THE INFLUENCE OF BIPEDALISM ON THE ENERGY AND WATER BUDGETS OF EARLY HOMINIDS

A model is described for estimating the net thermal loads, and associated demands for drinking water, experienced by bipedal and quadrupedal hominids in open equatorial environments. Comparisons of the results obtained with the thermoregulatory capabilities of living primates indicate that the equatorial African savannah would have been a difficult habitat for hominoids to exploit. However, under all temperature regimes examined distinct advantages would have been conferred by bipedalism, allowing hominids to forage at higher temperatures and over greater distances, while consuming less food and water, than quadrupeds. © 1991 Academic Press Limited.