Mammoths and humans spent about 1,000 years together in Beringia, the far northern swath of land revealed during the last ice age. A new study from UAF shows how mammoths traveled across the northern side of the continental ice sheet, and sheds some light on how humans hunted them. The research published this week in the journal Science Advances used chemicals found in the mammoth’s tusks to track where the pre-historic animal lived.
Audrey Rowe is getting her PhD at UAF and is the lead author on the paper published this week in Science Advances.
“I do chemical analyses to try to reconstruct the movement of large mammals in Alaska,” she said.
She studied a 14,000-year-old tusk from a female mammoth that was found at the Swan Point archeological site near Quartz Lake in Interior Alaska.
“The interesting thing about tusks, they grow throughout the lifetime of the mammoth, sort of like they're ice cream cones being stacked on top of each other every single day,” Rowe said.
Every day of a mammoth’s life, there's a new layer of minerals being laid down in the tusk. Rowe’s colleague, and one of the co-authors of the study, professor Mat Wooller in the College of Fisheries and Ocean Science says looking at those cones, you can tell where the mammoth has been.
“Luckily for us, mammoths carry this kind of chemical GPS unit on their face, which is their tusks," Wooller said.
"And that tusk has a little bit of strontium in it, um, from the location that the mammoth is in, that's being laid down in that sort of daily growth layer,” said Rowe.
“And so that tusk is gradually getting forced out of the head of a mammoth and is recording the entire lifespan of that mammoth's movement, its diet, its behavior, its age,” Wooller said.
Rowe and Wooller split the tusk right down the middle, and took samples from the center, to measure the chemical isotopes.
Then they compared the strontium in the tusk layers, to what’s known about the element around Alaska.
“Yeah, it’s chemistry. The U. S. Geological Survey has a pretty good grasp on what minerals are where in the bedrock in Alaska and how old these rocks are,” Rowe said.
“We analyzed a whole bunch of isotope chemistry, along the length of that tusk, and then we compared changes in that chemistry to maps that we have of the chemistry of Alaska,” Wooller said.
They were able to back calculate where the mammoth lived and travelled.
“It turns out that Interior Alaska site that she used the most, overlaps stunningly with all of the archaeological sites from around that time period,” Rowe said.
They found that she was born and grew up east of the Yukon, but wandered west before she died about 45 miles south of where Fairbanks is now.
Oh, and they named the mammoth they were studying.
“Her full name is Élmayųujey'eh. We abbreviate that to Elma, and it was a name that was given to this particular mammoth by the Healy Village Council," Wooller said.
"We worked with them to come up with a name, and so they came up with Élmayųujey'eh, which translates to something like hella looking. Not beautiful, but very striking in appearance.”
Elma was about 20 years old, and healthy when she died 14,000 years ago, likely harvested by human hunters.
