In an earlier post, I noted that some researchers place the evolution of my Dad's I-M223 ancestral genetic fatherline in Doggerland (Europe's Atlantis now submerged under the North Sea).
Eupedia gives even more specific information on the matter:
The best living candidates for Doggerland haplogroups seem to be I2a2a-Cont, including its British subclade I2a2a4-Cont2c; I2a2a-Roots, including its British subclade I2a2a1-Isles; and I2a1b2-Isles, which has a continental cluster "B." All of these are split between the continent and Britain and have TMRCAs that allow for them to be dated to Doggerland. I2a1b1-Disles/Dinaric and I2a1c1-Western are also possibilities, although they present more complicated pictures.
In the old phylosystem, my dad's I-M223 haplogroup is called I2a2a-Cont (he is in the Continental Group 1 also known as Cont1 at Family Tree DNA). He doesn't have the mutations for any of its native British subclades. So, when my ancestral fathers left Doggerland, it looks as if they didn't move toward the isles, but toward the continent instead - most likely Northern Germany - Netherlands - Denmark -Southern Sweden areas. All of these areas are consistent with known general genetic matches for my Dad's Y-DNA haplogroup.
In my Dad's I-M223-Cont1 Group 1 at FTDNA (where individuals in the greater I-M223 haplogroup are further subdivided based on each person's specific results into marker-clustered groups), there are 18 gentlemen from Ireland (including 3 specifically from Northern Ireland), 4 from England/UK, 2 from Germany, and 1 each from Scotland, Netherlands, Croatia, France and South Africa. There are 7 unknowns.
Well, the current location of my Dad's closest genetic brothers is consistent with what is known via oral family tradition about my paternal family's origins - English, Irish and German. From the numbers though, it looks like the ethnicity of the recent ancestors in my Dad's paternal line are Irish, English and German.
Given that my Dad does not carry the native British M284 mutation for the I-M223 Hg, and that the M284 mutation arose approximately around 300 BCE during the Iron Age, then it's very likely that my Dad's paternal line migrated to the isles long after Doggerland became submerged, and probably did migrate to the isles during the Anglo-Viking invasions.