From the BBC website:
Scientific evidence of an ancient invasion of Scotland from Ireland may have been uncovered by DNA techniques. Researchers from Edinburgh University said studies of Scots living on Islay, Lewis, Harris and Skye were found to have strong links with Irish people.
Early historical sources recount how the Gaels came from Ireland about 500 AD and conquered the Picts in Argyll. Scientists said the study was the first demonstration of a significant Irish genetics component in Scots’ ancestry.
The research, which features work by geneticist Dr Jim Wilson, a specialist in population genetics, is being featured in programmes on Gaelic television channel BBC Alba. The study also suggests intriguing ancestry of Scots living on the Western Isles and in the north and north east of Scotland.