There's a line from Henry David Thoreau that's an old favorite of environmentalists: "In wildness is the preservation of the world." Not many people have taken that idea so much to heart as the great Brazilian photographer Sebastião Salgado, who spent much of the past nine years trekking to the last wild places on earth to take the pictures collected in his new photography book, Genesis (Taschen; 520 pages), a window into the primordial corners of creation.
The Genesis project grew out of two episodes in Salgado's personal life. In the late 1990s, his father gave him and his wife Lélia...