It has been found that woolly mammoths had suffered a genetic meltdown during their final days on Earth. At their prime, woolly mammoths had dominated most of Siberia, Alaska and several parts of North America. But as the climate turned warmer some 10,000 years ago, the woolly mammoths faced an extreme challenge which, unfortunately, they were unable to overcome.
First of all, the change in climate had turned the grasslands where the mammoths had grazed into forests, and to add more conflict to their already diminishing situation, humans hunted them relentlessly as hunting one mammoth provided quite the bountiful feast. Eventually, the woolly mammoths then vanished from the mainland. However, a small group of them would hide out on an island in the Arctic, Wrangel Island, and survive some 6000 years more before truly vanishing from the face of the earth.
A new study reveals that the last woolly mammoths suffered from a 'genetic meltdown' which contributed to their population's demise. By comparing DNA from a 45,000-year-old woolly mammoth tissue to DNA from a 4,300-year-old woolly mammoth tooth from Wrangel Island, scientists have discovered that the latter contained an excess of bad mutations, BBC reports. According to Dr. Rebekah Rogers of the University of California, Berkeley, when there is only a small population of a species for an extended period of time the species can go into a genomic meltdown.
In the woolly mammoths of Wrangel Island's case, natural selection became inefficient due to the small population and the woolly mammoths weren't able to weed out the bad genes from the good ones. In a different report published in the New York Times, it is revealed that the Wrangel Island woolly mammoths have accumulated many mutations in their genes resulting even in the loss of the olfactory genes as well as other components that affect mammoth behavior and disrupting their social status and mate choice.
One damaged gene found in the DNA sample is FOXQ1 which turned their hair shiny and less stiff, giving a more satin-like appearance. Mammoths usually have thick and rough hair which provides them effective insulation. But with the damage in the FOXQ1 gene, their insulation has ultimately been jeopardized as well as their survival.