Crowding created modern civilization
— -- Cram enough monkeys and typewriters into a room, goes the argument, and eventually you'll get Shakespeare's sonnets. But if you crammed enough prehistoric humans together, would you eventually get warfare, kings, cellphones and reality TV shows — the stuff of modern human's lives?
Pretty much, suggest some new studies.
Looking at the growth of prehistoric hunter-gatherer societies, the study authors suggest that population pressure alone may have spurred tool use, art and music, as well as the cooperation essential to civilization.
"The origins of modern human behavior are marked by increased symbolic and technological complexity in the archaeological record," begins the Science journal study led by Adam Powell of University College London.
Modern-looking humans — thin-boned, big-brained and slim-faced — turn up as African fossils that date to about 200,000 years ago. However those folk's tools and decorations — flint blades and shell beads — turn up (and then disappear for millennia) only around 75,000 years ago in Africa and about 45,000 years ago in the Middle East.
Why, ask Powell and colleagues, was there "a delay of some 100,000 years between anatomical modernity and perceived behavioral modernity?" Perhaps the behaviors were the fruit of a long-developing genetic change, suggest researchers such as Stanford University's Richard Klein. Or expansion into new climates outside of Africa may have forced the delay, suggest others.
Powell's team modeled how people develop and transmit skills to one another and set them migrating in a mathematical recreation of the prehistoric "Pleistocene" era that ended 10,000 years ago. The larger the population, the more individuals bump into each other and transmit survival skills, eventually including tools and decorations.
The model's results jibe roughly with the archaeological evidence that there was a cultural upswing in Africa that died out with worsening climate, only to revive there and the Middle East thousands of years later.
