Understanding AncestryDNA Genetic Communities

Recently, AncestryDNA has added over 300 new genetic communities. Here’s what they are and why they matter.

 
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AncestryDNA test results give you two different kinds of information in your DNA Story: your ethnicity results and genetic communities. We talk regularly about DNA ethnicity results: where they come from, what they mean and why they keep evolving. But in the wake of hundreds of new genetic communities recently added by AncestryDNA, I think it’s time to remind everyone what THESE mean and how they might help your genealogy research.

AncestryDNA genetic communities

Genetic communities are “clusters of living individuals [who] share large amounts of DNA due to specific, recent shared history,” explains an AncestryDNA white paper on the topic. “For example, we identify groups of customers that likely descend from immigrants participating in a particular wave of migration (e.g. Irish fleeing the Great Famine), or customers that descend from ancestral populations that have remained in the same geographic location for many generations (e.g. the early settlers of the Appalachian Mountains).”

The company uses the genes you have in common with others to assign you to various ancestral genetic communities. Then they assign places to each of those clusters by drawing on both the ethnicity data and family trees of everyone assigned to that cluster. Once they get enough data on a particular community, they can confidently say something like, “What these testers all have in common is that they descend from Irish immigrants who came to the United States during the famine of the mid-1800s.”

New European genetic communities

 

As the company gradually amasses more data from its more than 15 million testers (and growing!), they periodically add new genetic communities.

 

About a month ago, new communities were announced for those connected to France, Canada, the United Kingdom, Australia and New Zealand. There are more than 35 new French American communities; over 120 new Canadian communities (which encompass British, French and Acadian roots); 73 new United Kingdom communities; and 14 communities “for descendants of primarily British settlers in Australia and New Zealand.” The time frame for these communities ranges from the past 75-300 years.

African-descent genetic communities

In February 2019, Ancestry also added 94 African American and Afro-Caribbean communities: clusters that can help identify migratory groups active between about 1700 and 1950. Researching African descent in the United States and Caribbean can be challenging. Far fewer African ancestors are mentioned by name in historical documents. Forced migrations and family separations during slavery compounds the difficulties of reconstructing these family trees. Furthermore, major migration in the early 1900s removed many African Americans from their birthplaces in the South: one more step removed from the more distant past.

 
Overview of all AncestryDNA African American communities from 1925-1950. This image shows the exodus of many African Americans from the South to areas in the North and West. This event is commonly known as the Great Migration. Source:  Ancestry.com .

Overview of all AncestryDNA African American communities from 1925-1950. This image shows the exodus of many African Americans from the South to areas in the North and West. This event is commonly known as the Great Migration. Source: Ancestry.com.

 

These are just the most recent additions. Ancestry has identified more than 500 genetic communities. Use them to make educated guesses about the geographic origins of a partly-known group of ancestors. Or explore them to discover something about unknown branches of your tree.