An ancient volcano may have caused a massive migration of caribou and people from the Southern Lakes region 1,000 years ago, suggests new research from Simon Fraser University.
The displacement allowed for new caribou families to move in and may have also helped introduce new hunting tools to the people in southwestern Yukon, say the researchers.
“(The volcano) was equal to or larger than Krakatoa,” said Tyler Kuhn, a Whitehorse-raised master’s student who spent three years digging through layers of ancient sediment for caribou samples and human artifacts.
The evidence of a giant caribou migration came to light after Kuhn and his peers compared genetic information from modern-day caribou with DNA from caribou remains up to 6,000 years old.
Those ancient caribou families are remarkably similar to the animals that cover most of the Yukon today, from the Fortymile herd east of Dawson City and other herds that roam across the eastern edge of the territory.
But around 1,000 years ago, the Southern Lakes caribou begin to come from a different family lineage which continues in the region to this day.
That means the older caribou - which have gone on to populate the animals in the rest of the Yukon today - left the region just as one of the largest ancient volcanoes known to man erupted.
“(The volcano) may not have killed them off, it may have just pushed them out of the area,” said Kuhn.
The volcanic eruption, situated near the Alaska border in Kluane Park, was one of the largest in the last 10,000 years, he said. It covered the southern Yukon in a thick layer of ash known as the White River Tephra.
It’s tough to say how long the region was uninhabitable, but it’s clear a new caribou family that matched current Southern Lakes caribou arrived soon after.
“Those caribou arrived on the scene about 1,000 years ago,” said Kuhn.
The study, which was done with the help of researchers in Pennsylvania and Oxford, involved comparing genetic material from caribou cells.
Geneticists can recreate rough sketches of ancient family trees by comparing fragments of DNA that come from mitochondria, a kind of cellular “organ” which
produces energy in a cell.
“The field of ancient DNA has really taken off in the last 10 years due to advances in technology and how we can get DNA out of things,” said Kuhn.
Students are now able to ask more precise questions about the history of animals and collaboration is getting easier and faster, he said.
When Kuhn first got into genetics and paleontology, people were flocking to the classic extinct animals like woolly mammoths.
“No one had worked on caribou yet, so it was open, the technology was there and we went ahead,” said Kuhn.
The caribou samples were collected in ice patches between Carcross and Aishihik Lake. There were 40 ancient samples and 400 modern caribou samples.
Ice patches are areas of hardened ancient snow that have been compacted into ice. Unlike glaciers, they are unable to move under their own weight, said Kuhn.
Those ice patches revealed another major shift in the region - the disappearance of atlatl technology, which are hunting darts, and the arrival of bows and arrows.
“Prior to 1,000 to 1,200 years ago, (atlatl darts) were the only hunting technology found in the ice patches,” said Kuhn. “Following that break, we start to see bow and arrows in the region.”
“The idea is that people got pushed away at the same time as this volcanic eruption happened and then when they came back into the area they had had a chance to pick up new technologies from other people,” he said.
DNA comparisons can go as far back as 50,000 years ago, and more research on ancient northern life is on its way, said Kuhn. A group of researchers from Copenhagen are currently mapping the ancient family lineages of caribou from around the world, including the Yukon, said Kuhn.
Contact James Munson at
jamesm@yukon-news.com