Poachers hunting elephant ivory may have met their match in one of nature's greatest forces: natural selection. In at least two national parks in Africa, where poaching has been a huge problem, most female elephants are now born without tusks.
Until the 1990s Gorongosa National Park in Mozambique was home to about 2,500 elephants. But during the civil war that raged from 1972 to 1992, about 90 per cent of that population was killed.
Many of those elephants were slaughtered for their ivory tusks, which were sold to purchase weapons and food to feed the fighters. It now seems that this slaughter was a strong form of evolutionary selection on the elephants, which has increased the frequency of genetic variations that result in tusklessness in female elephants and smaller tusks in males.