Shared Matches Shared Cluster - Ancestry

[DavidG02]

Please bear with me as I ramble some thoughts

I was scrolling through some names and I noticed I have a group of 7-9 DNA matches who all share matches with each other and no other - some have trees, some have extensive trees others have none.

Of these 7 have the same matches and the other  are missing a name or two

I have determined they all hail from Ireland . I havent used a painter but just comparing tree names ( if they have trees) and only  two of the 9 have a shared tree name - Camblin

This doesnt mean that Camblin doesnt occur in other trees - just that the tree doesnt exist or its visible. Camblin may not be the common ancestor either. I just used Camblin to highlight two of the matches have that link

I have come across other smaller clusters usually no more than 3 and I wondered if anyone else has a larger cluster of shared matches

Alternatively - what can I do to narrow the common ancestor or do I need to message each one hoping they have a bigger tree available?

[melba_schmelba]

I have come across other smaller clusters usually no more than 3 and I wondered if anyone else has a larger cluster of shared matches

Alternatively - what can I do to narrow the common ancestor or do I need to message each one hoping they have a bigger tree available?

Oh yes, I have clusters of over 100 shared matches that are American, possibly Mormons I am not sure. Yes, unfortunately you do need to rely on the Ancestry messenger if they have no trees, but you could also check their profiles to see if they give any more contact details.

[rlw254]

I've identified a few clusters like this in my own research. In almost all cases, the shared ancestor will be very distant, likely born in the 17th century. This is at the limit of what many people quote as being the range for autosomal testing but I believe the clusters are likely from disproportionally-segregating regions of the chromosome (similar to pile-up regions). The likelihood of finding the exact shared ancestry for the group and yourself is slim considering Irish research this far back is a tough ask.

[DavidG02]

Thank you to both - it looks to be as I thought  - an interesting conundrum

[brigidmac]

How high cm to you are the matches in this cluster ...it might not be as distant as rlw suggests

I have 5 people who I now know how they match and have small tree or no tree they are a father who is 2c1r his son and 2 grandchildren ...!  And the first man's 1c1r This 3 generation  matches are becoming more common and often 1 person manages the others trees so you can see that they are probably close relatives

Let us know if you work it out 😉

[Pheno]

Also at this point, assuming the initial cluster is on Ancestry, I have tried looking at another DNA site (often MyHeritage) which might conveniently have one of this cluster - hopefully using the same user name - where there might have a more expansive tree.

It does happen.

Pheno

[DavidG02]

How high cm to you are the matches in this cluster ...it might not be as distant as rlw suggests

That's what made me look deeper. . One was 35cm - which is distant - and the others are around 24-21cm

Usually if I have matches at that number I get many more matches than 7-9

I recognize those numbers align with 6-8th cousins but it was more the lack of variation that made me notice it

[rlw254]

I should have mentioned that in my cases most members of these clusters have segments around 20-30 cM.