Radiator Theory

A theory that explains how the human brain evolved from a 500-gram chimpanzee-like brain in early hominids to the current size of ± 1400 gram in less than 2 million years—a very short time span in evolutionary biology. Per Falk’s theory, selection for habitual bipedalism in early hominids necessitated a reconfiguration of the cranial vascular supply in response to changes in hydrostatic pressure. The critical event that allowed Australopithecus (and not Parathropus) to survive bipedalism was development of the emissary venous network