Author Topic: Skewed geographical distribution of DNA matches  (Read 1268 times)

Offline rlw254

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Skewed geographical distribution of DNA matches
« on: Thursday 31 August 17 18:33 BST (UK) »
Only one pair of my great-great-grandparents was born in Newfoundland and Labrador in the mid-late 1800s. The rest were pretty significantly geographically separated (Italy, Polish-Russia, Pennsylvania, Barbados). I recently analyzed my matches through Family Finder and GEDmatch to find that several of my top 10 matches must be through these Newfoundland ancestors. Additionally, of my top matches that I couldn't immediately identify a common geographical region or surname with myself, many of these had a match within a genealogical timeframe with these Newfoundland matches. Using this type of reasoning, I (roughly) calculated that about 70% of my top 150 matches on GEDmatch are probably linked to myself through Newfoundland.

I'm a little confused as to why this might be. I would (perhaps naively) assume that genetic ties to Newfoundland should only represent 1/8th of my matches, give or take.

Thanks for any input!

Offline davidft

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Re: Skewed geographical distribution of DNA matches
« Reply #1 on: Thursday 31 August 17 19:28 BST (UK) »
You can only match with those of your ancestors descendants who themselves have tested. In your case these are heavily skewed towards those with a link to your Newfoundland ancestors. Its a random occurrence and nothing more. Maybe over time people from your other ancestors lines will test and then your results will even out a little more.
James Stott c1775-1850. James was born in Yorkshire but where? He was a stonemason and married Elizabeth Archer (nee Nicholson) in 1794 at Ripon. They lived thereafter in Masham. If anyone has any suggestions or leads as to his birthplace I would be interested to know. I have searched for it for years without success. Thank you.

Offline Redroger

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Re: Skewed geographical distribution of DNA matches
« Reply #2 on: Thursday 31 August 17 20:03 BST (UK) »
Bearers of my surname in Newfoundland seem reluctant to come forward for testing.is it expense or something else?
Ayres Brignell Cornwell Harvey Shipp  Stimpson Stubbings (all Cambs) Baumber Baxter Burton Ethards Proctor Stanton (all Lincs) Luffman (all counties)

Offline rlw254

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Re: Skewed geographical distribution of DNA matches
« Reply #3 on: Thursday 31 August 17 21:00 BST (UK) »
Do folks in Newfoundland have a higher natural propensity to learn more about their ancestry?  :P

I assume it is as you say, a random occurrence. It just seems like a quite dramatic skew.


Offline sallyyorks

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Re: Skewed geographical distribution of DNA matches
« Reply #4 on: Thursday 31 August 17 21:36 BST (UK) »
Could it be because DNA testing is much more popular in North America than it is in Europe?

Offline hurworth

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Re: Skewed geographical distribution of DNA matches
« Reply #5 on: Thursday 31 August 17 22:58 BST (UK) »
I manage the kit of someone with about 40% Scottish ancestry.  Many of his matches have links to Newfoundland and Prince Edward Island.  Because a 3C1R has tested, by using triangulation I can see which gt-grandfather the matches are likely to be connected through.  He was born in 1829 in Aberdeenshire but the origins of his paternal side is unknown as his father (born 1796) was not on any census. 

The trees of the Canadian matches generally peter out in the early 19th century or they don't know where in Scotland their ancestors were from.  Few records exist in Newfoundland for that period.  Some of the mutual matches are born and bred in Ross and Cromarty.  I wish more Scottish people would test!

I get the impression that there was a lot of intermarriage in Newfoundland initially, so if you match one person from often you will match many.


Offline Redroger

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Re: Skewed geographical distribution of DNA matches
« Reply #6 on: Friday 01 September 17 19:39 BST (UK) »
This applied in many village communities in Britain too, so it was exporting the practice really.
Ayres Brignell Cornwell Harvey Shipp  Stimpson Stubbings (all Cambs) Baumber Baxter Burton Ethards Proctor Stanton (all Lincs) Luffman (all counties)

Offline rlw254

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Re: Skewed geographical distribution of DNA matches
« Reply #7 on: Saturday 02 September 17 19:15 BST (UK) »
Yes I have found in my research many surnames from the Newfoundland area that seem to overlap. There must have been select few early settler families that came to this area and populated it densely with these names which have stuck around for centuries.

Offline Redroger

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Re: Skewed geographical distribution of DNA matches
« Reply #8 on: Sunday 03 September 17 11:03 BST (UK) »
Very many of the named are indigenous to Dorset and nearby counties, many sailed through Poole. I am researching Luffman a rare(ish) English surname pre conquest in origin which has around 2500 instances world wide, 600 in UK, least rare in Dorset and Somerset, but highest density in the world is Newfoundland. Not yet linked though.
Ayres Brignell Cornwell Harvey Shipp  Stimpson Stubbings (all Cambs) Baumber Baxter Burton Ethards Proctor Stanton (all Lincs) Luffman (all counties)