A paleontologist testified in the Dover school board trial about how fossils connect species.The ancestor of the whale and its first cousin the hippopotamus walked the Earth for 40 million years, munching on plants, before dying out in the ice ages. Known as the anthracotheres, it became extinct 50 to 60 million years ago, but not before its evolutionary tree diverged — the whale forging into the oceans, the hippopotamus to the African swamps. Kevin Padian, a University of California-Berkeley paleontologist, told the story of the whale’s journey, along with the travels of its closest living relative, in U.S....