Are elephants evolving in response to poachers?

Originating from an organism the size of a dog, elephants spent 50 million years evolving into the magnificent beasts we know and love today.

Elephants boast a spectacular list of unique adaptations, from their prehensile trunks to their ultra-sensitive but armour-like skin. And now biologists are seeing rapid adaptations in their tusks. Are poachers to blame?