Hi all,
I was wondering if maybe someone with a lot of experience would be able to explain what is going on, what do i wrong or help me in any other way.
A long story short is that i am 50 years old and i do not have any clue who could be my father. The recent DNA test confirmed the family tree from my mothers side wich did not bring any surprises. Because of all that happened when i was young and trying to find any answers back then i was convinced that my parents would be related, that this was not the case was the biggest shock for me. I really expected that they would have been related.
Now my DNA test brought a lot of new " coussins " but all of them are verry far. I started to build trees from my shared matches to see where it would lead and i have multiple matches in several trees that all lead back to a shared ancestor. Now the problem is that this is confirmed with a lot of matches but....this leads back to a commom ancestor born in 1760, i was born in 1972 and following the normal rules of cM' s would make it impossible to track it back to me, if cM's would really double or half every generation, even downsizing this makes it impossible. A shared match with 40 or 50 cM' s would normally mean 7 generations distance, well back to the common ancestor is often allready 6 or 7 genearations, and then you need to add the generations from the shared ancestor back to me. If this would be regarding one or two matches maybe something went wrong, but i am talking about more then 10 matches, all indicating to be 6, 7 or 8 generations away from me, all confirmed in more ways, but in reality it would take 12 generations or even more. Even if the results would show a much too high amount of cM's it still makes it very hard to connect the dots here. Unfortunely i can not ask anyone i know about my past or relatives from my fathers side so trying to find a way back from a common ancestor is the closest i have ever been with clues.
Any suggestions how to explain a lot of shared matches with 40 to 50 cM's in common showing acommon ancestor 6 or 7 generations ago?
I also noticed i have DNA matches where i share 85 cM with the father and still 81 cM with his son ( so not half) but the largest segment i share with the son is bigger, 52,3 over 49,2. Would this be normal?
Anybody interested to solve this almost impossible sudoku?
Help, my trees lead to an impossible way back from shared greatparents
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Hi,
Welcome to the forums. I moved your post to the DNA forum which is more appropriate for your question.
Remember that the statistics on shared DNA are probabilities and averages, not absolute formulas. You inherited 50% of your DNA from each parent, but the DNA you inherited from your father may come more from the part he inherited from his father or his mother. So while on average you inherit 25% from each grandparent, in reality, you may have inherited 30% from some and 20% from others. As you go back further, the difference between theoretical average and the reality increases.
Some segments don't divide at all between 2 generations, so it's not unusual to share the same segment with a match and with the match's child. As for the child's shared segment being slightly longer, it could be that an adjacent segment inherited from the other parent matches yours, or could be due to imputation.
Finally, one could assume that all members of a cluster share an ancestor while in reality, some may be related to you through different branches. It's also not unusual for people to have more than one branch in common, especially going back a number of generations.
As for your goal, if it's possible to test your mother, you can then make a phased DNA kit and identify which matches are on your father's side and which are on your mother's.
Eric
Welcome to the forums. I moved your post to the DNA forum which is more appropriate for your question.
Remember that the statistics on shared DNA are probabilities and averages, not absolute formulas. You inherited 50% of your DNA from each parent, but the DNA you inherited from your father may come more from the part he inherited from his father or his mother. So while on average you inherit 25% from each grandparent, in reality, you may have inherited 30% from some and 20% from others. As you go back further, the difference between theoretical average and the reality increases.
Some segments don't divide at all between 2 generations, so it's not unusual to share the same segment with a match and with the match's child. As for the child's shared segment being slightly longer, it could be that an adjacent segment inherited from the other parent matches yours, or could be due to imputation.
Finally, one could assume that all members of a cluster share an ancestor while in reality, some may be related to you through different branches. It's also not unusual for people to have more than one branch in common, especially going back a number of generations.
As for your goal, if it's possible to test your mother, you can then make a phased DNA kit and identify which matches are on your father's side and which are on your mother's.
Eric
Eric's comments are very good, I'll add a little bit to it.
Yes, it's possible to match a longer segment with a child than their parent, not common but possible. Probably happens when there are parents or common ancestors from the same small population, that lived in one place for many generations and therefore probably all related distantly, and have a common pool of shared segments.
And yes, that 50% rule only applies to what you get from your parents, after that it's much more random. It's possible to get 40% from one grandparent, and therefore only 10% from that other grandparent. So a 45cM match could come from as close as 3rd cousin or as far as 8th cousin or worse.
That 85cM match sounds like your best one for finding a relative in common, but as you've found, it's still pretty hard to work with. What you really need is a closer match than that, a much higher cM result. My suggestion is to "fish in more ponds", take more DNA tests from other DNA companies. In order to find that one great tester that will break open your father's ancestry, you have to test in the same company that they tested in (most people only test once). Each DNA company has favored groups of testers, Ancestry DNA, FamilyTree DNA, and 23&Me are great for American testers, not so good for European and other testers. MyHeritage is rather universal, but especially good for Scandinavian testers. I can't tell which company you tested with, but I strongly recommend testing with the other companies also, perhaps when the next round of sales begins. Plus, upload to GEDmatch, it's free and it's another good pool of testers.
Yes, it's possible to match a longer segment with a child than their parent, not common but possible. Probably happens when there are parents or common ancestors from the same small population, that lived in one place for many generations and therefore probably all related distantly, and have a common pool of shared segments.
And yes, that 50% rule only applies to what you get from your parents, after that it's much more random. It's possible to get 40% from one grandparent, and therefore only 10% from that other grandparent. So a 45cM match could come from as close as 3rd cousin or as far as 8th cousin or worse.
That 85cM match sounds like your best one for finding a relative in common, but as you've found, it's still pretty hard to work with. What you really need is a closer match than that, a much higher cM result. My suggestion is to "fish in more ponds", take more DNA tests from other DNA companies. In order to find that one great tester that will break open your father's ancestry, you have to test in the same company that they tested in (most people only test once). Each DNA company has favored groups of testers, Ancestry DNA, FamilyTree DNA, and 23&Me are great for American testers, not so good for European and other testers. MyHeritage is rather universal, but especially good for Scandinavian testers. I can't tell which company you tested with, but I strongly recommend testing with the other companies also, perhaps when the next round of sales begins. Plus, upload to GEDmatch, it's free and it's another good pool of testers.
My page: https://www.wikitree.com/wiki/Jacobson-1250
My DNA: https://www.wikitree.com/wiki/Jacobson-1250#DNA_Evidence
yDNA Haplogroup: R-S23346 https://www.wikitree.com/wiki/Space:YDNA_Haplogroup_R-S23346
mtDNA Haplogroup: K1c2 https://www.wikitree.com/wiki/Space:K1c2_mtDNA_Haplogroup
mtDNA Help: https://www.wikitree.com/wiki/Space:K1c2_mtDNA_Haplogroup#About_Your_mtDNA_Test_and_Haplogroup
My DNA: https://www.wikitree.com/wiki/Jacobson-1250#DNA_Evidence
yDNA Haplogroup: R-S23346 https://www.wikitree.com/wiki/Space:YDNA_Haplogroup_R-S23346
mtDNA Haplogroup: K1c2 https://www.wikitree.com/wiki/Space:K1c2_mtDNA_Haplogroup
mtDNA Help: https://www.wikitree.com/wiki/Space:K1c2_mtDNA_Haplogroup#About_Your_mtDNA_Test_and_Haplogroup
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- Posts: 2
@ericdubois
@robjaco
Thank you both for your reply, they were both very helpfull.
Unfortunely a bigger match is a matter of waiting and hoping, i did the test at myheritage and uploaded it to gedmatch and several other sites.
For ten matches between 30 and 50 cM' s i ve worked the tree out to through 4 different branches to a common ancestor born around 1760, for most matches 6, 7 or 8 generations back. Mathematical that does not add up, but considdering that the cM's are not absolute that would explain allready a part of everything.
Fingers crossed for a bigger match one day.
@robjaco
Thank you both for your reply, they were both very helpfull.
Unfortunely a bigger match is a matter of waiting and hoping, i did the test at myheritage and uploaded it to gedmatch and several other sites.
For ten matches between 30 and 50 cM' s i ve worked the tree out to through 4 different branches to a common ancestor born around 1760, for most matches 6, 7 or 8 generations back. Mathematical that does not add up, but considdering that the cM's are not absolute that would explain allready a part of everything.
Fingers crossed for a bigger match one day.