What is Neanderthals?

David Reich explains why the Neanderthal phylogeny may need a fundamental revision: modern human mitochondrial DNA and Y chromosomes entered the Neanderthal lineage via a ~200,000 to 300,000 year old interbreeding event and swept to 100% frequency, yet represent only 5% of the genome, making Neanderthals genomically mostly Denisovan but maternally and paternally modern human.

“The Y chromosome sequence of Neanderthals and the mitochondrial DNA of Neanderthals, is actually modern human that came through interbreeding 200,000 or 300,000 years ago and then shot up to 100% frequency.”

Neanderthal mitochondrial DNA and Y chromosome are only 300,000 to 450,000 years diverged from modern humans, while the rest of the Neanderthal genome is roughly 700,000 years diverged from Denisovans, implying a recent partial introgression event covering just 5% of the genome.

“What the current genetic work is asking us to believe is that even though this is only 5% of the whole genome, it introduces mitochondrial DNA and Y chromosomes, and they jump up to 100% frequency.”

Neanderthals were eating whole grains at least 60,000 years ago, directly undermining the paleo diet claim that grains are a modern agricultural invention.

“Neanderthals seem to have been eating whole grains at least sort of 60-odd thousand years ago.”

Neanderthals in Spain ate almost no meat, subsisting on things like mushrooms and moss, demolishing any single-template notion of a 'paleo diet'.

“Neanderthals in Spain almost had no meat in their diet, and they seem to be eating things like mushroom, moss, and so what is the modern paleo diet?”

David Reich on the Neanderthal reclassification puzzle

“I'm interested in the possibility that the right way to think about Neanderthals is actually as somehow culturally modern humans, even though genetically they're mostly Denisovans.”

David Reich on the current archaic-human phylogeny model as Ptolemaic epicycles

“We still say, 'Oh, the whole genome says Neanderthals and Denisovans are sisters, so that's the truth.' We've patched it all together and gotten it all to work.”