tag:blogger.com,1999:blog-11673175.post5304353414402963300..comments2023-10-09T04:56:52.251-04:00Comments on On Genetics: Genetic Genealogy and the Single SegmentStevehttp://www.blogger.com/profile/15264977010144529019noreply@blogger.comBlogger37125tag:blogger.com,1999:blog-11673175.post-65720788962236467112019-08-15T17:34:12.275-04:002019-08-15T17:34:12.275-04:00Yikes!
Thank you for catching that error. I've...Yikes!<br />Thank you for catching that error. I've corrected it. Stevehttps://www.blogger.com/profile/15264977010144529019noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-49686891731202843492019-08-15T06:18:30.990-04:002019-08-15T06:18:30.990-04:00Thank you for a very helpful blog post. One small ...Thank you for a very helpful blog post. One small point. We actually have 32 great-great-great grandparents. We have 64 great-great-great-great grandparents.Debbie Kennetthttps://www.blogger.com/profile/11573470282571579765noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-90653430427278599002019-08-04T20:13:13.536-04:002019-08-04T20:13:13.536-04:00ongenetics@gmail.comongenetics@gmail.comStevehttps://www.blogger.com/profile/15264977010144529019noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-57931906658848405562019-08-04T20:04:50.841-04:002019-08-04T20:04:50.841-04:00Thanks very much for the response. Jo is actually ...Thanks very much for the response. Jo is actually much younger than Dale. Dale is 81, I am 61 and Jo is about 49. So, I think that the very most likely scenario is that Dale is Jo's half uncle. My parents and grandparents were of above average age when having children, so I think that Jo and I are of the same generation, and Dale is one generation older.<br /><br />Dale and I are in communication. Jo only communicated with me once, and told me the name of her birth mother, and her birth mother's father.<br /><br />Dale has tried to reach out to Jo, but has received no response.<br /><br />If you would like to contact me, let me know, and I will send you an email.<br /><br />JenniferJenniferhttps://www.blogger.com/profile/08007770461119371047noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-51790273712406842542019-08-04T19:00:29.287-04:002019-08-04T19:00:29.287-04:00Based on their degree of relationship, Jo and Dale...Based on their degree of relationship, Jo and Dale are second degree relatives. <br /><br />First degree relatives share about 50% of their DNA by descent, and examples would be parent/child or full siblings. There are differences between parents and siblings in that you share one complete copy of your genome with each parent, but have a mixture of 0, 1 and 2 copies in common with a sibling.<br /><br />Second degree relatives share about 25% of their DNA by descent, and examples would be half-siblings, aunt-uncle/neice-nephew, or grandparent/grandchild.<br /><br />You can reliably distinguish first degree relatives from second degree relatives, but you (and 23andMe) cannot distinguish different types of second-degree relative (niece, nephew / aunt, uncle; grandparent / grandchild; half-siblings. <br /><br />Since you are <b>probably</b> more closely related to Jo than to Dale, I favor scenarios where Jo is closer to a common ancestor. Is Jo older than Dale? Could she be his aunt? Could she be his grandmother? Are Jo and Dale happy talking about these possibilities? I don't want to participate in the invasion of anyone's privacy. Stevehttps://www.blogger.com/profile/15264977010144529019noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-30127722140861100622019-08-04T13:29:20.969-04:002019-08-04T13:29:20.969-04:00Hi Steve,
I really appreciate this thread, and al...Hi Steve,<br /><br />I really appreciate this thread, and all the help you continue to give people.<br /><br />I have two DNA relatives tested on 23&Me, Dale (male) and Jo(female). Dale and I share only 35 cM, 3 segments, Jo and I share 174 cM and 11 segments, while Dale and Jo are very closely related and share 1017 cM and 33 segments. All of the 3 segments I share with Dale, I also share with Jo. The largest is 21 cM. I think this definitely indicates that the three of us have a common single ancestor.<br /><br />I have two theories for our relationships, and I'm wondering if you can help me decide which is more likely. In both theories Jo and Dale are half niece, half uncle. They were both adopted as children.<br /><br />Theory A is that we share only one female relative (who had two husbands). This person would be my and Jo's 2nd great grandmother and Dale's great grandmother. I would be Jo's half 3C, and Dale's half 2C1R. But my shared cM with Jo are very high for this scenario.<br /><br />Theory B is that we share one male common ancestor, as well as the common female ancestor from Theory A. This second person would be my and Jo's great grandfather, and Dale's grandfather. I would be Jo's half 2C+ and Dale's half 1C1R+.<br /><br />I've put in the + because that is taking into account only the shared male ancestor, and not the additional female ancestor. (there is a close consanguineous relationship in Theory B)<br /><br />Theory B fits my 174 cM match with Jo much better, but doesn't fit the relatively low 35 cM match I have with Dale. Any insight you can give would be helpful.<br /><br />Jennifer<br /><br />Jenniferhttps://www.blogger.com/profile/08007770461119371047noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-27064806537553101192018-04-01T18:48:38.365-04:002018-04-01T18:48:38.365-04:00Hi Terri,
Based on the 29% number, you are almost...Hi Terri,<br /><br />Based on the 29% number, you are almost certainly second-degree relatives. Second degree relatives share about 25% of their DNA by descent, and examples would be half-siblings, aunt-uncle/niece-nephew, or grandparent/grandchild.<br /><br />Two half-sisters with the same father share their entire X chromosome, which would explain the 191.9 cM. match (that would be the size of most of the X). If she were your aunt, then the shared X would probably have undergone recombination, which would have almost certainly resulted in some discontinuity. I've known several cases of women who discovered a half-sister, previously unknown to them, in exactly this way.<br /><br />I encourage you to be understanding when you correspond with your relative. This can be a very sensitive matter, particularly if their family was unaware of yours.<br /><br />If you have any further genetics questions I'm happy to help. You can write to me at gmail using the id ongenetics.<br /><br />Good luck with this. <br /><br />Steve<br />Steve On Geneticshttps://www.blogger.com/profile/15695457074293331422noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-20737469208193418812018-04-01T10:21:53.372-04:002018-04-01T10:21:53.372-04:00I took the DNA test on ancestry and I have a close...I took the DNA test on ancestry and I have a close relative that I share 32 segments with. The largest is 191.9...shared dna is 29.2%.<br />I don't know how we are related ..<br />I don't know who my Father is!!<br />Any Help would really be Wonderful..Anonymoushttps://www.blogger.com/profile/06561218207130241449noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-67030204635069067352017-11-26T12:04:36.940-05:002017-11-26T12:04:36.940-05:00I have a new unknown if cousin who was put up for ...I have a new unknown if cousin who was put up for adoption in 1986 in California. She shares 44cms across 4 sectors. She is 15 years younger than I am. She is biracial. All of our shared matches on ancestry are my daughter, my brother, my 1st cousins on my father’s side and second cousins that all connect to my father’s side. My father’s ancestry I’d Irish and German and this woman’s highest amount is in that range. After reading this article I wonder whether the 4th cousin would be true or if she is actually closer than that and whether she could be closer than tha5. Thoughts?Paige's Lifehttps://www.blogger.com/profile/05234717147803864346noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-83744707699550283122017-05-02T03:22:07.063-04:002017-05-02T03:22:07.063-04:00I hope I'm not commenting twice. I hit "p...I hope I'm not commenting twice. I hit "publish your comment," and it disappeared.<br />My comment was:<br />A) Thanks for your reply. I apologize for not explaining that the test I referred to in my previous question was a Y-DNA test of 67 alleles, starting with "DYS393", done on my brother. Can a change in the value of 1 allele between two men really equal a "genetic distance" of one century between the men and their common ancestor?<br />I was originally wondering if it were really right to use a term for the distance between loci on a Genetic map to mean a measure of the relatedness between two people.<br />B) The outfit which analyzed my brother's DNA result uses this method for computing mutation rates per century: They discard the maximum 9 rates and the minimum 9 rates, and average the rates for the middle 47 participants in their project. This doesn't sound scientific to me.<br />I would appreciate your thoughts on these two subjects. Thanks again!Mary of Sherwoodhttps://www.blogger.com/profile/02843234037235116080noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-36323904705517923212017-04-30T11:51:45.547-04:002017-04-30T11:51:45.547-04:00Mary,
Without knowing what DNA kit you are talkin...Mary,<br /><br />Without knowing what DNA kit you are talking about, or what markers were used, or even what type of markers were used, I can't give you a good answer. Several (maybe most) genealogy companies use reasonable statistical models, but many (maybe all) overstate the confidence with which they can say that you have ancestors of a particular ethnicity.<br /><br />Also, as this blog post points out, no one can rule out from your DNA that someone who lived 400 years ago was a genealogical ancestor. It is quite possible to inherit no DNA whatsoever from such an ancestor.<br /><br />I might also reiterate that in 2017 it makes no sense for anyone to buy a DNA kit that involves less than 200,000 markers.<br /><br />Best of luck,<br /><br />Steve MountSteve On Geneticshttps://www.blogger.com/profile/15695457074293331422noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-90602542846752616582017-04-30T09:37:53.381-04:002017-04-30T09:37:53.381-04:00Professor Steve,
What do you think about the DNA-k...Professor Steve,<br />What do you think about the DNA-kit sellers using the term "genetic distance," from studies of population statistics, to mean the difference in alleles as a function of the probability of having a common ancestor? Is there any validity to their calculations? I mean, if you share 26 markers of zero difference, and 16 markers of one difference, with a man who lived 400 years ago, does that really mean your common ancestor lived more than 2,000 years ago?Mary of Sherwoodhttps://www.blogger.com/profile/02843234037235116080noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-32147282313849458192016-03-16T08:41:22.073-04:002016-03-16T08:41:22.073-04:00My former husband has a child with a girl who shar...My former husband has a child with a girl who shares his last name and they are from the same town. They are not positive but are believed to be cousins. My husband was found to be the father of the child through dna. He has since passed away. The child has no resemblance to him or my former husbands family in anyway at all.<br />We have a son together that looks just like my former husbands mom. Is there any possible way the dna of him being the father could be false due to the mother and father being cousins?kat31504https://www.blogger.com/profile/15338508216865641446noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-64688096259974945672015-09-08T19:40:42.636-04:002015-09-08T19:40:42.636-04:00i wanted to post the ged natch test but could not ...i wanted to post the ged natch test but could not , but i got this Thanks to Felix Immanuel for making these ancient DNA samples available to GEDmatch users.<br />More info at his website on the Ancient DNA page at www.y-str.org/p/ancient-dna.html.<br />Segments shown are larger than 2.0 cM and 200 SNPs.<br />http://v2.gedmatch.com/gifs/archaic_M279778_EB4566.gifjita'ame salumahttps://www.blogger.com/profile/11806370301043105261noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-53801487964361918822015-09-08T19:13:06.323-04:002015-09-08T19:13:06.323-04:00i tested to 2cm's of dna to Clovis child who d...i tested to 2cm's of dna to Clovis child who died 12.700 years ago , i was left feeling confused about what this meant because i think thats pretty high for a person who was 2 and died that long ago , please could you tell me am i wrong , i think it means my ancestor must have been quite closely related to him ? jita'ame salumahttps://www.blogger.com/profile/11806370301043105261noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-84090159591324408652015-02-07T14:52:25.225-05:002015-02-07T14:52:25.225-05:00I've been on 23andme for a little over a year....I've been on 23andme for a little over a year. Besides my brother (whom I got to sign up) I found two definite relatives -- one a 2nd cousin once removed on my father's side (his great-grandfather was my grandmother's younger brother) and a 2nd cousin on my mother's side (her mother was my mother's 1st cousin). I recently got someone to agree to share. I have a 133CM match with him, but my brother has a 179CM match with him. What's even more interesting is that he shares two very long segments with my brother -- one 46CM and another 51CM. I suspect that he is really a 2nd cousin, but we can't figure out how. The closest that we've come is that his great-grandparents moved to Palestine in 1880, as did mine, but they lived about 20 miles apart. His grandparents emigrated to Australia, and my grandfather to the USA. I would think that having two such long matches makes it highly likely that this is not spurious, as many other Ashkenazi matches are. What do you think?Victorhttps://www.blogger.com/profile/12861873904800186860noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-72708448557268774692014-09-30T12:29:43.551-04:002014-09-30T12:29:43.551-04:00I was recently notified of an mtDNA HVR1 match in ...I was recently notified of an mtDNA HVR1 match in Haplogroup K1a1b1. I have hundreds of Y-DNA matches and to date have not been able to find any genealogical connections.<br /><br />The fact that this was through the mitochondrial side left me little hope of ever finding a connection to the other gentleman but in a few short days I was able to locate him, share our family trees and make the family connection.<br /><br />He and I are 10th cousins. We share Robert Rose born 1594 in Elmswell, Suffolk, England and his wife Margery Evered as 9th great-grandparents. <br /><br />Given the fact that we both had to have had myDNA tests run at the same genetics testing lab, we both had to have done extensive research into our family history and that we connect over 400 years ago I was curious as to the odds of actually discovering this relationship.Anonymoushttps://www.blogger.com/profile/15154749999811634852noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-2550997537475604202014-09-30T12:25:38.069-04:002014-09-30T12:25:38.069-04:00I was recently notified of an mtDNA HVR1 match in ...I was recently notified of an mtDNA HVR1 match in Haplogroup K1a1b1. I have hundreds of Y-DNA matches and to date have not been able to find any genealogical connections.<br /><br />The fact that this was through the mitochondrial side left me little hope of ever finding a connection to the other gentleman but in a few short days I was able to locate him, share our family trees and make the family connection.<br /><br />He and I are 10th cousins. We share Robert Rose born 1594 in Elmswell, Suffolk, England and his wife Margery Evered as 9th great-grandparents. <br /><br />Given the fact that we both had to have had myDNA tests run at the same genetis testing lab, we both had to have done extensive research into our family history and that we connect over 400 years ago I was curious as to the odds of actually discovering this relationship.Anonymoushttps://www.blogger.com/profile/15154749999811634852noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-90319110901136989732014-08-24T16:38:04.110-04:002014-08-24T16:38:04.110-04:00To answer Sarah:
You are likely to share more seg...To answer Sarah: <br />You are likely to share more segments with closer relatives, but it's not a simple relationship. Longer segments are also indicative of a close relationship (because the typical segment shared by descent will get shorter in each generation). Also, people with ancestors in a group with small effective population size due to isolation (for example, Puerto Ricans and Ashkenazi), will recognized closer relatives as those with larger segments, not those with more segments. Stevehttps://www.blogger.com/profile/15264977010144529019noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-55571566921347329052014-04-29T14:16:49.661-04:002014-04-29T14:16:49.661-04:00This comment has been removed by a blog administrator.Taylahttps://www.blogger.com/profile/06031066791339901627noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-65908445977569687142014-04-29T14:11:43.557-04:002014-04-29T14:11:43.557-04:00Hello Steve, I truly enjoyed reading your fascinat...Hello Steve, I truly enjoyed reading your fascinating post. Genetics and how it can be associated with genealogy is one of the parts of genetics that I find most interesting. Thank you for writing such an informative post. I'm glad that someone is able to clear up the simple misconceptions that have been created. Genes are wonderful parts of us that still have much to be discovered about them but they have been made out to be these miracle 'maps' to our entire ancestry paths, which is completely, as you rightly stated, false. Thank you again for you information. I have learnt a lot!<br /><br />Tayla Scott<br />BSc studentTaylahttps://www.blogger.com/profile/06031066791339901627noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-12663812161281677652014-04-24T09:30:15.340-04:002014-04-24T09:30:15.340-04:00Hi Steve,
I recently got on 23andme and I have ab...Hi Steve,<br /><br />I recently got on 23andme and I have about 995 dna relatives. I am adopted and to not have much family history. Do you know if the number of segments you have in common with someone affects how close the relationship may be? SarahAnonymoushttps://www.blogger.com/profile/11739392332163323355noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-6097813668135341772013-09-05T17:32:49.314-04:002013-09-05T17:32:49.314-04:00I heard there was inbreeding with my grandmother.....I heard there was inbreeding with my grandmother...her uncle may have been the father of some of her many children. She died very young, so no one really knew her in my family.<br /><br />How will that inbreeding most likely show up with DNA results of those children?<br /><br />I have two unknown relative matches who have 4 matching segments, .79% matches, on 23andme. They haven't written back to me, yet, but I'm wondering if they are possibly relatives from the children of my grandmother. <br /><br />Would the 4 matching segments possibly show inbreeding on their side?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-11673175.post-23544109408945179222013-07-30T14:13:26.052-04:002013-07-30T14:13:26.052-04:00I see it has been while since you posted this but ...I see it has been while since you posted this but I am finding how to look at the 23 an me genome is not easy. I have only had my result back for a couple of weeks with 993 matches. I have had about 60 respondents and am tracking the results in a spreadsheet and have a couple of genetic questions. I have one individual who matches me on three genomes (total 37 mb) all on the right. Does that indicate that she matches on my mother's side? I have another gal who matches me on the same genome on both the left and right side for a total of 33mg and she knows nothing of her genealogy. These two do not match but I understand that they may have just not inherited the same piece of DNA. Is any of this relevant?Miami Valley Emancipationshttps://www.blogger.com/profile/06020099715017714433noreply@blogger.comtag:blogger.com,1999:blog-11673175.post-69393790030226875212013-05-11T17:43:13.949-04:002013-05-11T17:43:13.949-04:00Sorry should have signed the above comment.
Grah...Sorry should have signed the above comment. <br /><br />Graham Coop.Graham Coophttps://www.blogger.com/profile/05140268044719927398noreply@blogger.com