Ivory DNA sequencing tracks elephant poaching hotspots

savannah elephants

The illicit trade in elephant ivory has been a ridiculous problem since the 1980’s, when Asian and African elephants were decimated to such a level that they made it onto Appendix One (“most endangered species”) of CITES. While all trade in their ivory was banned in 1989, poaching is still a huge issue, especially in the dense forests of Africa that camouflage a multitude of illegal activities. Large seizures of black market ivory have been made over the years, but without knowing precisely where in the world these materials are originating from, tracking – and stopping – poachers is a tricky business.

Scientists have made this challenge a little bit easier by developing a test that combines genetics with statistics to match ivory DNA sequences to within 500-1000km of the originating elephant’s habitat. Working up the method on tissue and poop samples from forest and savannah elephants at 28 locations throughout Africa, a team led by Dr. Samuel Wasser correlated sixteen regions of DNA, known to show heady levels of variation between individuals and to act as a unique genetic fingerprint, with location. On a blinded test, their strategy was able to correctly identify the geographic area of origin of forest elephants 83% of the time, and of savannah elephants 35% of the time. Even in the savannah elephants, the 65% of “incorrectly assigned” locations were typically still pretty near the actual location. This approach was then used as part of a criminal investigation into a 6.5 tonne illegal shipment of ivory seized in Singapore, shipped from Malawi, and estimated to be poached from 3000-6500 elephants. While it was suspected that the tusks had been widely culled from across Africa, researcher’s showed that almost all of it came from savannah elephants in Zambia.

This innovative method should make it possible to trace the origins of elephant ivory all over the world, enabling the focussed deployment of anti-poaching efforts. It could also conceivably be expanded to include other endangered species in the illegal wildlife trade.

Wasser SK, Shedlock AM, Comstock K, Ostrander EA, Mutayoba B, & Stephens M (2004). Assigning African elephant DNA to geographic region of origin: applications to the ivory trade. Proceedings of the National Academy of Sciences of the United States of America, 101 (41), 14847-52 PMID: 15459317

Wasser SK, Mailand C, Booth R, Mutayoba B, Kisamo E, Clark B, & Stephens M (2007). Using DNA to track the origin of the largest ivory seizure since the 1989 trade ban. Proceedings of the National Academy of Sciences of the United States of America, 104 (10), 4228-33 PMID: 17360505

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