This is scientific American 60 second science.

I'm Christopher Intagiyata.

In their heyday, woolly mammoths blanketed the Siberian step, Alaska,

and large parts of North America.

But by 10,000 years ago, warming climates had turned many of the grasslands they grazed

into forest.

And humans, well, they weren't so friendly either.

One mammoth provides quite a feast.

So the mammoths largely disappeared, except there's this one holdout population

on an island in the Arctic Ocean called Rangel Island,

where the last mammoths hit out for more than 6,000 years.

So the pyramids have been built and they had started to grow tea in China and civilization

had formed and then here are these mammoths that no one knew

were there for such a long period of time. Rebecca Rogers, an evolutionary geneticist

at the University of North Carolina. And then people finally found this island around 3,700 years ago around the time that they went extinct.

Rogers and her colleague Montgomery Slatkin analyzed the genome from the tooth of one of those island mammoths, which lived 4,300 years ago.

They compared it to the genome of a mainland mammoth

from much farther back 45,000 years.

And they found that harmful mutations had polluted the island mammoths genome in that time interval, mutations

that led to the loss of smell receptors and urine proteins, compounds they probably needed

for social signaling and made choice.

The animals also developed this satany coat that shines in the

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