Just so you know where this book is going, here is a short story of the origin of man propounded in this book. Much of it is, admittedly, speculative, but it provides a more-or-less complete story, even if it involves some guesswork, a better read than isolated facts separated by chasms of mystery. I will not endlessly repeat, “according to the author,” and the reader should realize that deductions and explanations are the author’s opinion, supported by the quotations and citations that are given.
Table of Contents
1. (Richmond, 2001). Longer legs use less energy; leg length increased about 2 mya. (Pontzer, 2007). Back
The story begins about 60 mya in the tropics of SE Asia. Early primates (“prosimians”) chatter in the trees where they are safe from most predators. Some of the prosimians cling to trees vertically and have a vertical posture. They support themselves and climb with their strong back legs and use their front legs to grasp branches and food.
Some primates become larger, making it more difficult to walk on top of the branches, so they begin to move by hanging from the branches by their feet and arms, then just by their arms; they are “brachiators.” Arms become longer as those with longer arms can move more efficiently with larger swings, just as longer legs make walking more efficient. Tails are no longer needed for balance and are a waste of the body’s resources, so the brachiators who have shorter tails now have an advantage and tails decrease in size, then disappear entirely.
Less mobile in the trees and too heavy to reach fruit on the end of small branches, the tailless brachiators spend more time on the ground, where their size eliminates the threat of small predators and enables them to eat foods, such as underground tubers, unavailable to their tree-bound predecessors. They have not evolved the anatomy needed for efficient walking on two feet so they walked partly bent over supported by palms in Eurasia and knuckles in Africa. The environment on the ground is more complex, giving a survival advantage to those who have larger brains and are more intelligent. It is about 25 mya and the tailless brachiators have become apes.
Some of the Eurasian apes live in swampy areas, near lakes or the sea, or in forests near rivers, where they feed on plants and aquatic animals. When they are in the water, they walk on two feet (“bipedalism”). Over time, they become more and more anatomically adapted to bipedalism and venture farther away from the safety of shallow water and nearby trees. This is the first “giant step for mankind” because bipedalism was the single most important adaptation in the evolution of man; man is the only habitually bipedal mammal. It is about 10 million years ago and bipedal apes have arrived.
The Eurasian bipedal apes follow the fruiting of trees and bushes and the herds of animals that predators feed on, scavenging the remains. Walking on two feet lets them travel farther and faster and with less energy than the quadrupedal apes, 1 and there are many other significant advantages as well. Their hands are free to carry food and rocks 2 and sticks for weapons, 3 standing upright presented less surface area to the sun, keeping them cooler and able to forage longer 4 and, by standing, they could better spot predators. 5 Weapons and tools improve, as they can now be carried with them instead of being made only when needed, then discarded. Larger brains enabled them to plan better hunting strategies, thereby obtaining more meat to fuel their growing brains, creating a feedback loop of bigger brain → better tools and weapons → more meat → bigger brain (where “→” means “makes possible” or “goes to”). 6
Because the bipedal apes move about on the ground so much, they are constantly in different environments. They must remember where to go, when to go there, and what dangers and food sources to look for in all the many different locations they visit. A larger brain, despite its high energy requirements and additional weight, becomes worth its high cost.
Moving around on two feet means that a mother can hold her baby with one hand and gather food with the other while it nurses. 7 Walking uses less energy if the legs are close together (Arsuaga, 2001, p. 92), and women with a narrower birth canal, and therefore closer legs, survive better. But a narrower birth canal means that babies must be born less developed so their brains and skulls can fit through the narrower canal during birth; the growth of the brain is delayed and it has its greatest growth after birth. 8 While that solves one problem, it creates new problems, for now the less-developed baby requires longer care in order to survive. 1 The bipedal ape’s numbers increase rapidly and like his predecessors he, too, migrates into Africa, where he drives all the other great apes to extinction, except for the chimpanzee and the gorilla, who retreat to more isolated and less desirable territories. It is about 4 mya; the bipedal ape has become Australopithecus, the last bipedal ape.
While Australopithecus ventured into the subtropics, man could go farther north, into a seasonal and colder climate. Had Australopithecus remained in the tropics, there would today be no men, Homo. But when the tropics were full, some Australopithecines, the losers in the competition for the best territories, were pushed into less desirable territories, one of which was the colder north.
A seasonal climate is vastly more mentally challenging than a tropical climate. In the tropics, different types of plant food are available all year long, but in a more seasonal climate, plants begin to limit their edible portions to only the warmer seasons, which also limits the biomass of the animals who eat them. Thus, more skill and intelligence are required than in the tropics. While some species of Australopithecines partially adapted to a cooler climate, they could not go as far north as man, and hibernation was not an option. 9
The seasonal climate strongly selected for the greater intelligence needed to survive in this more mentally challenging environment. Individuals who had it survived and passed their particular genes on to their children; those who lacked it did not. Gradually, they extended their northern range. By about 2½ mya, the combination of efficient bipedal walking, free use of hands, and greater intelligence had paid off big time and the ape had become man. Sometime around 2 mya, a dramatic change began in these more northern Australopithecines – their brains enlarged dramatically, as must have their intelligence. This was the birth of the genus Homo, the first men.
For early man, struggling to survive as seasonal differences became ever more severe with each extension to the north, his larger brain, and greater intelligence, was the key to the completely different mindset needed in this environment. Impulsiveness and immediate gratification was out; saving for the future was in. Ignoring the future consequences of actions was out; careful planning became a necessity. Nature’s price for becoming man was high, no more tropical Garden of Eden, but desperate preparation for the trials of winter. The hukana matata (“no worries”) grasshopper, 10 happily singing his days away in the sun, becomes Homo, the hard-working, struggling ant.
The relationship between the sexes also changed. In the north, where hunting was a more important source of food, women could no longer gather the provisions needed to sustain themselves and their children throughout the year. Without a man to provide for them, they died and their children died. 11 Men who committed to a single woman and cared for her, the “dads,” passed on their pair-bonding genes; fewer “cads” passed on their philandering genes.
An early species of man, Homo erectus, spread into the warmer areas of Africa, Europe, and Asia, as far north as his naked body could tolerate the cold, driving his predecessor, Australopithecus, to extinction. 12 When he had filled all the territory he could, his great expansion stopped. Any further migrations meant moving into territory already occupied by other erectus and fighting and defeating them. That was not easy to do because the resident erectus knew the land, the food sources, and the dangers, and he fiercely defended his homeland. 13
In widely separated and different environments, erectus continued to evolve, each population becoming better adapted to its unique environment; erectus, like Australopithecus before him, becomes distinct and genetically different races. 14 In the northern range of Asian erectus, the climate was much colder, so those individuals who had traits that made them better able to endure the cold survived there while others did not.
In Europe and western Asia, early erectus eventually evolved into Neanderthals (also spelled “Neandertals”) about 350,000 ya. In East Asia, cold-adapted erectus acquires control of fire, 15 moves still farther north, and evolves into Homo sapiens (Hs), archaic man, about 200,000 ya. Similar changes occurred in West Asia, but without cold adaptations. The last stage before becoming modern, Hs further improved his skills and increased his intelligence, extending his range still further north. By about 150,000 ya, archaic man became Homo sapiens sapiens (Hss), modern man. Where this happened is a major contention that is the subject of much of the rest of this book, but the author believes it happened in East and West Asia.
Like his predecessors, the new-found tools, weapon, and intelligence of Hss were an advantage not only in the north, but also in the south, still occupied by Hs and even by some erectus in the tropics. So, when his numbers increased and the climate became colder and winters so severe that the snow no longer melted, he moved south, invading Hs and erectus territory, driving them to extinction, but sometimes interbreeding with them along the way, creating hybrids. The glaciation of the north lowered sea levels and migration to Pacific islands and Australia became feasible. When the ice finally began to melt thousands of years later and the cold retreated, Hss moved north once again. West Asian Hss spread into Europe, where he bred to a limited extent with the Neanderthals, becoming today’s Caucasians.
About 50,000 ya, one or more mutations occurred in a Eurasian population that affect the functioning of man’s brain. These mutations were so favorable that they rapidly spread through to Eurasians. Man created an elaborate culture, acquired religious beliefs, and crafts, art, and tools that had to be visualized in his mind. Agriculture and the domestication of animals followed about 10,000 ya and the rest, as they say, is history.
This is our origin, according to the author of this book. Those who favor a divine origin for man will not agree, nor will most scientists who believe man’s origins were in Africa. Nevertheless, I hope the reader will carefully consider the evidence that supports this story before making up his mind.
2. Later bipeds carried round rocks (“manuports”) left over from chipping off cutting stones. These were ideal for throwing at predators and scavengers to drive them away from carcasses. Individuals who could throw the manuports hard and accurately, due to a superior brain that could precisely calculate the instant to release the rock, were more reproductively successful. Back
3. A significant advantage as big cats found them quite tasty. (Eppinger, 2006). Back
4. Compared to walking on four limbs, standing upright exposes only 40% of the body to direct sunlight (Haywood, 2000, p. 23). Also, standing reduces the exposure to heat radiating from the ground, and exposes the body to cooler breezes, keeping the brain from overheating and shutting down. (Wheeler, 1988). Back
5. Meerkats and other mammals also stand on two feet to watch for predators in the grasses. Back
6. Without meat, it is doubtful that man’s brain could have increased to its present size. (Taylor, 2007). Back
7. This simple act of carrying the baby with one arm may have profoundly affected man’s brain. Because the left ventricle of the heart makes the loudest sound and babies are quieter when they hear the heartbeat they heard in the womb, most women, even today, carry their babies on their left side. Women, like men, used their free right arm to throw stones at prey and predators and those whose left side of the brain (which controls the right arm) was more adept at accurate throwing had an advantage. Thus, man became predominately right handed and his brain became more asymmetrical, making the brain more specialized and sophisticated. (Calvin, 1991). Also, (Donohoe, 2003). Humans are the only primate that is predominately right-handed. (Corballis, 1991). Back
8. The infant brain is about a quarter of the size of the adult brain and grows most after birth, not stopping until about age 30. (Allman, 1994, p. 56; Schwartz, 1999, p. 122). A newborn chimpanzee brain is about 60% of its adult weight and grows 30% to puberty, while a newborn human brain is 24% of adult weight and grows 60% to puberty. (Corballis, 1991, pp. 69-70). Back
9. Even if man could have evolved to hibernate, because of his size he would be competing for suitable quarters with other animals, such as the powerful cave bear. Hibernation can be induced in man, but in nature he would die from hypothermia. (Stone, A., "Suspended Animation," Discover magazine, May, 2007, p. 43). Back
10. “The Dobe !Kung people of the Kalahari desert, for instance, are able to provide all the basics of life for themselves by about two to three hours work a day, depending on the season. The rest of their time is to be spent at leisure, either gossiping and socializing, telling stories, playing games, or resting.” (Haywood, 2000, p. 82). “In tropical environments where food is available all year round, hunter-gatherers rarely store food even overnight…” (Haywood, 2000, p. 90). Back
11. “…from birth to belated maturity it takes six times as many calories of food per kilogram of adult weight to build a man as to nurture any ordinary mammal to adulthood.” (Coon, 1962, p. 172) Without that greater intelligence, man could not have acquired that amount of food. Back
12. Not only did the brain of erectus jump in size in proportion to his body weight (Boaz, 1997, p. 141), but unlike Australopithecus, erectus could run! Two million year old erectus developed a delicate ridge at the base of his skull where a tendon (the nuchal ligament) was attached to keep his skull steady during running. Erectus may have been able to run down prey, especially in hot weather, giving him a food source unavailable to Australopithecus. (Bramble, 2004). Running down prey is a successful strategy only in high temperatures because, for it to be successful, the prey’s temperature must reach about 105° F, which shuts down its ability to run. Back
13. A successful invasion of occupied territory typically requires at least a 2 to 1 numerical superiority or a highly superior technology. Back
14. The large jump in brain size was due to a genetic change, though as yet it has not yet been attributed to any particular gene or genes. It is interesting, though, that chimps, gorillas, and orangutans have 48 chromosomes and humans have 46 chromosomes, due to the fusion of the two chromosomes into Chromosome 2 (Williams, 1999). It is not known, of course, how many chromosomes the Australopithecines had, so this may not have been the change that divided ape and man. The tarsier, an early primate, has 80 chromosomes, suggesting that as primates evolved, chromosomes fused. Back
15. Dragon Bone Hill, China, between 620,000 and 410,000 BP. Back
Table of Contents
1. (Richmond, 2001). Longer legs use less energy; leg length increased about 2 mya. (Pontzer, 2007). Back