Plot

Evolution, competition, mass extinction: 4 billion years of life's rules.

2 million years ago Earth is a very different place. A pair of Smilodon (a Sabre tooth tiger) successfully take down a Titanis (a giant terror bird which is 2 meters tall). Both sides are armed. The Smilodon has large sharp teeth and the Titanis has long claws. This represents the battle for survival and the dynasties that would take over the world.

Clues to the origin of life on our planet are still visible today. Sharks are the living fossils, unchanged for millions of years. Dolphins are air breathing mammals whose ancestors once roamed on land. Birds are the last survivors of the dinosaurs (The world's greatest dynasty). More than 10 million species of plants and animals are alive today. Yet, they are just 1% of all the species that have ever existed on the planet.

Life started 4 billion years ago, with the first sparks of energy coming from the sky. The planet had liquid water, energy from the sun, and chemistry for life to take hold. The process produced a tiny single living cell called LUCA (Last Universal Common Ancestor). This is the cell from which all life on Earth has descended. It took billions of years for life to achieve complexity. This first happened in the oceans around 450 million years ago. Ocean was full of invertebrates (animals without backbones), who ruled the seas for many million years. Plants were the first to conquer the land. Plants created the conditions for invertebrates to follow on land and take over. The invertebrates were surpassed by the Amphibians on land. Amphibians also came from the water. Amphibians had 4 limbs and a backbone and became a blueprint for success. Amphibians spawned the reptiles, who had no binds to water. Reptiles could survive in even the driest regions. Reptiles became a global power. From the reptiles came the dinosaurs, the most enduring dynasty of them all. They ruled for over 150 million years. Their dominion was cut short by calamitous bad luck. Out of the dinosaurs came the last great bloodline, the mammals.

Evolution was not unplanned. There were some fundamental principles at work. These are the rules of life. The best adapted will always win through. Every individual has a unique combination of genes that help them live and interact with their environment. Eventually one individual of the species has enough difference in genes to spawn a completely new species. Caterpillars eat leaves. Leaves evolve to have poison in them to kill the caterpillars. Then a new species of caterpillars evolves one that can eat the poison leaves, and the eggs of other butterflies. Butterflies evolve to lay eggs on leaves that don't have eggs on them. Plants evolve to have leaves that form growth which look like butterfly eggs. Fake eggs produce a nectar that attract ants, who feed on caterpillars.

Competition drives Adaptation. 2 million years ago male terror birds fight for their territory. The young male challenges the old male for its prime spot by the lake. They begin a ritual display. They get into a fight as there is nothing to separate them. But then the Smilodon attack and kill one of the terror birds as the other runs away.

Earth never remains stable for long. Volcanoes are the greatest agent of change. Eruptions can go on for thousands of years. They pump gases into the atmosphere, change the climate and can cause global mass extinction. World has never been stable. It was a realm of fire, and then a realm of ice. The changing planet creates ever new challenges for life. At 4 different times, climate had pushed life to the edge of existence. Each time, more than 75% of all species were lost in mass extinctions. There was one period when Earth for stable for a 100 million years. Dinosaurs ruled in this period 76 million years ago. A mother Maiasaura (a species of dinosaur meaning "Good Mother") navigates the nesting grounds. Her young ones hatch out of their eggs. She feeds them in a bird-like way. She protects them in the nest till they are big enough to join the herd. The stable period supported dinosaurs of every shape and size. Tyrannosaurus Rex (The ultimate predator) & her offspring attempt to hunt a Triceratops (weighs 5 tons and has 3 horns). Triceratops is saved only when she retreats behind the safety of her herd.

66 million years ago, as asteroid the size of mount Everest crashed into the Earth, travelling 20 times faster than a bullet. The hole was 20 Kms deep and 180 Kms wide. It kicked up a wall of ash and debris, hundreds of kilometers thick. It enveloped the globe and blocked out the sun-rays and led to the death of almost all dinosaurs, and 75% of all life on Earth. It was the 5th mass extinction.

The survivors formed the basis of all species that exist today. Birds were the only remaining dinosaurs. They number more than 10,000 species. Mammals also rose from the ashes. Without the asteroid strike, none of the survivors would have had a chance to rule.

But the rules of life still apply. Water and the sun still support life, as they have done for 4 billion years. Life today is the 1% that made it through.