I’ve long stated that humans are the only species in which individuals know of their own mortality, but this is no longer true. As documented in the video below, researchers at Tulane University in Louisiana have taught a gorilla, Quigley, that it will one day die. The results are sad and predictable, but scientifically enlightening. They’re now extending the work to other species.
In more recent work, not reported in this video, Quigley has been reported kneeling before he goes to sleep and making gestures very similar to human genuflecting.