Chapter 5 : Welcome to the Anthropocene (Angel Jorge)

In Chapter 5 of Elizabeth Kolbert's The Sixth Extinction, Kolbert introduces the ideas of Thomas Kuhn, the science historian who first introduced the concept of the "paradigm shift." Though Kolbert's book has a main focus on extinction it also focuses on the scientific process in general. Kuhn states that throughout history human beings are forced to adapt to changing environments. He explains that at first when humans are encountered with this they try to respond with the same strategies and mechanisms they've already learned but eventually learn new strategies for living in their new environment---a new paradigm for survival. Kuhn's ideas about paradigms and paradigm shifts are a lens which allows us to study the history of evolutionary science. "Leading up to every major biological discovery, there is a transition period in which scientists use old rules to explain new discoveries," (Page 94). Kolbert travels to the Scottish Highlands where she interviews Jan Zalasiewicz who shows her layers of rock dating back 445 million years to the era following the extinction of the dinosaurs. During this era, marine life boomed and coral reefs were formed. Then at the end of the era, almost 85% of marine life species went extinct. At the moment, the most common theory of the mass extinction that took place at the end of the Ordovician era is that glaciation killed many species. Around this time the temperatures were falling due to the carbon dioxide levels in the atmosphere decreasing. Kolbert continues to use Darwin’s ideas to analyze mass-extinction. For example, she writes about the graptolite’s useful evolutionary traits, such as its strong, V-shaped body. The natural question raised by this is why the graptolite’s evolutionary advantages became disadvantages. Like Cuvier and Darwin, the Alvarezes influence on science extended far beyond the original scope of their project. Inspired by the Alvarezes theory of mass-extinction, other scientists argued that the extinction of the dinosaurs wasn’t at all unique; there were many other mass-extinctions in the Earth’s history. As Kolbert admits, there is relatively little evidence to explain the other mass-extinctions in the Earth’s history. Extinction is such a new scientific concept that scientists will have to gather a lot more evidence before they can develop satisfactory theories of mass-extinction. The implication of this passage is that, at some point in the future, human beings will go extinct, due to the changing composition of the Earth’s atmosphere; changes that humans had a major role in causing. This relates to the theme that humans alter natural systems.