KATRINA VOSS
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Links and cool science
(Watch a video about my family's discovery of our Jewish roots through DNA testing, and read an article from the Jewish Daily Forward featuring my dad's story.)
Everyone's favorite subject is himself. So there is no better way to learn about science than making it personal. This is especially true of genetics.
23andMe is a direct-to-consumer genomics company that genotypes customers using over 600,000 markers and helps them understand their own genetic information. My parents, my husband Mark Shriver, and I have all been tested with 23andMe. We have uncovered many curious details about our ancestry, disease risks, and other traits. Of course, answers are rarely just answers. They often raise more complex questions. For example, our maternal and paternal haplogroup designations have led to yet more fascinating puzzles about who our ancestors might have been.
A mitochondrial haplogroup is matrilineal, passed from mother to children of either sex, but only daughters c
an pass it on to their children. We have learned that my mother's and my mitochondrial haplogroup is K1a1, a subclade of K, and that haplogroup K is found at high frequencies -around 32%- among Ashkenazi Jews. My father's is J2b, a subclade of J, and also may have Ashkenazi ties.Ancestry is also traced through the paternal line from father to son via the Y chromosome. My father's Y-DNA haplogroup is E1a (probably E1a1), a subclade of E. For a man of European ancestry, this is an intriguing result, as the E haplogroup is much more common in Africa, reaching frequencies close to 100% in some areas. In fact, E1a and E2 are found almost exclusively in Africa, while only E1b1b has been observed in significant frequencies in Europe.
We have since learned of a few likely scenarios explaining the presence of E1a and E1a1 in European-American men with no known African ancestry. One obvious possibility is that the man's paternal ancestor (his father's father's father, etc.) was an African slave or free person of color who had a relationship with a white woman (i.e., a woman of European ancestry). E1a1 may also have a Semitic tie; that is, the man's paternal relative might have been of Ashkenazi Jewish heritage. Yet another hypothesis is that the man's paternal line traces back to Arab expansion into the Mediterranean. (For men bearing this signature, the E1a Haplogroup Google community is a forum to explore these scenarios.)
So, to dig deeper, our next step was to test STRs on his Y chromosome with a genetic genealogy company, Family Tree DNA. This test gave my father the closest Y-chromosome matches to other men across the world. Since his matches were almost exclusively Ashkenazi men, we can conclude that the most likely explanation is that my paternal ancestors were Jewish, and somewhere along the way, they chose to hide the family history.
Since my mother and father both have possible Ashkenazi ties, we also tested ourselves on the Euro-DNA-Calc 1.1.1. This test uses selected markers to estimate Ashkenazi ancestry. My father's estimate is near 50%, my mother's, around 10%, with me somewhere in the middle. However, I must make a careful concession: No test is perfect and an estimate is just that. What's more, especially for a test of this sort, it's important to look at confidence intervals. Qualifications notwithstanding, these tests can give us a direction in which to look.
Mark's mitochondrial haplogroup, B2, was also an interesting, although not unexpected discovery, in
dicating an Indigenous American maternal ancestor (probably Mexican). Other tests Mark himself designed have revealed recent West African genetic ancestry, including a Duffy-null allele. This allele provides protection against Plasmodium vivax malaria and is essentially fixed in Africa today.Once you've discovered genetic information about yourself and your family, there are message boards and forums to discuss your results and connect with others interested in genetics and genealogy. Above, I mentioned one such community specifically dedicated to the exploration of the E1a Y-haplogroup. DNA Forums is another online community with discussions about maternal and paternal haplogroups, ancestry, and genetic science in general. Dienekes' Anthropology Blog explores human population genetics, archeology, and history. SciVee is an excellent resource where scientists share and explain their research through "pubcasts."
Genetic testing will certainly tell us a lot about what makes each of us unique. That said, it is important not to lose sight of our vast sameness. In the end, we are all, regardless of physical appearances and social identities, modifi
ed African apes. Genetically, less than one percent of the genome is different from human to human (and 2% from human to chimpanzee!). Whatever judgment a society makes about the value of that one percent is often a matter of timing, location, and ethics. Put another way, a mere subset of the ~20,000 genes in the genome are responsible for perceived racial differences, and yet this minuscule piece has provided apologia for genocide, appalling human rights violations, and social injustices.As we probe the genome, we should remember that we do not have to be the same to be equal.
