Pedigree

Like many – perhaps most – Americans my handle on my direct ancestors reaches as far back as the ones who arrived in the United States. Beyond that, things get a bit murky. Mine straggled over between 1850 and 1920. I know from what towns the emigrants hailed (Greifenhagen [presently Gryfino], Pressburg [Bratislava], Budapest, and Glasgow) and in a couple of cases the names of a few of the relatives they left behind, but that is about it.

For those who are interested in their family histories, traditional genealogical research can fill out family trees to varying extents. There are problems with this approach, however, quite aside from the expense in time and money. There is a high likelihood of omissions due to missing (or sealed) documentation. There is also an inescapable degree of uncertainty on the paternal line. Late 20^th century DNA tests done for medical research purposes showed that in Western countries including the U.S. more than 5% of men listed as fathers on birth certificates were misidentified; the rule among the researchers was, and still is, to not reveal this information to the cuckolded fathers. There is no reason to believe the percentage was any lower in earlier times. This indicates a better than even chance of deviation from a nominal family tree in a handful of generations. DNA tests in the late 20^th century were expensive and slow, but of course that is no longer the case. DNA testing is now cheap and easy. Nowadays it is the usually the first step for people interested in learning more about their ancestry.

DNA sampling companies such as 23andMe and Ancestry are wildly popular as many people are keen to learn more about themselves. Identity crises are the special domain of adolescents, according Erik Erikson, which ideally we resolve by the time we are adults, but, needless to say, we don’t live in an ideal world. “Who am I?” is a question asked by adults as well as by adolescents, and DNA tests promise a limited answer – very limited. Dr. Michael Zwick at Emory University's Departments of Human Genetics and Pediatrics explains, “What most companies offer today is a measure of ancestry that maps to a geographic region. The basic data consists of genetic variants (alleles) that are at different frequencies in different geographic regions.” Given past migrations of individuals and of whole populations, this tells us less than we might imagine. The DNA tests are excellent, however, at something for which they were not initially designed: revealing contemporary family connections to other people who have taken the test. The tests have turned up previously unknown relatives and revealed biological parents of adoptees. They also have been a boon to law enforcement. Ever increasing numbers of criminals who have left DNA at crime scenes have been caught thanks to these tests, even when they themselves didn’t take the test. It was enough that a cousin did. A partial DNA match to a cousin will give the police the family of the perp and from there it is easy to narrow down the suspects. Within five years some 90% of Americans should be identifiable through DNA in this way. Assuming a particular test-taker has no cause for concern from law enforcement, he or she still should be prepared for the possibility of some unwelcome surprises: revelations from test results could (and sometimes do) include deep family secrets such as adoptions, half-siblings, parental affairs, incest and more.

Most people seem willing to take the chance of uncovering family skeletons in order to learn more about their heritage, but one should be forewarned about taking the results too seriously. Given the halving of genetic ancestry at each generational step back in time, within very few generations our ancestors have little more in common with us genetically than do random strangers. Being told what percentage of our ancestry is of what ethnicity is, as British geneticist James Rutherford puts it, “something that is at best trivial and at worst astrology.” Ethnicity always has been a loose notion whether we claim it for ourselves or are categorized by it by others. Even more dubious is the identification of ethnicity with culture. As Sarah Zhang said in The Atlantic, your DNA “is not your culture.” As an example, none of my own direct ancestors (so far as I know, what with that 5% uncertainty thing) was in the Americas at the time of the Revolution or the Early Republic but The Federalist Papers are still culturally relevant to me.

People always divide themselves into “us” and “them” for all sorts of reasons (religious, economic, ideological, etc.) and fight viciously over them, but for the past few centuries ethnic nationalism has been the single biggest killer: a source of war and brutal oppression. To be sure, there is nothing wrong with social camaraderie based on some commonalities of experience and background; this is called harmless “granfallooning” in Kurt Vonnegut’s Cat’s Cradle. But such camaraderie couples all too easily with hate of an out-group. This is not just dangerous but intellectually unsound. Throwing rocks at out-group members is ill-advised not only because we all live in glass houses, but because in a larger sense it is always our own house. Our ill-defined ethnic distinctions do not really run so very deep into any of our ancestries. Everyone with a European ancestor somewhere in the past 10 generations, for example, is descended from Charlemagne. Genghis Khan has nearly as ubiquitous a presence in the ancestry of modern mainland East Asians. Going deeper, it is mathematically necessary that all living people share at least one direct common ancestor 3000 years ago. Science journalist Steve Olsen with the help of statisticians and computer specialists calculated that every person now living is descended from every person who was alive in the world in 5000 BC who left an intact line. Even the tiniest rate of infiltration over the steppes, the deserts, and the seas ensures this result – and migration was often anything but tiny. If you come face to face with an ancient Egyptian mummy or one from the Tarim Basin in China who left an intact bloodline, you are almost certainly looking at an ancestor. This is regardless of from where we consider our families to have “originated.” We may not think of ourselves as descending from farmers on the banks of the Chang Jiang River, herders on the grasslands of East Africa, and haulers of stones at Giza all at the same time, but we are. Our ancestors very likely included both besiegers and besieged at Troy.

We may not all be brothers and sisters, but we are at least cousins. Regrettably, cousins are apt to squabble. It’s in our DNA.

Screaming Females – End of My Bloodline