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General => Ancestral Family Tree DNA Testing => Topic started by: Lafrowda on Wednesday 26 December 18 19:43 GMT (UK)

Title: Possible Relationship ?
Post by: Lafrowda on Wednesday 26 December 18 19:43 GMT (UK)
What is the possible common ancestor to two people who share 828 cms across 25 segments ?
We see no paper trail connection despite a fairly full tree on each side, apart from geographical proximity with our parents, grandparents & before.
Title: Re: Possible Relationship ?
Post by: squawki11 on Wednesday 26 December 18 20:44 GMT (UK)
It might be useful to refer to the DNA Detectives Autosomal Statistics Chart via google or similar. There is a range of possible relationships between 2 people sharing c.575-1330 cMs, average 900 cMs, 1st cousin/Half Aunt/Uncle/Niece/Nephew/Great-Grandparent/Great-Grandchild/Great Aunt/Uncle/Niece/Nephew. What fits best?
Title: Re: Possible Relationship ?
Post by: Gadget on Wednesday 26 December 18 20:56 GMT (UK)
 This will give you a range of possibilities:

Quote
Relationship probabilities (based on stats from The DNA Geek)

    95.72%
    Great-Grandparent /Great-Aunt / Uncle Half Aunt / Uncle 1C/ Half Niece / Nephew /Great-Niece / Nephew /Great-Grandchild
    4.28%
    Half Great-Aunt / Uncle †/ Half Great-Niece / Nephew †/ Great-Great-Aunt / Uncle/ Half 1C   /1C1R/ Great-Great-Niece / Nephew

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

For comparison, my great nephew shares 1100cM over 49 segments  with me.

Gadget



Title: Re: Possible Relationship ?
Post by: sugarfizzle on Thursday 27 December 18 04:07 GMT (UK)
Various possibilities, as listed by squawki11 and Gadget, but it is obviously a fairly close relationship,

As always, it will be good to look at your shared matches.  Identify shared matches you know to be on your side, and those on the other person's side. Look at trees where available. Tell each other how the shared matches are related, where known, especially for any 2nd or 3rd cousins, if any, but also any 4th to 6th cousins (at ancestry).

Any new match comes along, check if it is shared with this person.

Regards Margaret


Title: Re: Possible Relationship ?
Post by: Janelle on Thursday 27 December 18 09:08 GMT (UK)
GEDmatch will be really useful if both these cousins and their families also are uploaded from other platforms.

You share kit numbers, and nicknames, and then you can both see the extent of common matches
and extract matrices to demonstrate the shared from just yours and just theirs

We have scored a 3rd cousin doing this.
He is a close yDNA match to our brother, which means this 3rd cousin’s father should have our surname.
Softly softly ...
Title: Re: Possible Relationship ?
Post by: Lafrowda on Thursday 27 December 18 10:17 GMT (UK)
I should have said at the start that I am not conversant with DNA technical terms and will need leading slowly.  For example matrices to me are something you sleep on, albeit spelt differently.  I am 76 and a bit slow with new concepts.  We are on GEDMATCH but I don't see common surnames with our match, so I suspect "wrong side of the blanket" somewhere, but where do I look and how close ?
Title: Re: Possible Relationship ?
Post by: Gadget on Thursday 27 December 18 10:27 GMT (UK)
Hi again

I gave a list of possible relationships in my earlier reply. The ones in bold are the most likely. You'd need to work from the person's available tree.

Have you contacted  them?

Gadget

(PS - I'm not much younger than you  :) )



 
This will give you a range of possibilities:

Quote
Relationship probabilities (based on stats from The DNA Geek)

    95.72%
    Great-Grandparent /Great-Aunt / Uncle Half Aunt / Uncle 1C/ Half Niece / Nephew /Great-Niece / Nephew /Great-Grandchild
    4.28%
    Half Great-Aunt / Uncle †/ Half Great-Niece / Nephew †/ Great-Great-Aunt / Uncle/ Half 1C   /1C1R/ Great-Great-Niece / Nephew

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

For comparison, my great nephew shares 1100cM over 49 segments  with me.

Gadget




Title: Re: Possible Relationship ?
Post by: Gadget on Thursday 27 December 18 10:34 GMT (UK)
I found this article useful:

https://www.lostcousins.com/newsletters2/wedding18.htm#Masterclass

I think it was recommended by Margaret  :)

Gadget
Title: Re: Possible Relationship ?
Post by: sugarfizzle on Thursday 27 December 18 11:43 GMT (UK)
I am also approaching my 70s and find some aspects of DNA very difficult to get my head round. I fear it has come too late for me to get full value from it,, but hope my daughter, currently uninterested in family history, will gain from both of her parents being tested.

I took no interest until in my 50s, so there's hope yet.

You say you will need leading slowly - it is only by taking an active interest in the subject that you will learn, and you are doing so. The mud becomes clearer after a while, but not completely clear for me as yet!

Wrong side of the blanket does immediately spring to mind, so tread carefully.

As I said before, shared matches should give you a lot of information.

Depending upon the age of your match, you could be looking at a number of different generations.

Gadget says most likely relationships include  Great-Grandparent /Great-Aunt / Uncle Half Aunt / Uncle 1C/ Half Niece / Nephew /Great-Niece / Nephew /Great-Grandchild, from DNA painter.

So, given your age, not likely to be your great grandparents, or even your great aunt/uncle that the match shares.

Match is more likely to be your great niece/nephew or your great grandchild etc.

If the match is about the same age as you, consider closer relationships, nephew/niece

Whichever way, it is probably either yourself or your parents the likely common ancestor.

Regards Margaret
 :)
Title: Re: Possible Relationship ?
Post by: lydiaann on Thursday 27 December 18 12:38 GMT (UK)
I cannot see the benefit in getting tested.  I have the satisfaction of knowing that I have relatives that are now firmly established going back to the 1700s (and in one line, confirmed back to the 1600s) and I have the trees to prove it.  I am in contact with 1st cousins several times removed in Australia who also have the same line as I do.  The only reason I wanted Himself tested was to prove to me he was of Viking stock...now I find out that it cannot be that specific, so we won't bother.  It has been proven that most people will have roots in various countries/areas through the world, but I know that - so far - all my roots are in Scotland and England.  Job done!   :)
Title: Re: Possible Relationship ?
Post by: Gadget on Thursday 27 December 18 13:14 GMT (UK)
How lucky you are, lydiaann  :)

A few months ago, via DNA and a lot of paper work, I was able to discover who my grandfather's father was and thus give him a branch. I would not have been able to find him without doing the test  :)

DNA tests are not a substitute for thorough genealogical research/paper trails but they can confirm possible lines and discover otherwise unknown connections.


Gadget
Title: Re: Possible Relationship ?
Post by: sugarfizzle on Thursday 27 December 18 13:34 GMT (UK)
lydiaann

Good to know you are so confident. So am I, and so, presumably, are Lafrowda and her match.

Surprises happen all the time with DNA, just Google 'DNA surprises' and you will see, or read some of the other threads here.

Regards Margaret
Title: Re: Possible Relationship ?
Post by: medpat on Thursday 27 December 18 13:51 GMT (UK)
I have a French 2nd cousin found due to DNA testing, we are trying to find out which of my gt uncles was responsible during WW1 ;)
Title: Re: Possible Relationship ?
Post by: lydiaann on Thursday 27 December 18 15:19 GMT (UK)
Gadget and sugarfizzle:  Yes, I can see why you get the benefit of DNA testing; I guess it is different for everyone.  Perhaps what I should have added to my first sentence was "...as far as I am concerned....".  And DNA is certainly of assistance in regard to the nastier things in life - murder, assault, etc.  Forty years ago, a friend started tracing his family tree and did it all without these modern aids, uncovering quite a surprise at one point which helped to explain a lot of things to him.  It would have been revealed within a few weeks had DNA been available then - what an amazing time we live in!
Title: Re: Possible Relationship ?
Post by: sugarfizzle on Thursday 27 December 18 15:51 GMT (UK)
Gadget and sugarfizzle:  Yes, I can see why you get the benefit of DNA testing; I guess it is different for everyone.  Perhaps what I should have added to my first sentence was "...as far as I am concerned....". 

My point was, you can't be certain how 'truthful' your paper trail is. You may have made an error at grandparent level, you may have made an error at 7G grandparent level, or anywhere else in between. Either Lafrowda or her match has made an error.

In a Lost Cousins recent newsletter Peter Calver says it is almost our duty to have DNA testing. Whilst not going quite as far as that, I would say that any serious genealogist should strongly consider DNA testing, before it is too late.

I wish my father had been tested (whether he would have been willing is another matter), my mother died many years ago, but he only died 5 years ago. An opportunity missed.

I am not really doubting your paper trail, but even ignoring any possible NPEs, I am just wondering if you have traced all of your 8G grandparents back.

I certainly haven't - either records don't include mother's name, records are missing or not readily available, etc, etc.

To me, DNA testing has given another valid source to a name in my tree, has helped break down a brick wall, or helped to confirm an assumption.

Think of all the trees on Ancestry - if only half of them had DNA testing, how much more would we be able to confirm or refute?

But you are right, it is different for everybody.

Regards Margaret
Title: Re: Possible Relationship ?
Post by: sugarfizzle on Thursday 27 December 18 16:24 GMT (UK)
Found the link, couldn't find it before.

https://www.lostcousins.com/newsletters2/middec18news.htm#Marx

Peter compares genealogists who don't have DNA testing to Luddites who don't use computers or internet for their research, which is possibly stretching things a bit!

Regards Margaret
Title: Re: Possible Relationship ?
Post by: lydiaann on Thursday 27 December 18 16:40 GMT (UK)
When I asked someone about my grandmother, someone posted back that "there are [surname]s in Melbourne who look exactly like her".  That line is particularly strong in the 'appearance gene'.  When I met my cousin's boys for the first time I nearly wept, they looked so much like my late brother.  Himself's family (paternal) is the same; old photos that look like the generation down from us - uncanny.  Don't need DNA for that! ;D
Title: Re: Possible Relationship ?
Post by: Ruskie on Friday 28 December 18 08:41 GMT (UK)
Two days ago I contacted someone who matched with my daughter and her father. He has a fairly extensive paper trail tree. As well as his own kit this person was managing the kits of his brother and his uncle. Or so he thought. He discovered last year via a DNA test that the man he had thought was his father for fifty years, was not his biological father. Without a DNA test he would never have known.

Apart from that, having a DNA match with someone provides another nice little puzzle to solve to find your common ancestors. Good to keep the interest going when the paper trail runs cold. Frustrating when you can't find it though. (Happens a lot with me.)  :)
Title: Re: Possible Relationship ?
Post by: CelticMom on Sunday 30 December 18 03:43 GMT (UK)
What is the possible common ancestor to two people who share 828 cms across 25 segments ?
We see no paper trail connection despite a fairly full tree on each side, apart from geographical proximity with our parents, grandparents & before.

Any possibility of a half sibling that you don’t know about that could of been adopted out to another family. I share similar centimorgans to a half niece.
Title: Re: Possible Relationship ?
Post by: Gadget on Sunday 30 December 18 09:24 GMT (UK)

Any possibility of a half sibling that you don’t know about that could of been adopted out to another family. I share similar centimorgans to a half niece.



Unlikely to be a half sibling as cMs are a bit too low, I'd think.  These are the most likely relationships that I got after entering 828 into dnapainter (Reply #2 of this thread). The most likely relationship is bolded:




Quote
Relationship probabilities (based on stats from The DNA Geek)

    95.72%
    Great-Grandparent /Great-Aunt / Uncle Half Aunt / Uncle 1C/ Half Niece / Nephew /Great-Niece / Nephew /Great-Grandchild
    4.28%
    Half Great-Aunt / Uncle †/ Half Great-Niece / Nephew †/ Great-Great-Aunt / Uncle/ Half 1C   /1C1R/ Great-Great-Niece / Nephew

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

For comparison, my great nephew shares 1100cM over 49 segments  with me.

Gadget
Title: Re: Possible Relationship ?
Post by: sugarfizzle on Sunday 30 December 18 10:04 GMT (UK)
CelticMom did say possible half niece, which is amongst the relationships indicated by gedpainter.

The fact is, it could be any of several relationships, which will take time and effort, if both the parties are willing and able.

Regards Margaret
Title: Re: Possible Relationship ?
Post by: Gadget on Sunday 30 December 18 10:12 GMT (UK)
I assumed that he/she was referring to a half sibling.

Added - I re quoted because it could be any of several possiblilities, all of which were discussed on the thread before it was taken over  by the remarks about DNA  from lydiaanne
Title: Re: Possible Relationship ?
Post by: Gadget on Sunday 30 December 18 10:20 GMT (UK)
I have a related problem, which you might remember from a few months ago.~ the case of a 'paper trail' 3rd cousin having cMs more likely to be at the 2nd cousin level.

I've been looking through all possiblilities but have still not found an answer.
Title: Re: Possible Relationship ?
Post by: CelticMom on Sunday 30 December 18 13:49 GMT (UK)
CelticMom did say possible half niece, which is amongst the relationships indicated by gedpainter.

The fact is, it could be any of several relationships, which will take time and effort, if both the parties are willing and able.

Regards Margaret

Thanks Margaret. I did indeed say half Niece. I shared similar centimorgans as the OP has with the person match they are enquiring about.

Which is why I asked about the possibility of a half sibling they don’t know about as the dna match could be to a child of theirs.

With a dna match that close if they have a name they should be able to work back and try and tie it in. If it can’t be tied in then my theory or a similar story is possibly even more likely.
Title: Re: Possible Relationship ?
Post by: Gadget on Sunday 30 December 18 13:53 GMT (UK)
I have a related problem, which you might remember from a few months ago.~ the case of a 'paper trail' 3rd cousin having cMs more likely to be at the 2nd cousin level.

I've been looking through all possiblilities but have still not found an answer.

Spent a while this morning doing a bit more searching and find that there was another connection further back, so I was related on two lines. It's worth looking at this possibility also.


Gadget
Title: Re: Possible Relationship ?
Post by: Gadget on Sunday 30 December 18 13:59 GMT (UK)
Just a side comment on the dnapainter/Bettinger tool:

Although it includes half relationships, it doesn't include double relationships.


Gadget
Title: Re: Possible Relationship ?
Post by: Mart 'n' Al on Sunday 30 December 18 15:20 GMT (UK)
Just a side comment on the dnapainter/Bettinger tool:

Although it includes half relationships, it doesn't include double relationships.


Gadget

I'd be interested if you could expand on that further, especially the arithmetic.

Martin
Title: Re: Possible Relationship ?
Post by: Gadget on Sunday 30 December 18 15:44 GMT (UK)
I can't really say much apart from if you have  one relationship + another relationship

e.g.

 140 cM + 150 cM = 290 cM

So Ancestry and other sites will say you have 290 cMs in common. This puts it into the 2nd cousin range. Instead, it's really (say) 3rd cousin from one line and 3rd cousin from another line.
Title: Re: Possible Relationship ?
Post by: Mart 'n' Al on Sunday 30 December 18 15:46 GMT (UK)
What would be the paper double relationships in your example?

Martin
Title: Re: Possible Relationship ?
Post by: sugarfizzle on Sunday 30 December 18 16:04 GMT (UK)
Martin, Two explanations -

https://genetics.thetech.org/ask-a-geneticist/double-cousins-share-one-quarter-their-dna

https://www.famlii.com/what-is-a-double-cousin-genetically/

Basically, although you are cousins you share twice as much DNA as would be expected.

This also works for double second, third cousins etc.

Regards Margaret
Title: Re: Possible Relationship ?
Post by: sugarfizzle on Sunday 30 December 18 16:20 GMT (UK)
Just think of the effect of identical twin cousins marrying identical twins.

The children of each couple would probably share near identical DNA!

Lafrowda. Sorry if this thread has gone a bit off course! Most of the replies are from regulars here.

Please let us know how you get on.

Regards Margaret
Title: Re: Possible Relationship ?
Post by: Lafrowda on Sunday 10 May 20 21:23 BST (UK)
Thank you for all the thought that has gone into my question.  It seems that at the age of 76 I have discovered I am not who I thought I was.  The relationship is half niece. Her grandfather being my father (hitherto unknown). Her grandparents and my "parents" occupied the same farm prior to my birth.  Thirty years of barking up a wrong tree.