Why upgrade to Y-DNA111?

[stennor]

Six years ago, I bought a Y-DNA67 test in hopes of learning anything about my paternal grandfather's father, whose identity is a mystery. The closest matches have been four men at the Y-DNA37 level, each with a genetic distance of four. One has a Y-DNA111 test. At the Y-DNA25 level, I have 23 matches, all with a genetic distance of two, and one man has a Y-DNA111 test. I can't sift by surname because, as I say, we don't know the name of my mysterious paternal great-grandfather. What advantage, if any, would there be in upgrading to Y-DNA111?

[vvesper]

To me (and others who are more experienced may disagree with me), the value of the Y-111 test would be when you are trying to determine paternity in a situation where, perhaps your candidates are brothers who lived maybe 6-10 generations ago. In a case like that, if you could compare Y-111 tests between various descendants of the brothers, the test would most likely tell you which line you most likely came from. Or for an adoptee, the closer the matches you can get, the more likely they are to give clues for further research. If you have quite a few matches at the 67 level, the 111 level would weed them out to tell you who is closest. I'm sure others can think of other situations where it would be useful as well.

However, keep in mind that the markers can change literally at any time. My father and his brother took the 12-marker test years ago when it was new. They had a mismatch on one marker. The lab re-ran the test to be sure! So I imagine if they had taken the 111-marker test they'd match on 110 markers. (Autosomal tests have since shown that they are indeed brothers.) But be aware that changes didn't necessarily happen 100-200 years ago!

The big caveat here, of course, is whether you have matches at that level. However, at the 67 level, you don't have any exact matches yet. If they don't match at the 67 level, they probably aren't going to match any better (very likely more markers different) at the 111 level. My personal opinion is that you probably wouldn't get anything useful immediately with a 111 test. Having said that, though, you don't know who's going to test tomorrow who might be a good match.

[BrianG]

I am in the same situation as you are Stennor. I have an unknown father of my paternal grandfather.

I am wondering if the y-dna37 test would be sufficient to identify anybody out there who is genetically linked to my mystery g-g-father. I am not too interested in going back to earlier generations, although that could be an interesting bonus.

If I did the y-dna37 test about how many hits could I expect? As the y-dna is largely unchanged over past generations does that mean that there could be thousands of people out there who have the same y-dna as me, my father, my grandfather, and my g grandfather? If I and everybody else in the world has the same y-dna as Adam I am not sure how the results would be of any use in identifying my mystery ancestor.

Obviously I am a beginner so the above statements are probably wrong, but I would appreciate some guidance on this matter.

I already have Autosomal DNA results from ftdna but cannot identify any matches related to my mystery g-grandfather.

[BrianG]

“..... every other male in the world ....”

[stennor]

BrianG, thanks for posting. I'm far from an expert, but I'll share what I've read.

Although we do all descend from a common male ancestor who lived in Africa at least 115,000 years ago (see https://www.familytreedna.com/learn/...o-back-africa/), my understanding is that Y-DNA does recombine over time and through generations, but slowly, (see https://isogg.org/wiki/Portal:Y-chromosome_DNA and also https://isogg.org/wiki/Mutation_rates). If it didn't change at all, then every man on the planet would have the same Y-DNA, but that's not the case.

So I infer that the closer your common relative, the more likely you and a male cousin will match perfectly. My best possible scenario would be to match with a man whose father was the son of another son of my mysterious great-grandfather; that man would be a half-second cousin, and I'll guess that our Y-DNA would be identical or very close. Of course, it's possible that Mr. X had no other children or no other sons, and the same possibilities apply to his father, his father's father, and so on. If I find someone with a common ancestor farther back, I suppose that the Y-DNA could have morphed to some extent.

Of course, the glitch in the Y-DNA hunt is the requirement of an unbroken male line. Each of us must have such a line--that is, each father had a father, etc. etc. The question is how far back one would have to reach in order to intersect with another man's unbroken male line. Bear in mind that if you go back ten generations, you have 1024 ancestors, but only one is that male-line progenitor. So most of your cousins descend from those other 1023 people.

I don't know my great-grandfather's name, and I gather that you don't either, so we have a handicap in that we can't cull out Y-DNA matches by surname. My hope is that I find a strong match with someone so I can suppose that his surname tells me the surname of my great-grandfather. So far, though, I don't have such a match.

I don't know the answer to your question about how many hits you could expect from a Y-DNA37 test. I have just four, all with different surnames, all with a genetic distance of 4. I assume that it's a matter of luck with regard to how many other men are in the database.

[BrianG]

Thanks Stennor. We have the same "Mr X" situation so your comments are much appreciated. My present thinking is still to get the Y-DNA37 test and see if it identifies anybody of interest. I will let you know what the results are.

[mabrams]

Stennor, I always encourage upgrading to higher levels, particularly at sale times. However, in your case, with only 4 matches at GD of 4 at 37 (in other words, barely matches), its hard to say that you will get any immediate benefit from going to 111. If you get 0 at 67, you are not likely to have someone pop up at 111. Although, that can happen. I have a match at 25 that skips 37 and 67 but re-emerges at 111, albeit GD of 9.

It sounds like your paternal Y ancestors are from some under tested population. If they were British/Irish/Western Euro, I think you would have matches. Sometimes your haplogroup points to a nationality, sometimes not.

You might want to consider BigY700 and working from that approach. At least you will get a detailed haplotype and you might be able to suggest an origin by looking at your haplotype matches.

I dont think you are going to get quick answers. But testing at a higher level puts your 'flag' out there for someone to find you, at a future time. So if budget is not an issue, you should get a BigY when on sale, You will also get a further discount for 67 markers.

[The_Contemplator]

If I did the y-dna37 test about how many hits could I expect? As the y-dna is largely unchanged over past generations does that mean that there could be thousands of people out there who have the same y-dna as me, my father, my grandfather, and my g grandfather? If I and everybody else in the world has the same y-dna as Adam I am not sure how the results would be of any use in identifying my mystery ancestor.

The number of YDNA matches will depend on how many paternal cousins you have out there and how many got tested. In my own initial Y67 I had zero matches at every level. I tested an uncle from my maternal grandfather's side and he had 30+ matches at Y37. About half with his surname with the rest with similar origins. I tested an uncle from my maternal grandmother's side and he had 300+ matches at Y37. None with his surname and only a handful with the same country of origin for that paternal line. Y-DNA does not recombine, but it does accumulate changes over a long period of time.

So if you do take the YDNA test, you may or may not have meaningful matches at first. However, you could use your autosomal matches to narrow things down. If you have the rest of your family tree mapped out, you can narrow down which autosomal matches may be from your mystery branch. Talk them into taking a YDNA test and see if they match you. If you have a cousin from that same mystery ancestor, have them take an autosomal DNA test. Whatever you both share in common may point to matches from that shared branch. Just make sure that cousin does not also share one of your other branches so you don't get false leads.

Though the more distant the cousin the less you will share with them. In the cases of stennor and BrianG , they can get a 1st cousin that shares the same known grandfather. First cousins will share autosomal DNA with each other so that can filter out autosomal matches that come from that grandfather's side of the family. This of course would include the shared grandmother's matches as well but at least you have a filtered set of matches to work on. Always test for the oldest living relatives so you have more data to work with. If the grandfather is still around, test him. If he has siblings they are also an option unless you suspect they are half-siblings. If the grandfather is not an option, his children are.

You will only have about 25% of your autosomal DNA from this grandfather, which means you have on average 12.5% of your autosomal DNA from that mystery great grandfather. But your parent will have 25% and your grandfather will have 50%. More autosomal DNA means more matches you can work with as some will inherit other parts of his DNA than you.

[bartarl260]

You will only have about 25% of your autosomal DNA from this grandfather, which means you have on average 12.5% of your autosomal DNA from that mystery great grandfather. But your parent will have 25% and your grandfather will have 50%. More autosomal DNA means more matches you can work with as some will inherit other parts of his DNA than you.

The "about" part is more generally correct. I was happy to hear one of the presenters at RootsTech use an analogy I'd developed largely on my own.

Take several different decks of cards. Makes they're uniquely identifiable, as we're going to use them to represent ancestors. If you're only going to the grandparents 4 decks will suffice. (It's an oversimplification, but not too far from the point.

Take 2 of the decks, split them in half, then take two of those halves, and shuffle them together. That's one of your parents.

Now repeat that with the other two decks, that's your other parent.

Now split those two decks in half, and now combine two of those respective "half-decks" from each parent together. That's you. Now go back through that deck and look at the distribution of cards from each of those 4 source decks. It isn't going to be as evenly divided as the statistics claim it should be.

On average it should split 25% 4 ways(52 cards in a "standard deck", or 13 cards per "ancestor deck" when split 4 ways), if you run it across enough iterations. But in practice, it's another matter. (Doing siblings in that example would get messy as you would need to reconstitute the deck(so "you" no longer exist) and require repeating the example again for that specific (representation of a) person, but it could be done)

In any case, it's a decent demonstration as to why Autosomal DNA results can come back with seemingly strange results in some cases.