Techniques for estimating genetic admixture and applications to the problem of the origin of the Icelanders and the Ashkenazi Jews.

A method is introduced for simultaneously using multiple loci to estimate admixture and test goodness of fit of the model of admixture. Deviation of observed frequencies from expectation caused by sources of error such as sampling and/or drift is allowed for all loci in all populations. This allows investigation of the effects of different assumptions about sources of error on the estimates. Admixture is then investigated for Icelanders and Ashkenazi Jews. Results indicate that the Icelanders have a large Norse contribution, and that the Jews may have a small to moderate contribution from the European gene pool. There are some indications that AB0 and G6PD give abnormal estimates of admixture compared to other loci, and that the Jewish gene pool may be derived from additional populations in addition to the populations considered.