File <>diamond.htm> Index <American Archeology>

2005 Brief Summary of the Origin of Humans, Homo sapiens

A excellent summary of the origins of humans was presented by Jared Diamond (The Shape of Africa, National Geographic Mag. Sept. 2005, p. xxx):.”… As to its human history, this is the place where some seven million years ago the evolutionary lines of apes and protohumans diverged. It remained the only continent our ancestors inhabited until around two million years ago, when Homo erectus expanded out of Africa into Europe and Asia. Over the next 1.5 million years the populations of those three continents followed such different evolutionary courses that they became distinct species. Europe’s became the Neanderthals, Asia’s remained Homo erectus, but Africa’s evolved into our own species, Homo sapiens. Sometime between 100,000 and 50,000 years ago our African ancestors underwent some further profound change. Whether it was the development of complex speech or something else, such as a change in brain wiring, we aren’t sure. Whatever it was, it transformed those arly Homo sapiens into what paleoanthropologists call “behaviorally modern” Homo sapiens. Those people, probably with brains similar to our own, expanded again into Europe and Asia. Once there, they exterminated or replaced or interbred with Neanderthals and Asia’s hominids and became the dominant human species throughout the world.”

“In effect, Africans enjoyed not just one but three huge head starts over humans on other continents. That makes Africa’s economic struggles today, compared with the successes of other continents, particularly puzzling. It’s the opposite of what one would expect from the runner first off the block. Here again geography and history give us answers.”

“It turns out that the rules of the competitive race among the world’s humans changed radically about 10,000 years ago, with the origins of agriculture. The domestication of wild plants and animals meant our ancestors could grow their own food instead of having to hunt or gather it in the wild. That allowed people to settle in permanent villages, to increase their populations, and to feed specialists— inventors, soldiers, and kings— who did not produce food. With domestication came other advances, including the first metal tools, writing and state societies.”

“The problem is that only a tiny minority of wild plants and animals lend themselves to domestication, and those few are concentrated in about half a dozen parts of the world. As every schoolchild learns, the world’s earliest and most productive farming arose in the Fertile Crescent of southwestern Asia, wheat, barley, sheep, cattle, and goats were domesticated. While those plants and animals spread east and west in Eurasia, in Africa they were stopped by the continent’s north-shout orientation. Crops and livestock tend to spread much more slowly from north to south than from east to west, because different latitudes require adaptation to different climates, seasonality, day lengths, and diseases. Africa’s own native plant species—sorghum, oil palm, coffee, millets, and yams—weren’t domesticated until thousands of years after Asia and Europe had agriculture. And Africa’s geography kept oil palm, yams and other crops of equatorial Africa from spreading into southern Africa’s temperate zone. While South Africa today boasts the continent’s richest agricultural lands, the crops grown there are mostly northern temperate crops, such as wheat and grapes, brought directly on ships by European colonists. Those same crops never succeeded in spreading south through the thick tropical core of Africa.”