Science and technologyEvolution in actionSpoils of warHow tuskless elephants evolved in MozambiqueEVOLUTION ENSURES that animals are well-adapted to their circumstances.Sometimes, as with predators and prey, those circumstances include the behaviour of other creatures.And, as a paper just published in Science describes, that includes the behaviour of human beings, which can force drastic changes on a species in an evolutionary eyeblink.Shane Campbell-Staton, a biologist at Princeton University, studies how animals adapt to human creations like cities and pollution.His interest was piqued by a film about the tuskless female elephants of Gorongosa National Park, in Mozambique.Their lack of tusks was thought to be a consequence of another human creation―the Mozambican civil war, which lasted from 1977 to 1992 and was partly paid for by the killing of elephants for their ivory.Around 90% of the pachyderms living in Gorongosa are thought to have been killed.Biologists therefore wondered if rising tusklessness might be an adaptation to make elephants less attractive to human hunters.It was a plausible theory, says Dr Campbell-Staton, but no one had actually tested it.Through a mix of old video footage and surveys, he and his colleagues concluded that around 18% of the female elephants in Gorongosa lacked tusks before the war.
