Cheetahs and the open-country hunters

Open habitat rewards a different predator design: instead of ambush from cover, sustained high-speed pursuit. Acinonyx appears in the Pliocene with the lightened skeleton, semi-retractile claws, enlarged nasal passages and flexible spine of a sprinter, giving up climbing ability and fighting strength in exchange. The living cheetah carries a signature of near-extinction in its genome — extremely low diversity consistent with a severe bottleneck — which is why individuals will accept skin grafts from unrelated animals.