The illegal ivory trade causes elephant populations to diminish at an alarming rate. To access the tusks, poachers kill elephants by either poisoning or shooting them. In March 2018, Singaporean authorities seized more than 60 bags of ivory worth around AUD$3.3 million from a Vietnam-bound ship. Conservation biologist Samuel Wasser extracted DNA from the elephant tusks and compared it to DNA he had previously collected from elephant dung across Africa. As a result, Wasser was able to pinpoint exactly where the animals had been killed, and he discovered that ivory shipments came from a few poaching hotspots. This was valuable information in the fight against ivory poachers and corrupt wildlife rangers.
https://blogs.scientificamerican.com/extinction-countdown/poachers-versus-poop/