Cleveland researchers and their international colleagues studied a 4.4 million-year-old skeleton from Ethiopia for the past 15 years; they say the result will completely shift understanding of human evolution. Ardipithecus ramidus walked upright but could also climb trees pretty well, though not as well as a chimp. A million years older than her more famous cousin Lucy(Australopithecus afarensis), Ardi, as she is now known, was closer to human size. Monday morning at 9, we'll hear the story of her discovery, how researchers pieced together an understanding of her life and our ancestors, and the debate she has opened on the exact shape of the hominid family tree.