Thrulines

[allmat]

One of my DNA matches (‘X’ to preserve her anonymity) has only five other matches in common with me. I know who they all are, and they (and I) are all descended from the same couple – my 2xg.grandparents (so also our common 3xg.grandparents).  But X is not – she’s probably two generations earlier. I manage her test. Thrulines is essentially ‘top down’: pick an ancestor and the tool shows the matches that share that ancestor.  Can I run the tool in reverse, to ask it to show me which ancestor X has in common with me and our five other shares? If so, how?

[Gadget]

Ii tend not to use Thrulines as  it's not always accurate . It uses others' trees to construct the relationships. If any one has made errors in their tree, it will just take the relationship from that:

See Ancestry's info on Thrulines:

Accuracy

ThruLines rely on family trees from you and other Ancestry members, so their accuracy depends on the quality of those trees. Mistakes in family trees can cause inaccurate ThruLines.

Because ThruLines are tree-based, they don't prove your relationship to a DNA match. For example, even if your tree lists someone as your second cousin and appears as a DNA match and in a ThruLine as your second cousin, they could still be a first cousin once removed, a half-first cousin, or another relationship.

To see how you might be related, click on the amount of shared DNA with a match. This chart also shows how often a likely relationship happens based on the amount of shared DNA.

Gadget

[Gadget]

If the 5 matches have accurate trees, you could probably do what you want from that info rather than using Thrulines.

Gadget

[Gadget]

You could also subscribe 
 to Ancestry Pro Tools for a month and use the Shared Matches Pro. This is likely to show the probable relationships.

https://support.ancestry.co.uk/s/article/Ancestry-Pro-Tools-Membership

It's on a monthly sub so you can stop it as soon as you think you've got what you want.

Gadget

[allmat]

Thanks.  I’m aware how Thrulines works and I already have ProTools and use the shared matches feature.  That’s how I know that X must be earlier connected as I can see her shares as well as my own with the other five.  None of those five has a tree any earlier than mine – indeed I suspect they all got the details in their trees from me in the past. And at that far a remove all of the possible shared common ancestors are ‘potential’ – and there’s a very large number of them.  So rather than follow each forward I’d hoped to trace X backward.  So as I asked originally, is that possible and if so how?  Because my connection with X is the first inkling I’ve had in over thirty years of a clue to solving the puzzle of the parents of my Somerset-born 3xg.grandfather, born about 1792, a Baptist minister in later life and almost certainly part of a large non-conformist community.

[Gadget]

Have you tried all possibilities of identifying X's ancestors?  I've done this with many of my matches using normal genealogical methods.

I assume that you've also used DNA Painter and other  Bettinger tools.

https://dnapainter.com/tools/sharedcmv4
https://dnapainter.com/tools


Gadget

[allmat]

I manage X’s test and am actively researching her tree for her – it’s a public AFT – so each earlier generation is researched and entered by me once I’m satisfied via appropriate source records.  I’ve already entered all sixteen 2xg.grandparents and have potentially identified but not yet entered the next thirty-two. Even though I’m pretty confident that only half are likely to assist me to pinpoint our common ancestors.  But beyond that (as our connection is likely to be a 4th or 4th g.grandparent) the circle gets very large indeed.  And all of those people will have been born in the middle of the 18th century or before.  Identifying even a majority by traditional methods is unlikely to happen.
I’m familiar with DNA Painter only as regards the Shared cM Tool – and I know little of WATO or Banyan, but gain the impression they test and evaluate various hypothetical links.  But unless I’ve really misunderstood their purpose I think I’d need to have already identified a hypothetical common ancestor – which is what I’m trying to do!

[Gadget]

So, with all that info and research, you should have some idea of X's ancestry. Just keep on. Eventually. you'll maybe find the link.

Good Luck 

[Gadget]

What amount of cMs do you share with X. Does she have any other matches and what amount of cMs  does X share with them.

What cMs do you share with the other 5?