How reliable is our genealogy evidence? We ask that question about evidence we mine from documents. When we use DNA, we should consider the reliability of our genetic evidence too.
If you watch much TV, you’ve probably seen the Ancestry commercial in which a man’s DNA results contradict his family tradition of a German heritage, so he trades in his lederhosen for a kilt! The irony is, no matter how German you may be, if you test at Ancestry, you won’t get German as a result in your ‘ethnicity’ pie chart; it’s not one of the categories they offer! (See, perhaps, a more generic ‘Western European’ as one possible alternative.)
Many genetic genealogists have written about how imprecise these predictions are within the continent of Europe. For example, see The Legal Genealogist Judy Russell’s blog post Those percentages if you must. Those estimates may be more reliable, however, in suggesting where some of your ancestors might have lived in the past 200 years or so.
Among DNA testing companies, 23andMe offers a unique chromosome tool to explore our biogeographic origins. It’s probably most valuable for people with ancestors from different continents, but I am going to create a lederhosen vs. kilt challenge for myself and more closely examine 23andMe’s identification of German/French roots in my DNA.
Starting off the new year with a new citizen.science post!
Has it ever crossed your mind that part of genetic genealogy is a little bit like The Big Bang Theory?
“The best laid schemes o’ mice an’ men / Gang aft agley”, as the poet [Robert Burns] says.
In other words, herein lies what worked in my project to identify a good cM threshold for “false positives”… and what didn’t.