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General => Ancestral Family Tree DNA Testing => Topic started by: larkspur3 on Sunday 29 March 20 03:44 BST (UK)

Title: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: larkspur3 on Sunday 29 March 20 03:44 BST (UK)
I'd love some advice from any of you who are more adept at the intricacies of DNA testing than my family is!

We had my brother's Y-DNA run on Family Tree DNA since he is a direct male descendant of our line, and he turned out to be a perfect match with someone who had a different last name. This has to be a NPE on the part of this other person, but we can't figure out how. While his last name, Terry, appears in the land records and church records of the very small local area where our ancestors lived, the name doesn't appear on our family tree, so there is no obvious place where someone might have had a child and handed it over to a brother-in-law or something like that. How do we go about eliminating possibilities to figure out how many generations back this event might have happened? Then we would at least know which group of men to start investigating.
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: rlw254 on Sunday 29 March 20 06:58 BST (UK)
A perfect match at what STR depth (i.e. Y-12, 37, 67)? If it is 67+ then I would suggest analyzing the person's autosomal matches for those with your surname and see if you can find clusters descending from the same ancestor.

If it is below Y-67 you could be looking at an event many many generations back. I have a perfect Y-67 match with no common paternal ancestor for a minimum of 8 generations; anything smaller than this could be very difficult to find.
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: Liz_in_Sussex on Sunday 29 March 20 08:08 BST (UK)
Hi,

This might not be what you want to hear (sorry) - might it be your brother’s tree with the npe?

I manage a DNA project and we had a similar situation - but it turned out to be the person who was convinced theirs was the ‘true’ line that was actually not. Unless of course your brother matches others of his surname.

I agree with rlw254’s comments as the way forward though.

Liz
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: Craclyn on Sunday 29 March 20 10:06 BST (UK)
I agree with rlw254. Would you like to tell us which level of test he took? Has he joined the relevant surname group where the admins may be be able to advise you?
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: Twdyr on Sunday 29 March 20 13:06 BST (UK)
I have a similar problem to Larkspur. My surname can be traced through parish records in Cheshire and North Wales to the 1670's, but Y FTDNA only gives me 'same surname' matches at 12 marker level of testing. Most of the few matches at 67 & 111 level are with surname 'Hughes' in America.

I suspect a non-paternity event, perhaps familial emigration before 1670 or even Welsh patronymic name change.

Any ideas where I can go with this? Suggestions gratefully received with thanks.
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: Craclyn on Sunday 29 March 20 15:42 BST (UK)
Before jumping to conclusions about misattributed parentage consider the possibility that there may be nobody from that particular line who has tested Y-DNA with FTDNA. The test I admin has no matches at Y-111 and only has a couple of matches with GD 6 at Y-67. However, autosomal results confirm paternal ancestry back to the late 1700s. If you want more information on how your branch originated take a Big Y-700 test which will show you your branch on the haplotree.
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: Twdyr on Sunday 29 March 20 16:06 BST (UK)
Many thanks for the advice, Y-700 looks the way forward.
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: rsel on Sunday 29 March 20 17:29 BST (UK)
As others have said knowing which level test has been taken is critical to knowing, when two people may be connected, and if the test was on FTDNA, the Genetic Distance (GD) will then give you an approximate idea on the time line.   At a lower level test a GD of 0, whilst you might think is an exact match it could still be 1000's of years ago before Surnames came to be common.

If the test is one on FTDNA, join one of the discovery projects, as the people there are real experts and will be able to give you more solid timelines.

Richard
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: Twdyr on Sunday 29 March 20 19:00 BST (UK)
Thanks Richard,

My two principal matches have a genetic distance of
5 & 8 at 111 markers
4 & 7 at 67 markers
with TIP common ancestor between 12 and 20 generations ago.

I have belonged to a 'one name' study group for a year with nothing obvious showing,

Many thanks for your help
Philip
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: rsel on Sunday 29 March 20 19:42 BST (UK)
My two principal matches have a genetic distance of
5 & 8 at 111 markers
4 & 7 at 67 markers

Philip,
With those GD's you could be looking long before surnames :-)   I don't know what your Y Halogroup is, but assuming its under r1b, look to join the 'R R1b ALL Subclades'  project, and ask the admin's on there, they can give you some really good advice on the timelines.  They will also recommend doing the BIG Y test as well, to really lock down where your branch belongs :-)

Richard
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: Twdyr on Sunday 29 March 20 20:07 BST (UK)
Richard,
Y DNA is R-M269
Thanks for the advice and suggestions, I will follow them up.

Philip
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: Craclyn on Sunday 29 March 20 20:14 BST (UK)
R-M269 is one of the most common haplogroups in Europe. It was formed tens of thousands of years ago. If you want to narrow down to a more specific group then you may want to consider Y-700. The kit I manage is also R-M269 and it moved to a split about 500 years ago as a result of Y-700, but like you has no matches at GD 0 at Y-67 or Y-111.
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: Twdyr on Sunday 29 March 20 20:30 BST (UK)
I will go with Y-700 - instead of a holiday, thanks to Covid-19 !  It seems a positive way forward, I have applied to join FTDNA R 1b All subclades, as Richard has previously suggested.

Thank you both for your time and good advice
Philip
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: Craclyn on Sunday 29 March 20 20:31 BST (UK)
Be aware that it will not help much with matches until more people test, but it will help you figure out where you fit in on the overall haplotree.
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: larkspur3 on Monday 30 March 20 03:01 BST (UK)
Thank you all for jumping in and supplying information. Here's where we are:
My brother Robert Lovett, matches 7 other people by the last name of Lovett. We also can trace our direct ancestry back to 1640 or so so we know we are not the NPE. His test was only Y-DNA-37. Patrick Terry matches that and has done much further testing. My brother has not run a Family Finder (autosomal) test but I have and Patrick and I have no overlap. Would it necessarily be different if my brother did the test? Patrick and my brother are listed as genetic distance 1 on the Lovett surname project, which is what led us to believe the NPE was somewhat recent.

Laura
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: rsel on Monday 30 March 20 16:22 BST (UK)
Thank you all for jumping in and supplying information. Here's where we are:
My brother Robert Lovett, matches 7 other people by the last name of Lovett. We also can trace our direct ancestry back to 1640 or so so we know we are not the NPE. His test was only Y-DNA-37. Patrick Terry matches that and has done much further testing. My brother has not run a Family Finder (autosomal) test but I have and Patrick and I have no overlap. Would it necessarily be different if my brother did the test? Patrick and my brother are listed as genetic distance 1 on the Lovett surname project, which is what led us to believe the NPE was somewhat recent.

Laura
Hi Laura,  a GD level 1 match at Y-37 is going to be a long time in the past, at least 1,000 years ago.  At that age range, an autosomal test will not find any link either.   Based on what I have learnt, to be brutally honest a Y37 test is never going to show you very much at all if you are looking for actual close relatives, it will only give a basic picture of the migration line for your family.

Richard
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: larkspur3 on Tuesday 31 March 20 03:47 BST (UK)
Richard, thanks for that honest assessment! Here's what's leaving me muddled, however.

Of the 6 people who match my brother, we have linked 5 of them to our family tree within about 8 generations or less. Most of these are people that have a genetic distance of 2 or 3. So it's a bit hard for me to wrap my head around the idea that the person with the genetic distance of 1 could link up to our tree as much as 1,000 years ago. The only place he and my brother do not match is in CDY, which mutates fast and is listed as a range of numbers, and none of 7 matches happen to have the same range for the SNP CDY. Go figure!

cheers,
Laura
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: rsel on Tuesday 31 March 20 16:55 BST (UK)
Of the 6 people who match my brother, we have linked 5 of them to our family tree within about 8 generations or less. Most of these are people that have a genetic distance of 2 or 3. So it's a bit hard for me to wrap my head around the idea that the person with the genetic distance of 1 could link up to our tree as much as 1,000 years ago. The only place he and my brother do not match is in CDY, which mutates fast and is listed as a range of numbers, and none of 7 matches happen to have the same range for the SNP CDY. Go figure!

cheers,
Laura

I you can have close matches as well, but unless you test at the highest level you will never know for sure how :-)  Like mentioned above if you join the various projects on FTDNA the experts there can provide real advice.  I know from my matches (at Big Y) each variant they say is on average about 83 years, my understanding is that the lower level tests that time range goes up quite quickly.

Richard
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: TunjiLees on Thursday 09 April 20 10:19 BST (UK)
Hi Laura,  a GD level 1 match at Y-37 is going to be a long time in the past, at least 1,000 years ago.  At that age range, an autosomal test will not find any link either.   Based on what I have learnt, to be brutally honest a Y37 test is never going to show you very much at all if you are looking for actual close relatives, it will only give a basic picture of the migration line for your family.

Richard
Hi everyone,

I'm still learning about Y-DNA so correct me if I'm wrong but I don't think what rsel is saying is accurate. Let me explain why.

I have one close Y-DNA match with a genetic distance of 3 at Y37.

According to FamilyTreeDNA's TiP Report, my match and I have a 71.79% chance of being related within the last 8 generations.

Through paper records, I know that we don't have a common ancestor within the past 5 generations. When I supply that fact to the TiP Report, I then get a revised estimate of there being a 58.85% chance of sharing a common ancestor within the last 8 generations.

Let's say a generation is 30 years. 8 generations x 30 years = 240 years ago

That is with a genetic distance of 3.

A genetic distance of 1 shouldn't be 1,000 years ago, but much closer to the present.
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: rsel on Thursday 09 April 20 16:19 BST (UK)

Hi everyone,

I'm still learning about Y-DNA so correct me if I'm wrong but I don't think what rsel is saying is accurate. Let me explain why.

I have one close Y-DNA match with a genetic distance of 3 at Y37.

According to FamilyTreeDNA's TiP Report, my match and I have a 71.79% chance of being related within the last 8 generations.

Through paper records, I know that we don't have a common ancestor within the past 5 generations. When I supply that fact to the TiP Report, I then get a revised estimate of there being a 58.85% chance of sharing a common ancestor within the last 8 generations.

Let's say a generation is 30 years. 8 generations x 30 years = 240 years ago

That is with a genetic distance of 3.

A genetic distance of 1 shouldn't be 1,000 years ago, but much closer to the present.
Hi, if you go onto the forums on FTDNA, where there are folks who know a lot more about this than I do provide lots of good information, they will always tell you don't take much notice of Y3 matches.   Whilst they can be close, they can also be a long time ago, you just don't have the detail to know anything for sure.   

Richard
Title: Re: Y-DNA Test Turned up a Perfect Match with Different Last Name
Post by: TunjiLees on Thursday 09 April 20 19:51 BST (UK)
This is taken directly from the FTDNA website for Y-37 matches at a Genetic Distance of 1;

Genetic Distance: 1
Relationship: Tightly Related
Interpretation: A 36/37 match between two men who share a common surname (or variant) indicates a close genealogical match. Very few people achieve this close level of a match, and it is within the range of most well-established surname lineages in Western Europe. It’s most likely that they matched 24/25 or 25/25 on a previous Y-DNA test, and the mismatch will be found within DYS576, DYS570, or CDY.

https://learn.familytreedna.com/y-dna-testing/y-str/two-men-share-surname-genetic-distance-37-y-chromosome-str-markers-interpreted/ (https://learn.familytreedna.com/y-dna-testing/y-str/two-men-share-surname-genetic-distance-37-y-chromosome-str-markers-interpreted/)

If there is not a matching surname then that likely indicates a NPE (non paternity event) or adoption on one of the lines.