If I understand your suspicion correctly, there is a table towards the bottom of this web site that correlates % IBD, % IBS vs cM. It essentially shows fro each cM below a 10 cM segment how quickly the probability of a true ancestral match drops to a match by identical state. Mike Z. ----- Original Message ----- From: peterebay@yahoo.com To: autosomal-dna-l@rootsweb.com Sent: Thursday, November 21, 2013 1:20 PM Subject: Re: [AUTOSOMAL-DNA] Finding shared atDNA ancestry without phasing I suspect a percentage estimate could be calculated for the likelihood of there NOT being shared ancestry when your matches on a particular 7+cM segment also all match each other on that segment. I would guess that it is less than one percent. This formula should include a variable for endogamy. I believe automated phasing is the ideal method. However very few people have the time or skill to use current procedures and tools. I contend that in the large majority of cases, you share a specific ancestral branch with your matches who all match each other on a specific atDNA segment measuring 7cM or greater. Sincerely, Peter Peter J. Roberts

Opps, I forgot I could not embed links in the text. The web site is at: http://www.isogg.org/wiki/Autosomal_DNA_statistics ----- Original Message ----- From: Mike To: autosomal-dna@rootsweb.com Sent: Thursday, November 21, 2013 1:33 PM Subject: Re: [AUTOSOMAL-DNA] Finding shared atDNA ancestry without phasing If I understand your suspicion correctly, there is a table towards the bottom of this web site that correlates % IBD, % IBS vs cM. It essentially shows fro each cM below a 10 cM segment how quickly the probability of a true ancestral match drops to a match by identical state. Mike Z. ----- Original Message ----- From: peterebay@yahoo.com To: autosomal-dna-l@rootsweb.com Sent: Thursday, November 21, 2013 1:20 PM Subject: Re: [AUTOSOMAL-DNA] Finding shared atDNA ancestry without phasing I suspect a percentage estimate could be calculated for the likelihood of there NOT being shared ancestry when your matches on a particular 7+cM segment also all match each other on that segment. I would guess that it is less than one percent. This formula should include a variable for endogamy. I believe automated phasing is the ideal method. However very few people have the time or skill to use current procedures and tools. I contend that in the large majority of cases, you share a specific ancestral branch with your matches who all match each other on a specific atDNA segment measuring 7cM or greater. Sincerely, Peter Peter J. Roberts ______________________________ 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 AUTOSOMAL-DNA-request@rootsweb.com with the word 'unsubscribe' without the quotes in the subject and the body of the message