Reconstruction and Comparative Analysis of a Large Late Pleistocene Modern Human Femur From Wajak, Indonesia.

Abstract

Objectives: A largely undescribed Late Pleistocene Homo sapiens femur from Wajak, Java, Indonesia (minimum age, 36.5 ka) is reconstructed. In conjunction with data derived from other fossil specimens, we test whether ecogeographic rules relating body size and shape to climate apply to late Middle to Late Pleistocene East Asian Homo.

Materials and methods: Preserved portions of the Wajak femur were micro-CT scanned and used to reconstruct the whole bone using a sample of modern human femora as a template. Body mass and stature were reconstructed from femoral head breadth and length. Similar data were derived from eight penecontemporaneous (40-28 ka) and five earlier (ca 260-112 ka) East Asian femora or tibiae, spanning a wide latitudinal range. Anthropometric data from 74 living Old World populations were also included in comparisons.

Results: Higher latitude individuals are heavier and relatively wider-bodied than lower latitude individuals in both fossil groups and among modern populations. There is also a temporal decline in body mass and relative body breadth in both latitudinal zones. Stature shows much weaker associations with both climate and time period. The Wajak femur is long (468 mm) and likely male, with an estimated stature of 170.5 cm but a relatively linear body shape, consistent with these patterns.

Discussion: Ecogeographic rules that relate surface area/body mass to temperature appear to apply to East Asian late Middle to Late Pleistocene Homo as well as modern humans. The temporal decline in body mass and breadth may be due to technological changes during the Late Pleistocene.