Although my husband and I do not show up in each other's matches at FTDNA or Gedmatch (10cm+), in using the "autosomal comparison with one ot her person" utility, I find that we match at 6.6 genera tions, 4.9 cm largest segment and 26.1 total segmen ts. In addition, I match all of his top 15 matches (10cm+) at 3.9 - 7.3 generations. He matches all of my top 24 matches at 4.5 - 7.4 generations. - Other than being shocked, how do you interpret this? - Since these generations are so remote, would they be so unreliable as to be invalid? - Or, would we probably be 5th cousins? Thank you for any clarity you could give me. ----- Original Message ----- From: "Tim Janzen" <[email protected]> To: [email protected] Sent: Friday, June 22, 2012 11:54:35 PM Subject: Re: [AUTOSOMAL-DNA] Chromosome Browser Dear Greg, You should review your family's list of matches to see what percentage of your parents' matches are also matching you. In theory, 50% of your parents' matches should also match you on exactly the same segment. However, you will probably find that if you do this that the percentage of your parents' matches who also match you on exactly the same segment is somewhat less than 50%. This would suggest that a portion of your parents' matches who don't also match you are false matches (IBS). You don't necessarily have to test your half-brother. However, if you did then you could be reasonably certain that any people who match both your half-brother and your father but don't match you are IBD. That can be helpful information to have, particularly if the matching segment is fairly short. You don't need to pursue your half-brother's maternal matches. You only need to concentrate on your dad's matches. I think that the best way to illustrate this problem is to post again some information I shared with this list on Jan. 9 and Jan. 10. See below. A portion of our lower level matches are IBS. It would be nice to know that a match is IBD before you go to a lot of work trying to research someone else's family tree trying to find a genealogical connection. I want to review and research the family trees of people I am reasonably certain share a genealogical connection with me and I want to avoid reviewing and researching the family trees of people who are false matches (IBS) to my family. Sincerely, Tim I decided to download the Ancestry Finder matches from 23andMe for my parents, my wife's parents, my wife, and me. I then sorted the data to remove the anonymous matches. I then compared my wife's and my matches to our parents' matches to see if any of my wife's or my matches in Ancestry Finder were not found in the Ancestry Finder matches for our parents. Below is an analysis of the results: cMs %IBD %IBS >10 100 (51/51) 0 9-10 87 (14/16) 13 8-9 91 (31/34) 9 7-8 79 (33/42) 21 6-7 67 (65/97) 33 5-6 43 (80/185) 57 I decided to download the latest Family Finder data for my wife's parents, my wife, my parents, and me yesterday. I then analyzed the data so see how many people appear in the FF match lists for my wife and me who don't appear in the FF match lists of our parents. I then used that data to create my own statistics regarding the percentage of matches at various segment lengths in cMs to see how my data compares to the statistics that John Walden generated. Here are my results: cMs %IBD %IBS >11 100 (52/52) 0 10-11 80 (12/15) 20 9-10 93 (25/27) 7 8-9 81 (34/42) 19 7-8 46 (11/24) 54 6-7 67 (4/6) 33 5-6 40 (6/15) 60 4-5 20 (10/51) 80 3.5-4 17 (11/66) 83 Below are John Walden's results from his analysis that I posted in another message several days ago: cM %IBD %IBS 10 99 1 9 80 20 8 50 50 7 30 70 6 20 80 5 5 95 -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Greg Matthews Sent: Friday, June 22, 2012 7:59 PM To: [email protected] Subject: Re: [AUTOSOMAL-DNA] Chromosome Browser Maybe I'm not understanding this, but why would you want to test your brothers if you already have both of your parents tested? I had my father tested with the last FTDNA sale so I now have results at FTDNA for both parents. I thought I'd be able to determine IBD segments now. If this isn't the case all I have left to me is a half-brother (from my father) that could be tested. I hesitate to go down that path because I have zero interest in the matches that might come from my brother's maternal side. Thanks Greg Matthews ______________________________ For answers to Frequently Asked Questions about mailing lists, please see: http://dgmweb.net/MailingListFAQs.html ------------------------------- To unsubscribe from the list, please send an email to [email protected] with the word 'unsubscribe' without the quotes in the subject and the body of the message
Dear eandmshafer, You should approach this situation very cautiously. You certainly don't need to be "shocked". Do you have a child who has also been tested? If so, then I would suggest that you first phase your husband's data, your data, and your child's data. I would then review the phased 4.9 cM segment and see if it a true match (IBD) or a false match (IBS). You need to bear in mind that there is at least a 50% probability that a 4.9 cM HIR will be IBS. Sincerely, Tim Janzen -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of [email protected] Sent: Saturday, June 23, 2012 4:25 AM To: [email protected] Subject: Re: [AUTOSOMAL-DNA] [AUT. OSOMAL-DNA] Chromosome Browser Although my husband and I do not show up in each other's matches at FTDNA or Gedmatch (10cm+), in using the "autosomal comparison with one ot her person" utility, I find that we match at 6.6 genera tions, 4.9 cm largest segment and 26.1 total segmen ts. In addition, I match all of his top 15 matches (10cm+) at 3.9 - 7.3 generations. He matches all of my top 24 matches at 4.5 - 7.4 generations. - Other than being shocked, how do you interpret this? - Since these generations are so remote, would they be so unreliable as to be invalid? - Or, would we probably be 5th cousins? Thank you for any clarity you could give me.