Mammoths are perhaps one of the most famous inhabitants of the last Ice Age. However, the extent to which they roamed in their lives remained a mystery. Experts have now used the chemical composition of the tusks to reconstruct where their bearer, a woolly mammoth, stayed during his lifetime. The team reports about Matthew Waller of the University of Alaska at Fairbanks in the journal “Nature Connections”.
Waller and his team measured the ratios of strontium isotopes of different weights over a tusk length of 1.7 meters. Then they compared these to isotopic proportions that occur in nature and created a kind of travel path for the mystical “mammoth”.
The woolly mammoth lived in what is now Alaska during the last Ice Age 17,100 years ago and was about 28 years old. During this time, it traveled enough distance to circle the Earth about twice: as a small animal mainly as part of an indoor herd, beginning sexual maturity as a long-traveling loner, until it finally died north of the Alaskan Brooks Range—perhaps by starvation.
The alkaline silver-earth metal strontium isotopes occur in different proportions in plants and soil depending on the region. Mammals incorporate strontium in small amounts instead of calcium into their teeth and bones. This is also the case with mammoths, whose teeth researchers examined with a laser: Because the tusk has grown throughout a mammoth’s life, scientists working with Wooller have found different concentrations of strontium isotopes at the tip of the tooth than at its base.