Conditions for Evolution of Small Adult Body Size in Southern Africa.

Human evolution; Body size; Fossils; Stone Age

Discoveries from diverse locales indicate that early Hotno was sometimes petite. Small body size among fossil forms is difficult to explain because its existence in modern human populations is not fully understood. The history, ethnography, genetics, and bioarchaeology of KhoeSan peoples of southern Africa are reviewed in the context of their small adult body size. Since the Middle Stone Age, at least some southern African foragers were petite. Throughout the Later Stone Age (LSA; the Holocene), most groups followed a mobile, coastally oriented foraging strategy that relied on small package size foodstuffs. Distinctive skeletal shape and allometry of LSA adult skeletons provide clues about selective factors. Neither dietary insufficiency nor heat dissipation models of selection apply in the LSA context. Energetics and avoidance of serious accidents may be relevant factors. An aspect of life history—the timing of cessation of growth—has been assessed by comparing dental and skeletal development within juvenile skeletons. After a slow start, LSA child growth shows a tempo like that of modern children and no evidence of early maturation. Among fossil or recent forms, small body size should be assessed not only as possible evidence of selection for smallness but also as evidence of the absence of selection for large body size. [ABSTRACT FROM AUTHOR]