DNA of Ireland and UK: what we can tell from the admixture chart from the new study.

[Sikeliot]

What is clear is the single largest component for all Brits and Irish is a "French" component, which is likely meant to represent Celtic ancestry as the sample is taken from northwest France, where Celtic ancestry has been best preserved. But by combining the German, Belgian, and Danish, we can get a sense of how much Anglo-Saxon, or continental Germanic, ancestry exists in the UK and Ireland.

The following are my observations and hypotheses:

1. The western part of the UK -- Wales, western England, and western Scotland -- shift toward Ireland genetically due to higher Celtic ancestry and lower Anglo-Saxon.

As far as England is concerned, this French component is highest in Devon, Cornwall, and the Marches region of Worcestershire, Gloucestershire, and so on. Therefore we can say this is the least Anglo-Saxon, and most Celtic, part of England, which matches history. These regions also are closest to Wales. As for Scotland, western Scotland is by far the closest to Ireland, with the cluster from there being closer to the Irish than to the rest of Scotland, which makes sense because SW Scotland had the highest concentration of Gaelic speakers and received significant historical migration from Ireland. Wales, too, is similar in this regard.

2. Northern England and northern Scotland on the other hand appear to have significant continental Germanic ancestry and a reduction to their Celtic ancestral base.

This can be seen in the reduced French component, and an increase to Belgian, German, and Danish. Still, it is necessary to note that even the least Anglo-Saxon areas of England have more of such ancestry than Ireland does.

3. Scotland, Ireland, and Orkney have elevated Norwegian affinity compared to England and Wales.

In particular, Orkney, Ireland, and western Scotland. It is possible that such ancestry in all three has been passed back and forth by constant migration between them. It also seems likely to me that some of the Norwegian in western Scotland arrived via Ireland, because northern Scotland has significantly less of this component. It also must have arrived separately from Anglo-Saxon migrations mediated through Germany, because the components are not correlated.

4. Northern Ireland's 3 clusters are closest to Northern Scotland, rather than to western Scotland which is more solidly Celtic.

To me, this implies that the Plantation settlement in northern Ireland was not simply a back-migration of western Scots to Ireland, but consisted of people from less Celtic areas of Scotland that had not been in contact with Ireland previously, as well as some settlement directly from England. This is supported by Danish and German ancestry being higher in Northern Ireland than in western Scotland, and noticeably more so than the Gaelic Irish clusters.

5. The Gaelic Irish clusters are all similar, but with subtle differences.

a. We can see once again that the high Norwegian is NOT correlated with Anglo-Saxon ancestry, because the areas with the highest Norwegian -- Ulster and South Munster -- have the lowest Belgian, Danish, and especially German. Therefore we can conclude that these areas either received Viking settlement that was noteworthy but received very little foreign settlement otherwise, or if we presume that Ulster and South Munster are the most "pure" and untouched Irish, that the Norwegian component is actually native and has been in Ireland well before Vikings. I tend to go with the latter, considering that most Viking settlements were in the center, east, and in Connacht, rather than in the extreme northwest and extreme southwest of Ireland represented by Ulster/South Munster.

South Munster, ultimately, is likely to have the least foreign input as it has the highest of the French component, and the lowest combined Belgian, German, and Danish.

b. Albeit still low, Anglo-Saxon (likely, ultimately, English) ancestry seems highest in Leinster and North Munster, as there is a slight increase to the Danish and Belgian components, and these are the only areas where the German component is even noticeable on the spreadsheet. This would make sense as these regions on the east coast of Ireland have the greatest continental Germanic y-dna in the Republic of Ireland, and they had the most contact with England and the highest concentration of non-Gaelic surnames.

c. Connacht, Dublin, and Central Ireland are somewhere intermediate between Ulster/South Munster on one hand (relatively pure, untouched Irish) and Leinster/North Munster (some evidence, though small, of English and continental Germanic ancestry). This is likely because these regions would have been the first ones to receive secondhand migration across Ireland from the more foreign-populated east coast, while Ulster/South Munster are at the extreme northwest and southwest of Ireland, always remained in ethnic Irish hands, and are some of the last regions to still speak Gaelic today.


http://i65.tinypic.com/28h0w7k.jpg

[Bobby Martnen]

Interesting...my great-grandmother was from an Irish-speaking village in Galway

[Sikeliot]

Interesting...my great-grandmother was from an Irish-speaking village in Galway

Galway is in Connacht.

For what it is worth, the "Connacht" cluster is centered on the extreme west coast of Ireland, "Leinster" on the east coast, while "Central Ireland" comprises of the entire inland region spanning Leinster and Connacht.

[Bobby Martnen]

Galway is in Connacht.

For what it is worth, the "Connacht" cluster is centered on the extreme west coast of Ireland, "Leinster" on the east coast, while "Central Ireland" comprises of the entire inland region spanning Leinster and Connacht.

I was wondering if the Irish-speaking villages in Galway would have less foreign influence than the Anglophone parts of Connaught.

[Sikeliot]

I was wondering if the Irish-speaking villages in Galway would have less foreign influence than the Anglophone parts of Connaught.

That I do not know. If you mean to say that the Gaeltacht region of Galway might be closer to the South Munster cluster or Ulster than to what is labeled Connacht, it could be. But I have no idea.

But I do know that the Connacht cluster, for how much people would have expected the extreme west coast of the province to have been shielded from all foreign influence, has detectable German (unlike South Munster and Ulster which you can't see a single trace) and higher Danish and Belgian than them too. The same is true for Central Ireland, which captures much of the inland part of Connacht.

[Sikeliot]

This is which cluster goes to which region. As you can see there is considerable overlap between Connacht and Central Ireland clusters.

https://i.pinimg.com/originals/b2/e6/e1/b2e6e1dac5199705246c9d487f504c80.png

[Sikeliot]

https://i.redd.it/4digx4hiub301.jpg

[Bobby Martnen]

That I do not know. If you mean to say that the Gaeltacht region of Galway might be closer to the South Munster cluster or Ulster than to what is labeled Connacht, it could be. But I have no idea.

But I do know that the Connacht cluster, for how much people would have expected the extreme west coast of the province to have been shielded from all foreign influence, has detectable German (unlike South Munster and Ulster which you can't see a single trace) and higher Danish and Belgian than them too. The same is true for Central Ireland, which captures much of the inland part of Connacht.

What do Danish and Belgian also represent?

Also, I really should Y-DNA test my grandma's brother - if he's R1b, he's a native Irishman, if he's I1 (like me, my father's father was of West German heritage), he's descended from invaders.

[Sikeliot]

What do Danish and Belgian also represent?

Also, I really should Y-DNA test my grandma's brother - if he's R1b, he's a native Irishman, if he's I1 (like me, my father's father was of West German heritage), he's descended from invaders.

I assumed Belgian, Danish, and German signal Anglo-Saxon input.

[Sikeliot]

Actually it seems more likely to me now that Norwegian DNA dispersed across Ireland and is actually Viking, because we see no higher Norwegian input in the more Celtic parts of England, so it is probably not a native Celtic remnant, it has to be a foreign/intrusive one. French and Norwegian components would correlate everywhere if both were native to the British Isles but they don't.

[Grace O'Malley]

Thanks for doing this breakdown Sikeliot and giving your observations. I agree with them in the most part.

They have dated the Norwegian admixture to the time of the Vikings so I think there is some credence in that. Also there was Viking settlements in Munster. The Vikings actually were all over Ireland as they travelled up the river systems.

http://i63.tinypic.com/iv96xs.png

This is a very brief summary of the Vikings in Ireland.

http://ireland-calling.com/viking-cities-in-ireland/

Here is an image of some of the early raids they conducted with their encampments displayed by a red dot.

http://i63.tinypic.com/mink7m.png

http://www.wesleyjohnston.com/users/ireland/past/pre_norman_history/vikings.html

So in short I do agree with the studies in that the Norwegian component is largely due to Viking raids as the Norse targeted the very areas where the Norse component is higher i.e. Ireland, West Scotland and the Scottish Isles i.e. Orkney, the Hebrides.

People might be interested in knowing that they are doing a study on Iceland and looking at what parts of Ireland contributed to the Icelandic people. They will also look at some of the islands like the Hebrides so more interesting information to look forward to.

[Sikeliot]

Thanks for doing this breakdown Sikeliot and giving your observations. I agree with them in the most part.

Which do you disagree with?

What it seems to me is that there is definitely a difference in Great Britain, with the western part more "Celtic" than the eastern part, and thus more Irish-like. Though you could see this even by comparing AncestryDNA results that have been shared online.

I also think that you can see, similarly, that Leisnter/North Munster show the most evidence in (Gaelic) Ireland of fairly recent British ancestry, which is seen through the German/Belgian/Danish components, while Ulster/South Munster have the least and everyone else in between.

Out of curiosity do you know which parts of Ireland most Irish Americans are from?

[Grace O'Malley]

Which do you disagree with?

What it seems to me is that there is definitely a difference in Great Britain, with the western part more "Celtic" than the eastern part, and thus more Irish-like. Though you could see this even by comparing AncestryDNA results that have been shared online.

I also think that you can see, similarly, that Leisnter/North Munster show the most evidence in (Gaelic) Ireland of fairly recent British ancestry, which is seen through the German/Belgian/Danish components, while Ulster/South Munster have the least and everyone else in between.

Out of curiosity do you know which parts of Ireland most Irish Americans are from?

The only thing was that you said in your original post that the Norwegian element was native but you did update your opinion. I was writing my post when you came to the same conclusion as myself. So I agree with all your conclusions.

From my understanding a lot of Irish from the western parts of Ireland went to the US as these were the areas more affected by the famine and also they were poorer. Many in my father's family immigrated to the US in the 1800s and early 1900s and they were all from Connacht. My mother's family were from North Munster and they didn't emigrate.

[Grace O'Malley]

I was wondering if the Irish-speaking villages in Galway would have less foreign influence than the Anglophone parts of Connaught.

No not really because most of Ireland was Irish speaking when these events occurred. Many Normans and early English ended up completely assimilating into Irish life. The Normans virtually started assimilating straight away and marrying into Irish families. Up until the 1800s a lot of Connacht was Irish speaking so the main admixture events in Ireland happened earlier. The only more recent admixture happened in Ulster and the Irish DNA Atlas dated that to the time of the Plantations of the 16th and 17th century.

[Sikeliot]

No not really because most of Ireland was Irish speaking when these events occurred. Many Normans and early English ended up completely assimilating into Irish life. The Normans virtually started assimilating straight away and marrying into Irish families. Up until the 1800s a lot of Connacht was Irish speaking so the main admixture events in Ireland happened earlier. The only more recent admixture happened in Ulster and the Irish DNA Atlas dated that to the time of the Plantations of the 16th and 17th century.

I'd ask you why Munster appears to have a divide. North Munster is closer to Leinster, Connacht, Dublin and clearly has a trace of German, but South Munster has almost none. The French component in South Munster is also elevated.

[celticdragongod]

4. Northern Ireland's 3 clusters are closest to Northern Scotland, rather than to western Scotland which is more solidly Celtic.

To me, this implies that the Plantation settlement in northern Ireland was not simply a back-migration of western Scots to Ireland, but consisted of people from less Celtic areas of Scotland that had not been in contact with Ireland previously, as well as some settlement directly from England. This is supported by Danish and German ancestry being higher in Northern Ireland than in western Scotland, and noticeably more so than the Gaelic Irish clusters.


http://i65.tinypic.com/28h0w7k.jpg

Excellent point! From Wikipedia:

Today, Scotch-Irish is an Americanism rarely used in England, Ireland or Scotland.[5] The term is somewhat ambiguous because some of the Scotch-Irish have little or no Scottish ancestry at all: numerous dissenter families had also been transplanted to Ulster from northern England, in particular the border counties of Northumberland and Cumberland. Smaller numbers of migrants also came from Wales and the southeast of England, and others were Protestant religious refugees from Flanders, the German Palatinate, and France (such as the French Huguenot ancestors of Davy Crockett).[10] What united these different national groups was a base of Calvinist religious beliefs,[11] and their separation from the established church (the Church of England and Church of Ireland in this case).

https://en.wikipedia.org/wiki/Scotch-Irish_Americans

[Grace O'Malley]

I'd ask you why Munster appears to have a divide. North Munster is closer to Leinster, Connacht, Dublin and clearly has a trace of German, but South Munster has almost none. The French component in South Munster is also elevated.

They did explain that in the Irish DNA Atlas to a certain extent. The divide is due to mountainous terrain separating North and South Munster and also to the influence of tribal influence which basically affected all of Ireland. The divisions in Ireland run along clan lines.

You can see why some areas would be more isolated than others by looking at this map.

https://upload.wikimedia.org/wikipedia/commons/c/c1/Topography_Ireland.jpg

This is from the IDA.
These clusters do however seem to reflect more recent historical events within Ireland. N Munster and SMunster together predict the boundaries of the province of Munster, and individually are associated with the boundaries of the kingdoms of Dál Cais and the Eóganacht13,28, respectively. Furthermore, within Munster, County Clare was originally under the rule of the people of Connacht, until being eventually acquired by Munster28

The Dál Cais were one of the most powerful dynasties in Ireland. They are the tribe from which Brian Boru emerged from. He is the most legendary High King in Irish history so some of the clans had a very powerful grip on their territories and beyond.

[celticdragongod]

I was wondering if the Irish-speaking villages in Galway would have less foreign influence than the Anglophone parts of Connaught.

Religion was also an effective barrier to gene flow between the British and Irish populations. Marriages between Catholics and Protestants are generally not that common in Ireland.

[celticdragongod]

What do Danish and Belgian also represent?

Also, I really should Y-DNA test my grandma's brother - if he's R1b, he's a native Irishman, if he's I1 (like me, my father's father was of West German heritage), he's descended from invaders.

R1b isn't exclusively Celtic. It also appears in Germanic and other non-Celtic groups.

[Grace O'Malley]

Religion was also an effective barrier to gene flow between the British and Irish populations. Marriages between Catholics and Protestants are generally not that common in Ireland.

Actually there were marriages especially in Northern Ireland. There was a very good discussion about this on Anthrogenica. Many people in Northern Ireland are a mixture and this is what the IDA also shows. Some famous Irish like Gerry Adams and Bobby Sands although from the Catholic community were originally from Planter families. It is not uncommon to have Planter names in the Catholics and Irish names in Protestant families. It is a bit of a misconception that they didn't intermarry.

[Grace O'Malley]

Which do you disagree with?

What it seems to me is that there is definitely a difference in Great Britain, with the western part more "Celtic" than the eastern part, and thus more Irish-like. Though you could see this even by comparing AncestryDNA results that have been shared online.

I also think that you can see, similarly, that Leisnter/North Munster show the most evidence in (Gaelic) Ireland of fairly recent British ancestry, which is seen through the German/Belgian/Danish components, while Ulster/South Munster have the least and everyone else in between.

Out of curiosity do you know which parts of Ireland most Irish Americans are from?

Just putting in a map of Plantations in Ireland which might correlate to what you have observed.

https://upload.wikimedia.org/wikipedia/commons/5/51/Ireland_1450.png

https://upload.wikimedia.org/wikipedia/commons/a/a9/Flight_of_the_Earls.jpg

https://upload.wikimedia.org/wikipedia/commons/8/87/Plantations_in_Ireland.png

https://en.wikipedia.org/wiki/Plantations_of_Ireland

[celticdragongod]

Actually there were marriages especially in Northern Ireland. There was a very good discussion about this on Anthrogenica. Many people in Northern Ireland are a mixture and this is what the IDA also shows. Some famous Irish like Gerry Adams and Bobby Sands although from the Catholic community were originally from Planter families. It is not uncommon to have Planter names in the Catholics and Irish names in Protestant families. It is a bit of a misconception that they didn't intermarry.

What evidence is there that Gerry Adams and Bobby Sands were from Planter families?

[Grace O'Malley]

What evidence is there that Gerry Adams and Bobby Sands were from Planter families?

The surnames for one are a dead giveaway.

But here is some research.

Bobby was descended from an English family which migrated to the Lowlands of Scotland in the early 1400’s before relocating to the northern Irish province of Ulster in the 1600’s. Gerry descends from some of the MacAdams of Galloway, a sept of the notorious Clan Gregor, who likewise crossed west over the Irish Sea to Ulster during the Plantations. According to Gerry’s bio he is related to the political Adams family of the early United States which produced the country’s second and sixth presidents, as are the Adams from whom I am descended that were among the first settlers of the original Warren County in Tennessee.

http://www.chattanoogan.com/2013/6/10/252998/Origin-of-the-Term-Scotch-Irish.aspx

[JQP4545]

What is clear is the single largest component for all Brits and Irish is a "French" component, which is likely meant to represent Celtic ancestry as the sample is taken from northwest France, where Celtic ancestry has been best preserved. But by combining the German, Belgian, and Danish, we can get a sense of how much Anglo-Saxon, or continental Germanic, ancestry exists in the UK and Ireland.

The following are my observations and hypotheses:

1. The western part of the UK -- Wales, western England, and western Scotland -- shift toward Ireland genetically due to higher Celtic ancestry and lower Anglo-Saxon.

As far as England is concerned, this French component is highest in Devon, Cornwall, and the Marches region of Worcestershire, Gloucestershire, and so on. Therefore we can say this is the least Anglo-Saxon, and most Celtic, part of England, which matches history. These regions also are closest to Wales. As for Scotland, western Scotland is by far the closest to Ireland, with the cluster from there being closer to the Irish than to the rest of Scotland, which makes sense because SW Scotland had the highest concentration of Gaelic speakers and received significant historical migration from Ireland. Wales, too, is similar in this regard.

2. Northern England and northern Scotland on the other hand appear to have significant continental Germanic ancestry and a reduction to their Celtic ancestral base.

This can be seen in the reduced French component, and an increase to Belgian, German, and Danish. Still, it is necessary to note that even the least Anglo-Saxon areas of England have more of such ancestry than Ireland does.

3. Scotland, Ireland, and Orkney have elevated Norwegian affinity compared to England and Wales.

In particular, Orkney, Ireland, and western Scotland. It is possible that such ancestry in all three has been passed back and forth by constant migration between them. It also seems likely to me that some of the Norwegian in western Scotland arrived via Ireland, because northern Scotland has significantly less of this component. It also must have arrived separately from Anglo-Saxon migrations mediated through Germany, because the components are not correlated.

4. Northern Ireland's 3 clusters are closest to Northern Scotland, rather than to western Scotland which is more solidly Celtic.

To me, this implies that the Plantation settlement in northern Ireland was not simply a back-migration of western Scots to Ireland, but consisted of people from less Celtic areas of Scotland that had not been in contact with Ireland previously, as well as some settlement directly from England. This is supported by Danish and German ancestry being higher in Northern Ireland than in western Scotland, and noticeably more so than the Gaelic Irish clusters.

5. The Gaelic Irish clusters are all similar, but with subtle differences.

a. We can see once again that the high Norwegian is NOT correlated with Anglo-Saxon ancestry, because the areas with the highest Norwegian -- Ulster and South Munster -- have the lowest Belgian, Danish, and especially German. Therefore we can conclude that these areas either received Viking settlement that was noteworthy but received very little foreign settlement otherwise, or if we presume that Ulster and South Munster are the most "pure" and untouched Irish, that the Norwegian component is actually native and has been in Ireland well before Vikings. I tend to go with the latter, considering that most Viking settlements were in the center, east, and in Connacht, rather than in the extreme northwest and extreme southwest of Ireland represented by Ulster/South Munster.

South Munster, ultimately, is likely to have the least foreign input as it has the highest of the French component, and the lowest combined Belgian, German, and Danish.

b. Albeit still low, Anglo-Saxon (likely, ultimately, English) ancestry seems highest in Leinster and North Munster, as there is a slight increase to the Danish and Belgian components, and these are the only areas where the German component is even noticeable on the spreadsheet. This would make sense as these regions on the east coast of Ireland have the greatest continental Germanic y-dna in the Republic of Ireland, and they had the most contact with England and the highest concentration of non-Gaelic surnames.

c. Connacht, Dublin, and Central Ireland are somewhere intermediate between Ulster/South Munster on one hand (relatively pure, untouched Irish) and Leinster/North Munster (some evidence, though small, of English and continental Germanic ancestry). This is likely because these regions would have been the first ones to receive secondhand migration across Ireland from the more foreign-populated east coast, while Ulster/South Munster are at the extreme northwest and southwest of Ireland, always remained in ethnic Irish hands, and are some of the last regions to still speak Gaelic today.


http://i65.tinypic.com/28h0w7k.jpg

Can you provide a link to the study?

[JQP4545]

The northwestern part of France (Brittany) was settled by Britons. So are the Irish really related to the French or are the researchers picking up on Celtic DNA in northwest France?

[Peterski]

Belgian component rather represents the Belgae, who settled in Britain (as attested by Julius Caesar). They settled in Britain long before the Anglo-Saxons. As for Danish ancestry - either it is indistinguishable from Anglo-Saxon, or most of Danes were really slaughtered (see my thread below):

https://www.theapricity.com/forum/showthread.php?235077-St-Brice-s-Day-massacre-and-its-impact-on-English-ancestry

The Belgae in Britain: https://en.wikipedia.org/wiki/Belgae#Britain

This was also a Belgic tribe: https://en.wikipedia.org/wiki/Atrebates#The_Atrebates_in_Britain

There were several Belgic and Gallic tribes in Britain already during Caesar's times.

============

As you can see the Belage probably settled also in Ireland:

"(...) T.F. O'Rahilly claims in his invasion model that a branch of the Belgae also settled in Ireland, and were later represented by the historical Iverni (Érainn), Ulaid, and other kindreds. He claims a variety of evidence suggests memories of this were preserved in later Irish tradition, and also makes an elaborate linguistic case.[36] According to his theory, the name of the legendary Fir Bolg (whom O'Rahilly identifies with the Érainn) is the Irish equivalent of Belgae. (...)"

[Peterski]

This is also interesting:

S8 Fig. ADMIXTURE analysis (k=2) for PoBI/Irish cluster groups with ancient British samples:

https://www.theapricity.com/forum/showthread.php?222207-How-much-of-English-ancestry-is-from-Germanic-invaders-vs-Irish-like-people&p=4959093&viewfull=1#post4959093

But K=2 is a bit too low resolution I think.

[celticdragongod]

The northwestern part of France (Brittany) was settled by Britons. So are the Irish really related to the French or are the researchers picking up on Celtic DNA in northwest France?

France was originally part of Gaul which was a Celtic territory.

[Grace O'Malley]

Belgian component rather represents the Belgae, who settled in Britain (as attested by Julius Caesar). They settled in Britain long before the Anglo-Saxons. As for Danish ancestry - either it is indistinguishable from Anglo-Saxon, or most of Danes were really slaughtered (see my thread below):

https://www.theapricity.com/forum/showthread.php?235077-St-Brice-s-Day-massacre-and-its-impact-on-English-ancestry

The Belgae in Britain: https://en.wikipedia.org/wiki/Belgae#Britain

This was also a Belgic tribe: https://en.wikipedia.org/wiki/Atrebates#The_Atrebates_in_Britain

There were several Belgic and Gallic tribes in Britain already during Caesar's times.

============

As you can see the Belage probably settled also in Ireland:

"(...) T.F. O'Rahilly claims in his invasion model that a branch of the Belgae also settled in Ireland, and were later represented by the historical Iverni (Érainn), Ulaid, and other kindreds. He claims a variety of evidence suggests memories of this were preserved in later Irish tradition, and also makes an elaborate linguistic case.[36] According to his theory, the name of the legendary Fir Bolg (whom O'Rahilly identifies with the Érainn) is the Irish equivalent of Belgae. (...)"

Yes the PoBI could not pick up much scent of the Vikings in England. They reasoned that because the admixture of that Danish/German component was fairly constant and didn't increase in parts of the Danelaw area there wasn't much ancestry left from the Vikings. It is quite odd really. They have put that component down to Anglo-Saxon admixture. Basically the Anglo-Saxon admixture is obscuring any Viking component. If it was Norse it would be easier to pick up but because England received Danish Vikings it is more difficult to differentiate their signal from the Anglo-Saxons.

Comparing clusters of genetic variation within Britain with DNA samples from Continental Europe, the study elucidated past immigration events via the identification and dating of historic admixture episodes (the interbreeding of two or more different population groups). Among its results, the study found “no clear genetic evidence of the Danish Viking occupation and control of a large part of England, either in separate UK clusters in that region, or in estimated ancestry profiles”, therefore positing “a relatively limited input of DNA from the Danish Vikings”, with ‘Danish Vikings’ defined in the study, and thus in this article, as peoples migrating from Denmark to eastern England in the late ninth and early tenth centuries (Leslie et al. 2015: 313).

There is archaeological and linguistic evidence of the Danish Vikings though so not sure what to make of their conclusions.

[Bobby Martnen]

Apparently Icelanders are the spawn of Norse men and Irish women.

[Grace O'Malley]

The northwestern part of France (Brittany) was settled by Britons. So are the Irish really related to the French or are the researchers picking up on Celtic DNA in northwest France?

This northwestern French component was old but Northern France and Britain and Ireland have very interwoven links. I do think that the Northwestern French component that is so high in the Celtic Fringe is also due to Celts from Britain escaping to Brittany in the 5th century as they were getting attacked by both Anglo-Saxons and Scotti (Irish) tribes. There is however deeper connections as is shown by the high L21 in Northern France and shared genetics across that region. I agree with the study that Northern France (or that vicinity) is where a lot of the Isles people came from as this component is in all British and Irish clusters.

[Grace O'Malley]

Can you provide a link to the study?

Here are the two studies. They are very interesting.

https://www.nature.com/articles/s41598-017-17124-4

http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1007152

[Grace O'Malley]

Apparently Icelanders are the spawn of Norse men and Irish women.

They are doing a study on Iceland and investigating the links with Ireland. It is well known that the Norse took women from Ireland and peripheral Scotland (i.e. Hebrides, Orkney and other Western Isles) to Iceland. They are going to be looking at what part of Ireland they came from and looking at admixture in the Icelanders.

[Bobby Martnen]

They are doing a study on Iceland and investigating the links with Ireland. It is well known that the Norse took women from Ireland and peripheral Scotland (i.e. Hebrides, Orkney and other Western Isles) to Iceland. They are going to be looking at what part of Ireland they came from and looking at admixture in the Icelanders.

I mean it's not hard to get Iceland from Ireland...just change 1 letter...