How we became in human

How we came to be

SOME 28,000 YEARS AGO this 60-year-old man was given an elaborate burial, rife with implications of ceremonial practices and of abstract belief. He was interred with rich grave goods and was wearing bracelets, necklaces, pendants, and a tunic on which hundreds of mammoth-ivory beads had been sewn. Along with two juvenile burials from the same site— Sungir in Russia— this isone of the earliest and most resplendent examples of human burials found in Europe.

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SCIENTIFIC AMERICAN

DECEMBER 2001

Copyright 2001 Scientific American, Inc.

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Book Excerpt

HUMAN
The acquisition of language and the capacity for symbolic art may lie at the very heart of the extraordinary cognitive abilities that set us apart from the rest ofcreation

by Ian Tattersall

W

hen we contemplate the extraordinary abilities and accomplishments of Homo sapiens, it is certainly hard to avoid a first impression that there must somehow have been an element of inevitability in the process by which we came to be what we are. The product, it’s easy to conclude, is so magnificent that it must stand as the ultimate expression of a lengthy andgradual process of amelioration and enhancement. How could we have got this way by accident? If we arrived at our exalted state through evolution, then evolution must have worked long and hard at burnishing and improving the breed, must it not? Yet that seems not to be how evolution works; for natural selection is not— it cannot be— in itself a creative process. Natural selection can only work topromote or eliminate novelties that are presented to it by the random genetic changes (influenced, of course, by what was there before) that lie behind all biological innovations. Evolution is best described as opportunistic, simply exploiting or rejecting possibilities as and when they arise, and in turn, the same possibility may be favorable or unfavorable, depending on environmental circumstances(in the broadest definition) at any given moment. There is nothing inherently directional or

inevitable about this process, which can smartly reverse itself any time the fickle environment changes. Indeed, as we’ll see a little later, perhaps the most important lesson we can learn from what we know of our own origins involves the significance of what has in recent years increasingly been termed“exaptation.” This is a useful name for characteristics that arise in one context before being exploited in another, or for the process by which such novelties are adopted in populations. The classic example of exaptation becoming adaptation is birds’ feathers. These structures are essential nowadays to bird flight, but for millions of years before flight came along they were apparently used simply asinsulators (and maybe for nothing much at all before that). For a long time, then, feathers were highly useful adaptations for maintaining body temperatures. As adjuncts to flight, on the other hand, they were simply exaptations until, much later, they began to assume an adaptive role in this new function, too. There are many other similar examples, enough that we can’t ignore the possibility thatmaybe our vaunted cognitive capacities originated rather as feathers did: as a very much humbler feature than they became, perhaps only marginally useful, or even as a by-product of something else.

Excerpted from The Monkey in the Mirror, by Ian Tattersall, © 2002 by Ian Tattersall, published by Harcourt, Inc.

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SCIENTIFIC AMERICAN

57

Copyright 2001 Scientific American,Inc.

Let’s look at this possibility a little more closely by starting at the beginning. When the first Cro-Magnons arrived in Europe some 40,000 years (kyr) ago, they evidently brought with them more or less the entire panoply of behaviors that distinguishes modern humans from every other species that has ever existed. Sculpture, engraving, painting, body ornamentation, music, notation,...