A New Perspective on Reticulate Evolution of the Genus Homo

Abstract

No consensus exists in human evolution research regarding the definition of genus Homo and its mode of evolution. We address these two questions with an integrated phylogenetic reconstruction approach applied to craniodental characters of 22 hominin species, combining Maximum Parsimony dichotomous tree and Phylogenetic Networks methods. Three Homo most parsimonious tree-based definitions are identified, with cumulative distinguishing feature changes in support of hypothetical last common ancestors highlighted by a novel elliptic representation. We analyze the complexity of the genus Homo evolutionary process by means of a Phylogenetic Networks method, and show its probable web-like reticulate mode of evolution that gave rise to the emergence of the only surviving paleospecies, Homo sapiens, further to the extinctions of preceding archaic human species such as Homo neanderthalensis. Our results confirm a paradigm shift in the study of human evolution in favor of reticulation, in accord with recent findings of introgressive hybridization in paleogenomics.