The limbic system and human evolution
The authors adduce evidence from the disciplines of paleontology, neuroanatomy, neuropsychology, and clinical neurology to support the hypothesis that significant neural changes associated with the initial development of the Hominidae occurred in the structures of the cerebrum that constitute the limbic system. Specifically, it is suggested: (1) that the functions currently attributable to the limbic system make it the most likely site for neuroanatomical changes to have occurred which would correlate with the social and sexual changes believed to have accompanied human evolution; (2) that the limbic system, as evidence by its connectivity with the neocortex and from clinical neurological studies, plays a role in many of the “higher” cerebral functions considered instrumental to human evolution, e.g. linguistic and mnemonic; (3) that comparisons of size and cellular composition of limbic structures among primates indicate notable differences between human and other primates; and (4) that the hypothesis of major initial modifications in the limbic system as opposed to neocortex is consistent with evidence from australopithecine endocasts indicating cranial volumes within the range of extant pongids.
