Evolution May Rescue Elephants From The Threat Of PoachingPosted on March 7th 2019
Poachers who hunt elephants in an attempt to taketheir ivory may have an obstacle they simply cannot overcome in the form ofnature’s most powerful force, natural selection. There are at least two Africannational parks which have suffered greatly from poaching. What is trulyfascinating is that in these parks the majority of females are now born withouttusks. This is an astonishingdevelopment and were the trend to carry into the wider elephant population, itwould have dramatic implications on elephant poaching.
Variation and natural selection save the day
Up until the 1990’s, Mozambique’s Gorongosa NationalPark served as home to approximately 2,500 elephants. During the course of the country’scivil war which ended in 1992, about 90 per cent of the park’s population werekilled. Many of those elephants lost their lives to poachers hunting them fortheir ivory tusks, with the money generated used to purchase weapons and foodfor the fighters. It now appears that this massacre resulted in a strong formof natural selection and evolution, increasing the frequency of geneticvariations that produce females without tusks and males that have smallertusks.
Tusks are a liability
Generally speaking less than four percent of femaleelephants are born tuskless, but experts say in Gorongosa there has been a hugeshift. Tusks suddenly became a liability which meant that animals with tusksand therefore the genes that cause tusks to grow have been removed by poachersfrom the population. Elephants without tusks have no appeal to poachers andcontinue to survive, which means those genes get passed on to futuregenerations and there is an increase in the number of elephants born withouttusks.
Smaller tusks is another trend
South Africa’s Addo Elephant National Park underwenta similar experience. Poaching has resulted 98 per cent of the female elephantsin the park being born without tusks. Tusks also seem to be growing smaller. Inone part of Kenya where poaching is rampant, male elephants have tusks whichare 20 per cent smaller whilst female elephants’ tusks are more than 33 percent smaller. This is quite astonishing and represents a massive shift.
Males continue to be born with tusks
As a rule, males have much bigger and heavier tusksin comparison to females, so naturally poachers target them first. Experts arenot sure exactly why males have not yet evolved to become tuskless, though itis believed that males use their tusks to do battle with other males for accessto females. The theory is that males benefit greatly from their tusks and thatis why the potential for the gender to become tuskless has been weeded out.