THE THERMOREGULATORY ADVANTAGES OF HOMINID BIPEDALISM IN OPEN EQUATORIAL ENVIRONMENTS - THE CONTRIBUTION OF INCREASED CONVECTIVE HEAT-LOSS AND CUTANEOUS EVAPORATIVE COOLING

The thermoregulatory advantages conferred by bipedalism to a large-brained primate on the African savannah could have been significant factors contributing to the adoption of this unusual mode of terrestrial locomotion. Although the major benefit is a dramatic reduction in direct solar radiation exposure, additional advantages also result from the higher distribution of the body surfaces. Windspeeds are higher and air temperatures lower away from the ground, both factors increasing the rate at which a biped dissipates heat by convection. The greater airflow and low relative humidity above any surface vegetation present will also increase the rate at which sweat can be evaporated from the skin. © 1991 Academic Press Limited.