You've probably heard some version of this idea before: that many of us have an inner Neanderthal." That is to say, around 45,000 years ago, when Homo sapiens first arrived in Europe, they met members of a cousin species-the broad-browed, heavier-set Neanderthals-and, well, one thing led to another, which is why some people now carry...

This is today's edition of The Download, our weekday newsletter that provides a daily dose of what's going on in the world of technology. The problem with thinking you're part Neanderthal There's a theory that many of us have an inner Neanderthal." The idea is that Homo sapiens and a cousin species once bred, leaving...