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.

Anthropologist Barbara J. King uses her wealth of research experience to open a window of understanding into the legacy left by the primate past. Explore a host of intriguing issues ranging from the development of human love and loyalty to the possible biological tendency towards aggression to what behaviors people inherit from their closest living relatives.