Dear Gordon Y-STR Marker mutation rates are, in practice, a large and quite complicated subject, mostly because folk do not appreciate that such rates are random and thus can only be applied to large datasets. Most folk want to apply them to their particular testing scenarios which almost always involves too few people. The ISOGG Wiki is a very good place to start to begin to understand the complexity involved. You just need to read some of the papers here to get some idea of the issues. https://isogg.org/wiki/Mutation_rates This is one area of DNA testing where it is quite challenging to produce a simplified explanation which is both useful and scientifically valid. Brian -----Original Message----- From: GOONS [mailto:goons-bounces+bps=norvic8.force9.co.uk@rootsweb.com] On Behalf Of Gordon Adshead Sent: 04 May 2017 16:51 To: GOONS <goons@rootsweb.com> Subject: [G] Y-DNA Mutation Rates I have a question please about likely DNA mutation rates So far, I have only managed to Y-37 test 18x ADSHEADs each in different Trees These form two quite separate genetic groups plus 3x odd-balls. In one group of 6x Manchester based trees:- 2 are identical at 37 markers and the other 4 all differ by one marker, but each at a different site. The two with the same signature at Y-37 have just up-graded the test to Y-67 and they remain completely identical at all 67 markers. This tends to confirm that the two documented heads of these trees <David bap.Manchester Cathedral 1750 : Father John> and <Nathaniel bap.Manchester Cathedral 1752: Father John> are in fact brothers. My issue is that the two persons tested are each 7 generations down from their presumed common ancestor John ie There are 14 births involved with apparently no mutations. Can anybody give me some idea please Is this a common or rare situation ? Or better still could you point me at some sort of quantification of the known mutation rates of each of the 67 markers So I can work out the probability of No mutations in 14 births. Many thanks Gordon [+Z] Gordon Adshead <gordon@adshead.com> [+Z] Beaumont House, 2 Goodrington Road, Handforth, Cheshire, SK9 3AT, UK [+Z] Tel:+44-1625-549770 Mob:+44-7776-145602 _____________________________________________ Information and admin page: http://one-name.org/guild-information-administration/ ------------------------------- To unsubscribe from the list, please send an email to GOONS-request@rootsweb.com with the word 'unsubscribe' without the quotes in the subject and the body of the message

The only couple I have (A and B) with a known common ancestor are 2 markers different at 37 markers. The common ancestor is 12 generations back in one line and 15 generations back in the other. A third person is an exact match at 37 markers with A (with the same two mutations), and three GD from B at 67 markers. That third person hasn't yet been linked to the tree or a common ancestor. Corinne, Sennett ONS > -----Original Message----- > From: GOONS [mailto:goons-bounces+bps=norvic8.force9.co.uk@rootsweb.com] On > Behalf Of Gordon Adshead > Sent: 04 May 2017 16:51 > To: GOONS <goons@rootsweb.com> > Subject: [G] Y-DNA Mutation Rates > > I have a question please about likely DNA mutation rates > My issue is that the two persons tested are each 7 generations down > from their presumed common ancestor John > ie There are 14 births involved with apparently no mutations. > > Can anybody give me some idea please > Is this a common or rare situation ? > > Or better still could you point me at some sort of quantification of > the known mutation rates of each of the 67 markers > So I can work out the probability of No mutations in 14 births. > > Many thanks > Gordon