The next programme explores the various sea-living invertebrates. In Morocco, the limestones are 600 million years old, and contain many invertebrate fossils. They fall broadly into three categories: shells, crinoids and segmented shells. The evolution of shelled creatures is demonstrated with the flatworm, which eventually changed its body shape when burrowing became a necessity for either food or safety. It then evolved shielded tentacles and the casings eventually enveloped the entire body: these creatures are the brachiopods. The most successful shelled animals are the molluscs, of which there are some 80,000 different species.
The episode begins in the South American rainforest whose rich variety of life forms is used to illustrate the sheer number of different species. Since many are dependent on others for food or means of reproduction, David Attenborough argues that they couldn't all have appeared at once. He sets out to discover which came first, and the reasons for such diversity. He starts by explaining the theories of Charles Darwin and the process of natural selection, using the giant tortoises of the Galapagos Islands (where Darwin voyaged on HMS Beagle) as an example. Fossils provide evidence of the earliest life, and Attenborough travels a vertical mile into the Grand Canyon in search of them.
1979 • Nature
The next programme explores the various sea-living invertebrates. In Morocco, the limestones are 600 million years old, and contain many invertebrate fossils. They fall broadly into three categories: shells, crinoids and segmented shells. The evolution of shelled creatures is demonstrated with the flatworm, which eventually changed its body shape when burrowing became a necessity for either food or safety. It then evolved shielded tentacles and the casings eventually enveloped the entire body: these creatures are the brachiopods. The most successful shelled animals are the molluscs, of which there are some 80,000 different species.
1979 • Nature
This instalment examines the earliest land vegetation and insects. The first plants, being devoid of stems, mainly comprised mosses and liverworts. Using both sexual and asexual methods of reproduction, they proliferated. Descended from segmented sea creatures, millipedes were among the first to take advantage of such a habitat and were quickly followed by other species. Without water to carry eggs, bodily contact between the sexes was now necessary. This was problematical for some hunters, such as spiders and scorpions, who developed courtship rituals to ensure that the female didn't eat the male.
1979 • Nature
This episode details the relationship between flowers and insects. There are some one million classified species of insect, and two or three times as many that are yet to be labelled. Around 300 million years ago, plants began to enlist insects to help with their reproduction, and they did so with flowers. Although the magnolia, for instance, contains male and female cells, pollination from another plant is preferable as it ensures greater variation and thus evolution. Flowers advertise themselves by either scent or display. Some evolved to produce sweet-smelling nectar and in turn, several insects developed their mouth parts into feeding tubes in order to reach it.
1979 • Nature
This programme looks at the evolution of fish. They have developed a multitude of shapes, sizes and methods of propulsion and navigation. The sea squirt, the lancelet and the lamprey are given as examples of the earliest, simplest types. Then, about 400 million years ago, the first back-boned fish appeared. The Kimberley Ranges of Western Australia are, in fact, the remnants of a coral reef and the ancient seabed. There, Attenborough discovers fossils of the earliest fish to have developed jaws. These evolved into two shapes of creature with cartilaginous skeletons: wide ones (like rays and skates) and long ones (like sharks).
1979 • Nature
The next instalment describes the move from water to land. The fish that did so may have been forced to because of drought, or chose to in search of food. Either way, they eventually evolved into amphibians. Such creatures needed two things: limbs for mobility and lungs to breathe. The coelacanth is shown as a fish with bony fins that could have developed into legs, and the lungfish is able to absorb gaseous oxygen. However, evidence of an animal that possessed both is presented in the 450 million-year-old fossilised remains of a fish called a eusthenopteron. Three groups of amphibians are explored.
1979 • Nature
This episode is devoted to the evolution of reptiles. They are not as restricted as their amphibian ancestors, since they can survive in the hottest climates. The reason is their scaly, practically watertight skin. The scales protect the body from wear and tear and in the case of some species of lizard, such as the Australian thorny devil, serve to protect from attack. The horned iguana from the West Indies is also one of the most heavily armoured. The skin is rich in pigment cells, which provide effective means of camouflage, and the chameleon is a well-known example. Temperature control is important to reptiles: they cant generate body heat internally or sweat to keep cool.
1979 • Nature
This programme focuses on birds. The feather is key to everything that is crucial about a bird: it is both its aerofoil and its insulator. The earliest feathers were found on a fossilised Archaeopteryx skeleton in Bavaria. However, it had claws on its wings and there is only one species alive today that does so: the hoatzin, whose chicks possess them for about a week or so. Nevertheless, it serves to illustrate the probable movement of its ancestor. It may have taken to the trees to avoid predators, and over time, its bony, reptilian tail was replaced by feathers and its heavy jaw evolved into a keratin beak.
1979 • Nature
This instalment is the first of several to concentrate on mammals. The platypus and the echidna are the only mammals that lay eggs (in much the same manner of reptiles), and it is from such animals that others in the group evolved. Since mammals have warm blood and most have dense fur, they can hunt at night when temperatures drop. It is for this reason that they became more successful than their reptile ancestors, who needed to heat themselves externally. Much of the programme is devoted to marsupials (whose young are partially formed at birth) of which fossils have been found in the Americas dating back 60 million years.
1979 • Nature
This episode continues the study of mammals, and particularly those whose young gestate inside their bodies. Attenborough asks why these have become so varied and tries to discover the common theme that links them. Examples of primitive mammals that are still alive today include the treeshrew, the desman and the star-nosed mole. Insect eaters vary enormously from the aardvark, giant anteater and pangolin to those to which much of this programme is devoted: the bats, of which there are nearly 1,000 different species. These took to flying at night, and its possible that they evolved from treeshrews that jumped from tree to tree, in much the same way as a flying squirrel.
1979 • Nature
This programme surveys mammal herbivores and their predators. The herbivores began to populate the forests when the dinosaurs disappeared, and many took to gathering food at night. To prepare for winter, some store it in vast quantities, some hibernate and others make do as best they can. However, the carnivores joined them, and when a drying climate triggered the spread of grass, they followed their prey out on to the plains. Grass is not easily digestible and most animals that eat it have to regurgitate it and chew the cud. Out in the open, the leaf-eaters had to develop means of protection.
1979 • Nature
The penultimate instalment investigates the primates, whose defining characteristics are forward-facing eyes for judging distance, and gripping hands with which to grasp branches, manipulate food and groom one another. The programme begins in Madagascar, home to the lemurs, of which there are some 20 different types. Two examples are the sifaka, which is a specialised jumper, and the indri, which has a well-developed voice. Away from Madagascar, the only lemur relatives to have survived are nocturnal, such as the bushbaby, the potto and the loris. The others were supplanted by the monkeys and a primitive species that still exists is the smallest, the marmoset. However, Attenborough selects the squirrel monkey as being typical of the group. Howler monkeys demonstrate why they are so named their chorus is said to the loudest of any mammal and their prehensile tails illustrate their agility.
1979 • Nature
The final episode deals with the evolution of the most widespread and dominant species on Earth: humans. The story begins in Africa, where, some 10 million years ago, apes descended from the trees and ventured out into the open grasslands in search of food. They slowly adapted to the habitat and grew in size. Their acute sense of vision led to them standing erect to spot predators, leaving their hands free to bear weapons. In addition, the primitive apemen also had stones that were chipped into cutting tools. Slowly, they grew taller and more upright, and their stone implements became ever more elaborate.
1979 • Nature
Huge changes have swept across Arabia since the discovery of oil and the Arab relationship with nature has changed too. This is summed up by the changes to camel racing, now an ultra hi-tech sport. Arabia's animals now live alongside a very modern society but Arabia's people are using technology to protect nature: dugongs are fitted with satellite transmitters; hunting falcons chase down radio-controlled planes and the world's first carbon-neutral city is being built in the very heart of oil country.
3/3 • Wild Arabia • 2013 • Nature
This episode describes the migration of most animals northwards (some from the Antarctic continent, others from the few islands surrounding it) as the continent and surrounding sea freeze over at the end of summer. It shows how young penguins often fall prey to Leopard Seals as they try to make their way across the already partially frozen water and how their stripped remains become food for isopods and meter-long nemerteans (ribbon worms). Before going to the sea, however, the adult penguins must shed their coats (molting).
S1E4 • Life in the Freezer • 2003 • Nature
Oxygen – we all need it, we can't live without it. It's integral to life on this planet. And it's probable that, as you watch this film, you will be breathing in an oxygen atom that was also breathed by Genghis Khan – or by the first ever apes to stand upright on the plains of Africa. The oxygen that we breathe is made from two oxygen atoms joined together – O2. They were first joined more than 3 billion years ago by the earliest blue-green algae to evolve. The oxygen molecule first came from bacteria and was present in the fires that destroyed the dinosaurs and the chemical reactions in all human cells, and as ozone they protect the earth from radiation. Since then, both together and apart, they've had the most extraordinary adventures. Each of the two atoms in an oxygen molecule is virtually indestructible – so they have been first-hand players in some of the most dramatic events in the whole of Earth's history. It's often said that we are breathing the same oxygen that the cavemen did. The life of a single molecule of oxygen is traced on it's astonishing journey spanning millions of years, from its creation, into photosynthesis, through the age of the dinosaurs, early man, and on into today.
2008 • Nature
At the southern tip of Africa lies an underwater forest of haunting beauty. Venture into the depths of this singular world of strange plants and exotic sex-changing fish as they take refuge in this fertile and unique ecosystem.
Coastal Africa • 2016 • Nature
Dive into the long year of the Alaskan brown bear through the Earth's seasonal cycle amid the frigid winter months and into the warmth of summer.
S1E3 • Our Universe • 2022 • Nature
Summer is the season of plenty for most animals, but not polar bears. Unable to hunt seals until the sea freezes over again, they grow hungrier by the day. For other animals summer is when youngsters must learn how to survive.
2/4 • Canada: A Year in the Wild • 2018 • Nature