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, andRhinopithecus) during the Pleistocene and Holocene in China indicates that the geographical ranges of individual genera shifted independently of one another in response to conditions of increasing seasonality. All genera examined saw their distributions shift southward, with the shifting subtropical and tropical zones, during the Pleistocene. This occurred earlier in the 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 brain as well as those of an absolutely larger body. Monkeys were somewhat less affected and their greater relative success is attributed to their abilities to survive in more highly seasonal environments by exploiting a wider variety of plant foods and to produce offspring more quickly, thanks to shorter gestation times and shorter interbirth intervals.