Same haplotype, different haplogroup?

[Victor]

Hello,

Sorry if this sounds like an elemental question to some of you, but please bear with us that are just embarking in this new genetic discovery journey.

Is it possible for two unrelated individuals to have the same haplotype values and belong to a different haplogroup?

Victor

[Jim Denning]

Hello,

Sorry if this sounds like an elemental question to some of you, but please bear with us that are just embarking in this new genetic discovery journey.

Is it possible for two unrelated individuals to have the same haplotype values and belong to a different haplogroup?

Victor

if you mean a 12/12 or 25/25 match and different haplogroup i wouldnt think so

[Bill Hurst]

Hello,

Is it possible for two unrelated individuals to have the same haplotype values and belong to a different haplogroup?

Victor

Victor, there is something called convergence where two men from two closely related haplogroups, say R1a and R1b, might have the same haplotype. When the SNP mutation forms a different haplogroup there is an original haplotype, which is possibly the current modal haplotype. Then STR mutations create new haplotypes, but eventually some move back to the original. If that happens in both haplogroups, they converge to the same haplotype. That's why STRs can predict, but don't define haplogroups.

Bill

[Victor]

Thank you Jim and thank you Bill for your feedback.

That's what I imagined. In a way this question is tied to one of my other questions, about the STR count.

The question about the STR count was if accumulated mutations always increase the number of STR or if it's possible that a mutation can decrease the STR count.

The notion I have is that it is possible to have new insertions as well as deletions of STRs, making a haplotype value to go up or down in a given mutation.

I'm guessing, Bill, that "convergence" can only occur when both, insertion as well as deletion of STRs are possible. Please correct me if I'm wrong.

Victor

[jablair]

Victor,

STR mutations can be both insertion and deletions. Maker values can go up or down.

As for two people having the same haplotype but different haplogroups, theoretically it is possible since two different tests are used to determine haplotypes and haplogroups. Haplotypes are determined based on STR testing while haplogroups are determined based on SNP testing.

As I said theoretically it is possible, but so far no one as been able to provide a single example of two people with the same haplotype (or even very close haplotypes, ie 24/25 or 23/25 matches) having different haplogroups. Both I and others have asked for such examples here and on the Genealogy-DNA-L mailing list and no one has ever been able to provide one.

John

[Victor]

Prediction algorithm vs. SNP test

Thanks for the clarification, Mr. Blair.

Now a different question, if you don't mind. Have you heard or read about an SNP test disproving a previous haplogroup prediction test?

Is it even possible to make a false prediction via the current prediction algorithms?

Victor

[jablair]

Victor,

First of all it's John, Mr. Blair was my father.

As for your questions on haplogroups, I'm afraid you're asking the wrong person. I don't really have any interest in haplogorup nor do I spend any time following their discussions. SNP tests and Haplogroups may be of great and interesting when studying the ancient origins of the male line, and for anthropological uses. But the SNP test is not required for a typical surname project for genealogically relevant times frames. When someone is trying to find their 4th, 5th, 6th, ......or even 12th generation ancestors, knowing that their ancestors from 10,000 years ago originated in a certain corner of the world is of little comfort. I think that most people who go into a DNA Surname Project are far more interested in how closely they match other participants on 25 or 37 markers than worrying about their haplogroup.

Until such time as we start seeing participants with very similiar 25 and 37 marker haplotypes being classified in different haplogroups I'm just going to pass on haplogroups.

John

[Victor]

Thank you, John. I guess calling you by your first name doesn't diminish politeness one bit.

I see your point about relevant time frames from the standpoint of a genealogist. As one who's also interested in genealogy, I appreciate your opinion just the same, even in your main interest is not on haplogroups.

In my case, at least at this particular time, I do find myself deeply interested in this topic, because haplogroup E3b is one of those haplogroups who's origins are not that clearly defined and there are conflicting points of view which can change one's outlook on life depending on what you believe. Hopefully, in time things will become more clear and the prevailing doubts will be resolved as new findings are made. Thanks again.

Victor

[jablair]

Victor,

There is no shortage of people who are interested in the subject of haplogroups. For someone like me, who has little interest in the subject, it sometimes seems like everyone else is interested in it.

If you haven't already checked it out, I strongly suggest you try the GENEALOGY-DNA-L mailing list. There has been considerable discussion of almost every aspect of haplogroups you can think of. You can get more information at
http://lists.rootsweb.com/index/othe...ALOGY-DNA.html

Good luck with your research,

John

[Victor]

John,

Your encouragement is appreciated, as well as the link to the mailing list.

And congratulations on your web site. I sincerely believe yours is one of the best genealogical web pages that I've seen. Sincerely!

Victor

[Jim Barrett]

There is no shortage of people who are interested in the subject of haplogroups. For someone like me, who has little interest in the subject, it sometimes seems like everyone else is interested in it.John

John, you aren't alone. I'm much more interested in my ancestors from the last few hundred years.

I also agree with Victor, you have a fabulous web site. I send many interested people to your '101' page, those with enough interest will dig deeper.

[[email protected]]

Distant, but not too distant, common ancestor

It two with the same surname match on 29 of 37, and all mis-matches are by one unit, then would an SNP analysis of each add any further information?

[Jim Barrett]

Have your Group Administrator go to the GAP for your porject. Click on the "Generate Y-DNA Results" link. This will create a results table. If your haplogroup is shown in red FTDNA says, "Haplogroups in red have been predicted by Family Tree DNA based on unambiguous results in the individual's personal page. This has been placed on this GAP page for your ease and convenience. Please note that for any predicted results we see no reason for ordering a SNP test to confirm the Haplogroup." Have him check the haplogroup for the other person also. If both are red, accept the haplogroup shown in your results page, do not order a SNP.

[Victor]

It two with the same surname match on 29 of 37, and all mis-matches are by one unit, then would an SNP analysis of each add any further information?

As I understand it, SNP analysis would be useful in those cases where there's ambiguity about the predicted haplogroup of an individual. If you were thinking of proving or disproving a common ancestry by SNP, then I don't think this is the test to order.

What you need to look into (assuming that you have some documentation to support or hint at your genealogical affinity) are the markers where the mis-matches occur, that is, rapid mutating vs. slow mutating markers. If you have mis-matches occurring on the slow mutating markers chances are lower that you share a common ancestor. On the contrary, if the different values appear on rapid mutating markers (those usually in red on the grid) then chances of a common ancestors are higher, although a genetic distance of -8 (29 of 37) would place your common ancestor way, way back.

Anyway, these are just my opinions. Hopefully, somebody with greater insight into this can provide some feedback to your question.

[[email protected]]

Distant, but not too distant, common ancestor

Thank you both. For better or worse, our results are not with FTDNA, so I don't have access to what you suggest.