Small ears, frizzy hair and dry ear wax - the genetics of mammoths

Genetic analysis of woolly mammoths has shown that they used a number of strategies to adapt to the arctic climate including small ears and frizzy hair

The largest-ever genetic assessment of the woolly mammoth has yielded new insight into this elephant cousin - an icon of the Ice Age - including about its fluffy hair, small ears, cold tolerance, fat storage and even dry ear wax.

Researchers on Friday said they had analysed the genomes of 23 woolly mammoths - including 16 newly sequenced ones - based on remains preserved in Siberian permafrost. They then compared them to the genomes of 28 modern-day Asian and African elephants.

"The objective was to find those mutations that are present in all mammoths but not in any of the elephants - that is, the genetic adaptations exclusive to the woolly mammoth," said evolutionary geneticist David Díez-del-Molino of the Centre for Palaeogenetics in Stockholm, lead author of the study published in the journal Current Biology.

"We find that woolly mammoths had molecular adaptations in genes related to coping with cold Arctic environments, such as thick fur, fat storage and metabolism, and thermal sensation, among others," Díez-del-Molino added.

The genomes included a mammoth from 700,000 years ago - near the origination time of this species on the Siberian steppes - and others that lived later in their history, thus showing how genetic adaptations evolved.

The species, which arose at a time when Earth's climate was cooling, inhabited parts of northern Eurasia and North America. Most mammoths went extinct roughly 10,000 years ago amid a warming climate at the last Ice Age's end, with scientists debating whether human hunting played a role. The last ones died out on Wrangel Island off Siberia's coast 4,000 years ago.

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