Battling insomnia, Campbell-Staton watched a video about Gorongosa National Park. The park was once Edenic, but during Mozambique's civil war, from 1977 to 1992, much of its wildlife was exterminated. Government troops and resistance fighters slaughtered 90 percent of Gorongosa's elephants, selling their ivory to buy arms and supplies. Naturally tuskless females, which are normally rare, were more likely to survive the culls; after the war, their unusual trait was noticeably common. Campbell-Staton, a biologist at Princeton who studies rapid evolution, had questions. Was this a dramatic example of natural selection in action? Why only the females? Which genes were involved? He idly emailed his questions to a colleague who studies elephants, inadvertently setting off a chain of emails that recast his casual curiosity as serious intent, and soon found himself being introduced to a large group of Gorongosa researchers as "a guy who wants to study the genetic basis of tuskless