Genetic Groups on MyHeritage: 2 Who I Am and Who I Am Not

 

Who I am not

Well, that looks interesting. Under the heading 'Your ethnicity results', MyHeritage appears to be informing me that in addition to being 91% Ashkenazi Jewish, I am 2.9% Celtic Fringe, 2.8% Middle Eastern, 1.9% Mizrahi Jewish, and 1.1% West Asian. I must say that this comes as a bit of a surprise, as we have always considered ourselves to be 100% AJ, my mother's side coming from Poland and my father's from Belarus.

At first glance the 2.9% figure seems to be suggesting that one of my great-great-great-grandparents might have been from one of the Celtic areas of Britain. However, I have researched all 4 of my grandparents' lines back to this level - to 1800 or earlier - and as far as I can tell there's no sign of an Irishman anywhere. There's Leweks and Jankels, Movshas and Chaims, but absolutely no Paddys. There's no indication that anyone from Ireland, Scotland or Wales migrated to Poland or Belarus, married a local Jew, and forwarded their DNA down through the generations. And the same goes for the other "ethnicities" that I seem to have been allocated.

Something's not quite right.

Who they are

The list is wrongly labelled. Look at the subheading under 'Ethnicities' at the top. This is not the distribution of my own ethnicity. It's the distribution of ethnicities across all of the people who match me. It's not who I am, it's who they are.

Which could be of interest in its own right, of course. How come I share DNA with over 2000 people whose DNA has a strong element of Irish, Scottish and Welsh?

How it comes about

Let's do a mind exercise.

This is what my Ancestor Chart, back to my 16 great-great-grandparents, looks like, with me at the bottom. Yours will be similar.

Now here's the Descendant Tree for one of these couples, Shmuilo Gronim Ilyutovich b 1825 and his wife Tauba Belagratsky (they are at the top here, and this chart also shows their parents). They're from Lida in NW Belarus. I've taken it down as far as my own generation.

The chart is illegible because there are 83 of us in my generation. At least those are the ones I have been able to trace, there may be a few more yet to be discovered. There are also a number of people down the generations who I have been unable to follow through, and there will certainly be some who have slipped through the net entirely, especially in 19C Belarus where the records can be patchy to say the least. But I do have names and places for the intervening generations of all the 3Cs shown here. None of these cousins, nor any of their Ilyutovich ancestors, were in Ireland, by the way. However, one or two of them may well have married people with Irish ancestry, once they reached countries where there was Irish immigration as well as Jewish, such as the UK or the USA.

Now consider that this is the Tree for only one of my g-g-g'parent couples. There are seven more couples at this level, each of which may well build up through the generations as this one does. Even if they "only" come down to half the size of this family, say to an average of around 40 in each family in my generation, that is potentially another 300 or so 3Cs.

I have developed some of these families to a similar level to this one, and the same arguments apply. However there are a few families I know little about. Those 40 potential 3Cs may well exist in these families, I just don't know anything about them. I have no idea who their ancestors married, or who they had children with. Did they move elsewhere in Poland or Belarus? Did they emigrate? Were they killed in the Holocaust? Might one of them have married an Irishman or woman?

What about his brothers and sisters?

But there's more. Take Shmuilo Gronim, for instance. He was one of seven children. I have information on just two of his brothers, and that dries up around 1900. I have no idea what happened to them or any of their families. Some of them may have had descendant charts as fully populated as that of Shmuilo. Their descendants would be 4Cs to me, and there could be another 400 potential cousins out there. I have no idea if they even exist, let alone whether any of them might carry any Irish DNA.

And of course, we can repeat this exercise for the siblings of each of my 15 other g-g-g'parents. There could be another 400 unknown 4Cs in each of those families. That's 6000 more cousins. As if I didn't have enough already.

Celtic Connections

And there's a good chance that somewhere along the line, an ancestor or two of at least a few of these unknown thousands might have married a Celt. And when a descendant of theirs in the 2010s or 2020s takes a DNA test with MyHeritage, their Celtic DNA will show up in their results, along with whatever AJ DNA has come down to them.

It's not me that has Celtic DNA, or Middle Eastern, or Mizrachi, or West Asian - it's my matches.

What about my brother?

My brother also has his DNA on MyH. Here's his Ethnicity results:

Oh? Wot, no Irish?? My brother has a similar number of matches to me with Celtic ethnicity, over 2000 of them. However, he doesn't seem to share any of their DNA. He also has more West Asian, plus a trace of Central Asian that I don't have, but none of my Mizrachi.

Of course, although my brother and I received our DNA from the same two parents, we only actually coincide on 36% of it. The other 64% of my DNA consists of segments that he doesn't have, and vice-versa. This explains why our match lists can seem so wildly different, outside of known cousins. Even with known cousins we share significantly different amounts with many of them, and often share on different segments.

So it shouldn't be surprising that we see a difference in the ethnicities of some of our respective matches. I have segments, some of which my brother doesn't have, that I share with matches who have Celtic, or Mizrachi, origins. Conversely, he has segments that I don't have, that he shares with matches who have Central Asian origins.

Again, it's not us, it's them.