Migration models of prehistoric postmarital residence.

It has previously been suggested that residential practices can be inferred from within- or between-group analysis of male and female skeletal morphology. Arguments have proceeded from intuitively derived hypotheses about the genetic consequences of drift and migration. In this paper, a formal basis is presented for these hypotheses using modified versions of Wright's island model and the migration matrix method. It is shown that the usual measures of standardized genetic variance or genetic kinship can be decomposed into male, female, and male/female components. The male and female components can in turn be used separately to assess the effect of different residential practices on the population genetic structure of the two sexes. Following upon these models, nonmetric cranial trait data from prehistoric sites in west-central Illinois are used to delineate the probable residential practices for this region.