Irish Mystery Ancestor

You (R-FT194071) and Irish Mystery Ancestor (R-M222) share a common paternal line ancestor (R-M222) who lived around 100 BCE (2,100 years ago).

One in six men from Ireland and more than one in 20 men from Scotland share a Y-chromosome signature stemming from a single common ancestor that is estimated to have lived about 2,100 years ago, between 400 BCE and 200 CE.

The notably high frequency of that signature among Irishmen, in combination with the relatively recent time estimate initially led to the theory that the semi-mythical 5th-century warlord known as “Niall of the Nine Hostages” (Niall Noígíallach) could be the ancestor of all these Irishmen and Scotsmen. Niall supposedly established a dynasty of powerful chieftains that dominated the island for six centuries.

The Niall theory is heavily contested, and we may never know who the mysterious progenitor was unless new evidence comes to light from testing of present-day or ancient DNA. Unfortunately, no remains have been found that can be definitively proven to be from Niall, and the 17 STRs used to make the original hypothesis have since been shown to be insufficient to draw any such conclusions. The R-M222 Haplogroup Project states, “There were other haplogroups and L21 subclades contemporary with R-M222 in Ireland during Niall’s and Ui Neill dynasty clans’/founders/leaders reputed times of living.”

Information sourced from Wikipedia, the FamilyTreeDNA R-M222 and Subclades Project, “A Y-chromosome signature of hegemony in Gaelic Ireland.” by Moore, McEvoy, Cape, Simms, and Bradley, 2006, and “A dated phylogenetic tree of M222 SNP haplotypes” by McLaughlin and Howard.