Genetic distance is a measure of the number of differences or mutations between two sets of results, such as Y-chromosome DNA or mitochondrial DNA test results. It is organized by the Step-Wise Mutation Model, which considers the number of Short Tandem Repeats (STR) markers between two people. A genetic distance of 0 on 12 markers could indicate a close relative or no connection at all, while a genetic distance of 0 on 111 markers would mean a close relative.
A “0” genetic distance for a FullSequence mtDNA test can mean that you have a “50 chance of sharing a common maternal ancestor within the last 5 generations”, or about 125. Genetic distance can be used to calculate the estimated time to most recent common ancestor (TMRCA) between you and your match, as Y-DNA will typically mutate at a fairly stable frequency.
In Y-DNA tests, “genetic distance” simply means the number of differences between two samples. If two samples, both tested for STR markers in the Y-37 test, match, genetic distance refers to the total number of differences in the STR values of two different people. The answer depends on what test you took.
For Y-DNA tests, “genetic distance” simply means the number of differences between two samples. If two samples are tested for STR markers in the Y-37 test, matching someone on 36/37 markers is a genetic genetic distance. In other words, genetic distance is how many mutations difference the participant (you) has with that particular match. When you match men with the same surname as yours (or a variant) on a Y-DNA test, it means that you have potentially genealogically relevant matches.
| Article | Description | Site |
|---|---|---|
| Meaning of Genetic Distance | The answer depends on what test you took. For Y-DNA tests, “genetic distance” simply means the number of differences between two samples. If two … | forums.familytreedna.com |
| In the simplest terms, what does a ‘genetic distance’ really … | It means the number of markers at which you match a person. If you get a Y-37 DNA test and you match someone on 36/37 markers, that’s a genetic … | reddit.com |
| Genetic distance – ISOGG Wiki | Genetic distance is the term used to describe the number of differences or mutations between two sets of Y-chromosome DNA or mitochondrial DNA test results. | isogg.org |
📹 Make Sense of Genetic Distance : Y DNA EXPLAINED
—————- CONTINUE LEARNING Brief Overview of y-DNA Haplogroups https://youtu.be/R1xCU91dPaQ Correcting for …
📹 Understanding Mitochondrial DNA
Your mtDNA is directly maternally inherited, meaning that you have the same mtDNA as your mother and all of your siblings.
My closest Y-DNA match was a 7th cousin 3 times removed with a distance of 3. It turned out his 7th great grandfather was the brother of my 4th great grandfather. All of this fit nicely into my family tree research. I’m very fortunate that when I tried to contact my Y DNA match that he responded. There are so many that don’t.
I have a match with someone where we’re only two steps away at Y-111, and 0 steps at all lower levels. Seems like a strong match. Our Big Y kits only have 3 differences between them, too, though I know that test is more for the pre-genealogical time frame. Both of our known EOLs (his in the 1750s and mine in the 1780s) were born in southern NY. We might never figure out how exactly we connect, but the fact that we got in touch with each other and become friends is something really special to me.
I’m the Group Administrator for my Surname Group at FTDNA, and I’ve had some success building a Phylogenetic Tree using an online tool that breaks down all of the group’s Y DNA matches into their individual branches (haplogroups) and provides an estimated value for TMRCA for the various common ancestors that are discovered by the tool. But we had to upgrade to the Big Y 700 test to obtain all of STR and SNP markers in the “test results” that are necessary for the online tool to build the phylogenetic tree. The Block Tree is nice but I like seeing the branching within the haplogroups provided by the Phylogenetic Tree as well as the Most Recent Common Ancestor Nodes and Group’s Most Recent Common Ancestor and the estimated TMRCA values.
This is so confusing! But I am going to keep reading, perusal articles, and studying to learn as I know it may help me break through my brick wall to identify my 2nd great-grandfather! My Uncle has one of his five DNA matches at Y-111 (RM) that shares 122 cMs on the atDNA results, and is showing as a 5 step match on the Y-111 kits. RM is a 1 step match with someone who is a 6 step match with my Uncle, RM is a 2 step match with someone who is a 7 step match with my Uncle, RM is a 3 step match with someone who is a 2 step match with my Uncle who shares 16 cM with my Uncle, and RM is a 5 step match with someone who is a 7 step match with my Uncle.
I had better luck with surname matches than you. My BigY700 results show 18 Nobles out of my 22 matches. I previously took the Y111 test, which showed 20 matches, 16 of which were Nobles. Between the 2 tests there are 20 Nobles and 3 other surnames. For me the BigY test was worth paying for as I have my haplogroup identified precisely and know who shares my spot on the haplotree. My best GD is 3, though. Records being what they are in Ireland, I can only hope a closer match eventually takes the test. It’s great to plant the flag. And I’m enjoying my Noble YDNA email group.
Question… I helped my uncle do a Y37DNA test and there were only TWO testers total in all the different marker categories. The surname for these two testers were “Gragg” and my uncles last name is Philyaw. One tester was an exact distance match at Y37 and the other one was distance of 1. My question is …. if there were only the two other testers, is it possible that there aren’t enough testers to know which of the surnames may have changed… My line or his? I hope that makes sense.
Most of my Y-111 on the 12 markers are Genetic Distance Exact Match and on the markers, 25 are mostly Genetic D. 1 and 2 and, on the markers 37 I only have 3 matches and the genetic d. between us is 3 and 4. My question is on markers 12, and 25 the genetic distance is mostly the same or 1 is that a good sign? And what relative should be between me and them? I’m completely new to this and I’m feeling so lost. And at my mtDNA, all the genetic distance is only 1 so, that means the relative near this match should be my great grandma’s mother? Or her mom?
FTDNA estimates are very conservative. My grandfather’s brother and I match 37/37 we have same last name and tip report estimates 59% chance at 4 generations and 89% at 8 generations! The actual facts are he is my father’s uncle (my grandfather’s brother) so 3 generations counting myself or only 2 if not. I think maybe if we didn’t share the same surname the match level we have could be more accurate. I wish that they would re vamp their system of matching.
I’m a G-M201 and don’t show any of my parental names in my 37 YDNA testing. (Sweden – About 4) I only had sixteen matches. 6 People had the same surname. I did notice that 5 of my 4 step matches had an 83.49% percent chance of having a common ancestor in 4 years. One 4 step match was at about 57 percent. My 3 three step matches had about a 28 percent chance of matching a common ancestor with in 4 years. 1 had about a 47 percent chance. Confusing indeed but I think the common answer is to upgrade but with the low number of matches and the step differences – I’d feel better about upgrading if there were a few 0 or 1 step matches also. Another thing i noted about the test was that two of the confirmed Haplogroups were different. A YDNA 500 marker test noted a BY166910 confirmation —- A YDNA 700 marker test noted a confirmation of BY166910- – A YDNA 700 test noted a G-Z45631 confirmation- – The two BY166910 Haplogroups noted the same last name.
Q. Can more than one sample point mutate at each conception? I have a cousin who is 4-STEPS different. Is it the number of the difference; eg; in 7-repeats or 10 repeats? or is it the number of DYS that show different repeats? I have:- The mutations occurred between brothers, 1873 >1877. OR one of the brother’s children between 1877 > 1898. (DYS385 = 1, DYS534 =1, DYS492 =2.) Barry P.
If you match with someone at 12 markers and not anything higher, does that mean yiur just not related. For instance, i have 29 matches with the surname or varation of the surname Gilliland / Gilland / Gilland / Gillian / Galant / Gillieland which is an accepted a variation of my own surname McClelland as per other mcclelland haplotrees and groups and yet none of them match with me above 12 markers. I have literally only got my big y 700 results back and not yet got a private snp hapologroup and only got 1 match at anything higher than markers. Is this merely a coincidence?
I also do not know my grandfather’s correct surname. I had my brother do a Y-DNA and have a Y-111 1 step match. As I understand (limited) the match has about an 85% chance of a common ancestor within 4 generations. Does that sound correct? He has a full proven tree so I thought I would look at the 4th generation and see if there were any commonalities with the very little info I have on my grandfather.
You have only tested on 67 markers, so the likelihood of the common ancestor of your 11 matches being a few thousands years back is very high. Hence the last names have to be widely different as last names were only formed some 600-800 YBP. You need to use a number of Big Y test to the “rule of four” to strategically add your own haplogroup to the tree of mankind which would allow to better differentiate your matches.
I don’t think you covered EXACT MATCH. My father has 2 and the MRCA is 4 generations away!! (5 for the son of match 1). I’m not as impressed with y-DNA as I was when it arrived on the scene and I think in the intervening years it hasn’t impressed most die-hard genealogists. But now I understand why you leave Phil Garnet’s test kit up on Ancestry… 😏 Personal anecdote: FtD’s Y was our first toe-dip into DNA back in 2004 at 12 markers. There were enough guys on the list with the suspected NPE surname and one close enough that we felt we had our answer. My Dad died in 2009. I recently upgraded the number of markers and this father/son tested and the father got the NPE surprise when he tried to join his surname group and the mod suggested he contact my Dad, his closest match. (I had contacted him years before on My Heritage and been dismissed because he didn’t have anyone in his extensive tree with that surname.) Uh oh… Suddenly he’s contacting me looking for answers. Lucky for him I’ve learned quite a lot in the last 18yrs and could tell him with almost certainty when the NPE occurred.
Not only do I appreciate you talking about the Y-dna test, but you hit it right over the head with how OFFPUTTING it is that the name changed upon coming here from England. Same here and I’d love to know why there are three or four variations of my biological paternal name (just like the adoptive name I carry).
At 111 markers and the Big Y I am what is known as Chandler Y-chromosome Group 7A. Most guys in the group are said to descend from the emigrant, John Chandler, who arrived in Virginia as a boy in 1609/10. But I have an NPE. My birth surname is the same as back to my great-great grandfather and it is not Chandler. Genetically and document wise I DO believe that I AM descended from the lines of my birth surname BUT through the probable mother of my great-great grandfather. That she gave him her maiden name and not his father’s name. I believe that the probability is higher that my great-great grandfather’s father’s surname was Chandler than that it was some other surname and that the NPE was further back. So my latest project is researching land records of the area where my great-great grandfather is first recorded and find out where his known relatives were located and compare that to the Chandlers who were closest in proximity and maybe I might find some patterns in those. And narrow down possible candidates for his father among those. Then I can search for other documents to see if possibly there might be some clues that could get me closer to the truth. Probably a long shot but it’s better than anything else I can think of. The best that I can determine from the Chandler geneticists is that I probably do descend from John Chandler the emigrant and ANY match that I have with ANY other guys in Group 7A despite their genetic distance could very possibly be through the emigrant or even before him and no way to narrow it down any closer than that.
Good article. Reading the other comments I see major flaws in the TIP calculator. The TIP calculator assumes the correct surname to be of any use. Having done a few big y tests on relatives, I have come to the conclusion this test is absolutely useless in genealogy. Not to discourage people from doing it. It is potentially very powerful, but is limited by the historical record needed to corroborate it. Given its limitations, this test NEEDS TO BE FREE WITH AN AUTOSOMAL TEST. THIS TEST NEEDS TO BE OFFERED BY ANCESTRY, THE DATABASE LEADER. AND FINALLY THE TEST NEEDS TO BE OFFERED AT THE BIG Y LEVEL ONLY. STRs 12-111 ARE FAIRLY USELESS AND UNRELIABLE BY THEMSELVES. THE ONLY WAY TO GROW THE PHYLOGENIC TREE AND FOR THIS TEST TO REACH ITS POTENTIAL IS FOR THIS TEST TO BE OFFERED AT THE BIG Y LEVEL ONLY.