It might be hard to imagine that your slobbery, cuddly best friend is part wolf, but it’s true. Nature’s upcoming two-part show Dogs That Changed the World tells exactly how over the last 15,000 years the wolf has transformed into more than 400 different breeds of today’s dogs — one of which may be your walk, purse or Frisbee companion. In Part One, “The Rise of the Dog,” biologist Raymond Coppinger discusses his theory on the origin of dogs and their domestication. Part Two, “Dogs by Design,” shows how a dog’s instinct to hunt, dig and guard can help save lives. You can start by watching a preview, or just dive right into it and watch the show: Part One airs Sept. 28 and Part Two airs Oct. 4. For local listings, visit here.