Author Topic: Is he my Great-Grandfather?  (Read 436 times)

Offline tinkerbell5

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Is he my Great-Grandfather?
« on: Thursday 21 January 21 23:05 GMT (UK) »
So I posted recently because I did an Ancestry DNA test which came up with a lot of matches with the same surname. Due to the privacy of the other family, I'll say their name was Smith. Through working with numerous 2nd and 3rd cousin matches, I was able to find a common ancestor, someone who would be my 2x Great-Grandfather. It transpires that this man's son was my Nana's Mum's best friend, let's call him John Smith.

Nana did an Ancestry test and her results have come back. Her top 5 matches, not including me, are from the Smith family. The other top matches we don't know, but my Nana's Mum was illegitimate. Anyway, we initially thought, right this proves it, her Dad was John Smith. However, I did some digging and Nana has 5th-8th cousin matches that show up as sharing a common ancestor on her Dad's (who she knew growing up) side of the family.

I know this is Ancestry trying to form a relation. However, it's now got me thinking. I'm now wondering if there is perhaps a chance that 2x Great-Grandfather Smith is the father of my Nana's Mum, actually making him my Great-Grandfather.

I looked at my top 2 cousin matches on MyHeritage (waiting on Nana's upload results). Person A is 191.5cM and 8 shared segments, and is the grandson of 2x Great-Grandfather Smith. Person B is 143.7cM and 4 shared segments, and is the granddaughter of John Smith. I would have thought that I would have a higher cM to the granddaughter of John Smith? Or is it just because I share more DNA with one than the other?

On Ancestry, Nana has 404cM across 21 segments and 302cM across 11 segments with the grandchildren of 3x Great-Grandfather Smith, who would obviously be her Great-Grandfather if John Smith is her Dad.

Could anyone please offer any help with this? I'm sorry if it doesn't make sense, I struggled with finding an easy way of explaining this. Thank you in advance! :)

Offline Liz_in_Sussex

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Re: Is he my Great-Grandfather?
« Reply #1 on: Friday 22 January 21 17:12 GMT (UK) »
Hi,

I've just tried to draw a quick tree to illustrate what you are describing and if I have understood correctly then you and the grandchild of John Smith are half 1st cousins 1x removed? Your grandmother would be a half aunt to the granddaughter?

The DNA of your Grandmother to the granddaughter of John Smith is in the right range for a half aunt / niece relationship. Yours is also in the correct range. Have a look at this chart for the ranges: https://thegeneticgenealogist.com/wp-content/uploads/2017/08/Relationship_Chart_FINAL_August_2017.jpg

But maybe I misunderstood the relationships - if so I apologise!

Liz
Research interests:
Sussex (Isted, Trusler, Pullen, Botting), Surrey (Isted), Shropshire (Hayward), Norfolk (Morgan), Lincolnshire (Brown, Richardson), Wiltshire (Bailey, Morgan), Schleswig-Holstein (Isted),  Nordrhein-Westfalen (Niessen).

Census information Crown Copyright, from www.nationalarchives.gov.uk

Offline tinkerbell5

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Re: Is he my Great-Grandfather?
« Reply #2 on: Friday 22 January 21 22:48 GMT (UK) »
Sorry, my explanation is terrible! According to the Ancestry tree I have built, I'm 2nd cousins with the grandchild of John Smith, which would make my Nana her half Great-Aunt I'm assuming?

Thank you so much for your help and for sharing the chart, that's so helpful!


Offline brigidmac

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Re: Is he my Great-Grandfather?
« Reply #3 on: Saturday 23 January 21 07:59 GMT (UK) »
I've had my mum's Ancestry DNA results for several years but have only just uploaded them to Gedmatch you get a whole list of names emails and matches from people who have tested with 23+me
My heritage and some I've not heard of .
Maybe useful for you to get extra hints


I'm a technophobe ..scared of losing stuff in computer hyperspace but my cousin uploaded his Ancestry to gedmatch
And when I get my new phone I will do mine and my paternal aunt.
I thought you needed to have a computer but the process worked from smart phone
Good luck
Roberts,Fellman.Macdermid smith jones,Bloch,Irvine,Hallis Stevenson

Offline Liz_in_Sussex

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Re: Is he my Great-Grandfather?
« Reply #4 on: Saturday 23 January 21 12:53 GMT (UK) »
Hi,

Quote
Sorry, my explanation is terrible! According to the Ancestry tree I have built, I'm 2nd cousins with the grandchild of John Smith, which would make my Nana her half Great-Aunt I'm assuming?

Sorry - I did misunderstand! You would be half second cousins with John Smith's granddaughter if your Nana was John Smith's half sister. I had read your opening post to say that John Smith was your nan's father:
Quote
It transpires that this man's son was my Nana's Mum's best friend, let's call him John Smith.
and
Quote
right this proves it, her Dad was John Smith.
and
Quote
if John Smith is her Dad.
.

Anyway - half great aunt and half second cousins fit the DNA cM matches you give well.

Liz
Research interests:
Sussex (Isted, Trusler, Pullen, Botting), Surrey (Isted), Shropshire (Hayward), Norfolk (Morgan), Lincolnshire (Brown, Richardson), Wiltshire (Bailey, Morgan), Schleswig-Holstein (Isted),  Nordrhein-Westfalen (Niessen).

Census information Crown Copyright, from www.nationalarchives.gov.uk

Offline JohnDoe2020

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Re: Is he my Great-Grandfather?
« Reply #5 on: Thursday 04 February 21 03:29 GMT (UK) »
Go to DNA Painter and enter the CMs mentioned. Go to the relationship chart below the probability estimate. The possible positions on the relationship chart will be highlighted. The correct relationship based on CMs is driven by the generation as related to you. (or your Nana if you are using her match data) This assumes you understand the match's approximate age in relation to the source match, either your or Nana.
Good luck