Over the past 500 million years, the Earth has undergone five mass extinctions of biological species. The Sixth Extinction is happening right now, and this time it's caused solely by human activity. A staff member of The New Yorker magazine, Elizabeth Colbert traced the stories of several species that have already irretrievably disappeared and still live next to us, having visited different parts of the globe and talked with leading scientists. Why is human activity so destructive to other species? Can we stop the Sixth Extinction?