Functional craniology, human evolution, and anatomical constraints in the neanderthal braincase

Abstract

Neanderthals and modern humans share a similar cranial capacity but different neurocranial organization. Recently, digital anatomy and computed morphometrics have generated a revolution in functional craniology, allowing quantitative analyses to investigate integration and correlation among the anatomical elements, both in ontogeny and phylogeny. Despite some derived endocranial traits, Neanderthals display a general plesiomorph organization of the braincase. Geometrical and structural constraints between the endocranial soft and hard tissues may have induced morphogenetic limits to the growth and developmental processes. At the same time, heat production associated with a large cranial capacity and a plesiomorph vascular system may have also involved thermal limits. Although in paleontology morphogenetic and metabolic processes can only be investigated through indirect evidence, such hypotheses merit attention when considering the patterns of brain evolution in the genus Homo. It is tempting to wonder whether these limits may be also related to possible factors associated with the extinction of Neanderthals.