Course Hero. "A Short History of Nearly Everything Study Guide." Course Hero. 18 Jan. 2018. Web. 25 Apr. 2018. <https://www.coursehero.com/lit/A-Short-History-of-Nearly-Everything/>.
Course Hero. (2018, January 18). A Short History of Nearly Everything Study Guide. In Course Hero. Retrieved April 25, 2018, from https://www.coursehero.com/lit/A-Short-History-of-Nearly-Everything/
(Course Hero, 2018)
Course Hero. "A Short History of Nearly Everything Study Guide." January 18, 2018. Accessed April 25, 2018. https://www.coursehero.com/lit/A-Short-History-of-Nearly-Everything/.
Course Hero, "A Short History of Nearly Everything Study Guide," January 18, 2018, accessed April 25, 2018, https://www.coursehero.com/lit/A-Short-History-of-Nearly-Everything/.
In this chapter Bryson discusses the conditions on Earth that both destroy and create life. He notes one of the inherent problems for humans is they evolved to breathe oxygen and live on the land. As a result, the majority of Earth's surface is not available to us. For example, humans can neither breathe underwater nor bear the pressure deep in the ocean.
Bryson transitions into an explanation of the "helpful breaks" that allowed life to take root on Earth. First, Earth is in an ideal location, not too close or too far away from the sun. To make his point, he discusses Venus, a planet very similar to Earth with a "small difference in orbital distance" that makes the planet uninhabitable. Life also benefited because the planet has a molten interior, allowing for an atmosphere and a magnetic field. The moon also provides a steadying influence on the planet and provides the tides. Finally, the timing of the planet's creation was ideal. Another factor Bryson brings up is humans are made of the stuff of this planet: "We have evolved to utilize or tolerate" the available elements on Earth.
At the end of the chapter, Bryson mentions another viewpoint: perhaps these circumstances are "not as extraordinary as we like to think." They are simply what we are used to.
Where Part 4 focused on Earth's destructive properties, Part 5 turns to a discussion of why and how life flourishes on the planet. Bryson emphasizes the seeming mystery of life by pointing out the small number of elements that are "of central importance to life." He thinks people take life for granted, in part because they fail to recognize its limitations. Since life forms evolved from a limited number of elements, and have adapted to different ecological zones, life exists within a narrow zone of survivability. Small deviations in an ecosystem can result in the extinction of a species.
Bryson prompts the reader to think critically about the information he is providing when he raises the possibility the rise of life on Earth was not, after all, extraordinary. His statement engages the reader and also provides an example of how scientists think. While this is a book about the history of science, Bryson asks his readers to engage with the text critically.