2.6 How People Began Version 1.2 March 2012

Where did people come from?

Aren’t people vastly different from apes and monkey?

2.6 Primatology and Paleontology Conclusions (Statement 12)

Science is developing explanations of how humans developed:

● Why humans, compared to apes and monkeys, chimpanzees and baboons, have so little hair and walk on two long legs, why men have big penises and women big breasts (by comparison to other primates);

● How other different hominid (human like) species developed but died out;

● How hominids, like some other species, learned to use tools;

● How earlier species of humans spread around Africa and Eurasia – home erectus, homo ergaster, Neanderthals etc – but died out or were superseded by homo sapiens.

…more

Science continues to investigate the early origins

This brief summary will be updated after more work and review against the experts, and over the longer term it can be updated as science learns more, but it will only be replaced by a better story.

Humans evolved from apes in East Africa. Initially the apes were essentially fruit eating tree dwellers, with occasional forays onto the ground, and occasional consumption of insects or small animals. The local climate changed, perhaps in response to the earth’s wobbling around the sun, and became hotter and drier, reducing the tree cover and turning forests into grasslands. Fruit became scarcer, and in desperation the apes turned to foraging on the ground and more active hunting.

Apes have no natural weapons, like teeth or claws, and are not particularly large, especially compared to the local herd animals, deer and wildebeest etc. Pack hunters like wild dogs and cats learned to cooperate in the hunt. Big cats, such as lions and tigers, can identify a weaker member of a herd, isolate it and give chase, but often the potential victim can run just as fast, the big cat tires after a short burst, and the victim escapes. Early humans had to be cleverer and more persistent. Those who could cooperate more, who were more aware of where the other hunters were, who could communicate their intentions better, and who could chase an isolated victim for longer, were more likely to be successful in the hunt. Those who had longer legs, less hair and more sweat glands over their bodies could run for longer without overheating and tiring, and could wear down the herd animals, in a way the big cats did not. The children of the more successful hunters were more likely to live and acquired their genes.

Various other species have learned to use simple tools, including birds, otters and apes. Tools can be used for digging to find edible roots, pulling food closer, cracking nuts and shells, cutting into wood to find grubs under the bark, carrying food and water back to the other members of the clan, clubbing and spearing prey and cutting up its flesh. Those better able to grip tools and imagine how tools could be used would be more successful, leading to opposable thumbs and bigger brains. Hunters and gatherers who could use tools were more likely to have children who passed on their genes.

Early hominid hunter gatherers ma have lived beside large lakes or in caves by the sea where they obtained fish, crustaceans, and edible plant food. Just as mammals such as whales adapted from being land animals to good swimmers, so early hominids may have began to acquire extra layers of fat as insulation against the cold water, and webbing between their fingers to help swimming.

The hard hunting an gathering life, involving long chases, feats of endurance, could not support unproductive people in the group. Compared to most other species, human females are very close in size and shape to human males: individuals where the differences were greater had fewer offspring.

When early hominids had babies, the babies would have had more difficulty clinging on to their mothers’ ape-like flat breasts when their mothers were losing their body hair. Human female breasts may have evolved to provide a better handle for baby to grip, a more steerable nipple for mother to insert into baby’s mouth, or an extension descending into mother’s lap as she sits feeding baby. Apes don’t generally have face to face sex: this is a human characteristic. As face to face sex evolved the human penis became larger compared to ape to still be functional with the more indirect entry position.

Archeologists are identifying and learning to understand a variety of hominid (human like) species which developed and spread over Eurasia, at least to Europe and the Middle East (Neanderthals), China (Homo Ergaster- “Peking Man”) and Indonesia (Homo Floresiensis – the “hobbits”). These other early hominids all eventually died out so now the only hominid is homo sapiens.