Atheist and scientist Richard Dawkins visits England, America and Israel interveiwing prominant people of faith; Islamic, Hasidic Jews, and the new Christian sects popping up throughout the world, and expressing his view of the extent to which this fanaticism has degraded our civilisation, and will continue to degrade it. "The God Delusion" explores the unproven beliefs that are treated as factual by many religions and the extremes to which some followers have taken them. Dawkins opens the programme by describing the "would-be murderers ... who want to kill you and me, and themselves, because they're motivated by what they think is the highest ideal." Dawkins argues that "the process of non-thinking called faith" is not a way of understanding the world, but instead stands in fundamental opposition to modern science and the scientific method, and is divisive and dangerous.

Few sounds are more beautiful or moving than the underwater songs of the humpback whale. Male whales compete with their songs, which often last for 10 minutes at a time, and can be repeated for hours on end. Whales separated by thousands of miles of sea will sing almost identical songs. Researchers have found that the songs change throughout the breeding months, following a mysterious pattern repeated across the waves. Whales also use sound to hunt. To catch herring, humpback whales release a stream of bubbles to form a shimmering, circular fishing net. Emitting a repetitive loud scream, they scare the fish into a tight ball, then lunge out of the water to swallow the shoal whole. Now it seems that the long-held image of the gentle giant must change to one of a ferocious and opportunistic hunter.

'Crude Awakening'- To combat the worst environmental disaster in American history, BP and the Coast Guard dumped nearly 2 million gallons of a chemical dispersant called Corexit into the Gulf. But instead of helping clean up the spill, Corexit made things worse. Shane Smith heads to Louisiana to report on the lasting effects of the BP oil spill. 'The Enemy of My Enemy' - Yemen, the fractured state in the Arabian peninsula, is at the top of the worry list for President Obama's national security team, and the rise of Al Qaeda there is only half the reason why. The real trouble is a current threat posed by the little-known Houthi rebel movement in the north of the country - a grassroots army, allegedly funded by Iran, that has never granted access to any other Western film crew before. Ben Anderson goes deep into Houthi-controlled territory to learn about the group that's fighting, and beating, Al Qaeda in the east, Saudi Arabia in the north, and Yemen's central government in the south.

Deep in the twisted roots of a giant strangler fig tree, hidden from view, lives perhaps the most bizarre nighttime creature of all. The spectral tarsier, tiny primates barely larger than a tennis ball. As darkness falls, a family of these small primates in Sulawesi ventures into the jungle to find food while protecting their babies.

In the second episode, Professor Iain Stewart discovers how flowers have transformed our planet. He journeys to the remote islands of the South Pacific to track down the earliest flowers. In the deserts of Africa and rainforests of Vietnam, he sees how they brought brilliant colour to the most barren landscapes and sculpted the earth itself. And he learns how they drove the evolution of all animals - kick-starting our human story.

Once life arrived in the Galapagos, it exploded into unique and spectacular forms. David Attenborough investigates the driving forces behind such evolutionary innovations. We learn that life must be able to adapt quickly in these ever-changing volcanic landscapes. It has resulted in species found nowhere else in the world, such as giant whale sharks and marine iguanas that can spit sea-salt from their noses, dandelion seeds that grow into tree-sized plants and spiders that can blend perfectly into the darkness. Adaptation has been the key to survival in these islands so far, but the story of life in the Galapagos doesn’t end here. The catalyst that triggers these explosions of life remains in place.