Evolution

Evolution is a science fiction novel by the British writer Stephen Baxter, published in 2002. It is built as a series of episodes that share a single bloodline rather than a single plot.

The episodes open with Purga, a Purgatorius living in Montana, a creature the size of a small rodent, barely self-aware, whose line will lead eventually to the primates. Her chapter ends with the impact of a vast asteroid, which the novel shows from the ground, through animals who cannot know what is happening to them. From there the book moves forward in jumps: early hominids, the first people, and then, beyond the present, the branches that human beings take as they spread away from Earth. Baxter gives each era its own protagonist, and each of them is limited by what their species is able to perceive, so a story spanning hundreds of millions of years is told by minds that never understand the whole of it. The later sections take in machine intelligence and the long-term fate of the universe. The result reads as a sequence of separate stories, but the descent from Purga is continuous.

Baxter writes hard science fiction, and the book is as interested in biology and geology as in character: the asteroid impact, the ice ages and the drift of the continents all happen on the page.