In August I asked several questions about the new Ancestry YDNA testing service. There were no substantive replies to the question asked, though several replies indicated skepticism about the use of YDNA. The question remains a matter of interest. In following up another problem this morning I came across the Sorenson site which provides a nice comparison of different YDNA testing services and the markers used for a 37 marker test. http://www.smgf.org/ychromosome/marker_standards.jspx These data seem to be directed more toward systematic differences in values assigned to the markers tested which seems to vary between testing services. In many cases there's a direct conversion from one service to another, but in other cases no conversion is known. As a result, if you make certain choices as to testing service, comparability with results from other testing services may be difficult, or limited. The Sorenson data does not immediately answer the specific questions asked. Vis-a-vis, Ancestry and FTDNA, the results look to be generally comparable. If you did a 33 marker test on Ancestry per their suggestion, it seems that it would be comparable with data from a 37 marker test on FTDNA, though obviously you wouldn't be able to compare results for the 4 markers not tested in Ancestry's 33 marker test. I note that four markers (probably different from the four excluded by Ancestry in the 33 marker test) require some degree of conversion. Q On Thu, Aug 7, 2008 at 10:17 AM, Q <quolla6@gmail.com> wrote: > Ancestry is now offering YDNA testing. Their on-site blurb for the > YDNA test reads > CHOOSING Y-33 VS Y-46 > > - > > The Paternal Lineage Y-chromosome 33 test is recommended because > it provides the minimum number of markers needed to obtain a > meaningful match between participants. > > - > > You may choose the Y-chromosome 46 test if you want to further > narrow the span of generations for finding a common ancestor with > another participant's Y-46 test. > > What this looks like is a test for 33 markers, versus a test for > 46 markers, but they do not state this explicitly. Nor do they > seem to indicate which markers are being tested. > > I have three questions I hope someone can speak to: > > 1. Does anyone have any experience with YDNA testing on > Ancestry? How does their presentation of results compare with > those of FTDNA (for example) > > 2. Is this indeed for either a 33 marker or 46 marker test? > > 3. If so, this does not match up with the number of markers > commonly tested by FTDNA. Presumably they are testing different > suites of markers. Does anyone know how well the Ancestry suite > compares to the FTDNA tests? > > Q <quolla6@gmail.com>