A Physical Anthropologist's View of the Peopling of the New World

Abstract

The putatively ancient New World skeletons thus far recovered show the presence of only modern man over a period of about 20,000 years. Already before that time related varieties existed in eastern Asia. When the first Asiatics crossed Bering Strait into America, they entered a huge cul-de-sac offering every variety of environment and no forerunners to mix with. A reconstruction of what happened thereafter takes into account that the resulting population at the time of discovery constituted a major isolate that was homogeneous, both phenotypically and genotypically. It is contended that such homogeneity is not consistent with the passage of a long period of time following the establishment of the first beachhead, because the hemisphere offered ideal conditions for the action of selection and drift, the two main agencies responsible for genetic changes in populations. It follows from this that the first beachhead was established by modern man.