27. The Middle Pleistocene Record

On the Ancestry of Neandertals, Modern Humans and Others  

Summary

Late Pleistocene Neandertals, so-called “Cro-Magnons,” as well as earlier Homo erectus, had been identified as early as the late 19th century. Primarily, these fossils share some derived characteristics with later humans, in particular a large brain size. Recognizing the identity of the Neandertal lineage has been paramount in the re-interpretation of Middle Pleistocene hominins. Two models have been proposed for the emergence of the Neandertal phenotype. The first model proposes that, before MIS 8 or 7, a quite distinct and stable hominin phenotype assigned to a distinct species (Homo heidelbergensis) can be identified. A second model purports that the emergence of the Neandertal morphology results from an “accretion” of derived features throughout the whole second half of the Middle Pleistocene and possibly starting shortly after the separation of the populations ancestral to Neandertals from their African counterparts.