For readers interested in the evolution, biology, and breeding of canines, this two-part PBS documentary will get their tails wagging. Fascinating footage showcases relationships between humans and dogs around the world, from sacred hunting dogs in the jungles of Papua New Guinea to one of the world's fastest animals, the Saluki desert dog of the Bedouin. The first part, Dogs That Changed the World: The Rise of the Dog, explores one theory of how dogs became domesticated from wolves and discusses significant canine-related scientific research of the past century. The second part, Dogs That Changed the World: Dogs by Design (linked in the More Episodes section below the media player), looks at how humans transformed working dogs into the most diverse mammal species on the planet, with over 400 breeds. Viewers can stick their noses into the world of competitive dog breeding, learn about new uses for working dogs in medical care, and consider how human choice and preference have impacted canine evolution. Each segment is 53 minutes long. The documentary was produced in 2007, which is evident in the video quality, but for stories and information it still gets two paws up.