Scientific American
Adam Rutherford
Oct. 15, 2018
Excerpt:
When it comes to ancestry, DNA is very good at determining close family relations such as siblings or parents, and dozens of stories are emerging that reunite or identify lost close family members (or indeed criminals). For deeper family roots, these tests do not really tell you where your ancestors came from. They say where DNA like yours can be found on Earth today. By inference, we are to assume that significant proportions of our deep family came from those places. But to say that you are 20 percent Irish, 4 percent Native American or 12 percent Scandinavian is fun, trivial and has very little scientific meaning. We all have thousands of ancestors, and our family trees become matted webs as we go back in time, which means that before long, our ancestors become everyone’s ancestors. Humankind is fascinatingly closely related, and DNA will tell you little about your culture, history and identity.
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https://www.scientificamerican.com/article/how-accurate-are-online-dna-tests/
