The phylogenetic significance of the Middle Pleistocene Narmada hominin cranium from central India

Abstract

A parsimony analysis of the Narmada cranium from central India and a number of other demes and species of Homo concludes that the Narmada hominin shares a closer relationship with the European Steinheim specimen, than with Asian H. erectus or H. pekinensis. This suggests that the population represented by the Narmada cranium is likely to have had its origins in Europe rather than in Asia. Overall the available evidence supports an 'Out of Africa' scenario, as the early Asian hominins belong to a distinct clade which has no extant descendants and thus appear to represent an evolutionary 'dead end'. The later African and European hominins are defined by a. clade including early H. sapiens from Africa. The main difference between these two distinct clades is that the H. erectus lineage is defined by increasing degrees of neuro-orbital disjunction associated with increased anterior cranial base extension, while the lineage leading to early H. sapiens is characterized by the opposite condition of reduced neuro-orbital disjunction associated with increased anterior cranial base flexion. While there is also evidence of differential patterns of head and neck musculature between these two clades, they are of secondary importance. Preliminary dating of bovid remains found in association with the hominin cranium by the gamma spectrometric U-series dating technique suggests a tentative minimum age of not less than 236,000 years. This is in agreement with evidence from biostratigraphical studies of the Boulder Conglomerate, which place these deposits in the Middle Pleistocene.