[tense music playing]
[growls softly]
[Morgan Freeman] Two million years ago, and our planet is a very different place.
[growls]
A saber-toothed cat, the Smilodon.
[ominous music playing]
[growls]
A fearsome predator of its age.
Standing in the way, a giant terror bird, two meters tall.
[barks, roars]
[growls softly]
Both sides are armed…
and prepared for a fight.
[roars]
[trills]
[dramatic music playing]
This is the story of the great battles for survival
and the dynasties that would take over the world.
[roars]
This is the story of life.
[music intensifies, ends]
[rousing music playing]
[low growling]
[snarling]
[trilling]
[screeching]
[rousing music continues]
[growling]
[wind howling]
[rumbling]
[rousing music intensifies]
[music fades]
[tranquil music playing]
If you know where to look,
you can still find clues to the origins of life on our planet.
This is not just a gathering of marine predators.
It is a coming together of ancient bloodlines.
Sharks, living fossils,
virtually unchanged for hundreds of millions of years.
Dolphins, air-breathing mammals
whose ancestors once roamed on land.
[clicking]
[bellows]
Whales, bigger than any other animals that have ever lived.
[bellows]
Birds,
the last survivors of the dinosaurs…
the world's greatest dynasty.
[dramatic music playing]
All predators,
all hunting the same prey,
but all with totally different origins.
There are more than ten million species of plant and animals alive today.
[rousing music playing]
And yet, they are just 1% of all species that have ever existed.
[birds chirping]
By traveling back in time,
we'll meet many of the 99% that have gone extinct…
[growling]
[roaring]
…to reveal the most extraordinary story of all,
the story of life on our planet.
[grunting]
[growling]
[roaring]
[music fades]
[thunder rumbles]
Life and all its incredible variety had to start somewhere.
[thunder continues]
The first spark appeared four billion years ago.
Perhaps uniquely, our planet had just the right conditions.
Liquid water, energy from the Sun,
and the perfect chemistry for life to take hold.
[dreamy music playing]
The exact process is lost in the mists of time.
But what it produced was a tiny single living cell.
LUCA,
the Last Universal Common Ancestor…
from which all life, everything, is descended.
[music ends]
From these humble beginnings,
life took billions more years to develop real complexity.
A feat it first achieved in the oceans.
[squelching]
The earliest animals to attain supremacy
were simple life forms.
[water babbling]
These invertebrates,
animals without backbones,
ruled the seas for many millions of years.
Throughout history, life has been waging an unending war.
One dynasty rising,
only to be vanquished by the next.
Plants were among the first to conquer the land…
creating conditions that, in time,
allowed the invertebrates to follow
and take over.
[chirping]
But the invertebrates could not rule forever.
[ominous music playing]
A new dynasty would surpass them.
One that also came from the water.
[growling]
The amphibians…
[grunting]
…whose novel body plan of four limbs and a backbone
would prove an enduring blueprint for success.
[grunting]
Their reach was limited by their ties to water.
But they spawned another dynasty with no such binds.
The reptiles.
[low growl]
Able to exploit even the driest regions,
their sprawling gait carried them around the world.
[growling]
For the first time in history, there was a global power.
From these early reptiles
came the most iconic dynasty of them all.
[majestic music playing]
The dinosaurs.
[bellowing]
[grunting]
They were to rule for over 150 million years.
[croaking]
[bleating]
A group of astonishing variety,
whose absolute dominion
was only cut short by calamitous bad luck.
[bellowing]
[squawking]
[wind howling]
Out of their shadows
rose the last great bloodline.
The mammals.
[low growling]
One of whom would go on to change our planet
like nothing before.
[music ends]
[birds chirping]
The rise and fall of these dynasties,
over four billion years,
has not just been a matter of chance.
The whole journey,
from the beginning of life to the infinite variety we know today,
has been driven by certain fundamental principles.
The rules of life.
The first rule is the best adapted will always win through.
Every one of these butterfly eggs looks identical.
But each has a different combination of genes
that makes them, individually, completely unique.
[birds tweeting]
[tranquil music playing]
Some will have genetic qualities that help them survive.
Qualities that will pass from generation to generation…
until eventually,
one will be so different to its predecessors
that it becomes an entirely new species,
better adapted to its environment.
This is evolution.
-[rustling] -[birds chirping]
[music intensifies]
But the caterpillars aren't the only ones evolving.
[rustling, creaking]
Everything in this forest is fighting for survival…
[swooshing]
…including the plants.
Unchecked, the caterpillars would strip them bare.
[munching]
[dramatic music playing]
But this plant has evolved its own adaptations for survival.
Poison in its leaves,
capable of killing anything that eats them.
It's chemical warfare.
[ominous music playing]
Then a new species of caterpillar evolves…
that can eat the otherwise poisonous leaves,
along with any eggs that might be on them.
In response,
other butterflies adapt to only lay on plants
that are free of eggs…
[birds tweeting]
[serene music playing]
…ensuring their young have the best possible start.
But the plants retaliate…
[sinister music playing]
…forming growths on their leaves
that mimic butterfly eggs…
deterring any females from laying there.
What's more, the fake eggs produce a sweet nectar that attracts ants…
that feed on caterpillars.
[sinister music continues]
The first rule of life, that the best adapted will win through…
[music ends]
…has produced the huge diversity that exists today.
[birds tweeting]
The next rule of life
is that competition drives adaptation.
And the most acute competition comes from one's own kind.
[ominous music playing]
A male terror bird.
His territory is the lakeshore.
[growls, roars]
-[distant call] -But he's not alone.
[roars]
A younger male wants this prime spot.
-[distant call] -[grunts]
[roars]
The older one can't ignore the threat.
[tense music playing]
[roars]
The youngster refuses to back down.
He needs a territory of his own.
[both roaring]
The two begin a ritual display.
[grunting]
Assessing the other's strength…
[snarling]
…while showing off their own.
Their coordinated moves
as formal as a dance.
[growls]
[snarling]
Who will be the first to back down?
Or attack?
[tense music continues]
With nothing to separate them, a fight is inevitable.
[roars]
[roaring]
-[roaring] -[tense music intensifies]
But they have company.
-[growling] -[grunting]
The Smilodon's mammalian cunning
was one reason terror birds went extinct.
[growling]
Competition, both within and between species,
has always driven evolution.
But it's not just those doing battle that are always changing.
So too is the battlefield itself,
which leads to the third rule of life.
Earth never remains stable for long.
Sometimes that helps life.
Sometimes it hinders it.
[dramatic music playing]
Throughout history, volcanoes have been one of the greatest agents of change.
[rumbling]
[explosive crashing]
Eruptions lasting thousands of years
have repeatedly engulfed vast swathes of our planet.
Pumping gases into the atmosphere,
changing the climate,
and, at worst…
[rumbling]
…causing global mass extinction.
The world has rarely been stable.
At times, a realm of fire.
At times, a realm of ice.
[wind howling]
Our changing planet has created so many challenges for life.
From toxic seas…
[cracking, rumbling]
…to global wastelands…
and periods of almost endless rain.
[whooshing]
[rumbling]
[thunder crashing]
At four different times,
the planet has pushed life to the very edge of existence.
Each time, more than three-quarters of all species
were lost in mass extinctions.
-[thunder crashing] -[wind howling]
Ours can be a brutal planet.
But there was one period
when Earth was stable for 100 million years.
[tranquil music playing]
A period which allowed one group to become the mightiest of dynasties.
This was the age of dinosaurs.
[grunting]
The long calm helped dinosaurs to proliferate in huge numbers.
These are Maiasaura,
gentle plant eaters that form herds many thousands strong.
[grunting, snorting]
This mass gathering provides safety,
and not just for the adults.
This rather cautious female
is keen to get back to her nest.
[snorts]
[growls softly]
Maiasaura means "good mother."
[growls softly]
Like the other females,
she has made her nest in an enormous colony.
To reach it,
she must run the gauntlet of defensive mothers
keen to protect their young.
[growling]
[snorting]
[hissing growl]
[growls]
In avoiding one aggressor,
she strays too close to the next.
-[snarls] -[grunts]
[snarls]
[grunts]
[grunts, roars]
[grunts softly]
At last, she reaches her own nest.
[bleating]
-[mother grunts softly] -[babies bleat]
She feeds her young in a very bird-like way.
[roars]
-[growls] -[grunts]
[roars]
She'll protect them in the nest for many months,
until they are big enough to join the rest of the herd.
[bleating]
Yet the planet didn't just support large numbers of dinosaurs,
its stability also supported dinosaurs of every shape and size.
[bellowing]
[squawking]
[trilling]
Triceratops is very different to the defenseless Maiasaura.
Weighing five tons and boasting three horns,
she is heavily armored…
adapted to a world where the best form of defense is attack.
With the breeding season imminent, she needs to be in peak condition.
And that means finding the best food wherever she can.
But her search has taken her far from the herd…
and closer to the edge of the forest.
[snorting]
She's right to be nervous.
Triceratops aren't the only giants in these woods.
[ominous music playing]
[quiet growl]
Tyrannosaurus rex.
[grunting]
The ultimate predator.
She has her two youngsters with her.
[growls quietly]
[hissing, snarling]
-[dramatic music playing] -[roaring]
The siblings are faster than their mother.
-[Tyrannosaurus squeals] -[Triceratops bellows]
They work as a team.
-[bellowing] -[hissing]
The Triceratops can hold off the youngsters,
but not the adult.
-[hissing] -[roaring]
[Tyrannosaurs squealing, roaring]
Only the protection of the herd can save her.
[Triceratops grunting]
They form a defensive wall.
[grunting]
[roars]
Even the world's greatest predator knows when she's beaten.
-[Tyrannosaurus snarling] -[Triceratops roaring]
[screeching]
Unlike the young male.
[roaring]
[squealing]
[roaring]
Dinosaurs might still rule today
if conditions on Earth had remained the same.
But everything was about to change,
and in just one day.
[explosive crash]
[rumbling]
An asteroid the size of Mount Everest,
traveling 20 times faster than a bullet,
smashed into the planet.
[dramatic music playing]
It blew a hole 20 kilometers deep and 180 wide…
setting off an earth-shattering chain of events.
Rising from the massive crater came the real killer.
A wall of ash and debris hundreds of kilometers thick…
that enveloped the globe.
[rumbling]
The cloud blocked out the sunlight,
leading to the death of almost all dinosaurs…
[melancholic music playing]
…and three-quarters of life on Earth.
The annihilation was global.
It was the world's fifth mass extinction.
[melancholic music continues]
[music fades]
But there were survivors.
Survivors that would form the basis of all species that exist today.
[peaceful music playing]
The birds were the only remaining dinosaurs.
Today, they number more than 10,000 species…
[chirping]
…occupying every habitat on Earth.
But the birds didn't have the planet to themselves.
Another great dynasty also rose from the ashes.
The mammals.
Under the dinosaurs, they had been a mere footnote in history.
[grunting, snuffling]
Without the asteroid strike,
none of these survivors would have had a chance to rule.
From the cataclysm of the mass extinction
came this new multitude of life
in all its wondrous variety…
[uplifting music playing]
…all perfectly adapted to the challenges of life.
[birds trilling, chirping]
The struggle to protect and raise one's young,
to find food,
and to breed.
The cast of characters may have changed,
but the essentials remain the same.
Water and the energy from the Sun continue to support life,
just as they have for billions of years.
[chirping]
Even today, the rules of life still apply.
Only the best adapted will win through.
[tense music playing]
[birds squawking]
Competition drives evolution.
And a rapidly changing planet causes chaos.
[grunting]
[squealing]
These rules of life determine how dynasties will rise
and how they will fall.
[chirping]
Every single thing alive today
can trace its heritage back four billion years.
This in the face of incredible odds.
[grunting]
[majestic music playing]
99% of all species that have ever existed
are now extinct.
[chirping]
Life today is the 1% that made it through.
[squeaking]
This series will explore the most important milestones
in the history of life.
[grunts]
From when mammals established themselves as a global power…
[heavy grunting]
…to the ancestors of the birds first taking to the air…
[triumphant music playing]
…to the evolution of hard-shelled eggs
that led to the rise of the mighty dinosaurs.
[growling]
And even the moment when animals first came out of the water.
[whooshing]
In the next chapter, we go back to life's origins in the sea…
and the very first fights for survival…
on our extraordinary planet.
[ominous music playing]
[music intensifies, ends]
[rousing music playing]