Souvenirs of the planet: Ten (and a half) life forms, each of which explains a key aspect of life on Earth.If an alien visitor were to collect ten souvenir life forms to represent life on earth, which would they be? This is the thought-provoking premise of Marianne Taylor's The Story of Life in 10 and a Half Species. Each life forms explains a key aspect about life on Earth. From the sponge that seems to be a plant but is really an animal to the almost extinct soft-shelled tu