Comparing Intergenerational Genetic Communities

It looks like April is when I get the blogging bug; sorry again for another lengthy absence! Right now I’m anxiously awaiting the release of Family Tree Maker 2017 and while so doing thought I would explore AncestryDNA’s new Genetic Communities feature.

There are plenty of people more qualified than myself who have written (and presented) about this new feature so I suggest you check out blog posts by Roberta Estes and Dr. Blaine Bettinger (as well as his excellent webinar at Family Tree Webinars which is free to view through April 6th) if you haven’t already. For a deeper delve into the science you can also read the article in Nature Communications by the AncestryDNA team.

I’m very fortunate that I have had both of my grandfathers do their autosomal DNA testing so I’m able to compare their results to mine. My paternal grandfather has 3 Genetic Communities and my maternal grandfather has 2. I am apparently anomalous in that I have 5 Genetic Communities so far. However, the “connection” confidence for 4 of the 5 is only 20% (in the “Possible” category), with 1 being at 40%:

My Genetic Communities list

I thought I would take a leaf out of Roberta Estes’ book and make a chart showing my ancestors’ years and places of birth to see if we can narrow down where some of these community results come from:

You can see from all of the “unknowns” that I have a lot of work still to do on my family tree, but here are some of the most common locations:

  • Illinois: 17
  • Wisconsin: 8
  • Tennessee: 7
  • Germany: 6
  • New York: 6
  • Norway: 4
  • North Carolina: 4

There are several people for whom I can guess their place of birth (mostly the parents of people I know were born in Norway). So here’s how my communities match up with my known places of birth.

Norwegians in Østlandet

Initial screen showing the Norwegians in Østlandet genetic community

My most confident community is “Norwegians in Østlandet“. I’ve got an upcoming post that delves more deeply into my Norwegian roots (at least one branch of them) and that jives with the locations I’ve discovered, specifically in the county of Oppland on my father’s side.

This is the only Genetic Community I share with my paternal grandfather (actually, the only one I share with either grandparent), and you can see our confidence levels vary wildly:

I have a 40% confidence level

My paternal grandfather has a 95% confidence level

In addition to the massive confidence level difference, only 66 of my DNA matches share this GC whereas my grandfather has 374 of his DNA matches in this community. That makes sense considering that my known Norwegian ancestors are all on his side starting with his grandfather, so he shares more DNA with those ancestors than I do.


In this particular community, the historical breakdowns don’t really follow my ancestors’ experiences. Instead of staying in the midwest and farming, or moving to large cities, my ancestors moved further west to the Dakotas and eventually even further north into western Alberta and eastern British Columbia. The variation is understandable given that these snapshots are only intended to discuss the “typical” experience for these people but it doesn’t correlate as closely to my ancestors as I might have hoped.

Interestingly, one of my paternal grandfather’s other Genetic Communities is Central Norwegians, which also includes the fylke of Oppland:

My paternal grandfather also shows a Central Norwegian GC with 20% confidence and 138 shared matches

I still have a lot more work to do to figure out who the rest of my Norwegian ancestors are so time will tell what other counties/fylkes they lived in and what is the most accurate GC.

Early Settlers of the Northeast

Although the only exact GC I share with either grandparent is the abovementioned “Norwegians in Østlandet”, my maternal grandfather has a GC that overlaps but is more specific than mine. I have a 20% confidence level for the “Early Settlers of the Northeast” while my grandfather has a 20% confidence level for “Settlers of Rhode Island and Southeastern Massachusetts”:

I have a 20% confidence (“likely” range)

My maternal grandfather has a 20% confidence level for the more specific GC

I know that my 2nd great grandmother (my grandfather’s grandmother) was Julia Augusta “Gussie” Tanner (wife of Carl Johann Schultz) whose ancestor Joshua Tanner I am in the process of joining the DAR through. Joshua was born in Rhode Island in 1757, and since this is an ancestor on my maternal grandfather’s line it makes sense that his GC is more specific than mine because he has more of that DNA from those ancestors than I do.


Interestingly, my maternal grandfather’s only other GC is “Mormon Pioneers in the Mountain West”, which has a 95% confidence level:

A very strong connection and 174 shared matches

This is through the same Tanner line, specifically Joshua’s son John Tanner who was a major financial backer of Joseph Smith and the Mormons. He traveled west with them all the way to Utah where he died in 1850. This is an especially interesting history for me since I grew up in the RLDS church but never knew this about my own family.

Take aways

Overall I’m finding exploring these communities to be very interesting. I am disappointed that I so far don’t have any communities in Germany or Eastern Europe, which is one of the places I’m stuck in my research currently. However, I just had my father do a DNA test and I’m hoping to have my mother do one soon, too, so hopefully their matches will help me triangulate and corroborate some of my theories, especially regarding the ancestors who match up with my other GCs in the south (I’m assuming most of those are on my father’s mother’s side).

I do hope that as this Genetic Communities tool continues to be improved that we will be able to have much narrower/more specific geographic results. For now, it is a neat tool to visualize geographic relationships in your genetic results.

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