The face of human evolutionary studies that outsiders most commonly see is a nomenclatural thicket pruned by recurrent extinctions. Hypothetical rounds of species succession are so characteristic of paleoanthropology that they often are echoed in novels that use the evolutionary past as settings. Thus William Golding's The Inheritors represents Neanderthals while they are being exterminated by anatomically modern humans, as do Jean Auel's Clan of the Cave Bear (plus its imaginative sequels) and Björn Kurtén's Dance of the Tiger. Works of this sort add a lot of local color and speculative detail to conceptions of phylogeny that date back over a century.

As a result of these works, professional and popular, many nonspecialists believe that the central activity in paleoanthropology consists of argumentation about how many species existed, how many of them lived simultaneously during various time periods, and which ones emerged as survivors while their contemporaries passed into the oblivion of extinction.

These recurrent disagreements make the field appear to be so forbiddingly complex that even scientists in closely allied specialties can feel overwhelmed. This comment is based on my own experience over a period of years with a respected colleague, Paul T. Baker, who now has retired from his position as Professor of Anthropology at the Pennsylvania State University. Paul's area of specialization is the biology of human adaptability. In this realm he has been recognized internationally with various honors, including the Huxley Memorial Medal of the Royal Anthropological Institute.