Cornish and Breton ancestry and DNA

[JonikW]

Does anyone with Cornish ancestry feel this has or hasn't been reflected in any of the DNA tests on the market? I have at least two Cornish surnames in my mainly South Welsh borders and surrounding counties tree in the past few generations (still researching) and have Cornish 4.72 and English 5.26 as my top populations on the Gedmatch Jtest, and the following results on the Living DNA test in cautious mode:
South Wales border-related ancestry 86.8%
Cornwall 8%
Cumbria-related ancestry 5.2%
Incidentally, my 23andme speculative results put me at British and Irish 66.4%, which is lower than my Welsh mother had.
As a related population, I also wonder if any Bretons have tested and what their results show.

[ajc347]

My maternal grandfather hails from a long-standing Cornish family and I've been able to trace the paper trail back to the marriage between my 4th great grandfather (who was from Lostwithiel) and my 4th great grandmother (who was from Lanlivery) in 1788. Cornish shows up at 3.8% across each of my Living DNA complete, standard and cautious modes. My great grandfather moved over the border to Plymouth (30 miles away), 113 years later and Devon only appears in my complete mode (at 5.3%).

I'm surprised at how low the percentages are considering how well other branches of the family are represented in the Living DNA results (with East Anglia & Ireland/SW Scotland, for example, giving significantly higher percentages despite having a similar paper ancestry to c.1770 and c.1775 respectively). Interestingly, my DNA Tribes report list Cornwall West Britain as being the first ranked population match, so I suspect that there may well be a potential under-reporting for Cornwall in my Living DNA results.

[JonikW]

My maternal grandfather hails from a long-standing Cornish family and I've been able to trace the paper trail back to the marriage between my 4th great grandfather (who was from Lostwithiel) and my 4th great grandmother (who was from Lanlivery) in 1788. Cornish shows up at 3.8% across each of my Living DNA complete, standard and cautious modes. My great grandfather moved over the border to Plymouth (30 miles away), 113 years later and Devon only appears in my complete mode (at 5.3%).

I'm surprised at how low the percentages are considering how well other branches of the family are represented in the Living DNA results (with East Anglia & Ireland/SW Scotland, for example, giving significantly higher percentages despite having a similar paper ancestry to c.1770 and c.1775 respectively). Interestingly, my DNA Tribes report list Cornwall West Britain as being the first ranked population match, so I suspect that there may well be a potential under-reporting for Cornwall in my Living DNA results.

That does seem surprising, although I see you have Cornwall rather than the broader Cornwall-related in cautious mode. So at least the test has picked it up.

[Saetro]

Does anyone with Cornish ancestry feel this has or hasn't been reflected in any of the DNA tests on the market?

If any test is going to show you Cornish it will be LivingDNA.

I am 3/16 Cornish
My FTDNA old-style "MyOrigins" showed 5% Southern Europe (Spain, S France, Italy) as well as a heap of British.
Others who had this had Cornish or occasionally Irish or Welsh.

My mtDNA subclade has identical matches with people's ancestors only from Cornwall/Devon, so that appears to be fairly specific for me.
Matches a little further away come mainly from Ireland, but basically British Isles and the Atlantic seaboard of Europe, so most people may not be able to achieve sufficient specificity from an mtDNA test.

My best ethnicity test has been locating my 16 gg grandparents and their origins.
All subsequent work, whether documentary back another few generations or DNA has merely confirmed it.
And when we judge a DNA test, we will be using our own understanding as the yardstick.
This may be based on what someone in the family told us, but for those who have researched back a few generations, it will be based on that.
It may be good to do a DNA test for confirmation, but when so many people blame the DNA test when there is a difference, why not just rely on the traditional research?
Humans are strange and wonderful beings!

Good luck with the Bretons. A few have tested despite the ban on DNA tests in France.

[firemonkey]

I would love to be able to prove my surname ,Gatty, is Cornish. The earliest birth I've found for Gatty in IGI was in Cornwall in 1568. From Cornwall the Gattys then moved to Devon and London.
On My heritage my father has a match with someone who has a Gatty ancestor from Cornwall in the 18th century. They are also matches on FTDNA. Unfortunately with our Gatty line we are stuck at my 4gt William Gatty who married Ann Murray in 1810 at Liverpool.

Living dna gives me 3.3% Cornwall in complete and standard modes. Eu test -4 Cornish 4.34, Jtest -5 Cornish 4.31



With dna tribes Cornwall is top with my 23andMe,Ancestry and FTDNA uploads. Also top with my father's FTDNA upload.

[MacEochaidh]

Does anyone with Cornish ancestry feel this has or hasn't been reflected in any of the DNA tests on the market? I have at least two Cornish surnames in my mainly South Welsh borders and surrounding counties tree in the past few generations (still researching) and have Cornish 4.72 and English 5.26 as my top populations on the Gedmatch Jtest, and the following results on the Living DNA test in cautious mode:
South Wales border-related ancestry 86.8%
Cornwall 8%
Cumbria-related ancestry 5.2%
Incidentally, my 23andme speculative results put me at British and Irish 66.4%, which is lower than my Welsh mother had.
As a related population, I also wonder if any Bretons have tested and what their results show.

I have 25% French Canadian ancestry with a paper trail that shows a majority of Bretange and Normandie. I haven't found Cornish ancestry on my 75% Isles ancestry (Ulster), but I do have a 6.5% Cornwall ancestry from LivingDNA. On Eurogenes Oracle (GedMatch) I often get Southwest England as my top single ancestry score, which I have always assumed was what you get when you mix 75% Isles with 25% French.

My mtDNA Tg2 traces back to an ancestor, Francoise Arguin, who was born in Cameret-sur-mer, Cournaille, Bretagne in 1698. My closest mtDNA match is from Normandie.

[Clarke]

On Jtest I get 2.7% Cornish? On Ancestry I get links to South-East/West England. I put this down to my maternal ancestry, my mother's maiden name is Clayworth, not being an expert in anyway this is mostly speculative.

[firemonkey]

My father's result- Jtest



# Population Percent
1 ATLANTIC 29.44
2 NORTH-CENTRAL_EURO 27.07
3 SOUTH_BALTIC 13.38
4 WEST_MED 11.8
5 EAST_EURO 9.45
6 WEST_ASIAN 4.04
7 ASHKENAZI 2.97
8 EAST_MED 1.87

Single Population Sharing:

# Population (source) Distance
1 Cornish 2.12
2 Orcadian 3.03
3 IE 3.45
4 English 3.82
5 Scottish 4.15
6 NL 4.76
7 West_&_Central_German 5.9
8 DK 7.04
9 NO 8.54
10 South_&_Central_Swedish 9.33
11 FR 10.17
12 AT 12.86
13 North_Swedish 13.28
14 ES 17.47
15 PT 17.6
16 HU 18.03
17 Serbian 20.5
18 North_Italian 21.38
19 South_Finnish 21.51
20 French_Basque 21.55

Mixed Mode Population Sharing:

# Primary Population (source) Secondary Population (source) Distance
1 80.4% Orcadian + 19.6% FR @ 1.8
2 72.4% Cornish + 27.6% Orcadian @ 1.92
3 88.1% Orcadian + 11.9% ES @ 1.93
4 80.8% Cornish + 19.2% Scottish @ 1.93
5 77.4% Cornish + 22.6% IE @ 1.95
6 95.6% Orcadian + 4.4% Sardinian @ 2.02
7 73.4% Scottish + 26.6% FR @ 2.03
8 88.7% Orcadian + 11.3% PT @ 2.05
9 90.1% Cornish + 9.9% English @ 2.09
10 97.8% Cornish + 2.2% South_&_Central_Swedish @ 2.11
11 99% Cornish + 1% NO @ 2.12
12 99.9% Cornish + 0.1% LIT @ 2.12
13 100% Cornish + 0% GE @ 2.12
14 100% Cornish + 0% AJ @ 2.12
15 100% Cornish + 0% Algerian @ 2.12
16 100% Cornish + 0% Armenian @ 2.12
17 100% Cornish + 0% Assyrian @ 2.12
18 100% Cornish + 0% AT @ 2.12
19 100% Cornish + 0% Balochi @ 2.12
20 100% Cornish + 0% Bangladeshi @ 2.12




Least-squares method.

Using 1 population approximation:
1 Cornish @ 2.421084
2 Orcadian @ 3.416026
3 IE @ 3.926509
4 English @ 4.377352
5 Scottish @ 4.655862
6 NL @ 5.493605
7 West_&_Central_German @ 6.836493
8 DK @ 8.064515
9 NO @ 9.763544
10 South_&_Central_Swedish @ 10.618692
11 FR @ 11.539428
12 AT @ 14.831588
13 North_Swedish @ 14.988324
14 ES @ 19.745224
15 PT @ 19.958075
16 HU @ 20.664074
17 Serbian @ 23.863899
18 South_Finnish @ 24.053795
19 French_Basque @ 24.184450
20 North_Italian @ 24.715273

Using 2 populations approximation:
1 50% Cornish +50% Orcadian @ 2.330048


Using 3 populations approximation:
1 50% Cornish +25% English +25% Scottish @ 2.197433


Using 4 populations approximation:
++++++++++++++++++++++++++++++++++
1 FR + Orcadian + Orcadian + Scottish @ 1.997446
2 FR + Orcadian + Scottish + Scottish @ 2.018913
3 FR + IE + Orcadian + Scottish @ 2.075364
4 English + FR + Scottish + Scottish @ 2.097383
5 FR + IE + Scottish + Scottish @ 2.171815
6 Cornish + Cornish + English + Scottish @ 2.197433
7 FR + Orcadian + Orcadian + Orcadian @ 2.201012
8 Cornish + Cornish + Cornish + Orcadian @ 2.203607
9 Cornish + Cornish + Cornish + Scottish @ 2.207961
10 Cornish + Cornish + Cornish + IE @ 2.213126
11 FR + IE + Orcadian + Orcadian @ 2.231220
12 FR + IE + IE + Scottish @ 2.267370
13 Cornish + Cornish + English + IE @ 2.273083
14 English + FR + IE + Scottish @ 2.279690
15 FR + Scottish + Scottish + Scottish @ 2.297243
16 English + FR + Orcadian + Scottish @ 2.310809
17 Cornish + Cornish + Orcadian + Orcadian @ 2.330048
18 FR + IE + IE + Orcadian @ 2.335629
19 FR + NL + Scottish + Scottish @ 2.359988
20 Cornish + Cornish + IE + Orcadian @ 2.362721

[[email protected]]

Does anyone with Cornish ancestry feel this has or hasn't been reflected in any of the DNA tests on the market? I have at least two Cornish surnames in my mainly South Welsh borders and surrounding counties tree in the past few generations (still researching) and have Cornish 4.72 and English 5.26 as my top populations on the Gedmatch Jtest, and the following results on the Living DNA test in cautious mode:
South Wales border-related ancestry 86.8%
Cornwall 8%
Cumbria-related ancestry 5.2%
Incidentally, my 23andme speculative results put me at British and Irish 66.4%, which is lower than my Welsh mother had.
As a related population, I also wonder if any Bretons have tested and what their results show.

LivingDNA, give me what I thought unexpected Cornwall, only to find out with more paper research that it was real. A nice shock actually..

[JohnHowellsTyrfro]

Only this morning I was contacted by someone who has just tested with Family Finder and it seems we have quite a close match, although to be honest I think sometimes these matches aren't always as recent as they seem.
Anyway, the point is that he thinks the match is through the Cornish side of his family, some of whom moved to Merthyr, he thinks from Towednack Cornwall. We are yet to find a paper trail proving this, so at the moment I'm just thinking of it as a possible reason for my Cornish percentage on LivingDNA. Unfortunately the possible connection may be through my "Jones" line which is very difficult to track back. John