Before 1500 A.D. , medieval Gaelic society in Ireland isolated itself from the rest of Europe,…
Before 1500 A.D. , medieval Gaelic society in Ireland isolated itself from the rest of Europe, physically as well as culturally. Men in the group are called “descendants of Niall,” and they all share a Y chromosome inherited from a single shared ancestor. In the society, men took several partners, and sons born out of wedlock were fully accepted. One male, for example, Lord Turlough O’Donnell, had 10 wives and concubines, who gave him 18 sons and 59 grandsons. Today, in a corner of northwest Ireland, 1 in 5 men has the “descendant of Niall” Y chromosome. In all of Ireland, the percentage of Y chromosomes with the Niall signature is 8.2 percent. In western Scotland, where the Celtic language is similar to Gaelic, 7.3 percent of the males have the telltale Niall Y. In the U.S., among those of European descent, it is 2 percent. Worldwide, the Niall Y chromosome makes up only 0.13 percent of the total. What concept from the chapter do the data illustrate?
