I came across this interesting article yesterday. In it the author demonstrates how our concepts of race are entirely arbitrary and that the pale skin mutation (i.e. "white people") probably first evolved in northern Europe relatively recently. He suggests that this probably happened 5000 years ago....which raises the possibility that the first residents of Ireland and indeed the occupants of sites like the Ceide fields in North Mayo where actually black. Indeed the climate change which initiated the growth of the Irish bogs may have reduced the level of sunlight and thus made it difficult for dark skinned peoples to live on agriculture alone.