Having sold an amazing amount of records, and gone through tumultuous personal problems that would have finished off most bands, Fleetwood Mac have created an enduring legacy for themselves. The band are captured performing live on 23–24 September 2003 at the FleetCenter (now known as the TD Garden) in Boston, Massachusetts during the group's Say You Will Tour, before a specially invited audience of industry insiders and friends.

The band are captured performing live on 23–24 September 2003 at the FleetCenter (now known as the TD Garden) in Boston, Massachusetts during the group's Say You Will Tour, before a specially invited audience of industry insiders and friends. Having sold an amazing amount of records, and gone through tumultuous personal problems that would have finished off most bands, Fleetwood Mac have created an enduring legacy for themselves.

It's 3.5 million years ago and in East Africa a remarkable species of ape roams the land. Australopithecus afarensis has taken the first tentative steps towards humanity by standing and walking on two legs. The rift valley was forming, and the rain forests dying as Africa dried out - turning the landscape into a mosaic of scattered trees and grass. In this new environment afarensis found it more efficient to move about on two legs rather than four.

One and a half million years ago, a new breed of ape-man walks the land. In southern Africa, Homo Ergaster has taken the next step to becoming human. They have long, modern looking noses, which cool air as they breathe. Their hairless bodies, with millions of tiny sweat glands, mean they don't pant anymore to control their temperature - they sweat. And, above all, they have big brains - nearly two-thirds the size of ours.

Take a dino's-eye view of life in the prehistoric past as cutting-edge filming techniques and hard science. When White Tip, a female velociraptor, loses the rest of her pack, she must struggle to survive on her own. In time, she locates a new pack, as well as a mate, only to find that her hardships are just beginning in the harsh desert environment.

The second programme deals with the mechanics of flight. Getting into the air is by far the most exhausting of a bird's activities, and Sir Attenborough observes shearwaters in Japan that have taken to climbing trees to give them a good jumping-off point. The albatross is so large that it can only launch itself after a run-up to create a flow of air over its wings. A combination of aerodynamics and upward air currents (or thermals), together with the act of flapping or gliding is what keeps a bird aloft. Landing requires less energy but a greater degree of skill, particularly for a big bird, such as a swan. Weight is kept to a minimum by having a beak made of keratin instead of bone, a light frame, and a coat of feathers, which is maintained fastidiously. The peregrine falcon holds the record for being fastest in the air, diving at speeds of over 300 km/h. Conversely, the barn owl owes its predatory success to flying slowly, while the kestrel spots its quarry by hovering. However, the true specialists in this regard are the hummingbirds, whose wings beat at the rate of 25 times a second. The habits of migratory birds are explored. After stocking up with food during the brief summer of the north, such species will set off on huge journeys southwards. Some, such as snow geese, travel continuously, using both the stars and the sun for navigation. They are contrasted with hawks and vultures, which glide overland on warm air, and therefore have to stop overnight.