Sure it's easy to underestimate the Neanderthals as dumb cavemen - after all, they're extinct and we're still here. But were we wrong about our cave-dwelling cousins?
For instance, were Neanderthals just dumb cavemen or were they actually cave Casanovas? Here's an intriguing study that showed that early Homo sapiens ended up interbreeding with Neanderthals (and actually made us stronger):
Are scientists sure we mated with Neanderthals?
Yes: The proof is in our DNA. As much as four percent of the DNA in some people now living was originally Neanderthal, according to the study. Importantly, some of that DNA is found in the part of the human genome known as the HLA (human leucocyte antigen) sequence of genes, which plays a critical role in our immune defenses. "The cross-breeding wasn't just a random event," says lead researcher Peter Parham of Stanford University, as quoted in the Daily Mail. "It gave something useful to the modern human."