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A Godless Philosophy - Contents
Preface (What's this all about?)
The Story of Evolution
14,000,000,000 y.a. -- The Big Bang
4,600,000,000 y.a. -- Our Sun and Earth
Stars evolve, producing the complex elements of organic life
2,500,000,000 y.a. -- First life forms on Earth
A bacteria reproduces itself, and the race is on
220,000,000 y.a. -- First mammals
A tiny shrew survives among the dinosaurs
30,000,000 y.a. -- The great apes of Africa
Chimps achieve sociability, planned combat, and use of natural objects as tools
5,000,000 y.a. -- Earliest human ancestors
It looks like a chimp but walks upright
3,000,000 y.a. -- Earliest toolmakers
Still chimp-like, this larger-brained ape makes the first stone tools
1,800,000 y.a. -- Later pre-humans
More human-looking without fur, this naked ape conquers fire and reaches Eurasia
300,000 y.a. -- Neanderthals
Evolved in Europe's Ice Age, they hunt and kill 7-ton mammoths
50,000 y.a. -- Modern humans (Homo sapiens)
Fully human now, we narrowly escape extinction to follow our destiny
45,000 y.a. -- Spread of modern humans throughout Eurasia
Out of Africa, we encounter the pre-humans and fight our way north
30,000 y.a. -- Extinction of the last pre-humans
Neanderthals, the tough guys, hold out the longest
15,000 y.a. -- First settlements, city-states and empires
It takes us 35,000 years to create the first small city
600 y.a. -- Racial differences and European conquests
Guns, germs and steel
Now -- Human evolution in modern times
Where are we, and what lies ahead?
Theory or Science? Sources and References
The story of human evolution starts in Africa because that's where the great apes evolved, diverging from monkeys roughly 30 million years ago. Chimpanzees were well established as a species by around 5 million years ago, when the human-chimp split occurred.
These ancient chimps were not just the jumping-off point for human evolution. Their long shadow reaches all the way to modern humans; to this day, more than 98 percent of our genetic blueprints are still identical. With so much inherited from ancient chimps, we are naturally curious: what were they like?
Very much like modern chimps, it turns out. In contrast to the wild evolutionary ride of humans, the rest of the animal kingdom has evolved far more slowly. Since chimps still live in an aboriginal state in the African rain forests, our studies of them give us a reasonably close idea of how ancient chimps looked and behaved.
So here is what we started from: Our chimpanzee human ancestors were and are roughly 4 feet tall, with 350-400 cc. brain volume (roughly one-third of a modern human). They normally nest in trees, and can walk erect for short distances, but usually "knuckle-walk." They live in "troops" of some 30 to 80 individuals, with separate male and female hierarchies, and most infants are fathered by the troop's dominant male or one of his allies.
Omnivorous, they eat a wide range of fruits, plants, nuts, mushrooms, meat and more, but they depend especially on fruit. As foragers, they can move to a new part of the rain forest if fruit becomes scarce, but otherwise they prefer to remain in a more or less fixed territory.
Chimps are highly social. Members of a troop often hold hands and groom each other. They may kiss when they meet. Female chimps give their young a great deal of attention and help each other with babysitting chores. They are also among the noisiest of all wild animals: they hoot, grunt, scream and drum on hollow trees with the flat of their hands.
Chimps also have a primitive sense of justice. This refutes the evolution-deniers' claim that only divine intervention can account for our human sense of right and wrong. Many chimp behaviors are based on reciprocally altruistic relationships, such as babysitting for each other, and chimps keep track of who owes them favors. If a favor is not reciprocated, they will display moral indignation, "complaining" about being wronged to other chimps in the troop.
As opposed to other ape species such as gibbons, who mate for life, chimpanzees are polygamous. Females advertise when ovulating and are receptive to most of the males in the troop. As a result, male chimps have a very active sex life. Any tendency toward low libido, shyness or monogamy is non-competitive and quickly eliminated from the gene pool.
Most important, chimpanzees are the smartest non-human animal. They are status conscious and manipulative, capable of deception, and can plan ahead. They employ sophisticated hunting strategies involving cooperation and rank. They use sticks and stones as ad hoc tools.
While not dependent on meat for their diet, chimps are nevertheless quite predatory. Their most frequent victims are young antelopes or goats and other primates such as young baboons and monkeys.
They also wage war on other chimpanzee troops. This goes beyond defending their territory. Raids are often unprovoked but always rewarded: males advance in their hierarchy and win favor with the females by being successful warriors. Wanting the odds in their favor, three young males will often band together to go chimp-hunting. If they catch a male chimp from another troop, two will hold him down while the third will bite him and beat him to death with whatever "weapon" is handy -- a rock or a tree branch.
It's worth noting that this chimpanzee behavior is the highest level of aggressiveness displayed by any animal, out of four thousand mammals and millions of other animal species.
For better or worse, this was our starting point. In the pages ahead, we will trace how our chimp legacy has shaped human evolution.