The source of the earth's great variety of animals was a scientific mystery until Charles Darwin proposed the idea of natural selection. Nova presents breakthroughs in a new science nicknamed "evo devo" that are linking the enigma of origins to another of nature's mysteries, the development of embryos.

A counting primer that combines contrasting illustrations with animal facts, inviting young children to count a woodpecker's 30 roosting holes, a giraffe's 200 spots, and 1000 baby seahorses.