Introduction to the show's theme: key transformations in the development of life

• Human connections to all animal life
• Following the tree of life back four billion years

The mystery of whale evolution, solved by fossil research

• Understanding human evolution through the study of whale evolution
• Brief definition and history of mammals
• How did land-based mammals return to the sea?
• Fossils from "transitional species" trace whale evolution
• Studying whale movement to see evolutionary relationship with land mammals

Understanding the transition from water to land-based life

• Paleontological research into early tetrapod fossils
• Which came first: leaving the water or developing legs?
• The transition from fins to limbs; an evolutionary survival strategy

Exploring the origins of animal life

• The Cambrian explosion, the sudden appearance of animal life
• The Burgess Shale and its rich fossil record
• Trilobites, an extinct arthropod and relative of crabs, insects, and spiders
• Pikia, perhaps the earliest ancestor of modern vertebrates

The search for evolution's genetic mechanism, and the simplicity of the answer

• Fruit fly research into evolution and genes
• Embryo development and its clues to evolution
• The theory that genes are the architects of the body, and a universal set of genes builds all animals

The crucial transition to bipedal movement

• Human abilities are remarkable, yet we are built from the same genes as all animals
• Studying primate movement to understand human ancestors and evolution
• The existence of homo sapiens was not inevitable