AncestryDNA’s new Genetic Communities

AncestryDNA Genetic Communities went live this week! What does that mean for my genealogy? (And scroll to the end for something free that expires April 6 2017!)

And what is a Genetic Community, anyway? Well, AncestryDNA defines it as “a group of AncestryDNA members who are connected through DNA most likely because they descend from a population of common ancestors, even if they no longer live in the area where those ancestors once lived.” In fact, the where and when for these clusters is likely where some of your ancestors lived between 1750-1850.

Here’s an example. AncestryDNA tells me one of my sister’s Genetic Communities (or GC) is Irish in Connemara.

Image 1.

Connemara map

When you select that GC from your short list of GCs, a page comes up with two clickable tiles on the left: [Story] and [Connection]. The default view is [Story]: a map on the right (See Image 1, above) and, on the left, a brief chronological narrative of the area, broken into time-periods. Within each period (for example, 1825-1850 Life as a Tenant Farmer), Ancestry offers a paragraph about the time and place, and identifies people from your tree (if any) who lived there at that time.

If you click the [Connection] tile, you see how many people are in this GC (in this example, 18,000) and how many of them are on your DNA match list (in this example, 24). You’ll also get a confidence level: 20-45% is possible, 45-95% is likely, and 95% and above is very likely. Preliminary discussion on social media suggests that all of these seem fairly reliable.

You will certainly have ancestors from other areas that you weren’t assigned to. That can change over time, as Ancestry gets more DNA in their database and as people post and update their trees. (I believe Ancestry does not use surnames in building the geographic clusters, but they do use the places. So putting accurate locations in your trees helps.) And of course, you may have a confirmed line in a geographic area before 1800, but not carry enough DNA from those ancestors to meet the threshold. In any case, the clusters they assigned to you *do* appear to be pretty valid. Expect your results to get even better over time.

On this [Connection] page, there is a list of common surnames for that place and time (not necessarily in your tree) and a tile to click to see those 24 matches who share this GC and DNA with you. See Image 2 for a partial screen shot.

Image 2.


When you do that, you get the subset of your match list that has also been assigned to this GC. From there you can do everything you normally do with your match list. (You can also access this subset directly from your match list, without going through the Ethnicity pages.)

A few notes:

  • Just as ethnicity results between siblings aren’t exactly the same, GC aren’t exactly the same between siblings. See my March 2016 blog post How Irish Are We? for more discussion on that.
  • Most people have 1-2 GCs. Some have more, some have zero. Obviously, many people have ancestors from more than one or two clusters, but there are limits to what AncestryDNA can accomplish, based on DNA and family trees. (For example, I am 1/8th German but have no German GC. Relatively few Germans are testing.)
  • Having zero GC is okay. In my immediate family, my brother and my son have zero, but I have two. Genealogically, my clusters also apply to my brother and my son, even if genetically, their DNA didn’t meet the threshold at this time. I expect their GC may evolve.

How does this help my genealogy?

Some experts have suggested that Genetic Communities may be more reliable than your “ethnicity” report. For people with a completely unknown parent, grandparent, or great-grandparent, this information might be a very useful lead.

For others, it may not tell you anything you didn’t already know. To be honest, if a geographic cluster I’m in is an area my ancestors left before 1800, I don’t imagine it will be very helpful. (I think you need targeted testing and a chromosome browser and more to successfully identify common ancestors that far back.) But even in that case, a GC may be a confirmation of your research. I think it may also interest people new to genealogy into taking DNA tests and (I hope!) interest some enough to reply to messages about exploring matches!

How can we learn more?

For LOTS of technical details, you can read Ancestry’s white paper on Genetic Communities.

This blog post isn’t intended to teach, but I can refer you to someone who can! On Legacy Family Tree Webinars, Blaine Bettinger explains it all very clearly with lots of visual aids. Exploring AncestryDNA’s Genetic communities is free through April 6 2017. After that, you can purchase a digital download, or subscribers may watch for free. Legacy Family Tree subscriptions are $9.95/month of $49.95/year. (Go here to learn more about their offerings.) If you subscribe, check out their huge library of video lessons. There are 25 on DNA alone! But, of course, DNA works hand-in-hand with traditional genealogy, so consider those webinars too.

In conclusion… AncestryDNA’s new Genetic Communities can be fun! They may or may not help you discover something you didn’t know. But they can help confirm your documentary research. And if they interest some distant relative to take a DNA test or to reply to my message, that’s a win in my book!

Ann Raymont (c) 2017


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