The Origin of Humankind Read Free

as these two species are now man’s nearest allies, it is somewhat more probable that our early progenitors lived on the African continent than elsewhere.
    We have to remember that when Darwin wrote these words no early human fossils had been found anywhere; his conclusion was based entirely on theory. In Darwin’s time, the only known human fossils were of Neanderthals, from Europe, and these represent a relatively late stage in the human career.
    Anthropologists disliked Darwin’s suggestion intensely, not least because tropical Africa was regarded with colonial disdain: the Dark Continent was not viewed as a fit place for the origin of so noble a creature as Homo sapiens . When additional human fossils began to be discovered in Europe and in Asia at the turn of the century, yet more scorn was heaped on the idea of an African origin. This attitude prevailed for decades. In 1931, when my father told his intellectual mentors at Cambridge University that he planned to search for human origins in East Africa, he came under great pressure to concentrate his attention on Asia instead. Louis Leakey’s conviction was based partly on Darwin’s argument and partly, no doubt, on the fact that he was born and raised in Kenya. He ignored the advice of the Cambridge scholars and went on to establish East Africa as a vital region in the history of our early evolution. The vehemence of anthropologists’ anti-Africa sentiment now seems quaint to us, given the vast numbers of early human fossils that have been recovered in that continent in recent years. The episode is also a reminder that scientists are often guided as much by emotion as by reason.
    Darwin’s second major conclusion in The Descent of Man was that the important distinguishing features of humans—bipedalism, technology, and an enlarged brain—evolved in concert. He wrote:
    If it be an advantage to man to have his hands and arms free and to stand firmly on his feet, ... then I can see no reason why it should not have been more advantageous to the progenitors of man to have become more and more erect or bipedal. The hands and arms could hardly have become perfect enough to have manufactured weapons, or to have hurled stones and spears with true aim, as long as they were habitually used for supporting the whole weight of the body ... or so long as they were especially fitted for climbing trees.
    Here, Darwin was arguing that the evolution of our unusual mode of locomotion was directly linked to the manufacture of stone weapons. He went further and linked these evolutionary changes to the origin of the canine teeth in humans, which are unusually small compared to the dagger-like canines of apes. “The early forebears of man were ... probably furnished with great canine teeth,” he wrote in The Descent of Man; “but as they gradually acquired the habit of using stones, clubs, or other weapons for fighting with their enemies or their rivals, they would use their jaws and teeth less and less. La this case, the jaws, together with the teeth, would become reduced in size.”
    These weapon-wielding, bipedal creatures developed a more intense social interaction, which demanded more intellect, argued Darwin. And the more intelligent our ancestors became, the greater was their technological and social sophistication, which in turn demanded an ever-larger intellect. And so on, as the evolution of each feature fed on the others. This hypothesis of linked evolution was a very clear scenario of human origins, and it became central to the development of the science of anthropology.
    According to this scenario, the original human species was more than merely a bipedal ape: it already possessed some features we value in Homo sapiens . The image was so powerful and plausible that anthropologists were able to weave persuasive hypotheses around it for a very long time. But the scenario went beyond science: If the evolutionary differentiation of humans from apes was both abrupt and