Expanded Distance-based Phylogenetic Analyses of Fossil Homo Skull Shape Evolution

TL;DR

This study uses phylogenetic geometric morphometrics to analyze fossil and modern skulls, providing new insights into human evolution, archaic introgression, and the identification of distinct lineages, including a potential first lineage of modern humans.

Contribution

It applies expanded distance-based phylogenetic methods to fossil skulls, revealing new evolutionary relationships and lineage distinctions in human prehistory.

Findings

Iwo Eleru skull is a new near-human species.

Qafzeh 9 is confirmed as fully modern.

Evidence of archaic introgression in multiple populations.

Abstract

Analyses of a set of 47 fossil and 4 modern skulls using phylogenetic geometric morphometric methods corroborate and refine earlier results. These include evidence that the African Iwo Eleru skull, only about 12,000 years old, indeed represents a new species of near human. In contrast, the earliest known anatomically modern human skull, Qafzeh 9, the skull of Eve from Israel/Palestine, is validated as fully modern in form. Analyses clearly show evidence of archaic introgression into Gravettian, pre_Gravettian, Qafzeh, and Upper Cave (China) populations of near modern humans, and in about that order of increasing archaic content. The enigmatic Saldahna (Elandsfontein) skull emerges as a probable first representative of that lineage, which exclusive of Neanderthals that, eventually lead to modern humans. There is also evidence that the poorly dated Kabwe (Broken Hill) skull represents a much earlier distinct lineage. The clarity of the results bode well for quantitative statistical phylogenetic methods making significant inroads in the stalemates of paleoanthropology.