How confident should I be?

[clogdancer]

I've got four known 4th cousin DNA matches through Ancestry, to people descended though different lines to my supposedly Gr Gr Grandfather & Gr Gr GrandMother (Anthony Maughan and Honor Loftus).
I know my Gr Gr Grandfather was called Anthony Maughan and was from the same area.
The known birthyear for my Gr Grandfather (Charles) is within a few years of his supposed siblings (Margaret & Thomas)
I cant find birth records for my Gr. Grandfather (from Ballina area, Mayo, Ireland 1861-62) and quite a lot of records around the period and area are missing.
Without hard evidence, but assuming the records these four cousins has put on Ancestry are accurate, how confident can I be that Anthony and Honor were Charles' parents?
My 4th cousin matches have shared DNA in the region 26-64 cM (whatever that means)

[sugarfizzle]

Not sure I fully understand your query, but presumably you are talking about predicted 4th to 6th cousin matches, not actual 4th cousins.

If you match with 2 people descended from your possible 2G grandparents, you would obviously be 3rd cousins to some degree.

But they may be connected to a different family as well. So more research is needed, and more matches, perhaps a bit closer and a bit further back.

Certainly not at this stage confirmatory, but worth investigating.

Regards Margaret

[clogdancer]

The common (presumed) ancestor pair is my Gr Gr Gr Grandfather/Mother, and actual  Gr Gr Gr Grandfather/Mother to 4 people with the DNA link, not just 2.
That seems like a pretty sure bet to me, but I would like to find out more from someone more knowledgeable about DNA.
What do you call Gr Gr Gr Grandfather/Mother? 3G? 4G?
In any event, these 4 would be my 4th cousins surely?

[sugarfizzle]

The common (presumed) ancestor pair is my Gr Gr Gr Grandfather/Mother, and actual  Gr Gr Gr Grandfather/Mother to 4 people with the DNA link, not just 2.
That seems like a pretty sure bet to me, but I would like to find out more from someone more knowledgeable about DNA.
What do you call Gr Gr Gr Grandfather/Mother? 3G? 4G?
In any event, these 4 would be my 4th cousins surely?

Parents
Grandparents
1G great grandparents
2G great great grandparents
3G great great great grandparents
Etc.

In your case, descendants from your 3G grandparents, or great great great grandparents, would be 4th cousins to some degree, so sorry, I misunderstood you (not unusual for me these days, but I did say I didn't fully understand!).

4 descendants of possible 3G grandparents are matches to you, from 2 or more different children. Fairly likely that this is the right conclusion to make, that you are also related to this family.

But if it was me, I would still be looking for confirmatory evidence, exhausting any paper trails that would reach the same conclusion (I know you said that they are sparse, so you have probably done this already). I would also be looking for 5th cousin or further matches and 2nd and 3rd cousin matches from the same lines.

DNA evidence is another clue, but not at this stage confirmation. Since they are all descended from the same couple, by definition they are descended from the same 4G, 5G and 6G etc grandparents. It could be from one of those earlier lines that you are connected.

DNA painter gives the following relationship possibilities.
https://dnapainter.com/tools/sharedcmv4

64 cMs could be as far back as 6th cousins
32.27%Half 3C 3C1R Half 2C2R 2C3R 23.29%3C Half 2C1R 2C2R Half 1C3R 16.73%4C Half 3C1R 3C2R
14.10%Half 2C 2C1R Half 1C2R 1C3R
13.31%5C2R † 5C3R † 7C † 7C1R † 8C † 6C 6C1R 5C 6C2R 4C1R 5C1R Half 3C2R 4C2R 3C3R 4C3R
0.30%Half GG-Aunt / Uncle 2C Half 1C1R 1C2R Half GG-Niece / Nephew

26 cMs further back still
56.00%6C 6C1R 5C 6C2R 4C1R 5C1R 7C Half 3C2R 4C2R 5C2R 7C1R 3C3R 4C3R 5C3R 8C or more distant
16.60%Half 3C 3C1R Half 2C2R 2C3R
16.60%4C Half 3C1R 3C2R
8.60%3C Half 2C1R 2C2R Half 1C3R
 2.20%Half 1C2R † Half 2C 2C1R 1C3R

Regards Margaret

[clogdancer]

Yes, I see what you mean, we could be related further back, and thank you for the technical stuff. (Not that I understand it!)

[sugarfizzle]

Yes, I see what you mean, we could be related further back, and thank you for the technical stuff. (Not that I understand it!)

What technical stuff don't you understand? I'll try and explain if I can, as will others.
Another suggestion - use surname search for Maughan and Loftus. If both names come up it strengthens the suggestion, if only one name comes up, it could indicate a match further back. Look at these 4 matches trees, find out other names which might be expected to turn up as matches, or preferably do your own research. There again, if it is only Maughan ancestors or only Loftus matches that turn up, the likelihood again is it is further back

Repeat and repeat until 8th cousin level if possible, you could eventually end up with the right couple!! 

This DNA business is not as easy as it might seem!

Regards Margaret

[Maiden Stone]

sugarfizzle, it is technical. That's why I suggested that clogdancer start a new thread about the DNA aspect of the search. I don't do "technical".
Are results affected by 2nd or 3rd cousin marriages?

[sugarfizzle]

sugarfizzle, it is technical. That's why I suggested that clogdancer start a new thread about the DNA aspect of the search. I don't do "technical".
Are results affected by 2nd or 3rd cousin marriages?

I'm completely lost now, hopefully dementia is not rapidly setting in. Can't see any mention that clogdancer starts a new thread.

DNA is highly technical, interpretation of DNA results is technical as well, but tends to come a bit easier with reading about the subject, working with DNA results and also discussing it with forum members here. Especially the latter two.

1st 2nd and 3rd cousin marriage can influence results. In certain communities where intermarriage was normal, DNA results can be very difficult to work with. A 4th cousin of mine from Hawaii is related to practically everybody on the island. Whereas I have 240 closish (4th to 6th) cousins, she has 18,000. She has 68,557 matches in total. And only one of her parents was Hawaiian.

'Known second cousins on average share 212.5 centiMorgans (cMs), but in extreme cases can actually share as little as 47 cMs or as much as 760 cMs.'

https://isogg.org/wiki/Autosomal_DNA_statistics

DNAPainter is a very useful tool. Type in the amount of DNA shared with a match and it will come up suggestions, based on self-reported levels shared.

https://dnapainter.com/tools/sharedcmv4

Other useful links are given at the top of this forum. As I said at the beginning, DNA is highly technical, and I don't understand it fully, or even understand it well, but I know how it works for me, by working with my matches on a daily basis, comparing known paper trail cousins with their DNA results.

Regards Margaret

[Maiden Stone]

I'm completely lost now, hopefully dementia is not rapidly setting in. Can't see any mention that clogdancer starts a new thread.

Apology for confusion. This is clogdancer's new thread. The original thread, which is old, is about ancestor Anthony Maughan. Clogdancer returned to it a few days ago with news of a development through DNA, so I suggested a new thread to attract attention from people with appropriate knowledge. We were following paper-trails which peter out in Mayo.
Thanks for insight on cousins. The marriage register in the parish where my Loftus people lived didn't record degrees of consanguinity as some did.