"genetic diversity among Neandertals was higher than previously thought.."
So why are they extinct?
They were out-competed. Genetic diversity is no guarrantee of evolutionary success.
Because Cain killed Abel ...
Not sure it means they were all that diverse near the end of their walking-around time.
I think it refers more to the overall diversity across their entire era as it were. This sample was an early specimin. Indeed a bottleneck toward the end of their era might still have been a problem. Much like the present day cheetah story where they have almost no diversity among the immune response genes (and common cat viruses can wipe them out).
> So why are they extinct?
Compare a "diverse" group of street thugs against a non-diverse group of, say, all-white Navy SEALs or all-black Army Rangers or all-Innuit Delta Force.
Or a truckload of chihuahuas, pomeranians and other fishbait dogs against a pack of wolves.
Diversity does not necessarily mean strength. Nor does it mean weakness.
Still a supposition. They might (although the evidence is against it) have interbred their way out of unique status as a species.
They were antisocial and didn't band together well.
Also, this prevented the passing along of skills leading
to advancement, when one died all his skills died with him.
Homo Sapiens were more social and had strength of numbers
and by banding together and sharing skills, preserved them.
Don't come crying for a source either, I was there and I watched it happen. ;-)