The tree below shows the ancestors of Roger and Carroll Biggins Byrne.
Of the 64 great great great grandparents for Roger and Carroll, 47 are Irish, 8 are German, 5 are Scottish, and 4 are Swiss.
Their children, therefore, are 47/64ths Irish, 1/8th German, 5/64ths Scottish, and 1/16th Swiss.
Roger has "Isles-Scot DNA." His haplotype is: I-M223, CTS616, FGC15071, M284, L126, FGC20063, FT2393, S7753, Y6162, Y4751, BY3610, Y63570 (1350 AD). His DNA matches closest with a Donald Austin Byrne (1934-2017), whose ancestor, Austin Thomas Byrne (1859-1934), was born in Dublin. There is another Byrne who goes back to County Wicklow. Alistair Moffat and James F. Wilson in the 2011 book, The Scots: A Genetic Journey, say that "One of the most ancient Y lineages in Scotland is known as M284." They say it developed a later subset called L126 which is more common in Scotland. It is "also seen in Ulster, not only amongst plantation families (migrants from Scotland and elsewhere, most of whom arrived in the seventeenth century) but also in those of older pedigree. This shows an ancient connection across the North Channel."
Carroll's father Peter Biggins had his Y-chromosome DNA tested, and it matched descendants of Clan Colla, three brothers who lived in 4th-century Ulster. His haplotype is R-P312, L21, DF13, DF21, S971, F24434, Z3000, Z3006, Z3008, S953, ZZ13, FT14481, BY3164 (794 AD). The name Biggins comes from beag, the Irish for little. Biggins DNA matches with people named Beggan, Beaghen, Bigham, and Little. See Biggins/Beggan Irish Roots. Biggins DNA also matches names historically associated with Clan Colla, including McDonald, McGuire, Carroll, McKenna, McMahon, Boylan, Duffy, Kelly, MacDougall.
Carroll's maternal second cousin, Michael Patrick Carroll had his Y-chromosome DNA tested. Mike's DNA matches Ryan, O'Dwyer, Lee/Leary, Gorman, and Kennedy, as well as Carroll. These families descend from Breassal Breac who lived in Leinster around 200 or 100 BC. They settled in the 13th or 14th century in County Tipperary and County Limerick.