Where did all the mammoths go?
It’s a subject that has fascinated naturalists for 300 years. Scientists generally agree that most mammoths died off gradually during the late Pleistocene, probably due to a combination of hunting from humans and environmental change.
They’ve also known that a few isolated mammoth communities managed to survive into the Holocene, which began about 10,000 years ago.
Now a team of international researchers has studied the genetic changes of one of those populations from Wrangel Island, located in the Arctic Ocean off the north east coast of Siberia.
No one is sure how the Wrangel Island Mammoths went extinct, since scientists are pretty sure humans didn’t hunt them there, and radiocarbon dating shows the mammoths managed to survive the climate change associated with the Pleistocene-Holocene transition.
The scientists wanted to know whether centuries of inbreeding caused enough genetic weaknesses to wipe out the mammoth stronghold.
But they found a relatively constant level of genetic variation through time, followed by a sudden and rapid loss of DNA diversity near the end, suggesting a swift disappearance of mammoths from the island.
“One possible explanation for such a sudden change could be the arrival of humans on Wrangel Island,” the authors write.
It could also have been a disease or a previously unknown short-term climate change, they said.
The youngest genetic material they surveyed was from just over 3,600 years ago, though other scientists have found evidence of mammoths from as recent as 2,000 years ago.
Their findings are published online in the most recent issue of the journal Proceedings of the Royal Society.
Image courtesy of Flickr.