Watch The Shape of Life Season 1 Episode 5 Online

Behind the beautiful shapes and colors of seashells is the story of how a group of animals called molluscs evolved in order to survive. The wide variety of molluscs includes clams, oysters, snails, mussels, squid, and octopus. The word mollusc comes from Latin meaning "soft," a good description of the group's fleshy bodies. Of course, in an ocean filled with predators, a soft body is easily eaten. The early molluscs that happened to develop hard shells not only managed to survive but also succeeded in launching an ever-escalating 500 million year old battle between themselves and their predators.