Evolution by Stephen Baxter is a novel which presents a dramatized account of human evolution from the past and into the present and future. While Evolution largely attempts to stay true to the facts of human evolution, it has several speculative evolution elements, especially in the early chapters and the later chapters.


Evolution follows the evolution of humans and some other branches of the primate family tree, from just before the K-T extinction event, to 500 million years in the future, at which time the author hypothesizes that primates go extinct.

The book opens with a prologue set in 2031, in which the scientists Joan Useb and Alyce Sigurdardottir are on a plane to Darwin, Australia, along with the genetically enhanced daughter of Allison Scott. They are headed to a conference in which the future of humanity will be discussed and plans to stop the collapse of society will be drafted and put forward the United Nations. Joan is pregnant, and reminisces about a fossil hunting trip she took with her own mother, where they found a Purgatorius (the species is left unnamed) tooth.

The book then jumps to Montana, North America 65 million years ago, just before the K-T extinction event. It opens with Purga, a female Purgatorius hunting for food at night, then returning to her den to suckle her pups. The next night, she discovers a nest of Troodon eggs, which she tries to eat. Before she is finished, the mother of the eggs finds her and tries to attack her. Purga escapes, but the Troodon, named Wounding Tooth, goes insane with grief and rage and obsessively follows Purga to her nest, which she destroys and then kills Purga's cubs. Purga escapes while wounding tooth eats her cubs, and attempts to find a new nest. While running from Wounding Tooth, she finds herself far away from the forest, near a small sea. Nevertheless she builds a new burrow and finds a mate, however, he is soon killed by a pterosaur. This new mate, Second is taken to the pterosaurs nest and fed to the chicks. Observing this is a very large pterosaur, a hypothetical invention of the author's. It has a wingspan of more than 100 metres wide, lives high in the atmosphere, where it feeds a high concentration of aerial plankton reside, composed of midge and spider larvae. The author names it a Sky Whale, and notes that it will never be discovered by humans.