One day thousands of years ago, on a tiny island in the middle of the Bering Sea, a woolly mammoth made a fatal misstep. It fell into a pit-like cave with no escape, and there it died.
In 2003, another animal entered the cave — with a ladder. As he explored the space with his colleagues, Russell Graham, a paleontologist from Pennsylvania State University, lifted a rock near the back. There he found a single, pristine tooth from the mammoth, oblong and bumpy and as big as a loaf of bread. “It looked like you had just taken it out of the animal’s mouth,” says Graham, a tall, broad-shouldered man. With a beard and a slightly shuffling gait, he seems a bit of mammoth himself.
He had handled hundreds of mammoth teeth in his career, but this tooth, from the Alaskan island of St. Paul, was special. It would send Graham and a multidisciplinary team of experts on a quest to reconstruct the animal’s environment and solve a mystery — one that has implications for species facing climate-induced extinction today. The mystery began when carbon dating established the tooth was just 6,500 years old. That’s several millennia fresher than any mammoth find on the North American mainland. The date made Graham wonder: After the animals persisted on this wind-battered speck of land for so many millennia after mainland populations perished, what finally killed them off?