The older narrative was simple: modern humans arrived, Neanderthals died out, end of story.

Competition, climate change, or outright replacement.

The evidence now is considerably more complicated.

The ancient DNA evidence for interbreeding means that Neanderthals did not simply disappear.

They contributed genetically to the populations that replaced them.

People with ancestry outside of sub-Saharan Africa carry, on average, between one and four percent Neanderthal DNA in their genomes.

That percentage, sustained over tens of thousands of years of subsequent generations, represents real reproductive contact between the two groups.

But the Neanderthal contribution to modern human genomes is small relative to the overall ancestry.