Emily Chan
On a remote Arctic island, a small population of woolly mammoths persisted after the rest died out. The last woolly mammoths on Earth inhabited Wrangel Island, outliving those on the mainland by 7,000 years. Finally, the group perished about 4,000 years ago, causing the creatures to go extinct.
Now, scientists have learned more about what triggered the end of the species. A team led by Laura Arppe from the Finnish Museum of Natural History studied the population’s diet, nutrition, and metabolism through mammoth bones and teeth that were uncovered on Wrangel Island.
They analyzed the carbon and nitrogen isotopes, which revealed the mammoths’ nutrition levels and metabolic functioning during the thousands of years they lived before extinction. They also compared the mammoths on Wrangel Island to other populations.
The researchers found that the species’ demise was due to a catastrophic weather event that led to their starvation, debunking a study that was published in 2017, which claimed that a “genomic meltdown” resulted in the disappearance of the woolly mammoths.
Their declining numbers gave rise to mutations, contributing to their downfall. They lost their sharp sense of smell and their ability to detect pheromones. So, they were unable to socialize and reproduce properly.
However, the new study did not find any evidence of a diminishing population size prior to extinction. Instead, the culprit appeared to be the weather.
“Judged from the numbers of radiocarbon-dated mammoth bone finds on Wrangel Island, this last island population appears to have vanished rather abruptly,” Arppe said.
“There [are] no signs of a dwindling population size before extinction. [It’s] kind of like they hit a wall at approximately 4,000 years ago.”
She added that all the major transformations in climate and the size of their range had taken place long before their extinction.
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