Researchers aren’t sure:
With the issue of Neanderthal/modern human mating settled, scientists could focus on a new goal, says Akey, now at Princeton University. Namely, what was the consequence of this interbreeding? “Was it just this curious feature of human history that didn’t have an impact, or did it alter the trajectory of human evolution?”
In the past five years, a flurry of research has sought to answer that question. Genomic analyses have associated Neanderthal variants with differences in the expression levels of diverse genes and of phenotypes ranging from skin and hair color to immune function and neuropsychiatric disease. But researchers cannot yet say how these archaic sequences affect people today, much less the humans who acquired them some 50,000–55,000 years ago.
“So far I have not seen any convincing functional studies where you take the Neanderthal variant and the human variant and do controlled experiments” to identify the physiological consequence, says Grayson Camp, a genomicist at the Institute of Molecular and Clinical Ophthalmology Basel (IOB) in Switzerland. “No one has actually shown yet in culture that a human and Neanderthal allele have a different physiological function. That will be exciting when someone does.”
Jef Akst, “Neanderthal DNA in Modern Human Genomes Is Not Silent” at The Scientist
But the fact that they are even studying something like this helps us understand why it is no longer a career disaster to doubt textbook Darwinism.
It’s been nearly a quarter century since some of us read David Berlinski’s Commentary essay, The Deniable Darwin. Back then, the Neanderthal was the subhuman our kind had killed off. Survival of the fittest and so forth. There were lots of explanations around how stupid Neanderthals supposedly were. Maybe the explanations don’t age so well now.
See also: Neanderthal Man: The long-lost relative turns up again, this time with documents
and
A deep and abiding need for Neanderthals to be stupid. Why?