...but apparently not in Denisovans who accumulated deleterious mutations at a higher rate than modern humans. This may account for the fact that we haven't been able to find many Denisovans in the archaeological record as they may simply be a population that "failed" -- although apparently some distant relatives of the single Denisovan genome did admix into Australasians.
No evidence that natural selection has been less effective at removing deleterious mutations in Europeans than in West Africans
Ron Do et al.
Non-African populations have experienced major bottlenecks in the time since their split from West Africans, which has led to the hypothesis that natural selection to remove weakly deleterious mutations may have been less effective in non-Africans. To directly test this hypothesis, we measure the per-genome accumulation of deleterious mutations across diverse humans. We fail to detect any significant differences, but find that archaic Denisovans accumulated non-synonymous mutations at a higher rate than modern humans, consistent with the longer separation time of modern and archaic humans. We also revisit the empirical patterns that have been interpreted as evidence for less effective removal of deleterious mutations in non-Africans than in West Africans, and show they are not driven by differences in selection after population separation, but by neutral evolution.