We have all heard of the adage of "survival of the fittest." Clearly the giant African elephant qualifies as among the fittest of any animal. On the other hand, they are a magnet for poachers that can sell ivory tusks for $1,500 per pound and tusks can weigh 250 pounds. To heighten the concern, almost all of the ivory seized comes from elephants poached within three years. Moreover, survival of the species has been jeopardized by the tendency of the African female elephants to have tusks like bull elephants which is not the case for Asian elephants.
However, early evidence is appearing that Darwin's theory of evolution may be working to save African elephants. Darwin (1809-1882) stated that all species of organisms arise and develop through the natural selection of small, inherited variations that increase the individual's ability to compete, survive and reproduce. National Geographic recently published an article entitled Under Poaching Pressure, Elephants are Evolving to Lose Their Tusks. In Mozambique's Gorongosa National Park, a fifteen year-long civil war caused some 90% of the 4,000 elephants to be killed for ivory to buy weapons and provide food for the guerrilla fighters.
Hunting gave elephants that did not grow tusks a biological advantage in Gorongosa. Studies suggest that about one-third of younger females born after the civil war ended never developed tusks. Normally, as few as two percent of female African elephants lack tusks. Once poachers put pressure on the population the focus moves from the depleted males to the older females with tusks.
This evolutionary trend is not restricted to Mozambique. Other countries that have a history of substantial ivory poaching also see similar shifts among female survivors and their daughters. In South Africa's Addo Elephant National park, the females are almost always those without tusks. Among Addo's 300-odd females, the ones without tusks approaches 95 percent, a trend that has evolved rapidly over the past century. An increase in females without tusks has also been seen in Zambia, Tanzania and Uganda in recent years.
Although scientists have not evolved a genetic theory, the absence of tusks appears to be sex-linked trait and rarely occurs among males. Therefore, the unnatural selection brought about by poaching has not affected bull elephants though those with smaller tusks have a better chance of survival.
As herds reduce in size and evolve to tuskless females, inbreeding occurs which leads to an evolution which further increases the likelihood of females being born without tusks. Male elephants use tusks to fight other males and to guard their family herds. However, tusks are tools for gathering food, digging for water and fending off predators so cows do need them. Therefore, the focus of conservation has to be the elimination of the demand for ivory through stringent controls and, most importantly, education to make ivory very "uncool!"
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