Y-DNA

[Bryman]

Even now I only have 1035 matches at 23andMe, and whilst I've got 2219 at FamilyTreeDNA, it was only 700 when I first got my results.

I have just received my initial Y-DNA results from FTDNA and was very surprised to find ALL of the (only) 79 matches were for different surnames and I think that none are known in my tree. I was not expecting them all to be the same surname as me but I had expected most of them to be the same. I understand that there can be several reasons for different surnames and just hope that I am not descended from a host of naughty boys. I know of one direct ancestor who was but the issue was female so further descendants are not matching my Y-DNA. Still waiting for the Ancestry results.

 

[peter]

I have just received my initial Y-DNA results from FTDNA and was very surprised to find ALL of the (only) 79 matches were for different surnames and I think that none are known in my tree. I was not expecting them all to be the same surname as me but I had expected most of them to be the same. I understand that there can be several reasons for different surnames and just hope that I am not descended from a host of naughty boys. I know of one direct ancestor who was but the issue was female so further descendants are not matching my Y-DNA. Still waiting for the Ancestry results.

That's an awful lot of matches - you're very lucky. I have about 10 matches at all levels, even though I have tested 111 markers.

If there is nobody with the same or similar surname then it's quite likely there is an NPE in your paternal line - we all have many of them in our tree, it's just a question of which lines they happen to be on.

If there are several surnames the same then that's a clue to your paternal ancestors' surname.

 

[Alexander Bisset]

79 matches is a lot IF and only IF that's a Y-DNA test of at least 65 markers. If it's the 12 marker test (aka random numbers) then you'll pretty much get thousands of matches that are all different surnames. Similar but less so with the 37 marker test.

What you need to look at if memory serves is the number of variations. Basically anything that's the same or 1 variant is worthy of serious investigation. Anything that is 2 or 3 similar but might be a few oddballs - 4 or more well that's a lot of variations over the years and usually indicates a match way way back beyond what is likely with paper records.

Y-DNA is different from what's become the more common form of DNA testing in that the match passed 100% down the male line almost always with no changes. Occasionally there is one small change in the repeating counts and so you get a minor variation. The fact that there is normally no change means that this goes on for generation after generation. So where there is a match with 0 or 1 variation it is likely the change happened very recently (within last 250 years), where there are 2-3 variations closer to 300-400 years ago to the common ancestor where its 4 or more well the match is likely to be beyond the reckoning of paper records.

Of course as you then come forward from that shared common ancestor it will still be passed from father to son, but the father may not have been married to the mother and so the son may have taken the mothers name. Thus you get surname changes. If you imagine all the generations coming forward from a shared ancestor 700 years ago how many times is there going to be such a change? Well I'd suggest even with just 5% that's a LOT of different surnames. As it only takes one such change to change the surname all the way down and as such the living descendant could easily have traced their family back for 400 years to the 1600s and had the same surname all the way yet still be related to you via an NPE in the 1500s that they have no knowledge of.

NB. This is an illustrative overview of the possibilities the variations do NOT happen regularly they are random chance so you can have 4 changes in 200 years or zero in 600.