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Mystery of what caused the woolly mammoth to go extinct may be solved

Woolly mammoth (Credit: Flying Puffin)Woolly mammoth (Credit: Flying Puffin)Towards the end of the last Ice Age, around 12,000 years ago, woolly mammoths roamed across Siberia and the colder regions of North America. A warming climate and human hunters led to their extinction on the mainland about 10,000 years ago, but a small group of around 300 animals clung on in Wrangel Island off the Siberian coast until about 3700 years ago. Isolated from humans and well adapted to cold, tundra conditions, what caused them eventually to die out? Scientists have compared the DNA from one of these last mammoths with another that lived 40,000 years before, and now believe they have found the answer: gene mutations.

Wrangel Island tundra (NOAA)Wrangel Island tundra (NOAA)

Mammoth calf preserved in the icy ground (Woudloper)Mammoth calf preserved in the icy ground (Woudloper)Genes, coded instructions ”written" in the chemical structure of the DNA molecule found in every cell of a living thing, contain all the information that it needs to develop, grow and maintain itself through life. The complete set of genes in a living thing (humans have about 23,000 genes) is called the genome. 

A mutation is a permanent change in the genetic code. Some mutations are useful, enabling an animal to adapt to its environment, but others are harmful, causing disease, or hindering the animals' ability to find food or a mate.

Scientists think that "mutational meltdown" may have affected the mammoth population of Wrangel Island. The mammoths were so wracked with genetic disease that they lost their sense of smell, developed a strange shiny coat and tended to become solitary rather than live as a herd. 

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