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YSM Issue 97.1

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FEATURE<br />

Paleontology<br />

BY HANWEN ZHANG<br />

ART BY PATRICIA JOSEPH<br />

Tracking an Ancient Woolly Mammoth’s Journey of a Lifetime<br />

For all our Ice Age movies, artistic<br />

renderings, and sci-fi murmurings<br />

of de-extinction, mammoths have<br />

never quite lost their mythic proportions.<br />

The thirteen-foot darlings of every natural<br />

history museum continue to loom with about<br />

as much mystery as majesty. We know that<br />

they roamed the tundra steppes for roughly<br />

290,000 years, during which they grazed on<br />

arctic plants, briefly brushed shoulders with<br />

prehistoric humans, and had their likenesses<br />

transferred onto cave paintings. Then, around<br />

the time humans were building pyramids,<br />

they disappeared. The causes for their<br />

extinction—human hunting, climate change,<br />

or some mix of both—have been hotly debated<br />

as they remain tantalizingly unclear.<br />

Enter Elma, an ancient woolly mammoth,<br />

and one of only two specimens with complete<br />

tusks in all of Alaska. In a study published last<br />

month in Science, Elma is the star as a team<br />

of anthropologists and biologists provides an<br />

intricate reconstruction of her entire lifetime<br />

with the help of isotopic dating technologies.<br />

As just the second mammoth reconstruction<br />

of its kind, it offers an intimate glimpse into<br />

the creature’s habits—and an enticing glance<br />

at what mammoth interactions with early<br />

humans may have looked like.<br />

“We can’t [...] say for sure that humans killed<br />

this mammoth, but we’ve got means and<br />

motive at this point,” said Audrey Rowe,<br />

a PhD candidate at the University of<br />

Alaska and the lead researcher on<br />

the study. Elma<br />

was uncovered at Swan Point, the oldest<br />

archaeological site in Alaska, by researchers<br />

during the early 2000s.<br />

The study’s genetic and isotopic analysis<br />

chronicles an impressive yet punishing<br />

journey through the Alaskan hinterlands that<br />

ends in a cryptic fashion. According to the<br />

study, Elma trekked roughly one thousand<br />

kilometers from southeast Beringia, in<br />

present-day Canada, deep into interior<br />

Alaska in the span of two and a half years.<br />

Then, still at the peak of her life and roughly<br />

twenty years old, she died—right next to an<br />

area of known human settlement.<br />

This cold case has the set-up of a prehistoric<br />

Agatha Christie plot, but there’s no smoking<br />

gun. Elma’s remains were uncovered<br />

alongside another closely related juvenile and<br />

a newborn and were dated from around the<br />

same time humans had started populating<br />

the region. She died in healthy condition, and<br />

her body lacked physical evidence of having<br />

been hunted, unlike mammoth samples in<br />

Siberia or Poland, which feature spear points<br />

lodged in spinal vertebrae or microblades<br />

buried in ribs.<br />

Image Courtesy of Flickr<br />

All signs nonetheless point to death by<br />

humans. “These early people in Alaska also<br />

certainly seem to have the technology [...] to<br />

bring down a mammoth,” said Matthew<br />

Wooller, a University of Alaska professor<br />

of chemical oceanography and an author<br />

of the study. Elma was found in the same<br />

time layer as the remains of the two younger<br />

mammoths, and her path overlaps neatly<br />

with human settlement at a time when<br />

they were capable of developing lethal<br />

stone projectiles—there are simply too<br />

many coincidences.<br />

Researchers were just as lucky to come<br />

across a tusk as uncompromised as hers.<br />

The equivalent of rings on a tree trunk,<br />

mammoth tusks offer telling records of life.<br />

Rowe explained that their tusks—similar to<br />

those of elephants—stack new layers atop<br />

each other as they grow, almost like ice<br />

cream cones. Elma’s tusk unraveled her story<br />

from the tip to her trunk.<br />

Using recently developed isotope analysis<br />

techniques, the researchers were able to chart<br />

Elma’s footsteps across prehistoric Alaska.<br />

They sliced open her tusk, drilled into the<br />

ivory at millimeter-length increments, and<br />

measured the isotopic ratios of strontium,<br />

sulfur, and oxygen—all of whose stable halflives<br />

can be deeply informative. Levels of<br />

strontium-87, an isotope formed in rocks by<br />

decaying rubidium, vary across the world;<br />

what follows is a telltale geographic<br />

signature, since<br />

32 Yale Scientific Magazine March 2024 www.yalescientific.org

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