Tim, So you have Mom has HIR with A(21.7) Mom has HIR on same segment with B(6.5) and A has an HIR on same segment with B This is classic genetic Triangulation. Is there any reason to believe there is more than one Common Ancestor for the 3 of them? The possibility that we are studying is: Mom & A have an IBD HIR from Mom's Dad and A's Mom Mom & B have an IBD HIR from Mom's Mom and B's Mom A & B have an IBD HIR from A's Dad and B's Dad All 3 IBD HIRs are on essentially the same location on the same chromosome number. All 3 pairs would probably have different MRCAs. This is technically possible. The question is what is the probability. I've not seen it (that I recognize), yet. Jim Bartlett On 11/20/13, Tim Janzen<tjanzen@comcast.net> wrote: Dear Jim, The match who shares the HIR that is 21.7 cMs long with my mom also appears as a match on the same segment of chromosome 7 in Family Inheritance: Advanced at 23andMe with the person who shares the 6.5 cM HIR with my mom. I don't have the raw data files for these two matches, but I believe it is highly probable that the HIRs are both IBD given that my brother also shares the same HIRs with both people. We need to move to phased data for these types of comparisons in the future. Hopefully 23andMe and FTDNA will eventually provide that for us. Hopefully Ancestry.com will eventually provide us with the HIR data and will improve the quality of their phased data. I think it is important to note that it is essentially impossible for two or more people to share a phased autosomal haplotype of any significant length and have them get it from different ancestral lines. The phased haplotype must have come from a shared ancestor at some point in the past. However, that shared ancestor isn't always apparent to the testees. Sincerely, Tim -----Original Message----- From: a[1]utosomal-dna-bounces@rootsweb.com [[2]mailto:autosomal-dna-bounces@rootsweb.com] On Behalf Of Jim Bartlett Sent: Wednesday, November 20, 2013 5:17 AM To: [3]autosomal-dna@rootsweb.com Subject: Re: [AUTOSOMAL-DNA] Finding shared atDNA ancestry without phasing Tim Thanks for the examples. Four thoughts for all: 1. Tim didn't mention if the Matches matched each other, on this segment. We are particularly looking for 3 people who all match each other on one segment, and each pair got their atDNA from a different ancestral line. This is very rare, and we're trying to see if anyone has documented this, or if it is so rare that we can dismiss the possibility. 2. As we get beyond close cousins, we'll find there are shared segments and shared ancestry, but the shared ancestry is not from the shared segments. I have many of these cases, including one yesterday: my maternal uncle, Nathan Baker, did Y-DNA 10 years ago and helped prove the "Gunsmith" BAKER line; last night's atDNA match is also a Y-DNA match on this BAKER line - so we are definitely 7th cousins on my maternal BAKERs. Except in my atDNA spreadsheet I've got several folks who match him, who also match my Dad (5-way Triangulation); and a bunch of other folks with close cousinship on my Mom's side, whom he does not match. It is clear to me that this new Baker match and I have another Common Ancestor on my Dad's side, per the atDNA segment... Jim - Sent from my iPhone - FaceTime! References 1. mailto:utosomal-dna-bounces@rootsweb.com 2. mailto:autosomal-dna-bounces@rootsweb.com 3. mailto:autosomal-dna@rootsweb.com

Dear Jim, In my case, the question is whether or not the 6.5 cM segment came down through person #10 or person #15 on my mom's grandmother's pedigree chart, an older version of which may be seen at http://wc.rootsweb.ancestry.com/cgi-bin/igm.cgi?op=PED&db=janzen&id=I8. The 6.5 cM segment could have come from a different ancestor than the rest of the 21.7 cM segment. I don't personally get entangled in situations like the one you raise because I am already segregating my parents matches on any one segment of an isolated chromosome before I compare them to each other. I do that by separating those matches into those who also match me as compared to those who do not match me. This separates the matches into those matching on one chromosome and those matching on the opposite chromosome. Therefore in my parents' match lists I am never comparing A to B as in your situation. In any case, your situation will occur at least on rare occasion. I haven't seen that exact situation, however. Sincerely, Tim -----Original Message----- From: autosomal-dna-bounces@rootsweb.com [mailto:autosomal-dna-bounces@rootsweb.com] On Behalf Of Jim Bartlett Sent: Wednesday, November 20, 2013 8:19 PM To: autosomal-dna@rootsweb.com Subject: Re: [AUTOSOMAL-DNA] Finding shared atDNA ancestry without phasing Tim, So you have Mom has HIR with A(21.7) Mom has HIR on same segment with B(6.5) and A has an HIR on same segment with B This is classic genetic Triangulation. Is there any reason to believe there is more than one Common Ancestor for the 3 of them? The possibility that we are studying is: Mom & A have an IBD HIR from Mom's Dad and A's Mom Mom & B have an IBD HIR from Mom's Mom and B's Mom A & B have an IBD HIR from A's Dad and B's Dad All 3 IBD HIRs are on essentially the same location on the same chromosome number. All 3 pairs would probably have different MRCAs. This is technically possible. The question is what is the probability. I've not seen it (that I recognize), yet. Jim Bartlett