Why would a DNA heritage test say you are from a particular place if that particular place was occupied by multiple other empires historically?

Question

For example, my test came back Sicilian, and British. But both places have had various other countries occupy them in the past.

In: Biology

Answer 1

You’re kind of right in that it’s kind of arbitrary. But if a set of genes are historically found in a specific region, it’s easy to bundle them together and give them an easy name. Like of course there’s Angles and Saxons and Celtic and whatever else combined to make “British”, we just call this whole combination British since it’s a famous and notable distinction. 

If you want to look into it more granularly, you can probably break down what older groups you’re descended from (ie Celtic/Saxon, or Corded Ware, or what percentage Neanderthal you are) but this isn’t interesting or useful to many of their clients