If you want to see a case of evolution in response to changing conditions, consider the rising rate of tuskless elephants. In a natural setting, between two and four percent of female elephants never develop tusks. But in Mozambique, a steep rise in elephant poaching during their 15-year civil war that ended in 1992 left the elephant population with very different statistics, as seen in surveys of the elephants in Gorongosa National Park.
Decades ago, some 4,000 elephants lived in Gorongosa, says Joyce Poole—an elephant behavior expert and National Geographic Explorer who studies the park’s pachyderms. But those numbers dwindled to triple digits following the civil war. New, as yet unpublished, research she’s compiled indicates that of the 200 known adult females, 51 percent of those that survived the war—animals 25 years or older—are tuskless. And 32 percent of the female elephants born since the war are tuskless.
Having no valuable ivory tusks protected these elephants from death, and they managed to pass that trait to the next generation. It's an effect seen in other African countries that dealt with distinct periods of elephant poaching. Further research is looking into how these tuskless elephants interact with their environment, and what effect their numbers have on the ecosystem. Read about the rise of tuskless elephants at National Geographic. -via TYWKIWDBI
(Image credit: Taylor Maggiacomo, NG staff)