Some 4,500 years ago, the Bell Beakers invaded Britain. Roughly 90% of the genes of later Britons came from this group, named for the distinctive shape of their pottery. Archaeologists long thought that Britain’s early farmers, who built Stonehenge five millennia ago, adopted the pots from continental neighbors. Instead DNA evidence shows that the farmers were nearly annihilated by the Bell Beakers.
Mr. Hawks is a professor of anthropology at the University of Wisconsin-Madison.