[email protected] (J. Hugh Sullivan) wrote: > You might comment on this please... > > I am the only Sullivan (tested so far) who was predicted to be > in the R1a1 haplogroup - the rest are in R1b or R1b1. I > understand that both are (may I say subsets) of R. How likely > is it that I would differ that much unless there was basis? An > educated opinion is sufficient. I ordered a 37 Marker Y-DNA test from FTDNA and the predicated haplogroup provided along with those results was Q3. When I paid for the SNP test (P36+M3-), my haplogroup turned out to be Q. If you're curious, my results are posted here: http://www.Erbland.org/results.htm It's my understanding that haplogroup predictions are considered reasonable because there's a strong correlation between haplotypes (the Marker results) and haplogroups (the SNP results). I do not know if this correlation is uniform with respect to different haplotypes but I suspect not. If that's true, then estimating the likelihood of a prediction being accurate (for example, 19 times out of 20) would vary depending on the haplotype. I have no idea about the actual accuracy rate of haplogroup predictions made from haplotypes. All of this is why I finally ordered the SNP test. Bear in mind that haplogroups don't mean much for finding relatives. I was just curious. I'm no expert at any of this but I think that haplotype information is useful for genealogical purposes because it mutates over a period of a few hundred years or less. Haplogroups, on the other hand, were defined tens of thousands of years ago. This makes these results of very limited use for genealogical purposes. I do not know if it's possible to have a close haplotype match and a haplogroup mismatch; I would think not. If you are comparing your predicted haplogroup with someone else's predicated haplogroup, the chances of an incorrect prediction are doubled. My suspicion is that when two people have a closely matched haplotype, but a predicted haplogroup mismatch, something has gone wrong with the prediction. > Regardless of the haplogroup am I not looking for a 35/37 marker > match, or better, to have any genealogical meaning for me since > my provable data only extends to 1790? I have genealogies and > logic extending further back but no provable link. I'm not sure why you say this. I think it's the reverse. It's my understanding that to 'prove' (statistically speaking) a common relative, tests using more markers are warranted as the common relative gets closer. It must also be kept in mind that genealogical Y-DNA haplotype matches 'prove' things only to a certain level of statistical certainty. They do not have the same level of statistical certainty as the results of a forensic DNA test. Caveat: DNA genealogy is only part of my family history hobby. I'm the administrator of the "Erbland DNA Surname Project". I know nothing about DNA other than what I've picked up as part of my hobby. Cheers, Mardon Mardon <[email protected]>