Paleoamerican Morphology in the Context of European and East Asian Late Pleistocene Variation: Implications for Human Dispersion Into the New World

摘要

Early American crania show a differentnmorphological pattern from the one shared by latenNative Americans. Although the origin of the diachronicnmorphological diversity seen on the continents is stillndebated, the distinct morphology of early Americans isnwell documented and widely dispersed. This morphologynhas been described extensively for South America, wherenlarger samples are available. Here we test the hypothe-nses that the morphology of Early Americans results fromnretention of the morphological pattern of Late Pleisto-ncene modern humans and that the occupation of thenNew World precedes the morphological differentiationnthat gave rise to recent Eurasian and Americannmorphology. We compare Early American samples withnEuropean Upper Paleolithic skulls, the East Asian Zhou-nkoudian Upper Cave specimens and a series of 20 mod-nern human reference crania. Canonical Analysis andnMinimum Spanning Tree were used to assess the mor-nphological affinities among the series, while Mantel andnDow-Cheverud tests based on Mahalanobis SquarednDistances were used to test different evolutionary sce-nnarios. Our results show strong morphological affinitiesnamong the early series irrespective of geographical ori-ngin, which together with the matrix analyses resultsnfavor the scenario of a late morphological differentiationnof modern humans. We conclude that the geographicndifferentiation of modern human morphology is a latenphenomenon that occurred after the initial settlementnof the Americas