So pervasive is man's impact, it is said that we live in a new geological epoch—the Anthropocene.
-- Elizabeth Kolbert (Down the River: Chapter 1)

Importance: In the first chapter of "Down the River," Kolbert introduces her interest in exploring humans' relationship with the natural world. In this passage, she describes humans' negative impact on the environment. In the surrounding sentences, Kolbert goes on to name all of the ways that man has endangered a litany of species. This passage is crucial to understanding Kolbert's overarching thematic interests. It specifically contributes to her considerations regarding fragility and control.

Plaquemines has the distinction—a dubious one, at best—of being among the fastest disappearing places on earth.
-- Elizabeth Kolbert (Down the River: Chapter 2)

Importance: After journeying along and studying the Chicago Sanitary and Ship Canal in Chapter 1 of "Down the River," Kolbert takes an interest in other United States waterways. She ventures south to Louisiana in order to perform more in depth research on the Mississippi...