The Study of Racialism

kpauljohnson · Posted: Wed 14 Oct 2009 19:17 Post subject: 23andme results and comments

Several months back the question was raised about various autosomal tests. I just got results from the fifth such test I've taken, but as with the previous ones they raise as many or more questions than they answer.

The Ancestry Painting result from 23andme.com was 99% European, 1% African, based on a half-million snps. The only percentage-based results I had gotten previously were from DNAPrint; the first version of the test gave an MLE of 100% European based on 75 markers but the second yielded 94% European, 6% East Asian based on 173. Given the vastly greater number of markers involved with 23andme, my inclination is to assume that this is far more reliable than the DNAPrint results, and settles the question. It's quite impressive to see the color-coded scheme showing precisely where the European and African markers are located. When I started out years ago with lots of oral history about Indian blood in the family but finding only "free mulatto" ancestors documented as nonwhite, this was just the result I expected.

But since then, after the 6% East Asian estimate from DNAPrint's AncestrybyDNA, I took their EuroDNA test which reported Most Likely Estimates of 57% Northern European, 35% Mediterranean, 8% South Asian, which made me think that perhaps my "mulatto" ancestors were really Gypsy or East Indian. That suspicion got stronger when I took the DNATribes test, which with only 25 markers yielded matches that underscored the likelihood of Mediterranean and South Asian ancestry and again came up empty on Native American or subSaharan African both of which were much much lower. Four of the top seven Native Population matches were in Italy, with two more in North Africa and one in Romania. When broken down into 36 World Regions matches, over half my match scores were below 1 including every Native American option, every subsaharan African, and most East Asian categories. Highest scores were for:

Arabian 16.59
Northern European 12.52
Mediterranean 12.49
Aegean 10.04
North African 7.96
Levantine 7.28
Mesopatamian 7.09
Eastern European 6.44
Finno-Ugrian 6.17
Mestizo 4.09
North India 2.3
Altaian 1.27

So at this point I was ready to abandon hope of finding any DNA evidence of either Native American or African ancestry. Now from 23andme I get two kinds of results, one of which tends to support the above pattern but the other of which seemingly contradicts it. Ancestry Painting shows no Asian mixture whatsoever (which would also include Native American), and 1% African. Yet the other result from the same 23andme test, Global Similarity, echoes DNATribes fairly closely, with these rankings:

Northern European 67.72
Southern European 67.6
Near Easterners 67.03
Central Asians 66.8
Northern Africans 66.31
North Americans 66.07
South Americans 65.99
Siberians 65.99
Eastern Asians 65.73
Oceanians 65.67
Eastern Africans 63.63
Southern Africans 63.54
Western Africans 63.42

While the raw numbers don't seem to show a wide range, the bar chart shows the 67+ lines to be much longer than the ones around 66, and the ones under 64 to be extremely short. Without background on the range of possible scores (which I've yet to find on their site) this is confusing.

Could it be that these matches say nothing about me as an individual, and run very much the same for anyone with overwhelmingly northern European ancestry, because they are simply measures of distance among these groups? A friend whose roots are in the same county but who had no known mulatto ancestors came up with much the same results.

The only clue I can think of to reconcile these apples and oranges, the percentages vs. the matches, is the high North African results in both Tribes and 23andme. Seems like I might have neither Native American nor subsaharan African ancestry, but North African as part of a Mediterranean blend typical of Spain and Portugal. Which would point to 16th century Iberian arrivals rather than 17th century slaves direct from Africa?

Every few hundred dollars I shell out for DNA testing gets me more confused except for the Y and mitochondrial results which are crystal clear. But with 23andme, the medical and traits information alone is completely worth the price of the test, even though the ancestral aspects of the results are confusing.