DNA can tell us all kinds of things.
Genetic information can be used to uniquely identify a specific person using just a hair or a few drops of saliva. That data can also tell you if you have certain genetic ailments or are at an increased risk for others.
But one of the most common services provided by companies who do consumer DNA testing is an analysis of your "ancestry" based on your genetics, and there are real problems with that idea, geneticist Manolis Dermitzakis argued in a Reddit AMA question-and-answer session on November 17.
The University of Geneva genetics professor criticized attempts to pin down both "ancestral ethnicity" and "race" based on DNA.
That's because these things are concepts or ideas that humans have created, and they don't have a basis in genetics, according to Dermitzakis.
Genes can identify a person and find related people, but there's no genetic meaning of race or even ancestry — just because DNA can say you are related to a large number of people who live in a place doesn't mean you are...