4 ms·

I was born in Alabama. Growing up, I was repeatedly told that I was 1/256 Cherokee; this was supposedly the source of my mother's high cheekbones. When I got

I was born in Alabama. Growing up, I was repeatedly told that I was 1/256 Cherokee; this was supposedly the source of my mother's high cheekbones. When I got my 23andMe results, they showed 0% Native American, and .4% African. Well, .4% is of course just about 1/256. I believe the 23andMe result. I believe that the Cherokee thing was just a cover story concocted at some point to hide the fact that one of my family's ancestors was an African slave. And I think the outcome demonstrates that the 23andMe analysis is, in fact, pretty accurate. So when I read that some guy came out a whopping 14% African and wants to put it down to statistical error, I just laugh.

incompatible 9y ago
Once you go back 4 generations or so, the chance of inheriting no genes at all from a particular ancestor becomes quite high. The other interesting scientific result I've read is that there's more genetic variation within the traditional "races" than between them. I put "races" in quotations at this point because the whole concept is somewhat meaningless. There are certain genes that are more common in different groups. But if I understand it correctly, you'll be able to find people from a different "race" who are more genetically similar to you than some people from your own "race".
khawkins 9y ago
But if the results are generally unreliable, everything is open to one's own interpretation. In the article, they quote an genealogy expert who says the science is "murky": >J. Scott Roberts, an associate professor at the University of Michigan, who has studied consumer use of genetic tests and was not involved with the study, said the companies tend to be reliable at identifying genetic variants. Interpreting them in terms of health risk or ancestry, though, is another story. “The science is often murky in those areas and gives ambiguous information,” he said. “They try to give specific percentages from this region, or x percent disease risk, and my sense is that that is an artificially precise estimate.” I assume you're comfortable with the idea that you're descended from a slave and thus have chosen to override prior evidence to the contrary. But if you weren't comfortable with the idea, you can say the test is flawed and have just as powerful an argument. Unless 23andMe can show statistical rigor behind their methods, everyone is going to see what they want in the results.

incompatible 9y ago

Once you go back 4 generations or so, the chance of inheriting no genes at all from a particular ancestor becomes quite high. The other interesting scientific result I've read is that there's more genetic variation within the traditional "races" than between them. I put "races" in quotations at this point because the whole concept is somewhat meaningless. There are certain genes that are more common in different groups. But if I understand it correctly, you'll be able to find people from a different "race" who are more genetically similar to you than some people from your own "race".

khawkins 9y ago

But if the results are generally unreliable, everything is open to one's own interpretation. In the article, they quote an genealogy expert who says the science is "murky": >J. Scott Roberts, an associate professor at the University of Michigan, who has studied consumer use of genetic tests and was not involved with the study, said the companies tend to be reliable at identifying genetic variants. Interpreting them in terms of health risk or ancestry, though, is another story. “The science is often murky in those areas and gives ambiguous information,” he said. “They try to give specific percentages from this region, or x percent disease risk, and my sense is that that is an artificially precise estimate.” I assume you're comfortable with the idea that you're descended from a slave and thus have chosen to override prior evidence to the contrary. But if you weren't comfortable with the idea, you can say the test is flawed and have just as powerful an argument. Unless 23andMe can show statistical rigor behind their methods, everyone is going to see what they want in the results.