Curious Paternal Haplogroup for Danish Patrilineal Descent (R-Y4010)

[Mathurin Kerbouchard]

My Y-haplogroup, R-Y4010 (R1b, subclade of R-M269), is a relative rarity in northern Denmark, from where my 4x great-grandfather emigrated in the 1840s. I've confirmed with male-line relations -- two second cousins -- that they share the same haplogroup, and we all have a good enough sense of our genealogy/genomic breakdown to confirm Danish patrilineal origin.

(The family spent two generations in a mostly Danish LDS community in Utah after immigrating, so an Irishman sneaking into the family tree during that period is unlikely).

Is this at all an unusual result for Danish men? I read here (https://www.reddit.com/r/23andme/comments/iyxl70/what_do_these_mean_could_someone_specify/) that R-Y4010 is an "entirely Irish lineage", and I read somewhere else -- can't find the link -- that it originated around 550 AD in Ireland.

Could my having this haplogroup be explained by Viking Age population exchange between the British Isles and Scandinavia? Or is the ambient level of R-Y4010 in Denmark high enough that it doesn't require any special explanation?

[Edit] For reference, here's a heatmap of R-Y4010:

121989

[Mathurin Kerbouchard]

Some better graphics for R-Y4010:

Irish distribution centers on Ennis, County Clare.

121994

Very curiously, the reported US distribution is limited to a SE-NW axis following the Savannah River into North Georgia and Middle Tennessee. Likely a limitation of the dataset (N=3 in the US) -- I can't believe a haplogroup with 2% frequency in County Clare has 0% frequency in the US Northeast.

121995

I'd much appreciate any other visualizers for haplogroup mapping.

[Gaoyuan]

Probably Irish,Y4010 formed very late,1200 years or something

[Petalpusher]

Some Irish lad hopped on a Viking ship back home unnoticed, paddling like everybody else.

[nittionia]

My maternal grandfather is Swedish and R-S660. I assumed some Irish viking age explanation.

[Grace O'Malley]

My Y-haplogroup, R-Y4010 (R1b, subclade of R-M269), is a relative rarity in northern Denmark, from where my 4x great-grandfather emigrated in the 1840s. I've confirmed with male-line relations -- two second cousins -- that they share the same haplogroup, and we all have a good enough sense of our genealogy/genomic breakdown to confirm Danish patrilineal origin.

(The family spent two generations in a mostly Danish LDS community in Utah after immigrating, so an Irishman sneaking into the family tree during that period is unlikely).

Is this at all an unusual result for Danish men? I read here (https://www.reddit.com/r/23andme/comments/iyxl70/what_do_these_mean_could_someone_specify/) that R-Y4010 is an "entirely Irish lineage", and I read somewhere else -- can't find the link -- that it originated around 550 AD in Ireland.

Could my having this haplogroup be explained by Viking Age population exchange between the British Isles and Scandinavia? Or is the ambient level of R-Y4010 in Denmark high enough that it doesn't require any special explanation?

[Edit] For reference, here's a heatmap of R-Y4010:

121989

Definitely Irish. In yfull there is a Norwegian in my paternal group R-S588 which is under M222. Also there is a cluster of M222 in Sweden which would include R-S660 which is what Nittionia's great grandfather was. He might be part of this cluster. M222 is the Niall of the Nine Hostages marker although it is older than Niall but the O'Neill's and their relatives spread it in Ireland and of course to Scotland via Dal Riata. Yours is also very interesting in that it is derived from R-L226 which is the Brian Boru marker or the Dalcassian Clans. All these groups had heavy involvement with the Norse that were in Ireland so I suspect in Scandinavian populations it is related to Viking activity. That appears the most logical to me. I've also wondered if it was related to Wild Geese i.e. Irish soldiers that served in many European countries but I don't know why there isn't more Spanish and French people showing up with these Irish ydna markers so I'm leaning more towards Viking interactions with the Irish as to why there is this Irish ydna in Scandinavian countries.

https://www.yfull.com/tree/R-Y4010/

Anyway it is pretty cool to be connected through ydna to the greatest Irish High King of all time Brian Boru.

https://i.pinimg.com/736x/5f/4d/3f/5f4d3ff6383c3cde9d9b9c400833197f.jpg

[Figaro]

Seems Irish and not a very old subclade. I have a friend who is of this subclade and his paternal side is indeed Irish.