Hominids and hybrids: The place of Neanderthals in human evolution

As the first extinct human relatives to have become known to science, the Neanderthals have assumed an almost iconic significance in human evolutionary studies: a significance that has, of course, been greatly enhanced by the very substantial fossil and behavioral record that has accumulated since the original Feldhofer Cave skullcap and partial skeleton were accidentally uncovered, on a pre-Darwinian August day in 1856, by lime miners working in Germany’s Neander Valley (1–3). Yet even now, 14 long decades later, paleoanthropological attitudes toward the Neanderthals remain profoundly equivocal. Thus, although many students of human evolution have lately begun to look favorably on the view that these distinctive hominids merit species recognition in their own right as Homo neanderthalensis (e.g., refs. 4 and 5), at least as many still regard them as no more than a strange variant of our own species, Homo sapiens (6, 7). This difference represents far more than a simple matter of taxonomic hair-splitting. For, as members of a distinct species, of a completely individuated historical entity, the Neanderthals demand that we analyze and understand them on their own terms. In contrast, if we see them as mere subspecific variants of ourselves, we are almost obliged to dismiss the Neanderthals as little more than an evolutionary epiphenomenon, a minor and ephemeral appendage to the history of Homo sapiens.

Any new information bearing on this matter is therefore extremely welcome, and there is no doubt that the claims advanced in this issue of the Proceedings by Duarte et al. (8) will be closely scrutinized by their colleagues. Briefly, Duarte et al. propose that the skeleton of a 4-year-old child, recently unearthed at the 24,500-year-old (24.5 kyr-old) site of Lagar Velho in Portugal, represents not merely a casual result of a Neanderthal/modern human mating, but rather …