Common patterns of facial ontogeny in the hominid lineage.

Recent evaluation of Neanderthal and modern human ontogeny suggests that taxon-specific features arose very early in development in both lineages, with early, possibly prenatal, morphological divergence followed by parallel postnatal developmental patterns. Here we use morphometric techniques to compare hominoid facial growth patterns, and show that this developmental phenomenon is, in fact, not unique to comparisons between Neanderthals and modern humans but extends to Australopithecus africanus and to the hominoid lineage more broadly. This finding suggests that a common pattern of juvenile facial development may be more widespread and that the roots of ontogenetically early developmental differentiation are deep-perhaps predating the ape/human split of 6+ million years ago.