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The last woolly mammoth died 4,000 years ago on an island in the Arctic -- and that's significant
By Scottie Andrew, CNN
Updated 6:55 PM ET, Tue October 8, 2019
(CNN)The last woolly mammoths roamed the Earth as recently as 4,000 years ago, on a remote island in the Arctic Ocean.
Learning about what led to their extinction could potentially save existing species from a similar fate, researchers said.
Those mammoths outlived other members of their species by avoiding the environmental factors that led to their extinction, according to a study published in the journal Quaternary Science Reviews. They might've even lived longer, if short-term events hadn't tainted their water and drained their food supply.
Mammoths once roamed the entire northern hemisphere, researchers said. But when the last ice age ended and global warming followed 15,000 years ago, shrinking ice and rising sea levels isolated populations.
Some of the newly formed groups died as a result. Others survived another 10,000 years before finally succumbing.
To find out why some survived, a team of Finnish, Russian and German scientists studied clues in woolly mammoth bones, tusks and teeth collected in Canada, Alaska, Siberia and Wrangel Island in the Arctic Ocean. Any differences in composition of elements would indicate changes in diet, habitat and environment that could've prolonged or shortened their lives.
Wrangel mammoths outlived other members of the species
While other populations died out as climate change changed the composition of their environment and genetic diversity shrunk in their isolated populations, the Wrangel mammoths thrived.
That's largely due to the behemoth's use of energy. When compared to their Siberian counterparts, who relied on fat reserves to survive intense winters, the Wrangel mammoths likely expended less energy because their habitat's conditions weren't as intense, researchers said.
Researchers from the Universities of Helsinki and Tübingen and the Russian Academy of Sciences found that the Wrangel mammoths had higher amounts of sulfur in their bones toward the end of their death, indicating a toxic level of minerals in their water supply.
The impetus for the Wrangel mammoths' extinction was unique, too. Other mammoths died due to habitat loss or lack of food, but their samples showed the amount of sulfur in Wrangel mammoths' bones intensified toward the end of their existence. That indicates the weathering of bedrock, which unearthed harmful minerals that polluted their water supply, the study said.
An extreme weather event compounded their declining health. Rain and snow might've coated the ground in a thick layer of ice, researchers said, keeping the mammoths from foraging, starving them.
Humans might've played a role in their extinction, too, though their involvement is less likely. The earliest evidence of human life on Wrangel Island succeeded the mammoths by just a few hundred years, researchers said, though they hadn't found any signs of human hunting.
It's too late for mammoths, but there's still time to save critically endangered species. Studying the biosignatures in the remains of the last-surviving woollies and what caused their extinction might help conservationists prevent critically endangered species from dying out, too.
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