Why so much Scottish DNA?

[phil57]

I have some Scottish ethnicity on my paternal line according to Ancestry. I have no known direct ancestors from Scotland, but my direct paternal line goes back to Kent also for as far back as I have been able to trace it (mid to late 17th century).

But my paternal surname apparently derives from people in north west France around the Brittany/Normandy border - one of the areas of Celtic habitation included in Ancestry's definition of Scotland for ethnicity purposes.

Whether that is the explanation, who knows. Ethnicity estimates are what they say - estimates derived from data which has itself been estimated to lesser or greater extents. I find it can be useful as a comparison tool when looking at DNA matches who have tested with the same company. Other than that,  I concentrate on genetically related DNA matches, which are indisputable above low match lengths, and far more useful in my opinion than ethnicity estimates which may or may not be correct, but in either case may deviate substantially from the headline percentages ascribed to them.

[coombs]

If I ever hop on the DNA bandwagon I will try to avoid ethnicity estimates as they are as avoidable as the Dallas dream season. 

[brigidmac]

I agree with southseal

If he does have pure Scottish ancestry from a hitherto unknown ancestor
 it may well become apparent through comparing matches .

But don't dismiss ethnicity out of hand look at the DNA ethnicity breakdown ..it now differentiates between lowland + highland Scottish

My Celtic amounts changed over the decade  since testing my DNA 

 ethnicity got more precise Cornwell is now recognised as having specific regional traits too

[phil57]

But don't dismiss ethnicity out of hand look at the DNA ethnicity breakdown ..it now differentiates between lowland + highland Scottish

My Celtic amounts changed over the decade  since testing my DNA 

 ethnicity got more precise Cornwell is now recognised as having specific regional traits too

Aren't these regional breakdowns "communities" rather then ethnicity regions?

[brigidmac]

According to DNA experts some communities have specific DNA ethnicities .
Especially in more isolated regions

 For example my friend had Cornish community/ethnicity showing on DNA results for parent 1 before adding his father s side  to his tree.
Mother was half African and it also showed which area of Africa before birth father was identified...of course borders aren't the same as political boarders but the divisions were clear and helpful

[phil57]

DNA Communities assigned to Ancestry DNA tests are separate from ethnicity and use a completely different method of determination.

Ethnicity regions are determined by direct examination of the subject's DNA and comparison of segments having similarities to those in the DNA of people in the reference panels for various ethnicity regions, which are believed to be common to populations from those areas who are not necessarily genetically related by descent from common individuals. Its aim is to estimate regional ethnic origins from around 500 to several thousand years ago.

DNA communities are determined via an algorithm similar in some ways to Thrulines, which identifies common ancestors amongst all of the people who have taken a DNA test with Ancestry, and trawls through their family trees looking for communities shared between those matches' ancestors. It aims to identify much more recent locations where genetic cousins lived around the same period of time, as would be expected with information derived from family trees, which in most cases is unlikely to be more than 500 years old due to the limitations of paper records and similar evidence on which most of the information in those trees is (or should be) based.

Hence I have no North American ethnicity at all, but I am associated to two DNA communities in the USA. Neither I or any of my direct ancestors have lived anywhere on the American continent, but three half cousins, children of my GGF by a different marriage to his later marriage to my GGM, did emigrate to the US from the NW of England, and have between them more DNA tested descendants  by far, who are matches to me, than any of my other lines of descent. Hence Ancestry attaches me to those communities.

Having said that, other communities in England and Wales have recently been split into more localised areas and do show a pretty good degree of accuracy, again perhaps not all that surprising as they are determined from locations found in my trees and those of my genetic cousins.

So Thrulines looks for common individuals and lines of descent in the trees of DNA matches. DNA communities looks for common locations in the same trees.

[SouthseaSteel]

DNA Communities assigned to Ancestry DNA tests are separate from ethnicity and use a completely different method of determination.

Ethnicity regions are determined by direct examination of the subject's DNA and comparison of segments having similarities to those in the DNA of people in the reference panels for various ethnicity regions, which are believed to be common to populations from those areas who are not necessarily genetically related by descent from common individuals. Its aim is to estimate regional ethnic origins from around 500 to several thousand years ago.

DNA communities are determined via an algorithm similar in some ways to Thrulines, which identifies common ancestors amongst all of the people who have taken a DNA test with Ancestry, and trawls through their family trees looking for communities shared between those matches' ancestors. It aims to identify much more recent locations where genetic cousins lived around the same period of time, as would be expected with information derived from family trees, which in most cases is unlikely to be more than 500 years old due to the limitations of paper records and similar evidence on which most of the information in those tress is (or should be) based.

Hence I have no North American ethnicity at all, but I am associated to two DNA communities in the USA. Neither I or any of my direct ancestors have lived anywhere on the American continent, but three half cousins, children of my GGF by a different marriage to the later marriage to my GGM, did emigrate to the US from the NW of England, and have between them more DNA tested descendants  by far, who are matches to me, than any of my other lines of descent. Hence Ancestry attaches me to those communities.

Having said that, other communities in England and Wales have recently been split into more localised areas and do show a pretty good degree of accuracy, again perhaps not all that surprising as they are determined from locations found in my trees and those of my genetic cousins.

So Thrulines looks for common individuals and lines of descent in the trees of DNA matches. DNA communities looks for common locations in the same trees.

I agree.  Ancestry Communities seem much more believable, meaningful and useful in ascribing your ancestry

[brigidmac]

Great explanation Phil

My paternal  cousin has recently tested she has not yet linked her results to a tree but I can compare her ethnicity to mine
She is 58 percent Scottish and 6percent Irish

I'm 48percent Scottish 6 percent Irish from my father's side (& 4percentof my Scottish is from a maternal ancestor ).


Her mother whose dna I manage is 91percent Scottish 7percent Irish  2 percent English has now appeared but it specified northern

( last recalclation had zero English).