The Sixth Extinction Themes

The central theme of The Sixth Extinction is, unsurprisingly, extinction. In the book, Elizabeth Kolbert examines the different ways that scientists have understood species extinction. In particular, she argues for the “catastrophist” theory of extinction. According to this theory, species do not go extinct slowly and gradually; instead, there are eras of planetary history during which global catastrophe causes many thousands of species to go extinct almost simultaneously. It is likely, she argues…

Charles Darwin’s theory of natural selection is central to Kolbert’s study of the Sixth Extinction. Darwin posits that species are in a constant process of adapting to environmental changes based on competition for a finite number of resources (such as food, water, and shelter). The “fit” species (which can access the world’s resources and have offspring) survive, while “unfit” species die out. Generally, the “fit” species succeed at accessing resources because of their ability…

One of the most important points that The Sixth Extinction makes is that humans only learned about natural selection, extinction, and environmental degradation very recently. (Only a few decades ago, for instance, scientists didn’t realize that fossil fuels could change the pH of the oceans, devastating marine life.) In addition to being a study of extinction, then, Kolbert’s book is about the way science changes over time. Interpreted in this way, environmental science is…