Over at The Legal Genealogist (one of my favorite new blogs!), blogger Judy Russell, J.D., CG discusses Ancestry.com’s new autosomal DNA testing service in “Science and the “10th” cousin.”
As I noted in a recent blog post (see “WDYTYA Reveals More Information About Ancestry.com’s New Autosomal DNA Testing“), autosomal DNA testing was featured in the recent episode of Who Do You Think You Are with actor Blair Underwood. After revealing Mr. Underwood’s biogeographical estimates (74% African American and 26% European), they revealed a genetic cousin found in the Ancestry.com’s database:
The service identified a distant cousin (somewhere around the 10th cousin range) who lived in Cameroon (an Eric Sonjowoh). Mr. Sonjowoh was already in the Ancestry.com database, which is why they were able to compare him to Mr. Underwood. According to Eric, someone approached him in 2005 and asked him for his DNA because African Americans were trying to trace their family back to Cameroon. I’m not sure what database the DNA was in, but it shows that Ancestry.com has pre-populated its database with at least some samples from other public and/or proprietary data sources.
Ms. Russell expresses concerns over the identification of the relationship between Mr. Underwood and Mr. Sonjowoh as “1oth Cousins:”
I have a bit of an issue with telling person A (Blair Underwood) that person B (Eric Sonjowoh) is a 10th cousin when there isn’t a prayer of a paper trail to support that statement — and the science isn’t good enough to say it either.
She notes – very correctly – that autosomal testing alone cannot identify a relationship as being 10th cousins rather than anything ranging from 5th, 12th, or 15th cousins, or even beyond.
As you can see from my summary above, I had assumed that the label “10th Cousins” was not intended to be an exact identification of the relationship (I wrote: “somewhere around the 10th cousin range”), but an approximation similar to those used by both 23andMe (for example, “3rd to Distant Cousin”) and Family Tree DNA (for example, “5th Cousin – Remote Cousin”). Unfortunately, it’s difficult to determine from the portion of the user interface we saw in the program whether or not the “10th cousins” applies to a range or is intended to be a more definitive determination.
In any event, I agree with Ms. Russell’s conclusion. It is vital that users of any autosomal DNA testing service understand both the capabilities and limitations of the science, and that testing providers work to educate their customers. It will be interesting to see more of the Ancestry.com user interface when the product officially launches.
Here’s a few links to some other discussion of DNA testing and Ancestry.com’s service following Mr. Underwood’s episode of WDYTYA:
- “Blair Underwood, Who Do You Think You Are?” at tracingthetree;
- “Blair Underwood talks tracing his African roots and ‘Streetcar’ role” at the grio; and
- “Blair Underwood’s African Roots on WDYTYA?” at Ancestor Search Blog.
By the way, a congratulations to Ms. Russell on her recent certification as a Certified Genealogist!
Blaine, you’re far too kind! Thanks for the mention, the congratulations, and most especially for adding your voice to the “make sure you understand what this really says” point here. I really am a DNA junkie (your blog is one of MY favorites) but atDNA can be frustrating far more often than fulfilling. Even suggesting the kind of precision that a “10th cousin” label hints at isn’t fair to the customer. So sez I!