Knowledge of 15 million years of evolution, from microbe to humans, can help us to speculate about other life forms elsewhere in the cosmos. How did life come about and how can it develop new life?
The episode opens with the host, Carl Sagan, recounting the legend of the Heike crabs shell and how the shell actually came to represent a samurai warriors face through natural selection. This leads to a larger discussion of natural selection with Carl mapping out life over the cosmic calendar. Several of the topics he covers are the pitfalls of intelligent design, DNA, genetic replication, repairs, mutation, the chain of evolution from algae to humans, extinctions, and the common biochemistry of terrestrial organisms. Finally Sagan speculates on lifeforms that may inhabit the gas clouds of Jupiter.
In the Cosmos Update, Sagan remarks on how RNA also controls chemical reactions and how it reproduces itself. He also talks about the different roles of comets with how they could of potentially carried organic molecules that created life and how they could have caused the Cretaceous–Paleogene extinction event.
- Vangelis-Main Title Theme
- Johann David Heinichen
- Antonio Vivaldi
- Johann Pachelbel
- Wm. Jeffery Boydstun
- And more