As we bask in the golden age of Neanderthal discoveries, where it seems like every week or month, scientists uncover another fact that radically changes what we thought we knew about our ancient cousins, who we once thought were complete morons who were such idiots that they basically died from their stupidity, we have to keep making room for even more discoveries.

For instance, we thought their populations were so inbred that they basically died off from too much incest, but, according to a new study published in Nature, that assumption may not hold up either.

Researchers analyzed DNA from 27 Neanderthal remains found across 10 sites in Belgium and France, including just the fifth high-quality Neanderthal genome ever recovered. The now significantly larger dataset is telling us that Neanderthals living in northwest Europe around 40,000 years ago weren’t isolated family groups trapped in a doom cycle of inbreeding. They are actually part of big, interconnected groups that were sufficiently genetically diverse.

Scientists identified at least four distinct regional groups of mobile communities that intermingled for a lot longer than previous evidence suggested.

Scientists Just Challenged a Major Theory About Why Neanderthals Went Extinct

All of this sounds silly, but it’s actually rather important when trying to come up with a reason for why the Neanderthals went extinct, as the previous assumption was that all that inbreeding had caused them to accumulate tons of harmful mutations that eventually did them in. But the new study found no evidence that these western European Neanderthals suffered a stark decline in genetic diversity or were debilitated by negative mutations.

The research also had a little side-quest discovery: the researchers found no clear evidence of recent Homo sapiens ancestry flowing all the way back into these Neanderthal populations, even though Neanderthals and Homo sapiens lived alongside each other and intermingled to the point that some people today still carry Neanderthal genetic material. Why we can find Neanderthal DNA in people around today, yet can’t find recent Homo sapiens ancestry in the Neanderthal populations of the past is a bit of a mystery.  

The more scientists learn, the clearer it becomes that Neanderthals weren’t one homogeneous population interbreeding their way into self-destruction. They were a diverse and adaptable people, not dimwitted. They made tools, they cared for each other, created art, and buried their dead with respect and dignity. They were complex. They were more than we thought they were.