The fifth programme explores the alliances formed between the animal and plant worlds. Attenborough dives into Australia's Great Barrier Reef and contrasts the nocturnal feeding of coral, on microscopic creatures, with its daytime diet of algae. Some acacias are protected by ants, which will defend their refuge from any predator. Besides accommodation, the guards are rewarded with nectar and, from certain species, protein for their larvae as well. Fungi feed on plants but can also provide essential nutriment to saplings (Mycorrhiza). The connection is never broken throughout a tree's life and a quarter of the sugars and starches produced in its leaves is channelled back to its fungal partners. Meanwhile, fungi that feed on dead wood leave a hollow trunk, which also benefits the tree. Orchids enjoy a similar affiliation. Lichens are the product of a relationship between fungi and a photosynthetic associate, usually algae. They are extremely slow-growing, and a graveyard is the perfect location to discover their exact longevity. Mistletoe is a hemiparasite that obtains its moisture from a host tree, while using own leaves to manufacture food. Its seeds are deposited on another by the mistletoe tyrannulet, following digestion of the fruit. The dodder (Cuscuta) is also parasitic, generally favouring nettles, and siphons its nourishment through periodic 'plugs' along its stem. The rafflesia has no stem or leaves and only emerges from its host in order to bloom — and it produces the largest single flower: one metre across.

The planets of our solar system have experienced epic catastrophes throughout their long history, both raining down from outside and bubbling up from within. We'll voyage back in time to investigate the violent events that profoundly shaped the planets, including earth itself. We'll witness stunning revelations about what transformed Mars into a barren, hostile desert... The disaster that changed Venus from temperate to hellish... The impact that blew away Mercury's mantle, turning it into a planetary core... A colossal disturbance that rearranged the orbits of the gas giants... Titanic impacts on Jupiter... And how a lost moon may finally explain Saturn's rings.

Hosted by ABC journalist Bob Woodruff, this two-hour special explores what a worst-case future might look like if humans do not take action on current or impending problems that could threaten civilization. The problems addressed in the program include climate change, overpopulation, and misuse of energy resources. The events parallel the life of a fictitious storyteller, 'Lucy' as she describes how the events affect her life. The program included predictions of a dystopian Earth in the years 2030, 2050, 2085, and 2100 by scientists, historians, social anthropologists, and economists, including Jared Diamond, Thomas Homer-Dixon, Peter Gleick, James Howard Kunstler, Heidi Cullen, and Joseph Tainter. According to Executive Producer Michael Bicks, "this program was developed to show the worst-case scenario for human civilization. Again, we are not saying that these events will happen — rather, that if we fail to seriously address the complex problems of climate change, resource depletion and overpopulation, they are much more likely to happen.

What might happen if the first manned mission to Mars crashes hundreds of miles from the rocket that would take them back home? Could they survive the crash, and travel across the brutal Martian surface to their home ship? We'll show what the astronauts would have to do to survive dust storms and space radiation, while extracting vital resources like water from the Martian soil itself. It's a dramatic vision of the very near future, where survival can depend on pre-industrial technology and human ingenuity.

For thousands of years, humans have believed that there were once flying monsters. But did they really exist beyond our nightmares? 220 million years ago dinosaurs were beginning their domination of Earth. But another group of reptiles was about to make an extraordinary leap: pterosaurs were taking control of the skies. The story of how and why these mysterious creatures took to the air is more fantastical than any fiction. In Flying Monsters 3D, David Attenborough the worlds leading naturalist, sets out to uncover the truth about the enigmatic pterosaurs, whose wingspans of up to 40 feet were equal to that of a modern day jet plane. Attenborough works with scientists to understand the incredible story of the evolution of the pterosaurs, a story that unfolds in such stunning locations as New Mexico, the Jurassic Coast of Lyme Regis in Britain, an ancient pterosaur landing site in Southern France and a fossil pit in Germany where near perfect pterosaur specimens have been found. The central question and one of the greatest mysteries in palaeontology is: how and why did pterosaurs fly? How did lizards the size of giraffes defy gravity and soar through prehistoric skies? Driven by the information he finds as he attempts to answer these questions, Attenborough starts to unravel one of sciences more enduring mysteries, discovering that the marvel of pterosaur flight has evolutionary echoes that resonate even today. Flying Monsters 3D is a groundbreaking film that uses cutting-edge 3D technology and CGI to bring the story of giant flying monsters and their prehistoric world to life. Audiences of all ages will be in awe as they enter the world and experience, as never before, REAL Flying Monsters in 3D.

Since the dawn of civilization, humans have wondered who or what created the universe. Religion offers a spiritual answer, but do the latest discoveries in physics show evidence of a transcendent intelligence, or simply that the laws of physics by themselves could have led to the universe in which we live? This episode embarks on a mind-bending scientific search for God, asking physicists and theologians if the seemingly miraculous way the universe has been calibrated to support life is evidence of a creator...whether string theory will eventually be able to rule out the existence of God...why Stephen Hawking says the universe could have been created spontaneously...and how an advanced civilization in another universe could have conceivably created our own.