Author Topic: Am I on the right thinking here.  (Read 2468 times)

Online Biggles50

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Re: Am I on the right thinking here.
« Reply #9 on: Sunday 27 July 25 08:27 BST (UK) »
Where there is a person who is/was the child of a casual or undocumented liaison the only proof may well be DNA.

In crime thriller parlance, means, motive and opportunity.

In searching for an unknown Great Great Grandfather, DNA points to a trio of Brothers, one of whom lived in the next village, that is as good as it gets, at least for now.

Online Essnell

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Re: Am I on the right thinking here.
« Reply #10 on: Wednesday 30 July 25 05:07 BST (UK) »
Hi Biggles,
Yes I reckon we are looking at something like that and we aren't even as close as you are, yet...... 
i am still working on all these scraps and i have come across cross marriages and brothers and sisters fron seperate families marrying but they are not part f the issue just in one of the families beign looked into . 

I will keep plodding along. 

Cheers Essnell. :)

Online Essnell

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Re: Am I on the right thinking here.
« Reply #11 on: Thursday 07 August 25 08:52 BST (UK) »
Hello Everyone,
Essnell back again:....   yes

i have been working on as many of the scraps as i can.  now i have an interesting thing that i have noticed last evening. 

As i have said i had an invite to the DNA of the person looking for his grandparents  or more specifically his father's parents.  That got screwed up but i was able to get into some parts   yesterday through my cache back near when the invite was sent.  ,  I was able to see some of the results. 

Now i am looking at matches to the person who wants to know.  What i am seeing is that Ancestry has labeled people as on parent 1 side or parent 2 side.  I thought i had that sorted as parent 1 male and parent 2 female but it is not as clear as that. 

i really cant tell which side is which.  I am seeing the same people on both sides and the relationships provided are   way off the mark.
Everyone seems to eventually lead back to the same locality and the same root family. 

It is looking to me like just one big family with a division within that because of this undocumented parent.

Could he be part of that family and not someone from outside  that?   

Does anyone know how Ancestry would deal with such a scenario. 
here is an example .....

Person wanting to know has a half brother...same mother
Ancestry comes up with this:   
      1st Cousin or half Uncle,  14% shared DNA  976cM   37 Segs.    That does not make sense to me  at all. and there are others just as odd.   The half brother was adopted out. 

Anyone any ideas here.   

Thanks Essnell.


Online Biggles50

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Re: Am I on the right thinking here.
« Reply #12 on: Thursday 07 August 25 10:39 BST (UK) »
Endogomy screws up how DNA results are reported.

Can you advise each of the lines that Ancestry reports for the person especially the Unweighted DNA if it reports it?

Working through the Shared Matches may yield clues as might Pro Tools.


Online David Nicoll

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Re: Am I on the right thinking here.
« Reply #13 on: Thursday 07 August 25 19:21 BST (UK) »
Essnell,

   Hi, as Biggles50 says Endogamy makes things complicated.
   At first sight, if you are saying that you have two half siblings who share 976 cM, that seems unlikely, if you use the below it is well below the minimum expected for a half sibling.

https://dnapainter.com/tools/sharedcmv4

Ancestry use the Timber Algorithm to simplify finding close relatives. However, having looked a bit more deeply at it recently, it seems to make the assumption that there is no endogamy in play. Arguably true for recent USA population, but definitely not in your case.
This means that Timber may be artificially under reporting the match. Hence Biggles50’s request for the unweighted match.
Again with the Parent 1 / Parent 2 definition this can be difficult with endogamy in play. I have quite a few groups who seem to morph from Parent 1 to Parent 2, I think the reason being that the USA population in question was quite small early on and ancestors of both parents emigrated to the same area.
The below gives a better understanding of what Ancestry are doing and the numbers.

https://thednageek.com/ancestrydna-is-using-firs-to-distinguish-full-and-half-siblings/

Uploading the Ancestry DNA to one of the other sites, may give you a better understanding, but then you may lose sight of some of the matches.

Happy Hunting
Nicoll, Small - Scotland Dennis - Lincolnshire, Baldwin - Notts. Gordon, Fletcher Deeside

Online Essnell

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Re: Am I on the right thinking here.
« Reply #14 on: Friday 08 August 25 03:08 BST (UK) »
Hello everyone ..
Biggles50 where do I find the info you asked for?    I am feeling a little dumb here.

David Nicoll  I have looked at both links the painter one has the match also in another grouping other than half sibling  using the 976cM  or 14%  so it hasn't changed anything as far as I can see. 

on the DNA Geek one there is lots of information . FIRS seems to be a very useful piece of science.  but if ancestry has this why have they reported this match as other than half sibling.     I believe that this is because of the endogamy issue which thy clearly state is not accounted for. 

okay i do have protools  which is giving me the cross ref between a match pair.      I am about to se if there is anything else in protools. 

Still floundering......fish out of water.   
Regards Essnell


Online David Nicoll

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Re: Am I on the right thinking here.
« Reply #15 on: Friday 08 August 25 06:53 BST (UK) »

   Hi, every day is a learning day, I found out things myself last night.

Ancestry Unfiltered match data.
   In the Web browser, go to the matches page, then click on the predicted match which is hilighted in blue, (a link I have successfully ignored!). The unfiltered match data is shown there.

   You may already have found this.
   In the Shared CM tool, if you click on the boxes, you get to a more detailed window, showing the bell curve of the probability of a relationship given a cM value.

   The value you give is outside the 99 percentile, but does not mean it is impossible, it may be the original sample size does not capture a real relationship, with 1266 sibling data points, I would need to brush off my school statistics to work that one out!

   With Pro Tools you have to be patient, I am going through this process myself, albeit with more distant relatives.

   You need to build a DNA tree.

Take the first match, assign it a colour, and a name, this may change as you go through the process. Group 1 will do for this, then add all the shared matches of this person to this group.
If there are close shared matches, look at these and see if you can find the senior person, parent grandparent etc. add this name to the Group name, for clarity.
Then look round for people with trees, the best ones may be children, grand children or cousins, the most interested!
Repeat for the next of your matches unless they are part of the close family of your first group member.
Second and Third cousin matches can be useful for pushing the family back in time especially with big trees.
I have taken to labelling the people with big trees in the Notes, also the parent names of the tester where shown, or worked out.
It saves continuously diving back into their trees.
Reminder it can be a slow process.
And with what you are describing you probably have a tree that looks more like a net with the interconnections!
As you look through, you will work out what is clearest for you.

Happy Hunting

Nicoll, Small - Scotland Dennis - Lincolnshire, Baldwin - Notts. Gordon, Fletcher Deeside

Online Biggles50

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Re: Am I on the right thinking here.
« Reply #16 on: Friday 08 August 25 12:16 BST (UK) »
Alas there is no quick fire easy method of learning about DNA, only the hard slog method.

In post #2 I gave a link to the thread where I explain about Grouping.  This and the method explained by David are basically a variation on the Leeds Method which is well documented.

In DNA there is the Chromosome Browser which produces the Group Chart which may or may not be useful.  Unfortunately Ancestry’s ProTools still has a long way to go to be able to be worth its subscription for anything other than short term use. If only Ancestry could incorporate the Gedmatch tools then our research would be so much improved.

It may be that you will continue to have unanswered theories, DNA in practice is not at all like the vast majority of the tutorials that we may watch.  For us our issues tend to be restricted to the single Ancestry site and cannot be fully resolved.

I know that you have read many of my posts but for others who may find it useful I shall explain again:-

I have a 364cM match on Ancestry, her Son and Daughter have also tested and they fail to respond to messages and their DNA is not on My Heritage, ftDNA or Gedmatch. 

A Great Great Niece is on ftDNA and shares 96cM with me, her DNA is not on any other websites  and I am in contact with her but she has no actual contact with my 364cM match or her children.

I’ll call the above four people “Family X”.

On My Heritage are two Half Sisters who share 130cM and 90cM with me, their DNA is not on any other site.  The two Half Sisters are full First Cousins to my 364cM match and knew of her but have no contact details and I have talked to both of them on the telephone.

Also on Ancestry there are well over 100 DNA matches that I have who all link in to an Irish family, I now have about 20 of them in a Family Tree.

Pro Tools came in useful as I could see how much DNA each of these 20 also share with my 364cM match and this helped to validate their actual relationship with my 364cM match.

Now I have this “Irish” family tree, but where do I fit into it?

If I temporarily discount the Family X group then using the DNA cM of the other 20 DNA matches that I have in the Irish family tree then it looks like my Great Grandfather was not who I thought him to be.

On My Heritage and their Chromosome mapping, the Grouping feature offered zero new clues and the triangulation was inconclusive with no triangulation between me and both of the half Sisters.

The only scenario that works is that my Grandfather was the illegitimate Son of a specific identified person in the “Irish” family tree.

Now the problem being that each of the Family X group share more cM with me than they should. 

The two Half Sisters each share levels of DNA with me that are in the expected range as are the 20 Ancestry DNA matches who are also in the Irish family tree.

DNA matches both shared or not who link to specific family lines can also help in tree building.  The man who was probably my Great Grandfather is the MCRA to a number of known DNA matches who are also now in my Irish family tree. There are also people who are also my DNA matches who are in the Irish family tree but link to a MRCA beyond my Great Grandfather who was called John his Wife was called Kate, now for the but, I currently have no DNA matches that link to a MRCA beyond Kate.  So there is a dilemma, did John play away from home or is it just that I have not yet linked a DNA match to Kate’s family?

So I am left suspecting that Edgogamy occurred within the Family X group but I do not have access to the DNA tools to research further as the DNA of those affected are not on Gedmatch.

The wait continues.

Online Biggles50

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Re: Am I on the right thinking here.
« Reply #17 on: Friday 08 August 25 12:19 BST (UK) »
BTW

The “wait” being my standard “DNA can be a waiting game”.