THE RESPONSE OF CATARRHINE PRIMATES TO PLEISTOCENE ENVIRONMENTAL FLUCTUATIONS IN EAST-ASIA

Examination of the patterns of distribution for five catarrhine genera (Gigantopithecus, Pongo, Hylobates, Macaca, and Rhinopithecus) during the Pleistocene and Holocene in China indicates that the geographical ranges of individual genera shifted independently of one another in r esponse to conditions of increasing seasonality. All genera examined s aw their distributions shift southward, with the shifting subtropical and tropical zones, during the Pleistocene. This occurred earlier in t he Pleistocene for the larger apes, and later for smaller forms. This apparent paradox is readily explained by the inability of large-bodied apes to satisfy the high metabolic demands of a relatively large brai n as well as those of an absolutely larger body. Monkeys were somewhat less affected and their greater relative success is attributed to the ir abilities to survive in more highly seasonal environments by exploi ting a wider variety of plant foods and to produce offspring more quic kly, thanks to shorter gestation times and shorter interbirth interval s.