Brief communication: Paleoanthropology and the population genetics of ancient genes

The Mezmaiskaya cave mtDNA is similar in many ways to the Feldhofer cave Ne andertal sequence and the more recently obtained Vindija cave sequence. If we accept the contention that the Mezmaiskaya cave specimen is a Neandertal infant, its mtDNA provides no new information about the fate of the Europe an Neandertals. However, there is reason to believe that the Mezmaiskaya ca ve infant is not a Neandertal, and this places its importance in another li ght, because it delimits the possible hypotheses of Neandertal and recent h uman genetic relationships. One possibility is a that the pattern found in ancient mtDNA results from the replacement of an isolated gene pool (Neande rtals) by one of its contemporaries (modern humans). A second possibility i s natural selection expressed as the substitution of an advantageous mtDNA variant within a single large species, including both Neandertals and moder n humans. The geologic, archaeological, and dating evidence shows the Mezma iskaya cave infant to be a burial from a level even more recent than the Up per Paleolithic preserved at the site, and its anatomy does not contradict the assessment that the Mezmaiskaya cave infant is not a Neandertal. Theref ore, the second pattern can be favored over the first. (C) 2001 Wiley-Liss, Inc.