Well, not really. But here's a feature about a small town in northeastern Argentina which has had several centuries of self-imposed endogamy, resulting in a sharp increase in the incidence of albinism. This sort of thing isn't always a function of conscious custom or tradition, in Consanguinity, Inbreeding, and Genetic Drift in Italy L.L. Cavalli-Sforza documents the rapid drop in inbreeding with the penetration of modern transport into the mountains of Italy. Cavalli-Sforza notes that throughout much of 19th century Europe there were two opposing dynamics; on the one hand the decline in the power of the Catholic Church resulted in an increased frequency of consanguineous marriages (this happened in Protestant countries after the Reformation), but simultaneously more efficient transport increased gene flow across demes and many more people left their villages.

Labels: Genetics