Speaker 1: We are the most complex creature on this planet, a
Speaker 1: big brain, two legged mammal. We've risen from the raw
Speaker 1: materials of the Earth to dominate and shape it.
Speaker 2: Wind the clock backwards, and.
Speaker 1: The story of how we got to be us is
Speaker 1: a puzzle that defies all logic. Through nearly four billion
Speaker 1: years of evolutionary twists and turns, disasters, stripe predators threatened
Speaker 1: to wipe us out. From rodent to reptile, we face
Speaker 1: extinction at every turn, from the land into the water,
Speaker 1: fighting to survive every step of the way, from fish
Speaker 1: to worm, back to the.
Speaker 2: Very first spark.
Speaker 1: Of life, to a single simple self. And this is
Speaker 1: the most extraordinary, improbable story ever told, the story of
Speaker 1: mankind rising four billion years ago. A ball of rock
Speaker 1: and dust spins in the frozen vacuum of space. This
Speaker 1: isn't Mars.
Speaker 2: Or Venus. This hell is Earth.
Speaker 1: This seething, lifeless mass of molten lava will become home
Speaker 1: to nearly nine million living species. But generating life from
Speaker 1: this will take a chain of events that defies the
Speaker 1: laws of probability.
Speaker 2: There are many theories.
Speaker 1: Nobody knows exactly our where life began, but it couldn't
Speaker 1: happen without water. Experts believe asteroids or commets delivered it. Here,
Speaker 1: the water is churning with chemicals and organic compounds. Lightning
Speaker 1: strikes the chemical soup at the right place and the
Speaker 1: right time. Billions of volts of electricity trigger a chain
Speaker 1: of improbable coincidences. The chemicals atoms join up in a
Speaker 1: precise sequence, creating a bundle of genetic material. These fragile
Speaker 1: genes don't stand a chance in this extreme environment, but
Speaker 1: love strikes again. A blob of oily material engulfs a
Speaker 1: single chain to create the first ever cell. Now, the
Speaker 1: genes send out messages, chemical instructions, and three point five
Speaker 1: billion years ago, they do something extraordinary. They copy themselves
Speaker 1: and the cell to create a perfect clone. This is
Speaker 1: the very first living thing. Every human, every animal, every bug,
Speaker 1: every plant can trace its origins to this single cell.
Speaker 1: The genes tell each cell to reproduce, guaranteeing their survival
Speaker 1: as they pass from one generation to the next. For
Speaker 1: two billion years, the only living things are simple single cells.
Speaker 1: But a random accident changes everything. Two cells merge, their
Speaker 1: genes combine. The merge cell clones itself. Its offspring contains
Speaker 1: genes from not one, but two cells, two parents. We
Speaker 1: call this accident sex. Sex introduces variation. Occasionally things go
Speaker 1: wrong as the cells reproduce, genes get deleted, duplicated. These
Speaker 1: cells are mutants. Mutations pile up, differences increase until the
Speaker 1: cells become so different their separate species. The tree of
Speaker 1: life branches out into billions of species, but only one
Speaker 1: will lead to us. Mutating and diversifying, spreading out through
Speaker 1: the oceans, getting bigger, more complex, until our ancestor is
Speaker 1: a three inch long water worm. This is US five
Speaker 1: hundred and fifty million years ago. Mutations create distinct male
Speaker 1: and female sexes. We produce more offspring, passing on more
Speaker 1: genes Mars and venus. Boy meets girl.
Speaker 2: It all starts.
Speaker 1: Here, but finding a partner is almost impossible When every
Speaker 1: living thing is blind in this sea of darkness. The
Speaker 1: ability to see will give us a critical advantage. Nature's
Speaker 1: most perfect innovation begins to take shape. A handful of
Speaker 1: skin cells mutate. Now we can tell dark from light,
Speaker 1: find more prey, dodge more predators. We live longer and
Speaker 1: produce more offspring. Soon, creatures with light sensitive cells dominate
Speaker 1: the population over countless generations. More mutations refine the cells.
Speaker 1: This is natural selection in action, the process that allows
Speaker 1: every living thing to adapt to the world, and that
Speaker 1: gives our ancestor eyes. We can see, and everything we
Speaker 1: can see is descended from that first single cell. But
Speaker 1: we need to make sense of what we're seeing behind
Speaker 1: our eyes A tiny collection of nerve cells clustered together.
Speaker 1: They're no bigger than a pinhead. One day this will
Speaker 1: be nature's most complex and mysterious organ. Five hundred and
Speaker 1: twenty one million years ago, this is the very first brain.
Speaker 1: We are a fish like creature called Milo Conmingia. Our
Speaker 1: brain can make simple decisions, process basic information, but we
Speaker 1: can't outwith or outrun this anoma Lacarus, the great white
Speaker 1: of the ancient oceans. O odds of extinction are far
Speaker 1: higher than survival. Of all the species that have ever lived,
Speaker 1: ninety nine percent of them are extinct, But a lucky
Speaker 1: roll of the genetic dice helps Milo. Tough enough, your jaws,
Speaker 1: your teeth. They exist because over four hundred million years ago,
Speaker 1: we face the wrath of a primeval monster. Jaws and
Speaker 1: teeth mean more food and a bigger, stronger body. Until
Speaker 1: three hundred and seventy five million years ago, we're a
Speaker 1: foot long armored fish.
Speaker 2: We look invincible, but we're not. Now.
Speaker 1: The choice is simple, get out his way or die.
Speaker 1: We're safe in the shallow water, or are we. The
Speaker 1: water's stagnant, there's not enough oxygen. Starved of oxygen, cells
Speaker 1: shut down, Toxic carbon dioxide saturates the blood. We can't
Speaker 1: go back, we can't stay here. There's only one place
Speaker 1: left for.
Speaker 2: Us to go.
Speaker 1: It takes over three billion years for our ancestor to
Speaker 1: evolve from a single cell to a foot long armored fish.
Speaker 1: Now our future looks bleak, but natural selection throws us
Speaker 1: a lifeline. Over millions of years, thousands of generations, our
Speaker 1: body adapts until we do something no fish has done before.
Speaker 2: Breathe.
Speaker 1: There the air travels into a new organ, a lung.
Speaker 1: Take a breath, and remember it's because a monster fish
Speaker 1: chased our ancestor into the stagnant water, forcing them to
Speaker 1: breathe air. We're in ichthyostega. We can breathe air or water,
Speaker 1: closing off our windpipe to switch between lungs and gills. Today,
Speaker 1: our gills are gone, but the mechanism remains, and sometimes
Speaker 1: times at spasms, giving us the hiccups three hundred and
Speaker 1: sixty five million years ago. We stick our head out
Speaker 1: of the water.
Speaker 2: There's a swamp.
Speaker 1: Behind us, paradise ahead. The choice is simple, but the
Speaker 1: consequences are immense. We pull ourselves out of the water
Speaker 1: and change the course of history. This is the moment
Speaker 1: we leave the water for a new life on land.
Speaker 1: But all this food comes at a price. The fierce
Speaker 1: sun dries out our skin, the hard terrain tears at
Speaker 1: our soft feet. Ichthyostega is a fish out of water.
Speaker 1: We dodged extinction in a stagnant swamp, only to slam
Speaker 1: straight into another deadly environment. Countless creatures perish, but natural
Speaker 1: selection helps our ancestor adapt. Thicker skin protects us from
Speaker 1: the sun, and tough claws that will one day become
Speaker 1: our fingernails help us move across the rough terrain until
Speaker 1: we're cassanaria. We've adapted to life on life, but our
Speaker 1: eggs haven't. They need a tough shell to stop them
Speaker 1: drying out in the sun. The problem is males can't
Speaker 1: fertilize an egg through a tough shell, but they can
Speaker 1: fertilize it before the shell forms inside the female's body.
Speaker 1: Sex as we know it starts here. The result is
Speaker 1: a masterpiece of evolution, an egg in a tough shell
Speaker 1: with all the nutrients the embryo needs sealed inside. Sex
Speaker 1: is the best way to increase genetic variety and keep
Speaker 1: our species alive. Thanks to sex, three hundred and forty
Speaker 1: million years ago, Casinaria becomes the first of our ancestors
Speaker 1: to live entirely on land. It's a new world, different
Speaker 1: from anything we've experienced up to now. We breathe air,
Speaker 1: support our own weight, and wrestle with an onslaught of
Speaker 1: new smells, sounds, sights, bombarded with information, our brains evolve.
Speaker 1: We're smart, and we need to be. From that first
Speaker 1: creature to set foot on land, millions of species have evolved.
Speaker 1: More competitors mean less food to go round. A mutation
Speaker 1: gives us bigger, more powerful jaw muscles. It's a critical advantage.
Speaker 1: We can eat more food faster, and it shows we're Varnops,
Speaker 1: a slab of pure meat eating power. This little creature
Speaker 1: is a proterosaurus wants a competitor. Now he's prey with
Speaker 1: Varyonops for an ancestor. Our success seems certain, but our
Speaker 1: story is a rollercoaster ride, and there's a big dip coming.
Speaker 2: Two hundred and fifty.
Speaker 1: Million years ago, thousands of miles away in Siberia, the
Speaker 1: Earth tears itself apart. A giant plume of magma surges
Speaker 1: up from deep inside the planet. Molten rock oozes through
Speaker 1: cracks in the Earth's crust, covering an area the size
Speaker 1: of the United States under a layer one thousand feet deep,
Speaker 1: and it continues for half a million years. Trillions of
Speaker 1: tons of noxious carbon dioxide trapped the Sun's heat inside
Speaker 1: the atmosphere, Temperatures soar to over one hundred degrees. Plants,
Speaker 1: the plant eaters, and eventually the meat eaters perish. Ninety
Speaker 1: five percent of all species die, only a tiny handful
Speaker 1: hang off among them, us and another species that will
Speaker 1: one day become the dinosaurs. As the fight for survival
Speaker 1: winds down, the battle for supremacy begins. Thirty million years
Speaker 1: since volcanic eruptions wiped out ninety five percent of all
Speaker 1: living things. When the eruptions struck, we look like a
Speaker 1: large lizard. Now we're a catsized creature covered in fur
Speaker 1: called ectininion. Imagine you've survived the apocalypse, and today is
Speaker 1: the day it's finally safe to venture out of hiding,
Speaker 1: you discover.
Speaker 2: You're not alone.
Speaker 1: The last thing you want to see is a dinosaur,
Speaker 1: a five foot tall Herrerasaurus. She evolved from one of
Speaker 1: the small reptiles that survived the mass extinction. Her ancestors
Speaker 1: adapted faster than ours, putting the dinosaurs ahead in the
Speaker 1: game and leaving us playing ketchup. This one's fast, strong,
Speaker 1: and hungry. We're staring down the barrel of an evolutionary gun.
Speaker 1: Our only hope natural selection. Over millions of years, we
Speaker 1: get smaller.
Speaker 2: So we're harder to catch.
Speaker 1: We become nocturnal, making us harder to see.
Speaker 2: We're cold and scared.
Speaker 1: Tiny muscles around the base of each hair contract making
Speaker 1: our fur stand on end, trapping air as insulation. That's
Speaker 1: why today, when we're cold or startled, we get goosebumps.
Speaker 1: Our senses sharpened so we can see here and smell
Speaker 1: a dinosaur before a dinosaur sees us. Inside our brain,
Speaker 1: a new structure evolves, the neocortex, the home of complex
Speaker 1: thought that allows us to analyze the situation and respond.
Speaker 1: It will one day give us the power to imagine, create,
Speaker 1: and communicate. Sixty six million years ago. We're Batadom, a
Speaker 1: two inch long, shrewd like creature living on our wits
Speaker 1: in the ancient forests of Montana. Humanity's future depends on
Speaker 1: Badadan's sharp senses and supercharged brains. If these fail, we
Speaker 1: may never exist. The dinosaurs may be the best thing
Speaker 1: that ever happened to us. Thanks to them, we have
Speaker 1: powerful senses and brilliant brains. Without them, we could still
Speaker 1: be laying eggs to protect our offspring from hungry dinosaurs.
Speaker 1: We evolved to give birth to live young. Instead of
Speaker 1: leaving them to fend for themselves, we nurture them with milk.
Speaker 2: Sweat.
Speaker 1: Glens evolved to become mammary glands. It's a major milestone
Speaker 1: in our journey from cell to human, the birth of
Speaker 1: a new kind of animal, one that will branch out
Speaker 1: into more than four thousand species, from the smallest mouse
Speaker 1: to the largest whale. To us, the mammals have arrived.
Speaker 1: The dinosaurs help shape who we are, but we lost
Speaker 1: the battle for supremacy. The dinosaur's reign for over one
Speaker 1: hundred and sixty five million years. Nothing can stop.
Speaker 3: Them, or so it seems.
Speaker 1: Montana, sixty five million years ago, an asteroid strikes eighteen
Speaker 1: hundred miles away off Mexico's Yucatan Peninsula. A small rat
Speaker 1: like mammal is about to face the fight of his life.
Speaker 1: Lose and humans may never exist. Pulverized rock and dust
Speaker 1: engulfed the entire planet, the only way out is to dig.
Speaker 1: Smoke and ash from the fires block out the sun.
Speaker 1: Temperatures plummet, vegetation dies. The local disaster becomes a global catastrophe.
Speaker 1: For the dinosaurs, it's a disaster. They're big creatures with
Speaker 1: big appetites, and now that's a big problem. As the
Speaker 1: mighty fall, the small rise to the top. Bugs tough
Speaker 1: enough to survive the worst catastrophe, gorge on the dead
Speaker 1: and decaying, and they make the perfect snack. Next time
Speaker 1: you're about to squash a bug, remember that we wouldn't
Speaker 1: be here without them. Sixty four million years ago, our
Speaker 1: bug eating ancestor is purgatorious, just under six inches long.
Speaker 1: This little creature and the rest of his mammal family
Speaker 1: are the unlikely inheritors of the dinosaur's crown. Mammals become
Speaker 1: the dominant animals on land. They spread out across the
Speaker 1: newly formed continents. Our future rests on their tiny shoulders
Speaker 1: from the ashes of destruction. New life begins to sprout.
Speaker 1: Sixty million years ago, fruit ripens on the trees, packed
Speaker 1: full of nutrients. The more fruit we eat, the longer
Speaker 1: we live. We leave solid ground for a new life
Speaker 1: in the trees. A new world demands a new body.
Speaker 1: We've come a long way from that first single cell. Now,
Speaker 1: at last, we're beginning to glimpse of family resemblance. We're
Speaker 1: alti at Lassius, one of the first members of a
Speaker 1: new group of mammals, the primates.
Speaker 2: By fifty six million years.
Speaker 1: Ago, we've adapted to our world, but that world is
Speaker 1: about to change again. Over ten million years, extreme temperature
Speaker 1: shifts ravage the forests. Forests gets smaller, food gets harder
Speaker 1: to reach. Natural selection intervenes again. Our tail shrinks back
Speaker 1: to the base of the spine, where it stays as
Speaker 1: the coccix, a reminder of our days spent leaping through
Speaker 1: the trees. Instead of leaping, we stretch, our arms grow
Speaker 1: long and flexible. Changing temperatures changed our ancestors and us forever,
Speaker 1: but the planets not finished yet. Deep underground, the African
Speaker 1: and Arabian plates pull apart the land between them drops
Speaker 1: to form the East African Rift Valley. Along its edge,
Speaker 1: a three and a half thousand mile long mountain shape
Speaker 1: rises up rains from the Indian Ocean, once watered all
Speaker 1: of Africa. Now the mountains block their path, The trees
Speaker 1: get even further apart, the food harder to reach. We're starving, desperate.
Speaker 1: Four point four million years ago. The will to survive
Speaker 1: that's driven us from a single cell in the ocean
Speaker 1: to a complex primate in the forests of Africa is
Speaker 1: about to make us do something extraordinary, something no primate
Speaker 1: has ever done before. After three billion years of evolution,
Speaker 1: we hit an evolutionary dead end. We are Artipithecus ramidus,
Speaker 1: four feet tall at eighty pounds, with a brain the
Speaker 1: size of an orange. Our dense rainforest home has become
Speaker 1: patchy forest. We can stand on branches move along them,
Speaker 1: but to reach more food, we need to let go.
Speaker 1: Four point four million years ago, these are our first
Speaker 1: steps on two legs. Walking takes us to the food
Speaker 1: and leaves our hands free to pick it.
Speaker 2: It catches on fast.
Speaker 1: Artipithecus is smart enough to copy and learn. Walking gets
Speaker 1: past from parent to child. Over the next one point
Speaker 1: two million years Our body evolves so that we can
Speaker 1: walk further and faster. Finding shelter, a mate and food
Speaker 1: gets easier, but childbirth gets harder. With a narrower pelvis,
Speaker 1: giving birth to a fully developed infant becomes impossible. Babies
Speaker 1: have to come out early when their heads are smaller
Speaker 1: and they're barely developed.
Speaker 2: That's why we are.
Speaker 1: One of the few species to spend years caring for
Speaker 1: our offspring, protecting them, feeding them, and keeping them out
Speaker 1: of trouble. Three point two million years ago, we're an
Speaker 1: Australo pitheken. Our brain is the size of a grapefruit,
Speaker 1: and we walk on two legs all the time. We
Speaker 1: got lucky, the lion has already eaten.
Speaker 2: This time.
Speaker 1: We can't outrun our predators. The only way to survive
Speaker 1: is to outthink that the smarter we get, the.
Speaker 2: Longer we live.
Speaker 1: Natural selection promotes the mutations that improve.
Speaker 2: Our brain power. Your jaw muscles released from the.
Speaker 1: Muscle's vice like grip.
Speaker 2: The brain is free to grow.
Speaker 1: It doubles in size two point three million years ago.
Speaker 1: This is Homo habilis, also known as handyman. Walking on
Speaker 1: two legs with a big brain. We're the first of
Speaker 1: an entirely new type of creature. We're the first man.
Speaker 1: We're bigger, stronger, and hungry than ever before. There's food
Speaker 1: out there, but it's more likely to eat us before
Speaker 1: we can eat it. We're a scavenger working alone. We
Speaker 1: eat whatever we can find. The edge is razor sharp.
Speaker 1: We have just made the very first tool. Armed with this,
Speaker 1: we will change.
Speaker 2: The world.
Speaker 1: East Africa two point three million years ago, after over
Speaker 1: three billion years of evolution, we take our fate into
Speaker 1: our own hands. We are the first species to make
Speaker 1: tools in this hostile environment. We need every advantage we
Speaker 1: can get. We must fight off predators, starvation, and our
Speaker 1: own relatives. There's no meat left. It looks like we're
Speaker 1: going hungry again. But there's bone marrow locked inside packed
Speaker 1: within her. The tool is the key to a whole
Speaker 1: new way of life. We'll use it to grow crops,
Speaker 1: build cities, and travel into space. Our thumbs become stronger,
Speaker 1: puld a cup, pick up a pen. We can do
Speaker 1: this because two million years ago, tool use changed our
Speaker 1: bodies and the course of evolution. We've pieced together our
Speaker 1: ancestors story from their bones, but from the vastness of Africa.
Speaker 1: All the bones of our early human ancestors ever found,
Speaker 1: would fit into the back of a pick up. Less
Speaker 1: than one bone in a billion becomes a fossil factor
Speaker 1: in the chances of finding those bones across millions of
Speaker 1: square miles, and it's clear most of what has lived.
Speaker 2: Has been lost.
Speaker 1: Our family tree is a giant puzzle with most of
Speaker 1: the pieces missing. But one point eight million years ago,
Speaker 1: a piece falls into place and we find a new
Speaker 1: species on the scene, Homo erectus. Until this point we
Speaker 1: were scavengers, but now we're hunters, and we've learned how
Speaker 1: to work with other members of our species. The hunt
Speaker 1: is on. The impala can run fast, but we can
Speaker 1: run further. Low shoulders and long torsos stabilize us. Powerful
Speaker 1: buttock muscles contract, expand, and push us forwards. Sweat stops
Speaker 1: us from overheating. Covered in fur, the Impalla is exhausted.
Speaker 1: Fire it sparks an idea that will make our ancestors
Speaker 1: human warmth. Light, safety is within reach. Nature's power is
Speaker 1: in our hands. Protected from the terrors of the dark,
Speaker 1: our extended family gather round By working together, These earliest
Speaker 1: families get food more often, so we live longer. This
Speaker 1: is the advantage of family life, the reason most of
Speaker 1: us live as we do today. Meat is too precious
Speaker 1: to waste, and cooked meat is easier to chew. The
Speaker 1: powerful molars used to chew tough raw food retreat back
Speaker 1: into the gums, where they'll stay as our wisdom teeth.
Speaker 1: Thirty five percent of us never even grow them, a
Speaker 1: sign that they may be evolving out of existence. With
Speaker 1: less energy spent on chewing, our ancestors have energy to spare.
Speaker 1: The brain increases to the size of a softball, fifty
Speaker 1: percent larger than before the invention of cooking. Erectus is
Speaker 1: the cleverest, most cooperative ancestor to date, but with several
Speaker 1: adult males in an extended family, rivalries are inevitable, communicate
Speaker 1: and will live longer. A natural selection kicks in. Our tongue,
Speaker 1: changes shape and moves down our throat, carrying the larynx
Speaker 1: with it, allowing us to form different shapes in our mouths,
Speaker 1: making different sounds and ultimately words. Speech is our greatest tool.
Speaker 1: It's the last piece of the puzzle that turns our
Speaker 1: ancestors into us. Two hundred thousand years ago, after a
Speaker 1: three point three billion year battle for survival. We've arrived.
Speaker 1: We are Homo sapiens, meaning wise men. Pound for pound,
Speaker 1: we have the largest brain of any creature on Earth.
Speaker 2: Armed with tools, speech, and.
Speaker 1: Superior intelligence, we spread out across every continent, evolve and
Speaker 1: adapt to new environments, new challenges, until we become the
Speaker 1: undisputed masters of the world.