Back in 2002, I wrote a pioneering story on DNA testing for racial admixture based on the work of geneticist Mark Shriver: "How White Are Blacks? How Black Are Whites?"
Now, in The Root, Harvard African-American studies professor Henry Louis Gates continues on with his interest in ancestry testing, providing some updating for the preliminary data in my 2002 article. Gates writes:
* According to Ancestry.com, the average African American is 65 percent sub-Saharan African, 29 percent European and 2 percent Native American.
* According to 23andme.com, the average African American is 75 percent sub-Saharan African, 22 percent European and only 0.6 percent Native American.
* According to Family Tree DNA.com, the average African American is 72.95 percent sub-Saharan African, 22.83 percent European and 1.7 percent Native American.
* According to National Geographic's Genographic Project, the average African American is 80 percent sub-Saharan African, 19 percent European and 1 percent Native American.
Presumably, the National Geographic project is trying harder than the commercial projects to get a representative, non-self selected sample, so that sounds like the best set of numbers to use as a rule of thumb.
By the way, the notion that African Americans are about 1/5th white was an assumption of physical anthropologists back around 1950. DNA testing has just confirmed what your lying eyes tell you.
* According to AfricanDNA, in which I am a partner with Family Tree DNA, the average African American is 79 percent sub-Saharan African, 19 percent European and 2 percent Native American.
And for our African-American male guests, there has been still another astonishing fact revealed about their paternal ancestry -- their father's father's father's line -- through their y-DNA: A whopping 35 percent of all African-American men descend from a white male ancestor who fathered a mulatto child sometime in the slavery era, most probably from rape or coerced sexuality.
We can be confident of that because no woman in history was ever attracted to a higher social status man.
I find two things quite fascinating about these results. First of all, simply glancing at these statistics reveals that virtually none of the African Americans tested by these DNA companies is inferred to be 100 percent sub-Saharan African, although each company has analyzed Africans and African immigrants who did test 100 percent sub-Saharan in origin. Ranges, of course, vary from individual to individual. Spencer Wells, director of National Geographic's Genographic Project, explained to me that the African Americans they've tested range from 53 percent to 95 percent sub-Saharan African, 3 percent to 46 percent European and zero percent to 3 percent Native American.
So, in the National Geographic sample, every single self-identified African-American is majority black by ancestry, and thus is blacker than President Obama. In my article, the estimate was that 90% of self-identified African Americans were no more than 50% white. Gates ups that to 100%, which seems implausible.
And second, these findings show that the common claim that many African Americans make about their high percentage of Native American ancestry is a myth. Joanna Mountain broke down to me our low amounts of Native American ancestry in this way: "Eighty percent of African Americans have less than 1 percent Native American ancestry. Over 2.5 percent have between 2 percent and 3 percent. And of all African Americans who have at least 1 percent Native American ancestry, the average is 2 percent Native American." So much for all of those putative Cherokee roots on just about every black person's family tree, fabricated to explain why your great-grandmother had "high cheekbones and straight black hair"! Why there is such little evidence of genetic mingling between African Americans and Native Americans deserves a column of its own.
Shriver hadn't found any American Indian admixture in self-identified African-Americans, so what Gates reports sounds more plausible.
One possibility is that people of mixed black-Indian ancestry these days try to identify as Indian to get their cut of casino money. A hundred years ago, it was better to be Indian than black, then it became better to be black than Indian, but the casino law of the late 1980s may have shifted the balance again.
For example, I used to read that the first black man to play in the U.S. Open golf tournament was John Shippen in 1896, a caddy at Shinnecock Hills. But, recently, the Obama Administration declared the Shinnecocks an official Indian tribe, and they've been pursuing a casino ever since. The Cherokee Tribe recently kicked out thousands of members for being the descendants of the Cherokees' black slaves.
The results for Latinos, however, are quite different: "In our experience," Mountain says, "people who have both African ancestry [at least 10 percent, according to genetics] and a lot of Asian/Native American ancestry [at least 10 percent, according to genetics] are more likely to consider themselves Latino than African American."
And what about the percentages of "black" or sub-Saharan ancestry in the white American community? That will be the subject of another column. But suffice it to say here that, according to Mountain, "The bottom line is that 3 percent to 4 percent of people likely to consider themselves as all 'white' have some African ancestry -- between 0.5 percent and 5 percent."
In 2002, Shriver estimated that only 70 percent of American whites had no black ancestors, but now Gates says the consensus is over 95 percent of whites have no black ancestors. I'm not sure which number I find more likely.
If you do math on Gates' figures, that comes out to a tiny percentage of black ancestry among self-identified white Americans. Let's calculate the upper limit: 4% of white individuals times 5% black ancestors = 0.2% black ancestry among whites. That's basically nothing. And that's the upper limit.
If you do the math on the midpoints -- 3.5% of individuals times 2.75% ancestry -- you get just under 0.1% as the best guesstimate of self-identified white Americans' black genes. That's extraordinarily negligible. I'm shocked by what a small number less than 1/1,000 is.
Of course, when Gates goes to write it up, he'll probably emphasize the exact opposite. People don't reason comfortably with numbers, just with absolutes.