Steller's sea cow genome suggests this species began going extinct before the arrival of Paleolithic humans

Anthropogenic activity is the top factor directly related to the extinction of several animal species. The last Steller's sea cow (Hydrodamalis gigas) population on the Commander Islands (Russia) was wiped out in the second half of the 18(th) century due to sailors and fur traders hunting it for the meat and fat. However, new data suggests that the extinction process of this species began much earlier. Here, we present a nuclear de novo assembled genome of H. gigas with a 25.4x depth coverage. Our results demonstrate that the heterozygosity of the last population of this animal is low and comparable to the last woolly mammoth population that inhabited Wrangel Island 4000 years ago. Besides, as a matter of consideration, our findings also demonstrate that the extinction of this marine mammal starts along the North Pacific coastal line much earlier than the first Paleolithic humans arrived in the Bering sea region. A newly assembled Steller's sea cow genome suggests that this marine mammal had low levels of genetic diversity and began to go extinct along the North Pacific coastline much earlier than when the first Paleolithic humans arrived in the Bering sea region.

Automated summary

Anthropogenic activity is identified as a major cause of animal extinction, with the Steller's sea cow being hunted to extinction in the 18th century. New research reveals that the extinction of this species began earlier than previously thought.