TOWARD A LIFE-HISTORY OF THE HOMINIDAE

Two new developments promise to greatly improve our ability to reconst ruct the evolution of the human life cycle: 1. the introduction of the comparative methodology of life history into anthropology and 2. rese arch on bone and dental development that reveals a world of life histo ry preserved in the fossil record. Comparative study suggests that the human strategy depends on rich energy sources and low mortality and t hat our general rate of growth and aging evolved in parallel with brai n size. It now appears that the australopithecines were a substantiall y primitive grade of hominid with life histories more like apes than h umans. The life cycle of early Homo erectus was probably unlike any li ving hominoid: Evidence suggests that it grew up somewhat faster than living humans, it lacked an adolescent growth spurt, and H. erectus in fants were more helpless than those of chimpanzees (but conceivably of more mature body proportion and motor advancement than our own). The appearance of fully modern life histories is still not fully resolved: Early Pleistocene Homo probably did not share them, and late Pleistoc ene hominids probably did, but life history is still little documented in the intervening million years. Although many details remain to be uncovered, the combination of advancing method and theory should soon lead to more robust models of human origins.