MCCAMMON: Around 90% of the elephants there were killed, but many female elephants without tusks survived and thrived.ĬORNISH: Campbell-Staton had heard all of this before.ĬAMPBELL-STATON: But then I realized that there wasn't actually a lot of empirical data about what the response was from, you know, what the genetic basis of the trait was. UNIDENTIFIED PERSON: Large-tusked elephants in Gorongosa were killed for their ivory, which was sold to buy arms and ammunition. MCCAMMON: But the number of tuskless elephants was multiplying in Mozambique during and after the country's decades-long civil war, which ended in 1992.

UNIDENTIFIED PERSON: Some elephant populations seem to be missing their tusks.ĬORNISH: You see while most African elephants have tusks, some female African elephants are born without them and never grow them. Gorongosa - that's a national park in Mozambique. SHANE CAMPBELL-STATON: The Howard Hughes Medical Institute - they had this video that was called 'The Tuskless Elephants Of Gorongosa.' And I was like, ooh, what's this? That's where Princeton evolutionary biologist Shane Campbell-Staton found himself a few years ago. Our next story begins in a place many of us are familiar with - up awake, watching a YouTube video at 3 in the morning.