Humans have associated dogs with death for millennia. Ancient Persians believed a dog’s stare drove the demon Nasu out of a corpse. Some Mayan traditions say a black dog carries the newly deceased to the land of the dead. Cat Warren brings that heritage into the present with Solo, a bouncy cadaver-sniffing German shepherd. Host Anita Rao talks with Warren about Solo’s story featured in her upcoming young readers edition of her New York Times best-selling book, “ What the Dog Knows: Scent,