Earlier this summer, I decided to take a look at my genetic ancestry via the fine folks at 23andme.com. I bought two kits, one for me, and the other also for me in hopes of seeing how precise they could get with two samples from the same person. So they shipped out a couple of kits. Long story short, 30 minutes after the last time you ate, drank, smoked, gargled, or brushed your teeth, you spit in a tube. Then you seal it up, put it in a box, register the sample on the internet, and ship it off. Then you wait.

The first sample was taken at 4:47pm on July 26th and was labeled “Vincent.” The second sample was taken at 8:00pm on July 26th and was labeled “Dominic.” These are my first and middle names; they are not reflective of different personalities or identities or aspects of my being or any other such thing. Actually, that’s not true. “Dominic” is more sullen, but less morose. So I took the two samples, sealed them up, put them in boxes, registered them on the internet, and shipped them off.

The results came back this week.

One feature of 23andme is that it allows you connect to other users and compare your genetic ancestries. So I connected “Vincent” to “Dominic.” It correctly recognized that I was me, and that the relationship between the two samples was either “self” or “twin.” That was impressive. But despite the very explicit, boldfaced statement that “You share 100% of your [i.e., “Vincent’s”] DNA with Dominic,” there were some discrepancies.

Here are the results, keeping in mind that the “you” in the left column is “Vincent,” i.e., the 4:47pm me:

In a little over three hours, I became about 5 percentage points more Italian, about 4pp less Irish, about 2.5pp less Western Asian and North African, about 0.7pp more Balkan and 0.1pp less Siberian.

Oh, and I turned a teensy bit more Neanderthal:

How could this have happened? I could chalk it up to the mild imprecision that results from combining commercial-grade genetic testing with amateur, non-sterile sample collection. Or I could take a look at the “Ancestry Timeline” feature. Here’s “Vincent’s” timeline:

And “Dominic’s”:

In that three-hour window, someone could have altered the timeline. I don’t mean someone at the lab messed around with the results, I mean time travel. I think, if I’m reading this correctly, that at least one of my Irish ancestors from the original timeline went back to the mid- to late-1700s, killed or otherwise neutralized my would-be Siberian ancestors, and mated with some Balkan person, making him or her my ancestor in the new timeline. But if this is the case, then (A) how did the Irish ancestor get the time machine, and (B) why would I still have any evidence of the original timeline? And how does the Neanderthal stuff fit in?

This is silly supposition, of course. It’s just as feasible that the Irish time traveler corrected the timeline, wiping out an alternate history in which I had Siberian rather than Balkan ancestry, so I shouldn’t really commit to one story or the other. Either way, it was a fun though somewhat pricey exercise that made me feel more connected to you humans.