"Scientists compared the Neanderthal genome with the genomes of five present-day humans from different parts of the world: France, China, Papua New Guinea and southern and western Africa. The findings suggest that modern humans, after migrating from Africa 45,000 to 80,000 years ago, bred with Neanderthals then in the Middle East before spreading into Eurasia. The authors estimated that 1 to 4 percent of the modern human genome of non-Africans can be traced back to the Neanderthal.
* LeBlanc w/ Register 2003 p124
"Sometime between 40,000 and 30,000 B.C., Neanderthals were replaced in Europe by what is often described as 'the fully modern humans,' known colloquially as Cro-Magnon. Arguments rage whether this was an in situ evolution -- that is, the Neanderthals evolved into modern humans -- or a biological replacement -- biologically different people from Southwest Asia and Africa replaced them -- and whether, if it was replacement, it was peaceful and gradual, or rapid and competitive. The Upper Paleolithic period lasted from 40,000 B.C. until around 12,000 years ago, when the world began to warm up and the great glaciers that covered much of Europe began to retreat. Even the subsequent time period, the Mesolithic (10,000-6000 B.C.), was still the domain of foragers.
"Starting with the Upper Paleolithic period, the time of the famous cave paintings of France and Spain, scholars begin to uncover lines of evidence in addition to blows to the head or cut marks on bones, although these continue, including fifteen possible cases of cannibalism. The site of Dolní Veštonice in Czechoslovakia, dating from twenty thousand to twenty-five thousand years ago, where art objects were produced in great numbers, also provides a window on warfare at that time. The well-known 'village' consisted of a very large structure obviously occupied by many families, similar to the Iroquois longhouses, surrounded by some smaller structures. The entire area was surrounded by a wall or fence of mammoth bones. Typically thsi sort of barrier is used ethnographically around the world for defense. A number of multiple burials -- several people placed in the same grave at the same time -- have been found at Dolní Veštonice, especially mass burials of fighting-age males, a number of whom also have wounds to the head. It is unlikely that several males in their prime would die from disease at the same time. They could have been killed in a failed mammoth hunt, but death from warfare is certainly more plausible. This 'village' was located on a high point of land -- hills provide a good deal of defense, especially against spear-throwers, the best weapon of the times. Almost every line of evidence for warfare I would expect to find for this type of forager has been identified at Dolní Veštonice."
* Curtis 2006 p39-40
"[C]ertainly some of it [the Neanderthal extinction] was intentional. Certainly some of it was violent. Throughout history there has been violence whenever a stronger population on the move finds a weaker group living on desirable land. It is naive to suppose that in prehistory violence seldom occurred or that it had little overall effect on the extinction of the Neanderthals. ...
"It's true that there wasn't a great difference between the weapons on either side, and that the Neanderthals were physically stronger and had the initial advantage of complete familiarity with the territory where they lived. But the newcomers, or perhaps we should even call them invaders, were able to organize. We know from observing hunter-gatherer societies that still survive that no matter where they live, whether in the desert or tropical forests or the arctic ice, they have family groups of 10 or 20, then associated groups of 150 to 175, and then a larger regional group of about 500 individuals. It's reasonable to assume that the first modern humans lived in a similar family and social organization of about the same size, especially since the archaeological evidence is consistent with that assumption. The Neanderthals, meanwhile, lived in their small groups of maybe 15 to 30. Strong as they were, 30 poorly organized Neanderthals would have been no match for 150 to 500 humans who were organized enough to cooperate in a fight.
"There must have been attacks. Presumably the Neanderthals fought back. But much more often the Neanderthals probably just retreated and that is why no evidence of violence remains. Among the surviving hunter-gatherers, as among the tribes in North America before the arrival of Europeans, intimidation, threats, and boasting displays are much more frequent than actual combat. The invading humans would quickly have learned that a threatening display of their superior numbers would make the Neaderthals flee into the far distance."
* Paleonews 2009 Summer p40
"A team of France's National Center for Scientific Research, re-examined modern human bones found in a cave near Les Rois in southwestern France and found that one jawbone was instead Neanderthal. Crucially, it was covered in cut marks, indicating it had been butchered. The human bones were untouched. The scientists say, 'For years, people have tried to hide away from the evidence of cannibalism, but I think we have to accept it took place. This does not prove we systematically eradicated the Neanderthals or that we regularly ate their flesh, but it does add to the evidence that competition from modern humans probably contributed to Neanderthal extinction.'"
* Shipman 2015 p228
"Climate change undoubtedly accompanied and fostered the extinction of the Neanderthals and the other now-extinct predators of the Pleistocene, but climate change is an unsatisfactory candidate as the primary driving force because it fails to answer some key questions. Climate change does not explain why Neanderthals did not go extinct during previous cold phases that were as severe and long-lasting as the ones during MIS 3. If climate change drove Neanderthals southward -- and there is now no strong evidence that it did -- why couldn't they survive and recolonize the more northerly regions when the climate improved? Climate change does not identify any advance or new technical ability possessed by humans that was not possessed by Neanderthals, which would enable modern humans to survive when Neanderthals could not. Climate change does not account for the survival of one hominin species over the other and does not have any obvious bearing on the extraordinary changes that occurred in archaeological sites made by modern humans between 40,000 and 30,000 years ago."