Morphométrie géométrique et classification phylogénétique, application à la question de l'origine d'Homo sapiens en Asie

Abstract

The objective of this study was to find out whether or not there is a morphological gap between the fossils living in the last million years discovered in Asia. The geometric morphometric methods were applied to the skulls of 18 specimen Asian fossils dated 6,000 to 1,150,000 years. Landmarks were analyzed by Generalized Procrustes Analysis. Principal component analysis (PCA) and hierarchical classification methods (UPGMA and NJ) were applied to those samples in order to identify homogenous subgroups. The Mahalanobis distances between those subgroups have been calculated. Two phylogenetic analyses have been applied to the quantitative characters: the maximum likelihood approach and a cladistic analysis. A sample of gorilla and chimpanzees was used as the out-group. Classification and PCA analysis identified 2 subgroups in the fossil group: one with an Homo sapiens affinity and the other with an Homo erectus affinity. Both phylogenetic analyses identified Homo erectus as a monophyletic subgroup, but the fossil subgroup with an Homo sapiens affinity are scattered among the extant Homo sapiens. We finally concluded that the fossils belong to 2 different taxa. The first (fossil Homo sapiens) belong to the same taxon than extant Homo sapiens, and the second is attributed to Homo erectus. © 2010 Société d'anthropologie de Paris et Springer-Verlag France.