I am far from an "expert" on DNA, but have had to study it in the past few years as it is becoming an important tool in genealogical research. There is much - most - about DNA and DNA testing that I don't know. I see that Joe Anderson has given an excellent reply to your e-mail about the differences between SNPs which are tested to define your haplogroup (examples R1b -the most common in Europe, or E3a, or I1a or I1b, etc) and STRs which are what is tested in surname projects to define an individual's haplotype or set of results - that long string of numbers reported on the Pace DNA webpage, for example. Generally, DNA testing for surname groups is concerned with the Y-chromosome STR results as those results can be used for sorting out families in a genealogical time frame. Examples from the Pace DNA project would be the differences between the NC Paces Group 3a and 3b results, and also the differences in the results between the John of Middlesex group and the NC Pace Group 3 as a whole. But it should also be noted that the John of Middlesex group and the NC Pace group 3 are in different haplogroups as well. That is they not only don't share ancestors in a genealogical time period, but they don't share ancestors for thousands of years. There are a lot of interesting new developments in haplogroup testing in that several subgroups are being defined and that some of these subgroups are more prominent in different parts of Europe than in others. For most, knowing the new haplogroup subgroup is still an "interesting" new result rather than a result that can help in solving a genealogical puzzle, but in some cases knowing a particular part of Europe where their subgroup predominates may be helpful. But as I mentioned before, the only way to truly know the haplogroup a participant belongs to is by SNP testing. The algorithms used for *predicting* haplogroups based on a person's STR results (the results in the Pace DNA project for example) are very good for some haplogroups, but for other haplogroups where not so much is known there are still non-conclusive results. The problem with prediction is it is that it is an educated guess based on partial results. So, if the prediction is based on only 12 markers (not a very useful number in most cases) and it is wrong then wrong conclusions can be drawn about the ancestral groups in our backgrounds. Hope this helps. Rebecca Roy Johnson <royj@webster.edu> wrote: -----Original Message----- From: Addiefaye4@wmconnect.com [mailto:Addiefaye4@wmconnect.com] Sent: Friday, December 09, 2005 8:48 AM To: royj@webster.edu Subject: Re: [PACE-L] West African YDNA Roy, what is the SNP test? Maybe I need to do it to find my GGG Grandfather, Father of Wyche H. Pace b. 1817 in TN. Addie I used the wrong terminology. The Y chromosome test is an SNP test, as I understand the terminology, testing a snip of DNA. What I intended to say is that I need to upgrade to the 25 marker test. I run the DNA site but Rebecca Christenson actually has studied DNA mush more deeply than I, and I consider her the expert on the subject. Roy ==== PACE Mailing List ==== Check out the new Pace Society of America web page at: www.pacesociety.org, and please join the Pace Society of America for only $25.00 per year.