Where do dogs in all their amazing diversity come from? Tradition says that thousands of years ago someone tamed a wolf pup, thus creating the first of our best friends. But many scientists disagree. On "Dogs and More Dogs," NOVA goes to the dogs—and to leading researchers—to find out the truth. Narrated by John Lithgow, the program ranges from a wolf research facility in rural Indiana to the Westminster Dog Show in New York's Madison Square Garden. NOVA makes a fascinating detour to the city dump in Tijuana, Mexico, where viewers get surprising insight into the origin and evolutionary strategy of our canine companions.

• John Lithgow