Case in point, many of the people on this forum are British or have at least partial British ancestry, me included. How many know how our ancestors lived? To quote the Wikipedia article I cited above:
In The Gallic Wars, Book one, Chapter 14, Julius Caesar writes about the Celts who inhabited Kent in England: "Ten and even twelve have wives common to them, and particularly brothers among brothers, and parents among their children; but if there be any issue by these wives, they are reputed to be the children of those by whom respectively each was first espoused when a virgin."