Letting My Spit Do the Talking

My recorded family history doesn’t go back more than four or five generations. For thousands of years, Indians didn’t really keep records on genealogy unless you were a king. My family were priests, so most records were transmitted orally… until they weren’t. Names don’t really help because conventions were inconsistent and variable between regions. The result is that my family history lives in a data dark age once you go back past 1800 or so, in which all we have is a stray name or scrap of family legend. So when DNA testing became a thing, I determined to get one. Now I finally have.

I’ve wanted to get one of these for a long time, and off and on I’d done reading about population genetics in order to get familiar with the topic, and to make educated guesses about my ancestry at a time when I couldn’t afford the test. In this first part, I’ll tell you how I made those predictions and in the next, we’ll see how well they held up.

(NOTE: I approached the question from a cultural/historical perspective since I have a much better handle on that than on the biology. Though obviously the biology is where the science is, what we know about ancient history can both inform our interpretation of the results and provide some interesting avenues of speculation.)

Map of human mitochondrial DNA dispersion: from Wikipedia

Modern humans have been in India for 50,000 years. The subcontinent was one of their first stops on the way out of Africa, before they went off to Southeast Asia and Oceania. So maybe the markers in my DNA are 50,000 years old. On the other hand, the subcontinent has seen waves of migrations, linked to populations defined by genetic markers that arose as recently as 12,000 years ago. The one thing I’ve always been sure of is that I have a nearly purely Indian background, so barring any big surprises, the question I sought to answer with the test was one of which Indian population I could trace through my genes: an older population (the 50K-ers, closer to original Africans) or a newer population (closer to the 12K-ers and modern Europeans).

When trying to guess, I started with what I already knew. My family are Iyengar Brahmins from South India. Iyengars are a Tamil-speaking sect of Vaishnavite (Vishnu-worshipping) high-caste Hindus found mostly in the modern state of Tamil Nadu, though they also extend into Kerala in the west and Andhra Pradesh in the north (and with the advent of modern travel, pretty much everywhere). Brahmins make up about 4% of the modern Indian population. Previous genetic tests of Indian populations have suggested that “higher-caste” populations may have less genetic distance to European populations than Indians at large, but that northern Indian populations have less genetic distance to Europeans than southern Indian populations. Given this, being a South Indian Brahmin seems to not suggest anything in particular. It’s probably 50/50 in terms of falling in a 50K-er population as opposed to the 12K-ers.

My ancestors, up until a remarkably rebellious streak began in my great-grandmother’s generation, were probably pretty traditional, and kept marriages within the caste and sect. My maternal grandfather belonged to a subsect called the Vadakalai, and while I’m not 100% sure, I assume my father’s family did, too, or else my parents might not have been permitted to marry. Vadakalai is Tamil for “northern culture,” which might suggest a northern origin, but might also just refer to the community’s use of Sanskrit, the northern language. Maybe both. There are beliefs among some about a connection between the Iyengars and Kashmiri Brahmins from the far north of India going back as far as the 10th century. I’d call this nothing more than speculation, but if it were true, it might push my odds into the 55/45 territory in favor of the 12K-ers.

Finally, there’s bit of family lore that my maternal grandmother dug up that suggests that her father’s ancestors in maybe the 17th or 18th century might have originated outside the Tamil region, along the north-central stretch of the east coast of India, in the modern state of Odisha or up into Bengal. This might push me into 60/40 territory for some 12K-er origin, a more northerly origin than I might have expected given recent family history.

Under that assumption, I started looking at what haplogroups I might expect to fall into.

Common mtDNA haplogroups in India are: M, R, and U. These are all very old. R is a child of M’s sister clade, N, and U is a child of R. M and R are about 60,000 years old, while U is 55,000. As all of these groups would have been in India by 50,000 years ago, I couldn’t really make a better guess as to which one might be mine, specifically. I had to wait for the test.

For Y-DNA, common Indian haplogroups are: H, J2, L, and two variants of R. H is a pretty old clade, at about 40,000 years. This would put it as a middle wave of prehistoric migration into India, but if I was guessing that my DNA is younger than that, H probably wasn’t it. L is somewhat younger (30,000 years), but is found more frequently in northwest India and southeast Iran, and not among groups with whom I have any known connection. The same is true of J2, which is apparently common among Sephardic Jews. This leaves the two Rs: R1a and R2. The Rs are much younger lines–the canonical 12K-ers, and late migrants into India. R2 is found in concentrations of Bengali and Kashmiri Brahmins, so if any of the family lore or historical speculation is true, that might be a possibility, but I found that R1a, specifically the subclade R1a1, is found among 31% of Iyengar Brahmins. This was the clearest connection yet. Without a test in hand, I guessed my Y-DNA belonged to haplogroup R1a1.

Not like anyone reads this, but next up, we’ll see how right I was.