Features include: Seth Doane visits the Svalbard Global Seed Vault in Norway, repository of more than half a billion seeds beneath the Arctic tundra; actor Alec Baldwin talks to Rita Braver about his new memoir, "Neverthless," and the highs and lows of his life and career; Bob Schieffer sits down with country legend Willie Nelson; Erin Moriarty interviews the "Queen of Suspense," mystery writer Mary Higgins Clark; and Mark Strassmann rides in a submersible 715 feet down to the ocean floor, just 35 miles from Cape Hatteras, N.C., to the recently-discovered wreckage of a German U-Boat. Hosted by Jane Pauley.