Mammoth tusk in northeastern Siberia

Inbreeding in the woolly mammoth weakened its immune system

The last population of the woolly mammoth went extinct after 6,000 years of isolation on Wrangel Island. A new study led by researchers at the Swedish Museum of Natural History shows that prior to the extinction, mammoths lost genetic diversity at a functionally-important immunity gene, which possibly made them more susceptible to disease.