Interpretation of results

[Cromdubh]

I have established a connection with a person of the same surname and origin, no great surprise, both of us 37 marker GD-2 (one only); 67 marker GD-4 (one only);
I appear as one of 5 on his 25 marker GD-2 and he appears as one of 3 on my test at that level.
What I find surprising is that I have 23 exact matches at 12 marker, he has just 1, neither of us appearing in each other's test at this level.

Both of us grew up in the same geographical area and our families would have intermarried with much the same pool of people, but probably not with one another.

I realise that the 12 marker test is disregarded for most purposes, but this discrepancy intrigues me.

Could it be that I uploaded my results to Y-Search, but have not as yet got permission to do that for his?

Thank you.

I should add that we share the same Haplogroup R-L48, I have progressed to R-L47, which has a relatively low frequency in Ireland

[507]

You could be 1st cousins, or cousins with an ancestor 800 years ago. Honestly.

[nathanm]

What I find surprising is that I have 23 exact matches at 12 marker, he has just 1, neither of us appearing in each other's test at this level.

...

I realise that the 12 marker test is disregarded for most purposes, but this discrepancy intrigues me.

Could it be that I uploaded my results to Y-Search, but have not as yet got permission to do that for his?

You're probably matching people in projects you've joined, and he either hasn't joined the same project, or has a different project selected. If you look at the top of the left-hand column, where it says "My Project Groups," there are radio buttons next to the names of each project you've joined. If you choose a different one, and look at your Y-DNA matches again, you can find which project has those extras. Some people leave their user preferences to only match people within projects. I don't know that it's intentional, they probably just haven't changed the default.

[similligan]

Your cousin may have a difference from the modal that could account for fewer matches than you at 12 markers. My father is an R-M222 and differs from the modal at 2 of the first twelve markers. He has 10 exact matches at 12 markers while others who are exact matches to the modal currently have just under 1000 exact matches at that level.

[Cromdubh]

Thank you.

[Frederator]

If I understand correctly, the premise underlying your question is that the distribution of mutational differences must necessarily increase with each additional panel of markers you test. That is, that a person GD of 2 at 12 should never turn out to have a lower GD than another individual with GD of zero at 12 if both go on to test 25 or 37 markers.

That would be wrong, however. It's probably true that each additional panel contains more "fast mutating" markers--but that's only a population-wide average. Mutations are ultimately random in exactly where they occurr in a specific individual, though anomolies tend to few and far between.

The plain, bottom line fact is that the 67 marker test is probably the minimum # to test for anyone wanting to make clear, verifiable connections. I've seen too many weird things going either way to feel all that great about even 37 marker matches. 12 and 25 markers are just about useless in my opinion.

I think that expectation of a consistent, even distribution of mutations among the panelsis what you were getting at. Forgive me if I was misunderstanding you there.

I have established a connection with a person of the same surname and origin, no great surprise, both of us 37 marker GD-2 (one only); 67 marker GD-4 (one only);
I appear as one of 5 on his 25 marker GD-2 and he appears as one of 3 on my test at that level.
What I find surprising is that I have 23 exact matches at 12 marker, he has just 1, neither of us appearing in each other's test at this level.

Both of us grew up in the same geographical area and our families would have intermarried with much the same pool of people, but probably not with one another.

I realise that the 12 marker test is disregarded for most purposes, but this discrepancy intrigues me.

Could it be that I uploaded my results to Y-Search, but have not as yet got permission to do that for his?

Thank you.

I should add that we share the same Haplogroup R-L48, I have progressed to R-L47, which has a relatively low frequency in Ireland

[Cromdubh]

I was surprised by the fact that I had 23 exact matches @12 whereas the other chap had just one.
It would appear that this was due to me signing up to a few relevant projects whereas I didn't have permission to do likewise for the other person.
I reckon I had done well enough to get the initial sample from him.
We only had one another @37 -2 and 67-4.
Thank you for your input.
I'm trying not to appear too dim .
I should have started this when I had more grey cells than I have now.
Tom

[Frederator]

Yes--now that I read the other resonses more carefully, I see now that the possible explanation for the situation is a difference between your page settings and those of your match.

That's probably it. I only mentioned the above scenario as an alternative. While I don't have any statistically significant matches myself, all my "near matches" at higher resolutions (i.e., GD which are consistent with possible relationship since the middle ages) actually IMPROVE with each additional panel. I've heard of a number of other fellows who actually had latent matches at a statistically significant level out there in the database for years, but were unable to identify that fact until they broke down and upgraded from 37 to 67 markers.

Guess that's my own little bete noir: the fear that I have indeed had a significantly statistical match out there for 6 years but they haven't bothered to test up to an appropriate # of markers.

I was surprised by the fact that I had 23 exact matches @12 whereas the other chap had just one.
It would appear that this was due to me signing up to a few relevant projects whereas I didn't have permission to do likewise for the other person.
I reckon I had done well enough to get the initial sample from him.
We only had one another @37 -2 and 67-4.
Thank you for your input.
I'm trying not to appear too dim .
I should have started this when I had more grey cells than I have now.
Tom