Poachers

Due to poachers, elephants have devolved their coolest feature. Amongst female elephants, the (born) tuskless rates used to lie between 2% and 4%.

To finance the war in 1992 elephants were slaughtered for their valuable ivory tusks. Since then, around a third of all female elephants are born tuskless. There's just sadly a huge advantage to not possessing a feature that's sought-after by poachers.