Sep20

2 Comments

Hello out there in Genealogy Land! I have been running silent these last few months here on the blog, but continue to march yet unto that elusive tree of perfection. I have a quick item that I wanted to post today and file in Things That Make You Go, “Huh?”

When checking my matches over on MyHeritage DNA, I found one recently that is estimated at the 3rd – 5th cousin level.

DNA Match Summary
OK, I says, that’s not a bad match – although I strongly suspect that MyHeritage’s cousin-relatedness are overestimated by at least 1 or 2 levels. That would make me feel like this is really at the very best a 4th – 6th match and perhaps further. In fact, another factor feeds this assumption for me:

This match is from Norway. I am 50/50 Czech and Irish. While I understand those country-centric terms don’t accurately represent the mishmash of DNA we all carry, I have found that this match along with other matches from Norway have trees that go many generations back with clearly Norwegian names in them. (Go figure.)

So, OK, perhaps 5 or 6 generations ago someone from one of “my” countries headed up that way, or vice-versa and now I need to welcome my new Norwegian cousins and brush up on learning how to cook Kjøttkaker and Gravlaks. (Mmm, Gravlaks.) But, a couple of these Norwegian matches are in the 3rd to 5th cousin range, so you’d at least think we’d see some slightly similar locations on the map start to appear around the time our common ancestor would be. Nope.

But forget about all that – let’s look at the next thing that MyHeritage gives us for matches: Shared Ethnicities.

Now, I also understand that there is some algorithmic voodoo at play in mapping ethnicities. (By the way Algorithmic VooDoo is now my new band name.) Can one really attribute a particular snippet of DNA to a location absolutely? Eh, maybe in some cases, but overall I think they are smearing the lipstick a little broadly. In the case of this match, I found something else surprising.


Shared Ethnicities Chart

I pasted our “Shared DNA” numbers on this chart for reference – so assuming we share enough DNA to be in the 3rd – 5th cousin range, would we not also have at least one category of ethnicity that we are both a member of? I realize our total shared is only 0.4%, but even so, if they can estimate her Scandinavian ethnicity down to a 10th of a percentage, there shouldn’t really be any rounding error going on.

Yet, there is not a single ethnicity that we share.
And now I am left wondering what I should do with all of these Gravlaks?

(By the way: That Iberian % doesn’t show up at all in my 23andme results, and on AncestryDNA I have 3% Iberian in the Low Confidence Region. One of my favorite regions, doncha know.)

2 Comments

  • avatar

    Comment by David — June 25, 2020 @ 3:02 am

    Hey, it is funny. I also have this problem even after they made the matching update in 2018. Most of my 3rd-5th cousin matches (at least 2 out of 4) do not really share any ethnicities with me. Moreover, I have a Norwegian match whom I share 1.1% with (shown as 3rd-4th cousin, mind you, even closer than in your case), and we only share West Asian ethnicity (and based on their extensive trees they have nothing to do with West Asian continent, go figure what the deal of that is). It is probably an admixture to them, since they have less than 15% of it shown. I am not sure how reliable the whole matching algorithm is even now, definitely something feels off. Not only that, but some matches on FtDNA do not appear on MyHeritage either. Supposedly due to how segments are interpreted differently or missed altogether for those that transfer vs those that buy the test on MyHeritage. I used to think that ethnicity estimates are bogus, but now i am starting to lose faith in matching. These issues are simply confusing and not helpful to me.

  • avatar

    Comment by John — June 25, 2020 @ 10:57 am

    I have to go back and look at this match again and see if the algorithm changed things up over the last 3 years.

    I do agree that it is hard to lose faith in matching: I would have thought that by now with the boom in the sizes of each company’s database some of my harder to find parts of the tree would have had some serious matches.

    I have had quite a few closer known cousins test, which should really boost identifying things – but really, I have gotten nowhere with those ancestors.

    Meanwhile, on a couple of parts of the tree that I already had a full picture going back quite far in time: lots of matches. I think at least part of the whole process is luck of the draw on which distant cousins get into testing. My wife’s Nova Scotia Irish/Scottish side is bursting at the seams with matches, but my darn Tierney/McTiernans are still hiding in the bushes.

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