the sun as transforming four million tons of itself into light, as each second a huge piece vanishes into radiant energy, soaring off in all directions. Poets have seen the sun as sacrificing itself each day, giving itself over as food, which keeps us alive, dying for us in the process, and this is not a merely metaphoric vision.[14]

As we shall see in our focus on human history, the Aztecs saw the sun as the origin of life and made a connection with its sacrificing power. They turned their understanding of the sun into sacrifices, with symbolic force, as though wanting to replicate the sun’s power in order to revitalize the earth. Warriors and priests literally sacrificed prisoners, tearing out the victim's heart with a knife made of volcanic glass, sometimes eating the victim's flesh. They sacrificed young maidens, the dearest and most tender among their own people, to revitalize that power, to keep it active.[15] 

The history of the Big Bang and what followed with the atom and the formation of stars are consistent with the original meaning of the word “evolution.” The Latin evolutio means "to unroll" and implies the unpacking of a structure already present in a more compact form. It is in this sense that the first biological use of the term "evolution" referred to the growth of the embryo in the womb. Some people today still make an analogy between human birth and the development of life on earth.[16]

 

The History of the Molecule: Chemistry

A molecule is a stable group of at least two atoms in a definite arrangement held together by very strong chemical bonds. The history of the molecule shows a process of increasing complexity that began with the atom. The molecule transcends the level of the atom by developing a whole new energetic, self-organizing center.  Once molecules are formed, they assume their own field of autonomous energy, and develop their own lawful behavior.[17]

There are more molecules in the human body than there are stars in the universe. On the basis of their composition, they may be divided into nine classes ranging from "elements" to "organic compounds," including phosphates, sulphates, silicates, and others. Following their crystalline structure, they can be divided into seven systems, defined by the length of the axes and size of the angles of the crystal forms.

Molecules developed in sequence over time, but studies have not determined all their stages and causal connections. Analysts say that key phases in the history of molecules follow roughly in this order:  Monatomic (metals); Ionic compounds (salts, most acids, and bases); Nonfunctional compounds (the paraffin series); Functional compounds (compounds of compounds); Nonfunctional polymers (chains 100,000 units long); Functional polymers (proteins); DNA and virus (Double helix, self-replicating). All these periods in molecular history are related to the history of planets, including the earth.[18]

A. Lima-de-Faria, working in the Institute of Molecular Cytogenetics at the University of Lund in Sweden, contends that there is a reason for marked similarities in behavior between these different stages -- atomic, molecular, cellular, and mammal. History shows an intimate relationship between levels, as each entity moves toward higher levels of organization. The cell was built by self-assembly; every atom and every molecule recognized the next one in a specific way. This was the beginning of “identity.” Every chemical reaction and every self-assembly represented an integration process. The next step was conditioned by the properties of the previous one.[19]

 Lima-de-Faria argues that "natural selection" does not explain the changes that take place in biological life, because the source of change is beyond biology; rather, it is grounded in "molecular dynamics." Even social life, he argues, is shaped in part by the field of molecular dynamics. Biologists describe how the communities built by bees, wasps, ants, and termites are based on a "labor differentiation" and "reproductive dominance," but these processes are “actually” (in turn) governed by molecular structures, like pheromones.

Pheromones are a chemical secretion affecting the behavior and physiology of another animal of the same species. The mandibular glands of queens in insect societies, for example, produce a pheromone (a "queen substance") that suppresses the development of the ovaries in the female workers. The dissemination of this molecular pheromone through the colony is achieved by constant licking and grooming of the queen by the workers, and the workers, by sister workers. The two most important chemicals at the base of the queen substance are the 9-oxodecenoic acid and 9-hydroxydecenoic acid. In such ways, cellular life, and even social life, has a molecular foundation. This foundation shapes the direction of all life on earth.

Lima-de-Faria argues that all patterns of behavior—from rivers to cells, and all physiology—have origins and explanations in molecular energy. This argument, he contends, is not purely reductionist, i.e., assuming that the real explanation of everything exists in molecular structures. Instead, there is a dynamic connection between these levels of evolution: between the atomic fires of the sun and the chemistry of social life.

A History of the Earth: Geology

The earth was at first a molten gas. It evolved with eight other planets (Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto) forming around the sun. It began to organize the heaviest elements—iron and nickel— at its core, and its lighter elements—oxygen and silicon—at a layer further out.

The smallest planets—Mercury, Venus, and Mars -- developed rock formations; because of their size they could not generate enough gravitational pressure to break down the rocks. Mars continued building mountains until its rock crust choked off its interior heat of radioactivity. Jupiter, Saturn, Uranus, and Neptune, on the other hand, had so much power in their gravitation that they remained essentially balls of fiery gas.

Atoms, molecules, and stars in the universe help explain the evolution of the earth. Geophysicists integrate the tools of astronomy, geology, physics, and chemistry to explain the earth's formation. The earth itself is a rich mixture of atoms, mostly silicon, oxygen, aluminum, magnesium, and iron. Yet given all its physics, the earth operates at its own self-organizing level; it reveals its own autonomous laws of development, with its own interdependent forces.

In the last quarter of the eighteenth century, the “laws” of the earth became apparent as geology developed as a field of knowledge. The influential geologist and Scottish innovator James Hutton noticed that rocks decay to produce gravel and soil. Many rocks contain debris derived from older rocks that apparently had decayed similarly in the past, and he noted that counterparts of ancient sedimentary rocks were still forming in the sea. Based on these observations, he announced in 1785, a theory that the earth changed in a cyclic rather than a linear, progressive way. For Hutton, the sequential changes in the earth's condition involved the construction of new products that neatly balanced the destruction of the old, a view today recognized in theories of steady-state equilibrium.[20]  

Charles Lyell, born the same year that Hutton died (1797), illustrated the concept of uniformity in nature and exceeded Hutton in pursuing scientific laws to explain the cyclic nature of the earth's changes. At this point, we see one of the first clashes between disciplines on the meaning of historical change. British physicist Lord Kelvin criticized the Hutton and Lyellian steady-state dynamic earth view, which challenged the basic laws of physics at the time.

In the aftermath of the debate between Lyell and Kelvin, geologists became aware that the intensity of geologic processes had varied considerably through time. Consequently, it became clear that conditions on earth had changed irreversibly, so that different epochs of geologic time were sequential and unique. This was the beginning of a scientific outlook on earth-changes that has continued down to the present day. As a contemporary text in geology notes:

Today we envision neither a violently catastrophic nor a rigidly uniform earth, but rather an evolutionary one that has changed through an irreversible chain of cumulative historic events and that is still changing. [21]

Geologists and geophysicists formulate theories on the earth's history based on interactions that take place among rock formations, taking account of the laws of physics. At high temperatures, rocks will act according to normal physical laws. At the same time, the strata of rock formations interact with the heat of the earth itself at their own levels of interactive change. This can be accounted for only by a different set of geophysical theories.

 For example, the geophysical theory of plate tectonics claims that the outer layer of the earth, the lithosphere, comprises a small number of relatively rigid plates that are bordered by narrow zones, along which most forces—seismic, volcanic, tectonic—are concentrated. These plate margins are of three types:[22]

 

(1) divergent, where crustal material moves apart under the oceans by a process known as sea-floor spreading; (2) convergent, where one plate plunges down into the underlying mantle (also known as  subduction zones); (3) transform faults, where one plate slides laterally with respect to its neighbour.

 

Continents have been split, and components driven apart, when a divergent plate margin became established beneath them. They have collided with each other along the lines of “subduction zones” where mountain belts, such as the Himalayas, were generated. Major ice ages have resulted from the sliding of large continental masses in the Polar Regions. Then, extensive ice sheets became established, with big consequences for the world climate and the evolution of life.

The geological stages of the earth's evolution started with the Azoic era (beginning over 4 billion years ago), and continued through the Proterozoic, Paleozoic, Mesozoic, and Cenozoic eras. At this point, we find another intersection of disciplines, supplementing geophysics with biology and paleontology that contribute to an explanation of life history.

Life forms began to develop in the Cenozoic in stages that paralleled the earth's history during the Paleocene, Eocene, Oligocene, Miocene, Pliocene, and Pleistocene, and up to recent times. The short-term paleo-climatic fluctuations of the Pleistocene era strongly affected the direction of biological evolution, causing the rapid worldwide rise and fall of sea levels, as polar ice alternately froze and melted.[23]

 

The History of Cells: Biochemistry

Scientists in biophysics and biochemistry believe that life on earth was created from those atomic and molecular elements synthesized after the Big Bang. Gas clouds surrounding the earth were composed of hydrogen, oxygen, carbon, uranium, nitrogen, helium, iron, aluminum, gold, phosphorus, and silicon, all of which were affected by action of the sun. It seems a far leap from pure chemistry to the creation of life, but it is clear that hydrogen was a major catalyst in making the compounds that compose all plant and animal bodies. This involved a continuous combination and synthesis of new elements. Hydrogen combined with carbon to make methane, with oxygen to make water, with nitrogen to make ammonia, and with sulfur to make hydrogen sulfide.

It is not an absolute certainty that life began on earth. Chemical compounds such as formaldehyde and hydrogen cyanide have been detected in interstellar clouds.  Therefore, meteorites containing amino acids that hit the earth could have provided the basic ingredients for life forms. The biochemical potential for the evolution of life exists outside our solar system, leading some scientists to suggest that life could have started in outer space.[24]

Most scientists argue that life was created from the earth's chemistry. Radioactive-isotope methods dating stony meteorites give the time for the earth's origin at 4.6 billion years. Biochemists assert that life was formed from simple molecules that developed during the first billion years of earth history.

 Theories about how the chemical ingredients of organic life were synthesized are still being tested, but concepts of how life evolved have interdisciplinary significance. Biochemists, for example, describe a process called "self-organization" and "self-ordering" in the formation of proteins, which is the chemical basis for creating life forms. In this view, chemicals have self-directing features.

One problem in assessing the origin of life is that a genetic coding mechanism did not exist at this early stage of evolution. There was no DNA, no RNA, and no proteins. Therefore, Sidney Fox, a distinguished biochemist, argues that the only logical explanation for life-creation was that the reactant amino acids themselves carried the instructions for their own order. Fox describes the problem faced by scientists trying to determine whether the first primitive protein was disorderly or orderly.

 

When it became worthwhile to think about the reactions of amino acids by heating them, and with no prebiotic enzyme to help order the amino acids, the suggestion of self-ordering proved to be a lucky heresy. The same experiment that showed that one could heat a mixture of amino acids to yield what would later be called thermal proteins revealed, to a considerable degree, that the amino acids order themselves. Compared to a disorderly product, in which no two molecules would be alike, the idea of a product arranged by internal control opened up a whole new ball game. [25]

 

The concept of "self-ordering" spells a type of change that begins from within an entity, in this case within chemical ingredients, much like a reflex to survive building something larger than itself. The concept of "reflexive self" explains this process of change among chemicals.

Fox notes how physicists who refer to molecules use the concept of “self-replication,” and how biologists use the concept of “self-reproduction” for cells. He points out, however, that this common usage is not perfectly correct, because a chemical or living organism does not replicate itself without assistance from the environment upon which it depends for catalysts or for food. The self-action does not take place simply from within the unit; the unit is interdependent with the outside world and is relatively self-reproducing.[26]

Chemists describe two types of self-replication, also called catalytic cycles. One is autocatalytic, in which the product of a chemical reaction catalyzes its own synthesis. The other type is a cycle of cross-catalysis, in which two different products catalyze each other's synthesis. These two processes become key mechanisms by which simple structures become complex structures.

Ilya Prigogine, a Belgian physical chemist, won the Nobel Prize on the basis of his explanation of how order arises from disorder through such catalytic action. He found that a few chemical systems could build and sustain a high degree of order even though no such order was fed into them. One particular chemical reaction (the Belousov-Zhabotinsky reaction) illustrates how patterns of organization arise from a homogenous mixture. In this case, four chemicals (malonic acid, a sulphate of cerium, potassium bromate, and sulphuric acid) are mixed in specific concentrations and left in a shallow dish to react. Within a few minutes, concentric or spiraling waves are seen spreading out across the dish, continuing for several hours. The chemical process is cross-catalytic because the products of one stage act as catalysts for later stages.[27]

This physical state tends toward fluctuations, increasing the level of complexity and organization with more energy. For such “dissipative structures” (Prigogine’s term) to exist, there must be an open system that allows matter and energy to flow between the system and its environment. Indeed, to be self-organizing, the system must be far from a state of equilibrium; otherwise, it acts like a closed physical system, such as a dark, sealed jarcontaining chemicals. Finally, there must be certain elements of the system that catalyze the production of new elements, a process of self-reinforcement.

Over time, and within proper parameters of intensity, temperature, and concentration, catalytic cycles tend to interlock into hypercycles, a concept championed by Manfred Eigen, a German Nobel Laureate. Hypercycles are a cooperative series of interactions, of checks and balances —that is, cycles that maintain two or more dynamic systems in a shared environment through coordinated functions. For example, nucleic acid molecules carry the information needed to reproduce themselves as well as an enzyme; the enzyme catalyzes the production of another nucleic acid molecule, which in turn reproduces itself, plus another enzyme. The loop may involve a large number of elements; ultimately it closes in on itself, forming a cross-catalytic hypercycle, expressing very fast reaction rates and then stability under diverse conditions.

This chemical process is similar to the larger symbiosis of life forms and changes in society. Some of the concepts that chemists use to describe these processes (such as "cooperation," "checks and balances," "coordination") also apply to processes in human history, including the history of democratic government.

Hypercycles allow systems to emerge on successively more complex levels of organization. At each new level, the amount of information that can be handled by the cycle is greater than on simpler levels, due in part to the greater diversity of the components. The shift from one level to another level of organization by means of catalytic hypercycles involves a new integration of energy and greater levels of free energy available to the system at each new complex system level.

In light of these findings, Ervin Laszlo suggests that the sequence of historical stages in this physical-to-chemical-to-life formation can be measured by the extent to which "free-energy flux density" is captured in the environment. This is a measure of the energy available per unit-of-time per unit-of-mass, such as, erg/second/gram. With this measure, each new historical stage could be calculated. A living system contains more of this factor than a complex chemical system, and a chemical system retains more than a physical (monatomic) gas. He suggests this measure not only calculates the direction of history in scientific terms, but also defines the "arrow of time" in the physical, biological, and social world.[28]

Thus in the act of self-replication, there is something like a “limited transcendence.” Laszlo believes the creation of life transcends into systems that contain a high-state continuous energy flow. Such a theory changes the conventional picture of the chemical explanation of life's beginning. Life’s beginning attributes the action of the sun as instrumental in catalyzing basic reactions leading to the first protobionts in shallow primeval seas. New discoveries support Laszlo's thesis in suggesting that reaction systems under the sea may also be responsible for the catalytic action leading to life forms.

Hot fluid arising through rock on the ocean floor causes seawater to heat rapidly and react with chemicals in the rock and the surrounding seawater. As the hot fluid rises toward the surface, it dissipates its heat. The chemical building blocks of life would have been constantly mixed by the continuous flux of energy created by this hot magma erupting into the sea bottom as well as by the energy of the sun in shallow seas. The simplest cells of life most likely evolved out of these catalytic reactions.

This theory suggests that life could have begun from both below as well as above. That life began from below follows the self-reproducing, self-organizing theory of change. Carl Sagan reminds us that the Big Bang started changes from within itself, not from the outside. As was already affirmed above, the rule of "self-reproduction" (“self-replication” and “self-organization”) in the origins of life suggests a pattern for how everything changes from “within” rather than from the outside.

 Biologists argue that cellular life appears autonomously from chemicals. It begins as chemistry, but rises within and goes beyond chemical processes. Humberto Maturana and Francis Varela call this autopoiesis,  which refers to the continuously self-creating nature of organisms, that is, the self-producing and self-maintaining activity of all living entities.

Autopoesis refers, that is, to the character of life itself, as it emerges from the bacterial cell to the most complex organisms. All organisms have metabolic systems involving the constant build-up and breakdown of chemical components designed for survival. The simplest living cell has a metabolic nucleus interacting productively with its environment, which also produces membrane-forming components within itself. Autopoietic entities characteristically exchange their parts and continue to exist without losing self-identity; they maintain themselves within their boundaries, giving them memory.[29]

Autopoietic (living) systems are a qualitative break from the preceding nonautopoietic (chemical) systems because they metabolize. Metabolism includes gas and liquid exchange (e.g., breathing, eating, excreting), which in the simplest forms—such as in spores, seeds, or insect pupae—only stops (discontinues) when the system loses its coherence and dies.[30]

In contrast to autopoetic systems, proteins, viruses, plasmids, and genes are all components of live material, but do not metabolize. They exist within animal, plant, or other cells to support the autopoietic behavior of the latter organisms, but are themselves incapable of metabolism.

Autopoietic bodies developed during the earth's first billion years, when its atmosphere was without oxygen. Scientists argue that this lack of oxygen was essential to the formation of life. That is, with no oxygen in the atmosphere to destroy these organic compounds, they could remain in solution together and serve as the building blocks for the formation of life. At the same time, ATP, a molecule used by all living cells as a carrier for energy, could form from the union of adenine with ribose (a sugar with five carbon atoms) and three phosphate groups. Some molecules could then become catalysts for others, making it easier for molecules to join or split without being destroyed. Such catalysts were important before the origin of life because they worked against randomness to produce order in chemical processes.[31]

When a molecule absorbs light, its electrons are boosted to a higher energy state. The energy is then dissipated as light (or heat), but when molecules are bound to porphyrins, attached to proteins in membranes (as electron-transport chains), that energy can be put to use. It can be converted to ATP energy for movement and synthesis, such as conversion of carbon dioxide from the atmosphere into food.

Rocks 3,800 million years ago were too hot for bacteria, but paleontologists have found filaments like cynanobacteria (algae) appearing around 3,400 million years ago. About 500 million years after the oldest formation of rocks on earth, the first life forms must have been spheres of DNA, RNA, enzymes, and proteins (at about one millionth of a meter in diameter), with only a limited ability to direct metabolism. DNA is essential for the continuity of life, but not sufficient for “self-development,” which involves mutation as well as other processes.

A mutant DNA, building from the inside, must have enabled cells to use sugars and then to convert sugar to ATP energy. The byproducts of sugar (alcohols and acids) were then excreted as waste. The earliest bacteria most likely remained in the mud and water, staying away from surface sunlight that could break apart their DNA. For all practical purposes, these early cells lived off earth chemicals, developing sugar breakdown processes, known as fermentation.

An interesting form of fermenting bacteria today is Clostridia. It developed (synthesized) a function for taking nitrogen gas from the atmosphere and converting it to the ammonia-like side chain of amino acids, nucleotides, and other organic compounds. Clostridia is important because all organisms depend upon it and other similar nitrogen-fixing bacteria to supply the entire atmosphere with vital nitrogen compounds that are required for the survival of life on earth.[32]

The first photosynthetic bacteria, then, used hydrogen gas and never produced oxygen. Hydrogen was present in the Archaen Aeon (3,900,000 years ago), when the sun first began sending huge quantities of hydrogen to the earth, and volcanoes began producing hydrogen sulfide. But as hydrogen became depleted, photosynthetic bacteria began using light energy to cleave off hydrogen molecules and excreted congealed sulfur. This was a major historical change, leading to higher life forms.[33]

Oxygen began to appear in the atmosphere about two billion years ago, when photosynthetic organisms discovered water. New blue-green bacteria emerged, and hydrogen gas began escaping into space. The already-mutant photosynthetic bacteria with proteins developed (synthesized) a reaction center to absorb higher-energy light, to split the water molecule into hydrogen and oxygen. The hydrogen helped to make organic food and sugars.

Today, similar bacteria cover the earth generating oxygen. Oxygen continued to accumulate from this point forward until equilibrium was reached some l, 500 million years ago, and the biochemical revolution was accomplished. Oxygen came to compose 21 percent of the atmosphere and, with the help of these organisms, it continues to keep that balance today.

When the level of oxygen approximated 21percent, eukaryote cells evolved with a nucleus and with parts called mitochondria. Their fossils are visible at some 1,600 million years ago. Lynn Margulis and Dorion Sagan describe this development as though it were an evolving (transcending) system of government:[34]

 

The new cells seem to have bacterial confederacies. They cooperated and centralized, and in doing so formed a new kind of cellular government. The upstarts were increasingly centrally organized, and their various cell organelles became integrated into a new biological unit. For example, in modern eukaryotes, the cytoplasm streams about inside the cell as though with a purpose. Such directed intracellular movement is never seen in bacteria. But most distinctively, instead of the bacterium's single replicon, eukaryotes have beaded, protein-bound DNA structures, the chromosomes, with their massive amounts of DNA.

 

A concept of governance (e.g., confederacy) in the broad sense is used across university disciplines to explain all stages of human history. All living things are in some sense governed, indeed with some autonomy. The concept indicates a system of rules and regulations, by which life maintains a social order.[35]

 Margulis contends that the repetitive DNA came originally from different bacteria, such as anaerobes and other oxygen-users that were brought together and integrated into the new community to become the eukaryotic cell. Massive amounts of DNA were preserved because they were put to use in solving problems in the packaging and functioning of chromosomes. This process involved both synthesis and symbiosis. Independent prokaryotes entered others and came to live symbiotically inside them. Inside, they digested cellular wastes of their host, and their own wastes, in turn, were used as food by the host. The outcome of these intimate connections were permanent relationships, cells within cells. Over time, bacteria coevolved as communities. They were so deeply interdependent that, for all practical purposes, they became like single stable organisms.[36]

This cooperation among life forms is essential to explain their capacity to change. Let’s put it this way: Wholly different types of organisms cohabit within each other and use the products of each other’s metabolisms. One organism can even reproduce inside the invaded cell without causing harm. Over time, predators would give up their independent ways and "move in for good," to become a permanent part of the larger organism.

For example, the bacterium thermoplasma seems to be the best scientific guess for the nucleocytoplasmic portion of the eukaryotic cell. Its DNA is unlike that of other bacteria. It is wrapped in certain proteins similar to the histones of nearly all eukaryotes. As the predator made itself at home, it gradually lost some of its own DNA and RNA. Natural selection, say Margulis and Sagan, tends to eliminate redundancy.[37]

Margulis proposes that mitochondria organelles in the nucleus of many bacterial cells—cells that use oxygen to make energy available for cellular activity—were probably once predators, like Bdellobovibrio, an oxygen-breather, that eats from the inside. Predators can kill victims and self-destruct, or they can "restrain predation" by their incorporation into a foreign body, so that, as Margulis puts it, "animosity becomes an interchange." Some biologists argue that this type of symbiotic process is repeated on down through evolution.

But how? Plants transcended in this symbiotic manner through the simple act of eating. The forbears of plastids —the photosynthetic parts of nucleated cells—were probably organisms eaten by protoeukaryotes some 100 million years after mitochondria had become established. Every plant today contains plastids to make food from water and sunlight. These plastids are chloroplasts in plants, similar to bacteria but a little larger. Plastids have their own DNA and RNA with ribosomes the same size as those in bacteria. Like mitochondria, they are wrapped in a membrane that separates them from the rest of the cell, suggesting the integration that took place millions of years ago. [38]

 

The History of Organisms

Animals and plants evolved as multicellular living systems composed of millions, and in some cases billions, of individual cells. These multicellular organisms are generally divided into three kingdoms: l) metaphyta, such as plants (or autotrophs), which require only inorganic compounds as nutrients, and utilize sun energy to create living matter through photosynthesis; 2) fungi, such as mushrooms, which are plantlike, but feed by ingesting organic substances; and 3) animals, which also ingest organic substances. All of these multicellular organisms transcended from the kingdom of Protista, the eukaryotic unicellular organisms born on earth three billion years ago.

This history is not just linear in chronological terms, not, that is, one single chain of events following one after the other. Biologists believe multicellular organisms emerged independently from unicellular organisms many times. At least two million multicellular species exist today, while many others have become extinct. Multicellularity allows organisms to live longer because individual cells can be replaced. It allows them to produce more offspring since many cells can be devoted to reproduction; this gives them a greater internal stability and efficiency because of the division of labor among various cells in the body.

The earliest animal fossils appear in rocks dating about 700 million years ago, late in the Precambrian Era. It is impossible to tell how long thereafter the first animals actually evolved (or transcended); estimations range from as few as 50 million to as many as 500 million years. The first fossils indicate animals burrowed into rocks. Biologists know that they differentiated from hydrostatic skeletons, that is, fluid-filled body spaces that work against muscles, so that the animal could dig. The fossil record of animals called the Ediacaran fauna, found in the region of Australia, suggest they had soft-bodies, and lived between 680 and 580 million years ago.

Durable skeletal remains begin to appear in the fossil record in rocks that are some 580 million years old. The record continues with the phylum of Chordata and Broozoa, appearing less than 500 million years ago. These skeletonized invertebrates seem to have all lived on the sea floor originally, rather than burrowing in it. The extinct Trilobita, however, probably grubbed on the sea floor, digging (exploring) shallow pits in search of food. But the record keeps growing with continuity overall, and with discontinuities appearing based on innovative self-organization. From the evidence of embryologists and the morphological study of these fossil groups, it is possible to draw a continuous picture of all the early animal groups.

The early amphibians developed rather large bodies, becoming herbivores and predators living on aquatic food as well as terrestrial food. They were bound to the water for reproduction, as frogs and salamanders are today, but became extinct in the Triassic period. Today's amphibians, however, are unlike the large forms that ruled on land for some 75 million years. The modern, small-bodied forms probably arose during the late Paleozoic Era, adapting to marginal habitats, perhaps escaping competition with later vertebrates.

Reptiles arose from an early amphibian lineage, freed from dependency on the water by the evolution of an egg that could develop in a terrestrial environment. Reptiles diversified rapidly, spreading into amphibian territories. By the late Permian times, they were becoming dominant. The more successful group, the therapsids, eclipsed the others, but, in turn, were replaced by the dinosaurs. The dinosaurs evolved in Triassic times, remaining for 150 million years, and becoming extinct only about 75 million years ago.

Dinosaurs shared their world with small, hairy animals that evolved from a therapsid lineage as mammals. The history of mammals is recorded by fossils showing the differentiation of reptilian from mammalian skeletal features. Not all the mammalian features can be determined from fossils (warm-bloodedness, hair, respiratory diaphragm, increased agility, and facial muscles that allow suckling), but it is reasonable to assume that some of these features were shared with therapsid ancestors in an evolutionary process. Indeed, it is increasingly believed that the dinosaurs were themselves warm-blooded, explaining their long dominance. Once dinosaurs became extinct, mammals moved rapidly into their vacated habitats.

Some biologists hold that extinctions are paradoxically a measure of success on earth, because they cause new organisms to adapt to the environmental conditions. When adaptive conditions vanish, the organisms also vanish, thus creating opportunities for selection to develop new kinds of organisms among the survivors. The groups that disappear are not replaced by totally new groups, but by branches from the remaining lineages.[39]

The Co-History of Plants and Animals

 Plants preceded animals on land by about 35 million years, likely appearing through symbiotic (bonding) connections between algae and fungi. Botanists have proposed this bonding connection partly because 95percent of plants have fungi in their roots. The evolution of land plants is similar to that of land vertebrates, with waves of extinction and replacement and the rise of new forms.

From 2 to 300 million years ago, there were vast seed ferns covering the earth that eventually came to be replaced by conifers. The conifers then began an expansion that led them to dominate the Mesozoic floras. The earliest flowering plants seem to have been weedy, adapted (differentiated) for rapid reproduction. The reproductive specializations, including the development of flowers and the appearance of insect pollinating systems, gave these plants an advantage over the more slowly growing conifers, the work of natural selection.

The simultaneous appearance of plants and animals shows their interdependence and cooperation—rather than mainly competition—in their habitations. Some biologists have coined the concept of "co-evolution" to explain what was happening.[40] 

Co-evolution refers to the way different species of animals and plants influence one another in their ecological settings. A more restrictive definition means that a trait of one species has evolved in response to the trait of another species, which trait itself has evolved (integrated) in response to the trait in the first species. An example is the development of mimicry among species, where a mutual adjustment takes place between competing species.[41]  

The concept of co-evolution helps explain what happened when the first flowers were born along with the first mammals about 125 million years ago. The ecological relationships that developed in this period cannot be explained simply as a competitive struggle among individuals (or species) for survival. For example, the action of mammals in eating vegetation appears to have been a factor in helping them to disseminate angiosperm seeds by means of the waste from their bodies. Thus, the action to increase reproduction was a collaborative effort between and among "families," so to speak.

Angiosperms spread explosively to conquer the land in the Cretaceous Period. They were well established before the dinosaurs became extinct and about a quarter of a million species of angiosperms are still living today.[42]

While plants did not continue to differentiate into highly complex organisms in the manner of mammals, their capacity to create oxygen became the basis for animal survival and the appearance of mammals. It was a massive, cooperative, symbiotic action. Plants and animals, including humans, became interdependent and have coevolved (cooperated) in the larger scheme of things.

Plants remain at the foundation of all mammalian life. All primates, including humans, depend on them to sustain life. Natural history is a story of cooperation and teamwork, as much as of conflict and competition.

Cooperation and teamwork are visible at all levels of biological organization. Biologists describe how genes collaborate in genomes. Chromosomes collaborate in eukaryotic cells. Cells collaborate in multicellular organisms. The basic features of these different processes of cooperation, conflict, competition, and collaboration can be seen operating among all animals.[43]

But these terms (e.g., competition) are drawn from human experience. It is difficult to describe what actually happens between plants and animals without the analogy.

For example, biologists describe a type of cooperation called “altruism” in animals. Giving up one’s life for another would seem to reduce the fitness of the “altruist.” Population biologists argue that, except for altruism occurring among close relatives, human behavior that appears to be altruistic really should be called “reciprocity,” i.e., behavior undertaken with an expectation of some return.[44]

This is an ongoing debate. Bert Hölldobler and Edward O. Wilson (The Ants) have argued that ants, bees, wasps, and termites have achieved the ultimate altruistic behavior. This “eusocial species” is where one or a few females produce young, which other individuals in the colony care for—in lieu of producing their own offspring. They attribute this “self-sacrificing behavior” to the close kinship among colony members. But now in their most recent book (The Superorganism), they modify their conclusion, saying that the degree of family relatedness (kinship) simply affects how quickly a social system changes.[45]

They propose another analogy. The members of an ant colony are like one organism. Colony “members” could be called the organism's “cells.” The members act like a circulatory system, taking care of the distribution of food, dispersal of waste, and transmission of chemical cues. The colony has decision-making processes hard-wired into the colony members. Like computers with tiny repetitive algorithms, the tiny brains of ants and bees can store programs. The colony can make decisions: Where shall we roam for food? The decision-making teamwork brings them success.[46]

 But there are many types communication systems. It is all about teamwork. We know how the waggle-dance of bees informs the hive where a nectar source is. But current research reveals "other performances on the honeybee dance card." The returning bees do a shaking dance to get more bees onto an empty dance floor to receive the news, or they do a tremble dance if they can't unload the incoming nectar, a dance that recruits more bees to be food handlers.

There are also “atrocious” behaviors: some ants engage in “child labor”; the queen of the Dracula ants pierces her own larvae to feed on their blood; tropical weaver ants use the sticky threads produced by larvae, swinging the larvae back and forth like shuttles to bind leaves together to make a nest.

In sum, all the “vicious competition” and “collaborative teamwork” among plants and animals lays the foundation for another stage of history.

The History of Primates

Scientists believe the earliest primates could have originated 70 million years ago in the late Cretaceous Period because some characteristics are evident in the molars found in two species that were contemporaneous with the dinosaurs. But most paleontologists place them in the Paleocene Era because their fossils are much more clear and abundant there. Archaic primates are found in both Europe and North America with similarities that are striking.

For example, a cat-sized primate called Plesiadapis was first discovered in northern France, but similar fossils were also found later in Wyoming and Colorado. The similarity between these species, divided otherwise by the Atlantic Ocean, is explained geologically by the fact that a continental drift took place after this period to create what we now know as the major continents out of a single super-continent. The rest of the earth was covered by sea. Animals like Plesiadapis probably ranged across North America and Europe. The two continents were connected until about 50 million years ago.[47]

Primates transcended themselves, leaving behind their old way of life. The order of Primates is now divided into two suborders: the Prosimians and the Anthropoids. In the Primates we see a “leap” from a reliance on olfactory to visual organs. This led to a capability for detecting more detailed spatial patterning in a visual world. The cerebral cortex increases in size and complexity, and there is a lengthening of the prenatal and postnatal life, requiring prolonged infant care and more time for offspring to learn about their environment.

The Prosimians (lemurs and lorises) are closer in this respect to earlier mammals than are the Anthropoid primates, since they depend more on smell for information. The Anthropoids, in turn, are subdivided into tarsiers, New World monkeys, Old World monkeys, and the Hominoids, which include apes and humans.

There is some debate about whether the earliest primates lived in trees, but they were clearly living there in the Eocene epoch from 54 to 38 million years ago. Vertical clinging and leaping became a regular method of traveling. Gradually, their eyes became located closer to the front of the face, their snout was reduced, and digits became longer and specialized for grasping. In other words, the primates uniquely developed nails (instead of claws), prehensile (grasping with) hands and feet, five fingers and toes, and a forward placement of their eyes.[48]

The Anthropoids we know today (monkeys, apes, and humans) evolved from the Prosimians and include over 150 species.  The oldest primate (Amphipithecus) is thought to have been an Anthropoid living in the area of modern Myanmar (Burma) around 40 million years ago, but less disputed finds occur in the Oligocene, some 38 million years ago. During the Miocene Epoch (22 million years ago), monkeys and apes diverged in appearance, and many different kinds of apes appeared in Europe, Asia, and Africa.

Below is a timeline from Wikipedia. It has yet to be carefully edited but for our purposes, it offers a general picture of this sequence of events that began on earth. [49]

First animals

Date

Event

4000 Ma

 

Ma= a unit of time equal to one million years.

The earliest life appears.

Further information: Origin of life

3900 Ma

 

Cells resembling prokaryotes appear.

Further information: Cell (biology)#Origins of cells

2500 Ma

First organisms to utilize oxygen

2100 Ma

More complex cells appear: the eukaryotes.

Further information: Eukaryote#Origin and evolution

1200 Ma

Sexual reproduction evolves, leading to faster evolution.[1]

900 Ma

Choanoflagellate

The choanoflagellates may look similar to the ancestors of the entire animal kingdom, and in particular they may be the direct ancestors of sponges.[2] Proterospongia (members of the Choanoflagellata) are the best living examples of what the ancestor of all animals may have looked like.

They live in colonies, and show a primitive level of cellular specialization for different tasks.

600 Ma

It is thought that the earliest multicellular animal was a sponge-like creature.

Sponges are among the simplest of animals, with partially differentiated tissues.

Sponges (Porifera) are the phylogenetically oldest animal phylum extant today.

580 Ma

The movement of all animals may have started with cnidarians. Almost all cnidarians possess nerves and muscles and, because they are the simplest animals to possess them, their direct ancestors were very likely the first animals to use nerves and muscles together. Cnidarians are also the first animals with an actual body of definite form and shape. They have radial symmetry.

 

Swimming animals

Date

Event

550 Ma

Flatworm

Flatworms are the earliest animals to have a brain, and the simplest animals alive to have bilateral symmetry. They are also the simplest animals with organs that form from three germ layers.

540 Ma

Acorn worms are considered more highly specialised and advanced than other similarly shaped worm-like creatures. They have a circulatory system with a heart that also functions as a kidney. Acorn worms have a gill-like structure used for breathing, a structure similar to that of primitive fish. Acorn worms are thus sometimes said to be a link between vertebrates and invertebrates.

530 Ma

Pikaia

The earliest known ancestor of the chordates is Pikaia. It is the first known animal with a notochord. Pikaia is believed to be the ancestor of all chordates and vertebrates.[3]

The Lancelet, still living today, retains some characteristics of the primitive chordates. It resembles Pikaia.

Other earliest known chordate-like fossils are [[“fossils” plural?—ed]]from a conodonts, an "eel-shaped animal of 4–20 cm (1½–8 in) long" with a pair of huge eyes at the head end were and a complex basket of teeth.

505 Ma

Agnatha

The first vertebrates appear: the ostracoderms, jawless fish related to present-day lampreys and hagfishes. Haikouichthys and Myllokunmingia are examples of these jawless fish, or Agnatha. (See also prehistoric fish). They were jawless and their internal skeletons were cartilaginous. They lacked the paired (pectoral and pelvic) fins of more advanced fish. They were the Precursors to the bony fish. [4]

480 Ma

 

A Placoderm

The Placodermi were prehistoric fishes. Placoderms were the first of the jawed fishes, their jaws evolving from the first of their gill arches [5]. Their head and thorax were covered by articulated armoured plates and the rest of the body was scaled or naked.

400 Ma

First Coelacanth appears; this order of animals had been thought to have no extant members until living specimens were discovered in 1938. It is often referred to as a living fossil.

375 Ma

Tiktaalik is a genus of sarcopterygian (lobe-finned) fishes from the late Devonian with many tetrapod-like features.

 

Tetrapodes

Date

Event

365 Ma

 

Panderichthys

Some fresh water lobe-finned fish (Sarcopterygii) develop legs and give rise to the Tetrapoda.

The first tetrapods evolved in shallow and swampy freshwater habitats.

Primitive tetrapods developed from a lobe-finned fish (an "osteolepid Sarcopterygian"), with a two-lobed brain in a flattened skull, a wide mouth and a short snout, whose upward-facing eyes show that it was a bottom-dweller, and which had already developed adaptations of fins with fleshy bases and bones. The "living fossil" coelacanth is a related lobe-finned fish without these shallow-water adaptations. These fishes used their fins as paddles in shallow-water habitats choked with plants and detritus. The universal tetrapod characteristics of front limbs that bend backward at the elbow and hind limbs that bend forward at the knee can plausibly be traced to early tetrapods living in shallow water.[6]

Panderichthys is a 90–130 cm (35–50 in) long fish from the Late Devonian period. It has a large tetrapod-like head. Panderichthys exhibits features transitional between lobe-finned fishes and early tetrapods.

Lungfishes retain some characteristics of the early Tetrapodas. One example is the Australian Lungfish.

315 Ma

Acanthostega

Ichthyostega

Acanthostega is an extinct amphibian, among the first animals to have recognizable limbs. It is a candidate for being one of the first vertebrates to be capable of coming onto land. It lacked wrists, and was generally poorly adapted for life on land. The limbs could not support the animal's weight. Acanthostega had both lungs and gills, also indicating it was a link between lobe-finned fish and terrestrial vertebrates.

Ichthyostega is an early tetrapod. Being one of the first animals with legs, arms, and finger bones, Ichthyostega is seen as a hybrid between a fish and an amphibian. Ichthyostega had legs, but its limbs probably weren't used for walking, they may have spent very brief periods out of water and would have used their legs to paw their way through the mud.[7]

Amphibia were the first four-legged animals to develop lungs.

Amphibians living today still retain many characteristics of the early tetrapods.

300 Ma

Hylonomus

From amphibians came the first reptiles: Hylonomus is the earliest known reptile. It was 20 cm (8 in) long (including the tail) and probably would have looked rather similar to modern lizards. It had small sharp teeth and probably ate millipedes and early insects. It is a precursor of later amniotes and mammal-like reptiles.

Evolution of the amniotic egg gives rise to the Amniota, reptiles that can reproduce on land and lay eggs on dry land. They did not need to return to water for reproduction. This adaptation gave them the capability to colonize the uplands for the first time.

Reptiles have advanced nervous system, compared to amphibians. They have twelve pairs of cranial nerves.

 

Mammals

Date

Event

256 Ma

Phthinosuchus, an early Therapsid

Shortly after the appearance of the first reptiles, two branches split off. One branch is the Diapsida from which come the modern reptiles. The other branch is Synapsida, which had temporal fenestra, a pair of holes in their skulls behind the eyes, which were used to increase the space for jaw muscles.

The earliest mammal-like reptiles are the pelycosaurs. The pelycosaurs were the first animals to have temporal fenestra. Pelycosaurs are not Therapsida but soon they gave rise to them. The Therapsida are the direct ancestor of mammals.

The therapsids have temporal fenestrae larger and more mammal-like than pelycosaurs, their teeth show more serial differentiation; and later forms had evolved a secondary palate. A secondary palate enables the animal to eat and breathe at the same time and is a sign of a more active, perhaps warm-blooded, way of life. [8]

220 Ma

One sub-group of therapsids, the cynodonts evolved more mammal-like characteristics.

The jaws of cynodonts resemble modern mammal jaws. It is very likely this group of animals contains a species which is the direct ancestor of all modern mammals.[9]

220 Ma

Repenomamus

From eucynodonts (cynodonts) came the first mammals. Most early mammals were small and shrew-like animals that fed on insects. Although there is no evidence in the fossil record, it is likely that these animals had a constant body temperature, milk glands for their young. The neocortex region of the brain first evolved in mammals and thus is unique to them.

125 Ma

Eomaia scansoria

Eomaia scansoria, a eutherian mammal, leads to the formation of modern placental mammals. It looks like a modern dormouse, climbing small shrubs in Liaoning, China.

100 Ma

Common genetic ancestor of mice and humans (base of the clade Euarchontoglires).

 

Primates

Date

Event

65 Ma

 

Carpolestes simpsoni

A Plesiadapis without fur.

A group of small, nocturnal and arboreal, insect-eating mammals called the Euarchonta begins a speciation that will lead to the primate, tree shrew, and flying lemur orders. The Primatomorpha is a subdivision of Euarchonta that includes the primates and the proto-primate Plesiadapiformes. One of the early proto-primates is Plesiadapis. Plesiadapis still had claws and the eyes located on each side of the head, because of that they were faster on the ground than on the top of the trees, but they begin to spend long times on lower branches of trees, feeding on fruits and leaves. The Plesiadapiformes very likely contain the species which is the ancestor of all primates.[10]

One of the last Plesiadapiformes is Carpolestes simpsoni. It had grasping digits but no forward facing eyes.

40 Ma

Primates diverge into suborders Strepsirrhini (wet-nosed primates) and Haplorrhini (dry-nosed primates). Strepsirrhini contains most of the prosimians; modern examples include the lemurs and lorises. The haplorrhines include the three living groups the [[should this be “three living groups of prosimians?”—ed]]prosimian tarsiers, the simian monkeys, and apes. One of the earliest haplorrhines is Teilhardina asiatica, a mouse-sized, diurnal creature with small eyes.

30 Ma

Aegyptopithecus

Haplorrhini splits into infraorders Platyrrhini and Catarrhini. Platyrrhines, New World monkeys, have prehensile tails, and males are color blind. They may have migrated to South America on a raft of vegetation across the Atlantic ocean (circa 4,500 km, or 2,800 mi). Catarrhines mostly stayed in Africa as the two continents drifted apart. One ancestor of catarrhines might be Aegyptopithecus.

25 Ma

 

Proconsul

Catarrhini splits into 2 superfamilies, Old World monkeys (Cercopithecoidea) and apes (Hominoidea).

Proconsul was an early genus of catarrhine primates. They had a mixture of Old World monkey and ape characteristics. Proconsul's monkey-like features include thin tooth enamel, a light build with a narrow chest and short forelimbs, and an arboreal quadrupedal lifestyle. Its ape-like features are its lack of a tail, ape-like elbows, and a slightly larger brain relative to body size.

Proconsul africanus is a possible ancestor of both great and lesser apes, and humans.

15 Ma

Hominidae (great apes) speciate from the ancestors of the gibbon (lesser apes).

13 Ma

Homininae ancestors speciate from the ancestors of the orangutan[11].

Pierolapithecus catalaunicus is believed to be a common ancestor of humans and the great apes or at least a species that brings us closer to a common ancestor than any previous fossil discovery.

Pierolapithecus had special adaptations for tree climbing, just as humans and other great apes do: a wide, flat ribcage, a stiff lower spine, flexible wrists, and shoulder blades that lie along its back.

10 Ma

Hominini speciate from the ancestors of the gorillas.

 

Hominini

Date

Event

7 Ma

Sahelanthropus tchadensis

Hominina speciate from the ancestors of the chimpanzees. The latest common ancestor is Sahelanthropus tchadensis (ca. 7 Ma). The earliest known human ancestor post-dating the separation of the human and the chimpanzee lines is Orrorin tugenensis (Millennium Man, Kenya; ca. 6 Ma). Both chimpanzees and humans have a larynx that repositions during the first two years of life to a spot between the pharynx and the lungs, indicating that the common ancestors have this feature, a precursor of speech.

4.4 Ma

Ardipithecus ramidus ramidus

4.4 Ma

Some Australopithecus afarensis left footprints on volcanic ash in Laetoli, Kenya (Northern Tanzania), strong evidence of bipedalism.

3.5 Ma

Kenyanthropus platyops, a possible ancestor of Homo, emerges from the Australopithecus genus.

3 Ma

The bipedal australopithecines (a genus of the Hominina subtribe) evolve in the savannas of Africa being hunted by Dinofelis. Loss of body hair takes place in the period 3–2 Ma, in parallel with the development of full bipedalism.

2.5 Ma

Homo habilis

Appearance of Homo. Homo habilis is thought to be the ancestor of the lankier and more sophisticated, Homo ergaster. Lived side by side with Homo erectus until at least 1.44 Ma, making it highly unlikely that Homo erectus directly evolved out of Homo habilis. First stone tools, beginning of the Lower Paleolithic.

Further information: Homo rudolfensis

1.8 Ma

A reconstruction of Homo erectus.

Homo erectus evolves in Africa. Homo erectus would bear a striking resemblance to modern humans, but had a brain about 74 percent the size of that of modern man. Its forehead is less sloping and the teeth are smaller. It is believed to be an ancestor of modern humans (with Homo heidelbergensis usually treated as an intermediary step).

Homo erectus migrates out of Africa and colonizes Eurasia.

1.5 Ma

Dmanisi man / Homo georgicus (Georgia), tiny brain came from Africa, with Homo erectus and Homo habilis characteristics. Control of fire by early humans. Evolution of dark skin is complete by 1.2 Ma.

516 ka

(kilo-annum)

Common genetic ancestor of humans and Neanderthal.[12] At present estimate, humans have approximately 20,000–25,000 genes and share 99 percent of their DNA with the now extinct Neanderthal [13] and 95 percent of their DNA with their closest living evolutionary relative, the chimpanzees[14].

355 ka

Reconstruction of a Neanderthal child from Gibraltar (Anthropological Institute, University of Zürich)

Three 1.5 m (5 ft) tall Homo heidelbergensis left footprints in powdery volcanic ash solidified in Italy. Homo heidelbergensis is the common ancestor of both Homo neanderthalensis and Homo sapiens. It is morphologically very similar to Homo erectus but Homo heidelbergensis had a larger brain case, about 93 percent the size of that of Homo sapiens. The species was tall, 1.8 m (6 ft) on average, and more muscular than modern humans. Beginning of the Middle Paleolithic.

195 ka

Omo1, Omo2 (Ethiopia, Omo River) are the earliest fossil evidence for archaic Homo sapiens, evolved from Homo heidelbergensis.

160 ka

Homo sapiens (Homo sapiens idaltu) in Ethiopia, Awash River, Herto village, practice mortuary rituals and butcher hippos.

150 ka

Homo sapiens sapiens (Pioneer plaque)

Mitochondrial Eve lives in East Africa. She is the most recent female ancestor common to all mitochondrial lineages in humans alive today.

70 ka

Appearance of mitochondrial haplogroup L2. Behavioral modernity. The FOXP2 gene (associated with the development of speech) appears in this period.[15]

60 ka

Y-chromosomal Adam lives in Africa. He is the most recent common ancestor from whom all male human Ychromosomes are descended. Appearance of mitochondrial haplogroups M and N, which participate in the migration out of Africa.

50 ka

Migration to South Asia. M168 mutation (carried by all non-African males). Beginning of the Upper Paleolithic. mt-haplogroups U, K.

40 ka

Migration to Australia and Europe (Cro-Magnon).

25 ka

Neanderthals die out. Y-Haplogroup R2; mt-haplogroups J, X.

12 ka

Beginning of the Mesolithic / Holocene. Y-Haplogroup R1a; mt-haplogroups V, T. Evolution of light skin in Europeans (SLC24A5). First domestication of the dog. There is genetic evidence for much earlier split between dog/wolf lineages. Homo floresiensis dies out, leaving Homo sapiens as the only living species of the genus Homo.

10000 BCE

Beginning of the Neolithic / Holocene. The invention of farming in the Fertile Crescent occurred during this time.

 

The Beginning of Human History

The first hominid evolved in the late Miocene. Hominids lived in East Africa about 5 million years ago and ranged from gibbon-like to gorilla-like in size. Following this stream of history, anthropologists point out that the development of Homo sapiens was not directly linear, but rather a complex branching process.[50]

The hominid family includes Australopithecines (from the Pliocene and Pleistocene epochs), varieties of Homo Erectus and modern humans. Most physical anthropologists argue that Hominids walked upright for at least three million years. This is the age of a pelvis of Australopithecus, uncovered in the Afar region of Ethiopia by Donald C. Johanson. The early bipeds were shorter than humans and had small brains, averaging 450 cubic centimeters.[51]

Later, however, about 2.5 million years ago, these "bipeds" were making stone tools and hunting animals for food. About 2 million years ago, hominid craniums appear with a still larger capacity, and by 1.5 million years ago Homo erectus was on the scene with a brain that had doubled in size. The stone tools now included bi-faces, flaked on both sides, representing the Acheulian core-tool industry.

Molecular biology provides data to suggest a very short distance between humans and African apes. When the distance separating Old World monkeys from New World monkeys is given a value of 1, and other distances are expressed as fractions of that value, then the distance between humans and Old World monkeys is more than half a unit. The distance between humans and the orangutan is about a quarter of a unit (.25 to .33), and the distance between humans and the chimpanzee is about an eighth of a unit (.12 to .15). The advances in techniques of molecular biology are closely intertwined with anthropology in tracing the linkage between apes and humans.[52]

In Human History, we will trace this historic development into the Mesolithic period where people were living in sedentary communities. We shall see how people in the Neolithic period developed domesticated plants and built permanent villages. With the rise of the Bronze Age, they began to build cities and states, spreading civilization to all parts of the world.

Carl Sagan charted the process in terms of how it would look in the time of one calendar year. Notice the change in speed in the following chart.[53]

Evolution Charted in One Calendar Year

January 1, 12 am

Big Bang occurs

Early February

The Milky Way Galaxy forms

August 12 

The Earth and Sun are formed

September 28

First life arises on the Earth

December 13

First animals appear on Earth

December 25

Dinosaurs walk the Earth

December 30, 12:33 am

Dinosaurs wiped out

December 31, 9:00 pm

First humanoid life appears

December 31, 11:58 pm

Homo Sapiens first appear

December 31, 11:59 pm + 30 seconds

Agriculture developed

December 31, 11:59 pm + 47 seconds

Pyramids built

December 31, 11:59 pm + 59 seconds

Shakespeare.

In conclusion, it has been a long journey to civilization. Scientists say that the universe began over 13 billion years ago, when a powerful light energy formed into particles and evolved from atomic to molecular structures, then into star constellations and the formation of planets, like the earth. On planet earth, we saw the conditions for simple protozoa and multicellular organisms develop, and most recently, the complex animals we call humans who came to create cultures. By Sagan’s time scale, it looks like events move slowly at first and then speed up rapidly, moving toward greater and greater complexity.  But the concepts of time and complexity become part of a new inquiry as we move into human history.

 



[1] Steven Weinberg, The First Three Minutes (N.Y.: Basic Books, 1977), pp. 6-8.

[2] Astrophysicists are challenging the Big Bang theory. The discovery of "black holes" in galactic centers, for example, could affect ideas about the history of the universe. Quasars appeared when the universe was less than one billion years old, indicating that some galaxies had already developed dense central regions. The early appearance of quasars rules out many cosmological models, which predict that the formation of galaxies should require billions of years to form. It even raises problems for the "cold dark matter" model. Recent measurements of the cosmic background radiation intensify the puzzle. Martin Rees, "Black Holes in Galactic Centers," in Scientific American, Nov. 1990, p.56.

[3] Physicists speculate on the history of "particles" that appear before "quarks" on the way to forming the "atom." Quarks were the ancestors of protons and neutrons, though at a tiny fraction of a second after birth, they were rapidly interacting with and transforming one another. For some physicists, extreme symmetry and extreme simplicity were evident at these ultra-high energies. H. R. Pagels, The Cosmic Code, (London: Michael Joseph, 1982).

[4] See Weinberg. Op. cit. In an effort to study these origins comprehensively, astronomy and physics merged to become "astrophysics." Astrophysicists report on their findings monthly in the Astrophysical Journal, popularized in Sky and Telescope.

[5]  Here is a more recently reported timeline for this process. Up to 10–43 seconds after the Big Bang, the fundamental forces—electromagnetism, weak nuclear force, strong nuclear force, and gravitation—all have the same strength in one singular force. Between 10–43 seconds and 10–36 seconds after the Big Bang, gravitation begins to separate from other forces and the “unity” is broken. Between 10–36 seconds and 10–12 seconds after the Big Bang, the temperature is low enough to separate the strong force from the electroweak force, which triggers an expansion called “cosmic inflation.” Between 10–6 seconds and 1 second after the Big Bang, the quark-gluon plasma of the universe and hadrons, including baryons, such as protons and neutrons, can form. At about 1 second after the Big Bang, neutrinos decouple and begin traveling through space. Between 1 second and 3 minutes after the Big Bang, the majority of hadrons and anti-hadrons annihilate each other, leaving leptons and anti-leptons prevailing in the universe. Between 3 minutes and 380,000 years after the Big Bang, most of the leptons and anti-leptons are eliminated, and the universe is dominated by photons. The photons continue to interact with charged protons, electrons, and eventually “nuclei” for the next 300,000 years. Between 3 minutes and 20 minutes after the Big Bang, the universe falls in temperature to a point where atomic nuclei can begin to form. At this time, the densities of atomic nuclei and radiation (photons) are equal. B. Ryden Introduction to Cosmology, (Addison-Wesley, 2003.) V. Mukhanov, Physical foundations of Cosmology, (Cambridge University Press, 2005.)

[6] W. F. Bynum, E. J. Browne, and R. Porter, (Eds.) Dictionary of the History of Science (London: Macmillan, 1981.) 

[7] Andrew Scott, The Creation of Life, (Oxford, Basil Blackwell, 1986.) p. 53.

[8] Weinberg, op.cit. pp. 28-30.

[9] This Center will also look at cosmic strings. Strings are exceptionally thin, heavy vortices of energy predicted by the "grand unified theory" of physicists. If real, these strings would have condensed out of the superheated cosmic plasma during the first instants of the Big Bang, filling the universe with a dense network of threads and loops. The loops would have been massive enough to pull in clouds of ordinary matter around themselves by gravity, and thus serve as "seeds" for galaxy formation. The strings are believed to come out of the Big Bang in an unprecedented state of vibration and would have radiated away virtually all of their energy in the form of gravity waves.  By now this cosmic expansion would have stretched out most of this radiation into wavelengths measured in light years, making them completely invisible to any laboratory experiment. But they would not be invisible to something called “millisecond pulsars.” About half a dozen of these pulsars have been discovered since 1982, all rotating at roughly 500 to 1000 times per second, and as timepieces they have turned out to be considerably more accurate than atomic clocks on Earth. Using one as a gravity wave detector is fundamentally a matter of monitoring its pulses over time. If a long-wavelength gravity wave were to pass, its effect would be to push the pulsar signal in and out of phase on time scales of a year or more.  M. Mitchell Waldrop, "Pruning the Thickets of Cosmic Speculation," in Science, Jan. 13, 1989, pp. 168-69.

[10] Kenneth Kellermann and David Heeschen, "Radio astronomy in the 1990s," in Physics Today, April, 1991, p. 41.

[11] Quasars are compact sources of radiation, highly red shifted, with irregular variations in brightness. The first quasars were discovered through their intense emission of radio waves. Martion Harwit, Cosmic Discovery (N.Y. Basic Books, 1981), p. 329

[12] Ibid.,  4.

[13] Carl Sagan, Cosmos (NewYork: Random House, l980) p. 233.

[14] The sun converts itself into a flow of energy that the process of photosynthesis changes into plants, which in turn are consumed by animals, both of which are consumed by people. For millions of years, humans have been consuming sun energy stored in wheat or deer. The sun dies each day and is reborn into the earth, and not only in mythic or metaphoric terms. Its solar flares are the source of the energy moving through our nervous system.

[15]  The sacrificial practice was not common to early tribes. In ancient Israel, sacrifices of humans and animals were made to a blazing fire in a ritual called “a holocaust.” It was the Biblical Abraham who changed the course of history in ancient Israel. According to ancient tradition, Jehovah, the Hebrew God asked Abraham to sacrifice his son Isaac to the fire. Then, after seeing an angel, Abraham felt compelled to sacrifice his lamb instead, and changed the course of history.

 

[16] Ibid.

[17] The artificial creation of molecules is of as much interest to the chemist as the domestication of animals was to Darwin. Darwin started his epoch-making book on the topic of changes in animals caused by their domestication.

[18] Arthur Young, The Reflexive Universe (San Francisco: Delacorte Press, 1976.) p. 67.

[19] A. Lima-de-Faria, Evolution Without Selection (NY: Elsevier, 1988), p. 126. The author concludes:  "The self-assembly of organisms into societies displays many of the characteristics of the self-assembly of cells and of organizations." p. 146.

[20] James Hutton (1726–1797) was a Scottish naturalist. One of his key concepts was the “Theory of Uniformitarianism.” This was the belief that geological forces at work in the present day are the same as those that operated in the past. The rates at which processes such as erosion or sedimentation occur today are similar to past rates, making it possible to estimate the times it took to deposit sandstone of a given thickness. It became obvious from this analysis that enormous lengths of time were required to account for the thicknesses of exposed rock layers. Uniformitarianism is one of the fundamental principles of earth science. Hutton’s theories amounted to a frontal attack on a popular school of thought called “Catastrophism,” which was the belief that only natural catastrophes, such as the Great Flood, could account for the form and nature of an Earth that was only 6,000-years-old.

[21] Robert Dott and Roger Batten, Evolution of the Earth (NewYork: McGraw-Hill, 1981).

[22] A. Hallam, "Plate tectonics and evolution," in D. S. Bendall (ed.), Evolution from Molecules to Men (New York: Cambridge University Press, 1983), p. 368.

[23] Geologists assert, however, that the cubic capacity of the ocean basins is changed more effectively by the variance in the volume of mid-ocean ridges. An increase in volume will cause a displacement of sea water on the continents and vice versa. One popular hypothesis has it that variations in "rates of sea-floor spreading" are the controlling factor. Since ocean-floor basalt subsides as it cools, while migrating away from the spreading axis, a faster-spreading ridge will be hotter and more buoyant over a larger area, and hence will cause more displacement of seawater over the continents. J.D. Hays and W.C. Pitman, "Lithospheric plate motion, sea level changes and climatic and ecological consequences," in Nature (1973), No. 246, pp. 16-22.

[24] Sir Francis Crick proposed a theory of panspermia, that is, the idea that the first speck of life came here from elsewhere in the universe.

[25] Sidney Fox, The Emergence of Life: Darwinian Evolution from the Inside (NY: Basic Books, l988), p. 64. Fox writes:

The clues we had came from earlier studies of reactions of special amino acid molecules to make special peptide molecules in the presence of enzymes. In these experiments, performed in our laboratory in the 1940s, we thought we saw evidence that amino acids were ordering themselves. This suspicion went against the widely held view that the specificities of reaction were in each case due to an "outside agent," the enzyme used for the reaction. Essentially, no thought had been given to the possibility that the reactants might themselves contribute to their own reactions. The whole subject was in fact formally known as the Specificity of Proteolytic Enzymes.

 

      Fox describes how the concept of "self-organization" occurs, when protein molecules organize themselves into microscopic organelles.  The idea (that a first protein molecule could have organized itself) was based on his laboratory finding that modern protein molecules tend to do so. This notion was developing at the same time that the broader concept of "self-organization" was being helped by experiments defining primordial protein (p. 52).

[26] Ibid., p. 96. Fox also argues that each self-organization of protein is not what the word "reproduction" usually connotes. It is not “a handing down of metabolic pathways from a parent to its offspring.” Rather, it is more a reproduction that begins from the latest starting step, only guided in a slightly diversifying way by the parent(s). "When we question the concept of self-reproduction in the present context of origins, we may come to the variant idea that in each generation the production is begun anew" (p. 134).

Fox continues to explain the impact of these insights on the field of biology in "new principles" of the field. They are:  First, evolution proceeds in steps...Second, large molecules—proteins—organize themselves...Third, self-organization starts at a stage of self-ordering of the monomeric amino acids that go into protein. This sets the stage for extensive information and variety because the proteins are themselves variegated...Biology is entering a new phase as exemplified by genetic engineering. You can call it synthetic biology” (p. 119).

[27] Ilya Prigogine and Isabelle Stengers, Order out of Chaos: Man's New Dialogue with Nature (London: New Science Library, 1984).

[28] From this perspective of biochemistry, high-state energy flows between systems result in a qualitatively different order of things. For example, the flow of heat from fire to boil water changes the chemical composition of water and creates a different order of things. This is similar to the flow of heat from the center of a star to its outer layers, and the flow of warm air from the earth's surface toward outer space. In this latter case, the earth is warmed by the sun and heats the air from below while the air in the colder outer space absorbs heat from the top layers of the atmosphere. As the lower layer of the atmosphere rises and the upper layer drops, circulation vortices are created which take the shape of Benard cells (hexagonal cells of a specific size), the same as are found in boiling water.

[29] Humberto Maturana and Francisco Varela, The Tree of Knowledge (Boston: New Science Library, l987).

[30] In this view, DNA is capable of replication, but not self-maintenance, and therefore, is not an autopoietic body. DNA, replicating by making proteins to create more RNA, probably governed the first membrane-enclosed autopoietic bodies. All cells have DNA and RNA.

[31] J.B.S. Haldane, the British biochemist, was among the first to understand that, without oxygen, the earth's early atmosphere was a requirement for the evolution of life from nonliving organic matter. Oxygen would have stopped early life from developing. It would have created a high-altitude ozone layer to block ultraviolet radiation from the sun. But the unblocked ultraviolet radiation was needed first to supply energy for the synthesis of organic compounds, such as amino acids, nucleotides, and simple sugars from molecules such as water, carbon dioxide, and ammonia. Haldane's ideas appeared in Rationalist Annual in 1929.

[32] Margulis and Sagan, op. cit., p. 77. These authors note that to fix nitrogen takes an enormous amount of energy, from six to eighteen molecules of ATP for every molecule of nitrogen. To do this industrially, such as in the manufacture of plant fertilizer, requires at least 300 times normal atmospheric pressure at 500 degrees C. No plant or animal is capable of doing this, nor are most microbes. Without this activity of capturing nitrogen gas directly from the air, life on earth would have died out because of nitrogen starvation. Instead of being included in the proteins of all living cells as it is today, nitrogen would have become inaccessible, trapped as an inert gas in the air. Fermentation thus releases small quantities of nitrogen from within cells into the air, and nitrogen fixers return it to living organisms. If life forms had not retained the bacterial mechanism of nitrogen fixation, nothing could have lived because of nitrogen deficiency.

[33] Most researchers accept that nonoxygenic photosynthesis arose shortly after life originated more than 3.8 billion years ago.  The sharpest disputes revolve around when organisms shifted to oxygenic photosynthesis. At issue is how to interpret a watershed in the fossil record known as “the great oxidation event” (GOE). In rocks from about 2.4 billion years ago, geologists see the first unmistakable signs of sustained levels of atmospheric oxygen. These signs include red beds, or layers tinged by oxidized iron, i.e., rust. Mitch Leslie, “On the Origin of Photosynthesis,” Science 6 March 2009: Vol. 323. no. 5919, pp. 1286–1287

 

[34] Lynn Margulis and Dorion Sagan, Microcosm (NY: Summit Books, l986), p. 117.

[35] The concept of governance applies to democratic states and trade associations operating in today's markets as much as it does to bacterial confederacies. Confederacies and alliances are the way corporations organize themselves in a world economy.

 

[36] Ibid., p.119.

[37] Ibid., p. 132. Margulis and Sagan give an illustration of how a new species is born in this manner by citing an experiment conducted by Kwang Jeon, a biologist at the University of Tennessee. Kwang welcomed a new batch of amoeba to his laboratory, which were unexpectedly infected with 100,000 rod-shaped bacteria. With his care, a small group survived with the bacteria remaining in them. They became a new species of bacterialized amoeba. Keeping an evolutionary perspective in mind, the authors suggest that the deadliest of enemies can become indispensable to survival.

[38] Ibid., p.134. The authors note that obscure green bacteria, called Prochloron, grow on marine animals known as sea squirts. The bacteria coat the organisms with green and may supply them with certain nutrients. Some sea squirt larvae also carry pouches full of Prochloron, insuring their symbiotic growth with the next generation. It was thought at first that Prochloron was a green alga, but the first electron micrographs indicate it is an enormous bacterium.

[39]  Michael Benton suggests two ways of viewing evolution. It can be done through the spectacles of the Red Queen or the Court Jester. The Red Queen model stems from Darwin, who viewed evolution as primarily a balance of biotic pressures, most notably competition. It was characterized by the Red Queen's statement to Alice in Through the Looking-Glass that "it takes all the running you can do, to keep in the same place." The Court Jester model is that evolution, speciation, and extinction rarely happen except in response to unpredictable changes in the physical environment. This recalls the capricious behavior of the licensed fool of medieval times. In a Court Jester world, species diversity depends on fluctuations in climate, landscape, and food supply. In reality, both aspects might prevail in different ways and at different times, what could perhaps be called the “multilevel mixed model.” Traditionally, biologists have tended to think in a Red Queen, Darwinian, intrinsic, biotic factors way, and geologists in a Court Jester, extrinsic, physical factors way.

Michael J. Benton, “The Red Queen and the Court Jester: Species Diversity and the Role of Biotic and Abiotic Factors Through Time,” Science 6 February 2009:

Vol. 323. No. 5915, pp. 728–732.

 

[40] The concept was first used by Ehrlich and Raven in their discussion of the evolutionary influences that plants and insects had on one another. P.R. Ehrlich and P.H. Raven, "Butterflies and plants: a study in coevolution," Evolution, 1964. 18: 586–608.

[41] Douglas Futuyma and Montgomery Slatkin, Coevolution, (Sunderland, MA: Sinauer Associates, Inc. 1983), p. 1.

[42] This cooperative action of mammals—helping to disseminate angiosperm seeds—is one case among many that challenges the emphasis Darwin gave to the species as the determinant of evolution. Darwin once said in the Origin of the Species: "If it could be proved that any part of the structure of any one species had been formed for the exclusive good of another species, it would annihilate my theory, for such could not have been produced through natural selection." The coevolution of animals and vegetation, the development of early bacteria with one organism absorbed by another for the exclusive good of another, demonstrates how this happens in the theory of coevolution.

[43] Martin Nowak argues that cooperation means that selfish replicators forgo some of their reproductive potential to help one another. Genomes, cells, multicellular organisms, social insects, and human society are all based on cooperation. He discusses five mechanisms for the evolution of cooperation: kin selection, direct reciprocity, indirect reciprocity, network reciprocity, and group selection. For each mechanism, a simple rule is derived that specifies whether natural selection can lead to cooperation. Martin A. Nowak, “Five Rules for the Evolution of Cooperation,” Science, 8 December 2006:

Vol. 314. no. 5805, pp. 1560–1563.

[44] H.A. Simon, “A mechanism for social selection and successful altruism,” Science, 21 December 1990: Vol. 250, no. 4988, pp. 1665–1668.

[45] Bert Hölldobler and Edward O. Wilson say: "Eusociality … can, in theory at least, be initiated by group selection in either the presence or absence of close relatedness." But it could not arise without group selection. No eusocial species exist among the 70,000 species of parasitoid wasps and their relatives that travel from prey to prey to lay their eggs; whereas it arose seven times in the 55,000 aculeate (stinging) wasps that keep paralyzed prey in nests. Among the 9000 species of aphids and thrips, only those few that induce plant hosts to form galls--a nest of sorts--have become eusocial even though most of them form groups. And out of 10,000 decapod crustaceans, only snapping shrimp, which live in sponges, are eusocial. In these settings, species with the flexibility to live in groups can win out. Wilson thinks today's eusocial species likely had ancestors similar to a Japanese stem-nesting xylocopine bee and Ceratina flavipes. Most of the time females make do on their own, but every once in a while, they pair up and divide the labor, setting the stage for a "group" to outdo individuals and for the tendency to form groups to be favored. Reported in Elizabeth Pennisi, “Agreeing to Disagree”, Science 6, February 2009, Vol. 323. no. 5915, pp. 706 - 708

[46] Bert Hölldobler and Edward O. Wilson, The Superorganism, (NY: W.W. Norton, 2008). The authors say that these “social insects” are hugely abundant. They are only 2 percent of the 900,000 insect species, but in total weigh more than all the others. A measurement in the Amazon rainforest showed social insects to be 80 percent of animal biomass, more than the sum of the mammals, birds, reptiles, and amphibians.

 

[47] The explanation of pre-human history during these periods requires a dialogue among geologists, biologists, and anthropologists. The explanation cannot be based on the biological principle of natural selection alone, because it also involves the movement of continental plates, the major shifts of climates, and the formation of the brain. Indeed, there is a close relationship among climate shifts, vegetation, and fauna during these periods: shifts in climate often signaled the beginning of a major epoch. For example, the climate of the Cretaceous Period was almost uniformly damp and mild, but around the beginning of the Paleocene Epoch, both seasonal and geographic fluctuations in temperature began to develop. The weather became much drier in many areas, and vast swamplands disappeared. With these climatic changes came the development of deciduous plant life that was important for the evolution of insects. Insects proliferated enormously in number and variety in this period. In turn, this led to the development of Insectivores—an order of mammals, including modern shrews and moles—adapted to feeding on insects. Among the early kinds of Insectivores may have been the first primate with an enlarged cranial capacity.

[48] Frank Poirier, Understanding Human Evolution (Englewood Cliffs, NJ: Prentice-Hall, 1987), p. 46.

[49]  See http://en.wikipedia.org/wiki/Timeline_of_human_evolution

[50] Carol Ember and Melvin Ember, Anthropology (Englewood Cliffs, NJ: Prentice-Hall, 1973), p. 63. Anthropoids are one of the two orders of primates, which include monkeys, apes, and humans. This category contains at least two genera: Homo and Australopithecus.  Hominoids are the group of catarrhines that includes both apes and humans. Hominids are a group of hominoids, consisting of humans and their direct ancestors.

[51] Donald Johanson and Edey Maitland (Lucy: The Beginnings of Humankind. (New York: Simon and Schuster. 1981)

 

[52] A qualitative change in the history of nature took place at this point, as humans moved swiftly to develop language and culture. Language passed through stages from signs to symbols, from pictographs to ideographs to the alphabet. We see a complex transition from the earliest Homo sapiens (Neanderthal at 100,000 years ago) to Modern Sapiens in the Middle Paleolithic, the latter creating paintings in caves. Sherwood L. Washburn, "The Evolution of Man," Scientific American, p. 204.

[53] Carl Sagan, The Dragons of Eden: Speculations on the Evolution of Human Intelligence (NY: Ballantine Books 1986)