This page and the twenty-one pages that follow describe the dynamics that gave rise to life on earth, the religious viewpoint of hunter-gatherers and the transition, religious and otherwise, to the beginnings of civilization – societies with class divisions, wars of conquest and slavery – a story that ends with politics and philosophy in ancient Athens.
Please consider that astrophysicists do not know the beginning of the universe or the beginning of Being. They don't pretend to grasp the interconnected reality around us in its entirety. Scientists don't estimate whether they know most or just a small fraction of it. They prefer to stay within their ability to measure what they can perceive.
The physical stuff they do perceive they describe as energy and mass. Rocks have mass, and a rock's energy is detectable when its atoms are split. Scientists date rocks by measuring radiation decay – uranium breaking down into lead – and with this they challenge our imagination with an estimate of the Earth's age at 4.4 billion years.
Astronomers have mapped celestial bodies, and they see bodies in space moving away from a center: an explosion at a central point, the "big bang," energy concentrated at an extremely high density and temperature cooling as the bodies move outward, forming subatomic particles and simple atoms. Scientists consider that something unknown is pushing the universe apart, and they call this something "dark energy. And there is gravity that has brought particles together in the form of stars and galaxies. That is what they see, and they call it the universe without knowing whether there are or have been other universes.
Gravity pulls bodies toward the sun. Inertia is the tendency of bodies to move in a more-or-less straight line. Together these two forces produce orbiting around the sun. Without gravity everything would fly outward. Without inertia everything would have crashed into the sun.
It was gravitation that formed the Earth. Denser matter (iron and nickel) settled toward its center. Rocks moved upward toward the Earth's surface. Gasses moved to the surface to become atmosphere. When the temperature was right, gasses in the atmosphere produced clouds that contained moisture – hydrogen and oxygen. It began to rain, and water began to cover much of the Earth's surface.
From the sun, electro-magnetic radiation has been cast upon the Earth. Within this radiation is a wave length that we recognize as light. (Other wave lengths in this radiation are gamma rays, x-rays, microwaves, ultra-violet light, radio waves and more.)
Astrophysicists estimate that the sun has made 23 revolutions around our galaxy since the sun and earth were formed. One revolution of the sun around our galaxy is said to take 200 million years.
Scientists estimate the age of the earth to be 4.543 billion years. Across millions of years of chemical chaos on the earth's surface, molecules (two or more atoms) have bounced off each other and have bonded. The bonding has produced single cell organisms of various sorts: bacteria, archaea, protozoa, algae and fungi. According to the Encyclopedia Britannica, bacteria developed between 419.2 to 358.9 million years ago. Sunlight on single-cell matter released oxygen into the atmosphere – photosynthesis. Then, with more mixing and chemical bonding, multicellular organisms appeared. Life had begun. A part of these cellular structures were deoxyribonucleic and ribonucleic acids (DNA and RNA) carrying what we call genetic instructions to organisms. Only those organisms thrived that were constructed in a way that made that survival possible. Biological evolution had begun.
Plant life arose after fungi had been putting nitrogen and oxygen into soil. There were insects and other creatures with a sensory nervous system – systems that served them in seeking moisture, nutrition and escaping danger. Depending on environmental circumstances, species of trees evolved from ferns and other plant life.
Today, antibiotics is an environmental circumstance that can destroy much of a bacteria population, but a mutant bacterium that has an immunity to an antibiotic can survive and reproduce a new generation of bacteria that makes the antibiotic ineffective — evolution. Of the different kinds of bacteria, what has been described as "fast bacteria" divides every twenty minutes or so.
Some small creatures have a gene that programs them for death in days. Other creatures are programmed to live for decades if they manage to escape catastrophe. An ability to escape danger allows a specie to mutate to a longer life. Small birds can defend themselves by flying away have a normal life of a decade or more. Mice, on the other hand, die of old age in a year or two. In the plant world – also governed by genetics – giant trees had extraordinary security through their size, and this is matched by a lifespan for some species that span more than 1,000 years.
In addition to lifespan as a characteristic determined by genetics there are behavioral traits that play a role in a species survival. Big cats in the wild inherited what we call hunting instincts. Today we see survival of this instinct in our domesticated cats when they chase a toy or a bird. And in pet dogs we see inheritances from wolves – characteristics that made living in a pack and survival possible. This includes a capacity for empathy and bonding among pack members.
Evolution is a product of changing genetic structures and the affected organism transmitting the change to subsequent generations. With this, across a great span of time a great variety of species have developed – a species defined by its ability to interbreed. The variety comes with births are inexact copies of their parents. The microscopic world is too wild for continuous exactitude.
Millions of years ago, reptile species mutated. Around 245 million years ago giant lizards appeared that we call dinosaurs. These dinosaurs divided into more than fifty different species that were to be labeled by scientists as the Triassic dinosaurs and no longer lizards. (Triassic refers to the Earth's geologic period between roughly 252.17 to 201.3 million years ago.)
During the Jurassic geological period – 199 to 145.5 million years ago – when land was breaking up into separate continents, species of dinosaurs had become extinct and new species appeared. One was Brachiosaurus. There was also a pigeon-size dinosaur, Epidexipteryx, that had tail feathers. And living between 155 to 150 million years ago was the bird-dinosaur, Archaeopteryx, the size of today's eagles.
Around 115 million years ago a bird-like creature with wings of skin rather than feathers and a wingspan of around 16 feet was in the skies of what today is Brazil. Today it is called a pterosaur.
Among the last of the non-flying dinosaurs was Tyrannosaurus Rex, believed to have lived from approximately 68 to 65 million years ago. It was as much as 43 feet long including tail, and 13 feet tall with a running speed of approximately 18 miles per hour. No dinosaurs have been found in a layer of earth dated less than 65 million years ago, giving us a rough date as to when dinosaurs became extinct.
Being a large as a dinosaur had its disadvantages. Small creatures that could burrow into the ground to protect themselves and didn't need as much food.
Something like 17 million years after the great dinosaurs disappeared, a mammalian creature on earth was becoming more aquatic, and in the sea the mutations continued. Today they are a variety of species labeled as whales.
One of the creatures that survived the dinosaurs was a small mammal to be classified as a primate. Evolution produced many species of primate, and some primates became extinct. Around 7 to 5 million years ago, according to scientists, a species of primate was a common ancestor to today's chimpanzees and to humans. The Encyclopaedia Britannica states that comparisons of "specific DNA sequences" between humans and the chimpanzee reveal a percentage of genetic identity in the upper nineties.
According to Britannica, research suggests that humans and Neanderthals had a common ancestor between 700,000 and 500,000 years ago and that by 370,000 years ago they had become largely genetically separate. Some interbreeding between Neanderthals and humans is thought to have occurred between 60,000 and 50,000 years ago, leaving a Neanderthal contribution to the DNA of modern humans, and Neanderthals are thought to have become extinct about 40,000 years ago.
Then, according to the Old Testament, the Lord God placed man in the Garden of Eden, between the Euphrates and Tigris Rivers – today Iraq – of all places. A better location would have been the Hawaiian Islands, uninhabited until about 1,600 years ago.
CONTINUE READING: Humanity out of Africa
Copyright © 2016 by Frank E. Smitha. All rights reserved.