A Parthian shot

UNLESS creatures such as yeti and Bigfoot turn out to be real, the only kind of human in the modern world is Homo sapiens. But that is only recently true. For most of Homo sapiens’s 200,000-year history, it shared the planet with several cousins. The most famous were the Neanderthals, who were larger and heavier and who lived in Europe and Central Asia.

Neanderthals died out 40,000 years ago. Whether they were killed off directly by modern humans or were out-competed is a perennial topic of debate. But, either way, there was more to relations between the two species than just inter-hominid rivalry. In the past decade researchers have found that between 1% and 4% of the DNA of modern Europeans and their descendants on other continents is of Neanderthal origin. There must, in other words, have been a certain amount of interbreeding going on back in the day.