Just spent a few minutes trying to find the carved holes on the net but couldn't find it ~ will need to think of the words for that one first but it first appeared way back in Scientific American before it turned into a rag.
Again, my thesis is the Neanderthals weren't supermen but they were successful at hunting game, particularly reindeer. This depleted the supply available to other invading people of a different variety, and effectively kept them out of Europe. Europe was short serious quantities of food in the last glacial period.
Then, one day the Neanderthals died out ~ a disease possibly ~ maybe the Mother Ship ~ whatever, once they were gone, the game recovered and the Cro-Magnon people could hunt their way into Europe.
I think that essentially, Neanderthals and modern man were very close in most respects that any differences between us were minimal indeed - not they were insignificant.
In biology, we have “lumpers” and “splitters”. Lumpers are taxonomists or systematic zoologists who minimize the differences between populations and tend to have a broader definition of a species that includes more individuals despite minor differences in appearance, etc. The Splitters want to emphasize the distinctions and create more taxa.
I think, that when dealing with human populations in the fossil record, anthropologists tend to be splitters. If they were studying populations of say, rats or birds, I think the distinctions would be minimized.
A recent article posted on this forum indicated a new theory is that the European Neanderthals actually died out as a breeding population BEFORE the appearance of modern man. The same article indicated that relict populations of Neanderthals in the Middle East interbred with newly arriving “modern” man and contributed 1-3% of the genes of modern Europeans.
My guess is that if a Neanderthal was given a bath, a shave, taught to speak English and put in a suit, he would just look like a very strong, stocky, rough modern man to the casual observer.