What’s Endogamy?
Endogamy is when our ancestral communities intermarried a LOT over time. Maybe they were geographically isolated, such as an island community. Maybe they just stuck together due to culture by religion, marrying within the faith.
If you descend from such a community, you’ll likely have DNA matches who aren’t the “real” cousins they appear to be. They just share DNA from your common ancestral group.
Examples of endogamous groups include Jews, Polynesians, Low German Mennonites, the Amish, Acadians or Cajuns (French settlers in what is now Nova Scotia, Canada), French Canadians, people from many Arab countries, people from Newfoundland and people from many islands. Endogamy is also a problem in early Colonial American populations.
The interpretation of DNA results from endogamous populations can be particularly challenging because such people will typically have large numbers of matches in the DNA databases.
The interpretation of autosomal DNA matches can be particularly difficult, especially in the case of endogamous populations where the pedigrees cannot be traced back beyond the 1800s. The relationships will often be more distant than predicted.
