The myth of lemmings engaging in mass suicidal cliff dives dies hard, having entered our language as a metaphor for senseless crowd behavior. From an evolutionary perspective, of course, it makes no sense whatsoever. Not even kin selection could justify such genetic line-ending behavior as pack suicide.
This article from the Australian Broadcasting Corporation debunks the myth and explains how a staged plunge debuted in a Disney documentary and spread into our cultural heritage. It also lists a few other lemming tales that explain the rodents’ populations swings by their arrival from the sky.
Link via BoingBoing and the Disney Blog, which notes, “Disney’s True Life Adventures film series did great things for the advancement of understanding the world around us. However, the lemming suicide plunge debacle was not one of them.”