Did "we" kill the Neanderthals?
A case in point is a recent study about how modern humans replaced Neanderthals. The researchers found that Neanderthals in western Europe (particularly a sample from northern Spain) experienced a genetic bottleneck prior to the arrival of modern humans, suggesting that climate had already nearly wiped them out before any Homo sapiens sapiens showed up.
I found out about this study through this article, which puts a Eurocentric spin on the research. It opens by describing the time when "our ancestors reached Europe." But of course non-European people's ancestors never came to Europe at all. And depending on the extent to which the Indo-European expansion involved a spread of people and not just a spread of culture, only a very few people today (such as the Basques) might be directly descended from the people who encountered Neanderthals in western Europe.
More significantly, the article goes on to suggest that the research does away with the hypotheses of interbreeding, genocide, and out-competition. The author says it "raises the question of just how humans would have really fared against a Neanderthal population at full strength." But the research in question actually clearly states that humans did encounter full-strength Neanderthals -- just not in western Europe. The researchers clearly contrast the genetic bottleneck in Spain with more genetically diverse (and hence presumably larger) populations in eastern Europe and Asia.
Another interesting aspect to the reception of this study is the way that it's drawn into discourses about historical guilt. There's a persistent misunderstanding of leftist views of history that says the left wants people to feel guilty about the sins of their ancestors. Usually this concern focuses on comparatively recent events like the trans-Atlantic slave trade or Native American and Aboriginal Australian genocide. The actual leftist view of history is that it is important to recognize past injustices 1) so that we can understand why inequalities exist in the present (instead of attributing it to either personal failures or genetic inferiority on the part of present-day marginalized people), 2) so that it's reasonable to expect present-day descendants of the "winners" to invest some of the benefits they've gained from their ancestors' misdeeds in rectifying the legacy of the past injustice, and 3) so that we can be attentive to the possibility of similar misdeeds being repeated in the present. Many people insist on misinterpreting this leftist view of history as some sort of demand that the descendants of the "winners" feel guilty about their ancestors' sins. Guilt is actually one of the least productive responses to ancestral sin one could have -- it leads to wasting time in self-flagellation and centering the conversation on the guilty party and how horrible they feel.
The Neanderthal research then becomes a lever in this debate. Misinterpreters of the leftist view of history can assimilate Neanderthal extinction to more recent genocides, and then claim vindication (from a guilt nobody actually attributed to them) when research shows that climate did in (some of) the Neanderthal population. But even if research had shown that the extinction of the Neanderthals was a deliberate genocide by modern humans, there would be no grounds for guilt about it.