Lindsey The smaller X-matches at Ftdna are not very reliable. I apply the 23andme sex based filter when looking at Family finder X-matches. The match must be larger than both the cM and SNP thresholds X (male vs male): 200 SNPs, 1 cM X (male vs female): 600 SNPs, 6 cM X (female vs female): 1200 SNPs, 6 cM Females show a high percentage of false X-matches at Ftdna, probably over 70% of them are Identical by chance rather than by descent. I am male and show 21 X-matches out of over 1300 total matches. My full sister shows 287 X-matches out of over 1400 total matches My sister inherited about 10% more of our grandparents UK Dna than I did, which is reflected in our total number of matches. RPaine -----Original Message----- From: Lindsey Britton via Sent: Thursday, November 26, 2015 6:40 AM To: GENEALOGY-DNA@rootsweb.com Subject: [DNA] Question about Crossovers on X Chromasome I have done very little with my Mother's FF test but last week an e-mail from a match (I'll call her #1) inspired me to start searching for the common ancestor. That search produced a second (#2) and closer match (new on November 4th) for my mother. Match #1 has also tested her mother, son, and several other relatives; however, she matches my mother and match #2 on the X chromosome whereas the her mother does not, indicating that the X match came from her father's side.. (The other relatives, including her sister, don't match at all.) I wrote to Match #2 because she has ancestors in Oxfordshire just as we do, and her reply identified at least one ancestral line. I am now waiting to hear exactly how she is related to my mother's 3rd great grandmother Mary Eley. FTDNA lists them as 2nd-4th cousins--probably third, but she does not descend from Mary so the relationship will be somewhat more distant. There is no question about this relationship, though; our Eley line is well-documented back to the 1600s in Oxfordshire. The question is: do we have other lines in common which make this relationship appear closer than it is? Mary Eley passed her X chromosome to her son John Lindsey, but since it did not descend to his son (my mother's grandfather), there must be at least one more common line of descent unless the X matches lie within a pseudoautosomal region. Can anyone tell me the exact locations of PAR1, PAR2, and PAR3? The matches are at the centromere, but I don't know whether they extend beyond that region. Match 1: 53915099-67881743 Match 2: 51333207-67881743 I have checked every X match on the first two pages of X matches and discovered 14 more with the same end point. Of the four others with different end points, two had the same start point as Match #1. A third had the same start point as one of the group of 16, and the fourth, like Match 2, had a unique (so far) start point. Another related question--how does one decide, in the absence of paper evidence, that the match is actually on the same chromosome when either the start or end point doesn't match exactly or when the matching regions overlap but neither the start nor end point matches? Last question--does anyone know when FTDNA plans to make the new FF tools available? Lindsey ------------------------------- To unsubscribe from the list, please send an email to GENEALOGY-DNA-request@rootsweb.com with the word 'unsubscribe' without the quotes in the subject and the body of the message

Robert, Thank you--I thought there must be a problem somewhere, but didn't know the nature of it. I will use these filters from now on--they should shorten my list of 39 pages of X matches considerably. It's unfortunate FTNA doesn't have a sex-based filter and better tools in general for FF. I'm sorry 23 and me combines medical and genealogical tests--otherwise, I would probably have opted for 23 and me over FF because of the additional genetic information that test provides, but I don't want a medical test which might cause unnecessary concern. We haven't yet reached the point where the consequences of various mutations are properly understood. Lindsey -----Original Message----- From: Robert Paine <rpaine@vom.com> To: Lindsey Britton <lplantagenet@aol.com>; genealogy-dna <genealogy-dna@rootsweb.com> Sent: Thu, Nov 26, 2015 12:43 pm Subject: Re: [DNA] Question about Crossovers on X Chromasome Lindsey The smaller X-matches at Ftdna are not very reliable. I apply the 23andme sex based filter when looking at Family finder X-matches. The match must be larger than both the cM and SNP thresholds X (male vs male): 200 SNPs, 1 cM X (male vs female): 600 SNPs, 6 cM X (female vs female): 1200 SNPs, 6 cM Females show a high percentage of false X-matches at Ftdna, probably over 70% of them are Identical by chance rather than by descent. I am male and show 21 X-matches out of over 1300 total matches. My full sister shows 287 X-matches out of over 1400 total matches My sister inherited about 10% more of our grandparents UK Dna than I did, which is reflected in our total number of matches. RPaine -----Original Message----- From: Lindsey Britton via Sent: Thursday, November 26, 2015 6:40 AM To: GENEALOGY-DNA@rootsweb.com Subject: [DNA] Question about Crossovers on X Chromasome I have done very little with my Mother's FF test but last week an e-mail from a match (I'll call her #1) inspired me to start searching for the common ancestor. That search produced a second (#2) and closer match (new on November 4th) for my mother. Match #1 has also tested her mother, son, and several other relatives; however, she matches my mother and match #2 on the X chromosome whereas the her mother does not, indicating that the X match came from her father's side.. (The other relatives, including her sister, don't match at all.) I wrote to Match #2 because she has ancestors in Oxfordshire just as we do, and her reply identified at least one ancestral line. I am now waiting to hear exactly how she is related to my mother's 3rd great grandmother Mary Eley. FTDNA lists them as 2nd-4th cousins--probably third, but she does not descend from Mary so the relationship will be somewhat more distant. There is no question about this relationship, though; our Eley line is well-documented back to the 1600s in Oxfordshire. The question is: do we have other lines in common which make this relationship appear closer than it is? Mary Eley passed her X chromosome to her son John Lindsey, but since it did not descend to his son (my mother's grandfather), there must be at least one more common line of descent unless the X matches lie within a pseudoautosomal region. Can anyone tell me the exact locations of PAR1, PAR2, and PAR3? The matches are at the centromere, but I don't know whether they extend beyond that region. Match 1: 53915099-67881743 Match 2: 51333207-67881743 I have checked every X match on the first two pages of X matches and discovered 14 more with the same end point. Of the four others with different end points, two had the same start point as Match #1. A third had the same start point as one of the group of 16, and the fourth, like Match 2, had a unique (so far) start point. Another related question--how does one decide, in the absence of paper evidence, that the match is actually on the same chromosome when either the start or end point doesn't match exactly or when the matching regions overlap but neither the start nor end point matches? Last question--does anyone know when FTDNA plans to make the new FF tools available? Lindsey ------------------------------- To unsubscribe from the list, please send an email to GENEALOGY-DNA-request@rootsweb.com with the word 'unsubscribe' without the quotes in the subject and the body of the message