Old colony Mennonites in Mexico: Migration and inbreeding

Abstract

Among Canadian Mennonites whose ancestors left Flanders in the sixteenth century, one group separated as the Old Colony and part migrated in the 1920's from Canada to Mexico, where they constitute a large inbred isolate. In 1967, survey data including migration histories were collected on one‐third of the households in one subdivision, the “M Colony.” Church records were copied that gave vital statistics and surnames of almost all families in the Colony since the migration. Recent migration patterns show marriage restricted by distance and 37 per cent of resident married men remaining in their village of birth; but male migration history for those who migrate within the M Colony shows almost no effect of distance. Analysis of surnames gives an estimate of cumulative inbreeding of F = 0.0096, which is consistent with the individually estimated components, namely, founder effect, historical population constrictions, and slow genetic drift.