Does life exist on other planets? Astrobiology is a visionary new science that searches for life in space by combining the disciplines of astronomy, biology and geology. How did life evolve on Earth? What will life look like on other planets? These and other pertinent questions will be answered by a diverse group of scientists. Viewers will visit the Pilbara region of West Australia where the oldest evidence of life on Earth has been discovered. Travel to the moons of Jupiter and Saturn to test a theory that life could exist in the clouds of Venus. Finally, watch as experiments are done to see if life exists on exoplanets, earth-like planets beyond our solar system.

Richard Dawkins deals with some of the philosophical and social ramifications of the theory of evolution. Dawkins starts out in Kenya, speaking with palaeontologist Richard Leakey. He then visits Christ is the Answer Ministries, Kenya's largest Pentecostal church, to interview Bishop Bonifes Adoyo. Adoyo has led the movement to press Kenya's national museum to sideline its collection of hominid bones pointing to man's evolution from ape to human.[5] The collection includes the Turkana Boy discovered by Kamoya Kimeu, a member of a team led by Richard Leakey in 1984. Dawkins discusses social darwinism and eugenics, explaining how these are not versions of natural selection, and that 'Darwin has been wrongly tainted'. He then meets with evolutionary psychologist Steven Pinker to discuss how morals can be compatible with natural selection. He goes on to explaining sexual selection, with peafowls as an example. To find out whether sexual selection plays a role for altruism and kindness among humans, he visits women who are looking for sperm donors, as well as a sperm bank manager. Dawkins also explains kin selection and selfish genes.

The plant eaters take on the largely indigestible, spiny and poisonous defences of plants with some spectacular physical adaptations to diet. Plant Predators demonstrates the particular (and often peculiar) adaptations of herbivores

Are the wealthy just born in the right place at the right time? Are the poor victims of a system designed to keep them down? Or do physics and biology determine who is rich and who is poor? Throughout history, distribution of wealth is governed by hidden forces: DNA, environmental stress, patterns of human migration and even the laws of thermodynamics! Nature seems to demand winners and losers in life. But does this mean greed is king, and the rich can take what they want? Or is cooperation – between microorganisms, monkeys, and humans – more essential to survival of a species?

In the final challenge of the game of life, raising offspring is the ultimate prize. Continuing the line through the next generation, is the next best thing to immortality. But it’s far from easy... Some parents must risk their own lives for their offspring.

Brian travels across the US and encounters some astonishing creatures that reveal how the senses evolved. It is a story that takes him through life's journey, from single-celled organisms to sentient beings.