History can help understand DNA ethnicity profiles: an example #dna


Joseph Walder
 

A non-Jewish friend has great-grandparents who came from Sweden (maternal side) and Germany (paternal side). The latest iteration of her DNA ethnicity profile from Ancestry indicates a Swedish component approaching 75% and a German component of only a few percent. This result seems baffling until one considers an important detail: the German ancestors came from the region of Pomerania, that is, from along the south shore of the Baltic Sea. Pomerania (which with post-1945 borders is now mainly Polish territory) was only incorporated into the Germanic world in about the 15th century. The population along the south shore of the Baltic at that time was a mixture of Slavs, Balts, Finnic peoples, and Swedes--and indeed the friend's Ancestry DNA profile indicates greater Slavic, Baltic and Finnic contributions than Germanic. A plausible interpretation is that her German great-grandparents were the descendants of non-Germanic people who assimilated to German culture and language several centuries ago.

To the extent that Ashkenazi Jews intermarried with and assimilated non-Jews, the surprises that some Jews find in their DNA ethnicity profiles are, well, unsurprising.

Populations have always mixed with each other. Geography, culture and language cannot be simply superposed on one another. History can provide very useful guidelines for interpreting DNA profiles.

Joseph Walder
Portland, Oregon
j


Join main@groups.jewishgen.org to automatically receive all group messages.