The first episode tells how invertebrates became the first creatures of any kind to colonise dry land. Their forerunners were shelled and segmented sea creatures that existed 400 million years ago. Some of them ventured out of the water to lay their eggs in safety, and Attenborough compares those first steps with today's mass spawning of horseshoe crabs off the Atlantic coast of North America.
2005 • Nature
The next programme deals with flying insects. It begins in Central Europe, where the Körös River plays host to millions of giant mayflies as they rise from their larval skins to mate. — the climax of their lives. Mayflies and dragonflies were among the first to take to the air about 320 million years ago, and fossils reveal that some were similar in size to a seagull. Damselflies are also looked at in detail.
2005 • Nature
The final programme looks at the superorganisms formed by bees, ants and termites. Attenborough reveals that their colonies, whose individuals were once considered purely servile, are "full of conflict, power struggles and mutinies." They evolved when such creatures moved away from a solitary existence and started building nests side-by-side, which led to a collective approach to caring for their young.
2005 • Nature
It may take two to make a baby - but not necessarily two to bring it up. So what makes a parent decide to stay or go? Especially if that parent is a dad. From the California mouse mother who has to kickstart her partner's paternal instincts, to Adelie penguin parents who can't leave their eggs alone for five minutes; from cheetah mums practicing promiscuity to keep the dads on side, to flamingo parents both producing milk for their young. We see just how far these incredible parents go in order to protect and nurture as many offspring as possible through to adulthood.
What is it that makes things alive? What if we made robots that could sustain themselves? What if they could mine metals or recycle old robots, reprogram and remake themselves? There's nothing there we would traditional call alive, but they would have at least have the essence of this perpetual rube Goldberg machine.
Losing a parent in the wild can be deadly for young animals, but these orphans got lucky when conservationists stepped in. Meet clouded leopard cub sisters taken in by the Nashville Zoo, a baby wombat raised in an artificial pouch at Tasmania's Bonorong Wildlife Sanctuary, and more.
The rains are late. It is the most brutal time of year. Babies born into drought face starvation. The weak and the injured are weeded out. Everything is desperate for rain. When it finally arrives, it is a downpour on an enormous scale. Alien creatures emerge into a different world. The wet season begins.