As a result of mankind's technological prowess, evolution is accelerated, producing several species with varying intraspecific relations, many of them unrecognizable as humans.

[2] Instead of the field guide-like format of Dixon's previous books, After Man (1981) and The New Dinosaurs (1988), and instead of the conventional narrative style of most science fiction works, the book is told through short stories, isolated sequences of dramatic events in the lives of select individuals of the future human species imagined by Dixon.

[3][4] Eventually, as the creatures start to rediscover technology and civilization, they are visited by the descendants of people who fled the planet for space, millions of years ago, unaware that they’ve arrived at the home-world of their ancestors.

The book ends on a relatively hopeful note, with the text establishing that someday the last remnants of humanity may evolve to meet the radically altered conditions of the barren surface "if they can change enough."

Dixon's previous speculative evolution book projects, After Man (1981) and The New Dinosaurs (1988), used fictional examples to exemplify real-life factual natural processes.

The New Dinosaurs, meanwhile, focuses on the science of zoogeography, using fictional species in a world where the Cretaceous-Paleogene extinction event never happened to explain the process.

[3] Writing for the magazine The Skeptic, British critic and author David Langford stated that the book was a "superior coffee-table production", but found it "illuminating and fun" rather than realistic.

He found the most questionable decision to be the repopulation of Earth's ecosystem by human species engineered to be unintelligent, though noted that "the initial premise once accepted, this is good, striking stuff".

Gee found the book to be a "highly improbable mess" and criticised Dixon for "skirt[ing] over the ethics" of the different societal developments explored.

He also thought the book read more like the synopsis for a science fiction novel than a scientific work and found the illustrations to be "lumpen and adolescent".