Ancestry DNA expectations

[scottishlad]

So I’ve hit a roadblock in my family tree. Can’t get passed my 5x great grandfather. He died pre 1855 in Scotland so really no way to confirm death through church record, and obviously no statutory record to identify parents. My thought is he most likely had a brother who lived past 1855, and would therefore have a death record with parents listed. If I did ancestry DNA, would it be possible to positively identify that theoretical brother?

I guess ancestry would have to tell me that the 5x (or whatever) great grandson of that theoretical brother is a relation, and they’d have to have a tree that goes back that far. Would the 5x great grandson be too distant of a relation for ancestry DNA to even consider us related though?

Would ancestry DNA help me uncover this, or is that not really possible? Thanks!

[Glen in Tinsel Kni]

There are so many variables it's impossible to say, the only way to find out is to take the test and share the raw data result across as many sites as possible in order to maximise the chance of finding matches. I don't want to put anyone off but 4th cousins have about a 50/50 chance of sharing dna and the odds are lower at 5th cousins, the flip side is we have lots more distant cousins than close cousins so it's swings and roundabouts.

Ancestry have the biggest database and their results are accepted by several other sites but you can't upload from another site onto Ancestry. For that reason I'd suggest testing with Ancestry initially, there's nothing to stop anyone testing with another company that doesn't accept Ancestry results but I wouldn't make it a priority until sorting out the hundreds/thousands of matches that one test can bring when shared to other sites.

[Biggles50]

If you look further you will find that atDNA tests are only reliable to six generations.

Even as close as your 3xGGP it is possible that you inherit none of their DNA, and if you inherit none of there DNA you inherit none of their Parents and their parents.

See the diagram of DNA inheritance below, the white areas shows where none is inherited from the xGGP’s in that segment.  Each person will have their own version of this disgram.

[scottishlad]

Ok thank you for the replies! I’ll have to look into a bit more and then see what happens

[LizzieL]

I have two 6th cousins that I share over 20 cMs with (23 and 28). They are 5th cousins to each other. We all share the same set of 5 x great grandparents and a cousin marriage is involved in the line a few generations ago which would probably explain the higher than expected matches. If your ancestors also came from a small community with the likelihood of marrying cousins, you could be lucky and get a good match with a theoretical 6th cousin.

Added
Just checked my results and the two daughters of the 28cM match have also tested, I share 28 with one and 27 with the other, so looks likes the chunk of DNA has been handed down to them unchanged (virtually). They would be my 6C1Rs

[scottishlad]

I have two 6th cousins that I share over 20 cMs with (23 and 28). They are 5th cousins to each other. We all share the same set of 5 x great grandparents and a cousin marriage is involved in the line a few generations ago which would probably explain the higher than expected matches. If your ancestors also came from a small community with the likelihood of marrying cousins, you could be lucky and get a good match with a theoretical 6th cousin.

Oh wow, ok thank you!

[TreeDigger]

If your ancestors also came from a small community with the likelihood of marrying cousins, you could be lucky and get a good match with a theoretical 6th cousin.

Agreed.

When Geneanet still did the DNA thing, I decided to track one of the very few Dutch matches I had on there despite an insane small match of barely 11cM because it was obvious our MRCA came from the same fishing village (I was bored). Let's just say that community was very shy of foreigners 

After a whole week of going crazy from all the similar surnames combined with all the kids naming their eldest sons for their father, I finally discovered at least three mutual ancestors, all of them pre-1650. One MRCA born in 1622, one in 1602, and the last one in 1583. And as there had been quite a number of cousins marrying in later generations, and there were even more MRCA's pre-1600, this tiny bit of DNA had been passed on, and on, and on.. the elation of having a literal DNA connection to somebody born pre-1650 was somewhat offset by the realization that all the (original) inhabitants of the village must have a very similar genetic profile.

[Wexflyer]

If your ancestors also came from a small community with the likelihood of marrying cousins, you could be lucky and get a good match with a theoretical 6th cousin.

Agreed.

When Geneanet still did the DNA thing, I decided to track one of the very few Dutch matches I had on there despite an insane small match of barely 11cM because it was obvious our MRCA came from the same fishing village (I was bored). Let's just say that community was very shy of foreigners 

After a whole week of going crazy from all the similar surnames combined with all the kids naming their eldest sons for their father, I finally discovered at least three mutual ancestors, all of them pre-1650. One MRCA born in 1622, one in 1602, and the last one in 1583. And as there had been quite a number of cousins marrying in later generations, and there were even more MRCA's pre-1600, this tiny bit of DNA had been passed on, and on, and on.. the elation of having a literal DNA connection to somebody born pre-1650 was somewhat offset by the realization that all the (original) inhabitants of the village must have a very similar genetic profile.

I think you are trying to say the tree didn't branch....

[Lisa in California]

This is unrelated to your question, but something to keep in mind…reading your DNA results could present unexpected situations - would you be ok with that happening?  A friend found out his grandfather was not his biological grandfather.  One of my (unmarried) ancestors put her first baby up for adoption.  Both my friend and I easily accepted the findings but that isn’t always the case.

However, I had a couple of interesting findings.  I was bored one night and decided to check my (American) husband’s DNA matches for Mumford (a somewhat uncommon surname in North America) from my paternal family tree.  I was very surprised to find out that he also has (in most cases, very distant) Mumford ancestors.  Going one step further, I jokingly decided to check my mum’s DNA matches for Mumford, thinking what are the odds.  She also had a few Mumford matches but perhaps they were the result of a long ago Canadian marriage, rather than being a Mumford descendant.

So, you never know what could be uncovered.