Life on Earth, Part 2: From Sea Squirts to Birds

• 1979
• 1 hr 15 mins

• Watchlist

The history of the Earth, and the evolution of the species living on it, are the subjects of this BBC series, hosted by David Attenborough. The program follows the development of life, which began some 400 million years ago with single cell organisms. This episode focuses on the simple life form called the sea squirt, whose structure includes a flexible tail. The program shows how this advancement was the precursor for bird life that later developed on land and allowed for flight. Spectacular wildlife photography illustrates the story.