HAPLOGROUP I (M170) -Type Y-Chromosome - First appeared 20,000 years ago. One quote: "It is possible that the Vikings descended from this line. The Viking raids on the British Isles might explain why the lineage can be found in populations in southern France and among some Celtic populations." This would confirm the MacLeod (McCuaig is a sept of MacLeod) descendency from Harold the Black of Norway.