the universe vast empty and as far as we know lifeless with one exception Earth why what is it that makes our planet so special the answers are hidden deep in the earth's past to find them we must travel back in time to see for ourselves the first humans walk the earth ride continents on a collision course Face Killer dinosaurs dive into oceans full of bizarre life forms feel the bitter chill of global ice ages [Music] and experience the fury of cosmic missile attacks until we reach the very beginning to witness the birth of the Earth itself then we can piece together our planet's incredible story and discover why all of this all of us are here [Music] we've arrived almost 5 billion years ago this can't be right there's no sign of our beautiful blue planet just a newborn star our son surrounded by all this dust we've arrived too early before the Earth has even formed somehow out of this chaos our planet will emerge speed up time and we can see gravity pulling the dust into tiny rocks it hardly seems possible that something as complex as a planet is made from nothing more than rocks dust and gravity over millions of years these rocks are forming a planet this is it the Earth 4.54 billion years ago on [Music] [Music] but it looks more like hell than [Music] home up close the temperature is over 1200° C there's no air to breathe just choking carbon dioxide nitrogen and water vapor it's so hot so toxic get any closer and we'd be incinerated and suffocated in seconds the newborn planet is a boiling ball of liquid rock there are virtually no Solid Surfaces just an endless ocean of lava and the Earth is still being bombarded [Music] it's a young Planet the size of Mars and it's heading straight for us it's traveling at nearly 15 km a second 20 times faster than a bullet it's looming over us like a vast alien spacecraft [Music] the intruder's gravity is distorting the Earth's surface [Music] [Music] the blast wave is racing out around the planet it's as though both young planets are turning to liquid trillions of tons of debris are blasting out into space [Music] [Music] [Music] but over the course of Just A Thousand Years gravity Works its magic turning Rubble into a ring of red hot dust and rocks circling the [Music] earth and now from this ring a 3,500 km wide ball is [Music] [Applause] forming we're watching the birth of our moon it's much closer than the moon we recognize just 22,500 km away instead of over 400,000 km [Applause] [Music] [Music] the sun's rising over a cooling [Music] Earth but this is strange it's setting just just 3 hours after it [Applause] Rose the impact must have set the Earth spinning so fast that an entire day lasts just 6 hours the Earth may be turning fast but it's changing slowly to understand the making of our planet we need to fast forward through millions of years a hail of meteors 3.9 billion years ago and we're under attack from debris left over from the solar systems formation look inside at these strange crystals they look like grains of salt the same salt you'd put on your fries and inside these minute droplets of [Applause] water it seems these deadly missiles could contain the vital ingredient for life on Earth there's only a small amount of water inside each meteorite but as they bombard the Earth for over 20 million years pools of water grow the water collects On Solid Ground the Earth's core remains molten but its surface has cooled to around 70 or 80° C just enough to form a crust in the future we could swallow this water when we take a drink every sip every puddle every drop of water in every ocean is billions of years old and it's traveled millions of kilometers to reach us carried inside a meteor [Music] the earth looks more familiar but this is still a dangerous [Music] place this wind is fast perhaps faster than the most destructive hurricane we're caught in a mega storm whipped up by the planet's rapid rotation the Moon is so close to Earth its gravity is overwhelming it's creating these huge Tides racing across the planet's surface [Music] [Music] but over time the moon moves away the waves calm and the planet spins more [Music] slowly 700 million years after after the planet's birth lifegiving water covers its [Music] surface but not just water there's something down there tiny Islands they seem to have appeared from nowhere until molten rock bursts through the Earth's crust and Rises up through the ocean over time the lava cools and forms a volcanic island this is how these Islands formed in the future they will join together to form the first continents our planet has been forged in five and shaped by violence but out of this hell comes water and land and with them the first Clues to why our planet is so special why the Earth is home to life meteors they've been raining down since the planet's formation but now 3.8 billion years ago the assault is intensifying they already brought water to the planet but they're carrying something else too the seeds of life itself look the meteorites are dissolving they're transporting carbon and primitive proteins amino acids from outer space to the bottom of the [Music] ocean it's dark the sun's Rays can't reach Beyond 300 M and it's close to freezing [Music] wait this must be a mirage a city of underwater Smoke Stacks it's not smoke it's some kind of hot liquid seawater must have seeped down into the Earth through cracks in the crust getting hotter collecting minerals and gases on the way it's this potent mixture that's spewing back out into the ocean building these [Music] towers add to this all those minerals and chemicals from the meteorites and all around us the water is becoming a chemical soup it's full of microscopic organisms feeding on this soupy water these single cell bacteria are the earliest forms of life on [Music] Earth We're witnessing a defining moment in the making of the planet [Music] life is underway but then for hundreds of millions of years nothing changes there's no progress no evolutionary steps forward just single celled bacteria [Music] something somewhere has to take a giant leap forwards we're traveling over a shallow ocean 3.5 billion years ago [Music] are these rocks or plants they seem to be growing out of the seabed like a forest of stunted trees each one is a mountain of living bacteria a colony called a stromatal as if by Magic these bacteria are turning sunlight into food this process called photosynthesis uses the power of sunlight to transform carbon dioxide and water into glucose a simple form of sugar this is the first sugar ever created and pretty much the same stuff we put in our coffee and this magical transformation releases a byproduct a gas called oxygen underwater the stromatolites are SE slowly filling the oceans with oxygen and look it's turning traces of iron in the water into [Music] rust this is falling to the ocean floor forming deposits of iron rich Rock one day we'll use these to build Bridges ships skyscrapers [Music] but right now above the waves the oxygen is transforming the atmosphere these stromatolites are creating the single most important element for life on Earth without them virtually every living thing wouldn't exist when we take our next breath we're doing it thanks to these colonies of ancient bacteria over the next 2 billion years oxygen levels continue to rise and as the planet spin slows the days get [Music] longer now they last at least 16 hours we're discovering it takes a long time to make a planet 1.5 billion years ago 3 billion years after the planet's birth and there's no complex life no plants no dinosaurs no humans but the Earth has something that no other planet has a force with the power to change [Music] everything our planet a beautiful blue ball dotted with volcanic islands home to primitive life but 1.5 5 billion years ago changes are underway that will push life on Earth to the point of no return over millions of years we can see something is rearranging the islands hidden beneath the ocean the Earth's crust has broken into vast plates deeper still the earth's core is at work it's hotter than the surface of the sun so hot it generates movement in the rock beneath the crust these movements push and pull the plates around the globe and carry the oceans and the islands with them millions of years Race by seeing it like this our planet seems active changing alive over 400 million years a vast new supercontinent takes shape called rodinia [Music] in the shallow Waters around rodinia stromatolites have been working their magic here for billions of years pumping oxygen into the atmosphere the temperature is 30° C and the days are now 18 hours [Music] long the pieces are in place for advanced life to emerge but this looks more like Mars than Earth to find life here we need to move on through time hold on stop the great supercontinent is breaking up we're flying over Washington State 750 million years ago some force from deep inside the Planet itself is ripping the crust to Pieces it's as though the world is tearing apart and there's only one force powerful enough to do this heat it's escaping from the Earth's molten core stretching and weakening the [Music] crust centimeter by centimeter year by year the great supercontinent is splitting in two [Music] [Applause] [Music] [Music] the intense geological activity has spawned a massive volcanoes they're pumping carbon dioxide into the atmosphere there's smoke and gas everywhere [Music] all that carbon dioxide is mixing with water to make acid rain the Rocks absorb the acid rain including its carbon dioxide and there are a lot of rocks on Earth right now exposed when the continent tore apart so many that vast quantities of carbon dioxide are absorbed out of the atmosph spere and locked up in the Earth's rocks with little carbon dioxide in the atmosphere there's nothing to trap the sun's heat around the planet in just a few thousand years the temperature plummets to around -50° [Music] C this Frozen Wasteland is Southern Australia 650 million years ago a vast wall of ice is forming thousands of meters high the ice is Unstoppable the more ice there is the more sunlight it reflects away from the planet and the faster the ice spreads and there's a second ice sheet just as high the two sheets are heading towards each other at the equator that was close but even up here there's no escaping the ice now an ice sheet up to 3 km thick and tunes the entire planet first the planet was a molten ball of fire now it's a frozen ball of [Music] ice virtually all the Sun's light and warmth reflects back into space [Music] it seems nothing not even the sun can rescue our planet [Music] now the Earth is a vast Frozen snowball 635 million years ago ice has intuned the planet for 15 million ion years but it can't last forever something must release the Earth from this Frozen prison and when it does who knows whether life will have survived beneath the ice volcanoes have been erupting and breaking through the ice since the world began to freeze but it's but until now even their heat and power has made no impact on the ice volcanoes pump out billions of tons of carbon dioxide before the big freeze the Earth's rocks absorbed most of the CO2 but now with the Rocks smothered in ice there's nothing to absorb the gas so instead it fills the atmosphere like a blanket it traps the sun's warmth around the planet temperatures rise until now after 15 million years the ice begins to melt [Music] when the planet was frozen the ice pushed the crust down now as it melts the crust is bouncing up creating fissures in weak spots and more and more [Music] volcanoes these volcanoes are releasing more carbon dioxide and pushing the temperature up even further the Melt is gathering momentum through a series of chemical reactions the ice has created oxygen while the planet was frozen the sun's ultraviolet rays reacted with water molecules in the ice to produce a chemical rich in oxygen hydrogen peroxide the same chemical that bleaches hair now as the ice melts the hydrogen peroxide is breaking down and releasing massive amounts of [Music] oxygen after a 15 million year sleep the Earth is waking up a very different place [Music] [Music] now 600 million years ago the atmosphere is warmer it feels like a summer day and the days are about 22 hours [Music] long add all this water and it's the perfect recipe for life before the planet froze primitive bacteria had emerged in the oceans but surely they couldn't have survived an Ice Age 75 times longer than the entire span of human history if something is found a way to survive then our best chance of finding it is where we last Saw life in the ocean [Music] now 540 million years ago in an ocean full of oxygen those primitive bacteria have evolved a handful must have clung on through the big freeze now there are plants everywhere and something [Music] else it looks like some kind of armored slug they're called wiwaxia they're one of a new generation of complex multi-celled [Music] organisms The increased oxygen levels are enabling creatures to grow larger and develop bony skeletons there are worms sponges and these they're trilobites distant relatives of insects lobsters even [Music] scorpions life in the oceans is blossoming from microscopic bacteria to a monster like this this is anomalocaris it's about 60 cm [Music] long look at its large eyes its razor sharp teeth and grasping limbs [Music] all anomalo Caris has to do is take its [Music] pick the troby can't write itself its soft belly is [Music] exposed these are picaya they're just a couple of centimeters long but they've got what may be the first ever spine over millions of years this simple structure will evolve into the spine that keeps us standing [Music] up we dived into the ocean expecting to find life in ruins in instead we've entered a world full of life where trilobites scavenge and monsters prowl and creatures are beginning to take on familiar [Applause] forms if the oceans are swimming with life what's happening on land there must be unimaginable wonders strange creatures incredible PL PL just waiting to be [Music] [Applause] discovered we're looking for life on land 460 million years ago and the plates have moved [Music] again below lies a new continent gondwana it's a warm 30° C oxygen levels are close to those in which we [Music] live the land should be covered with plants crawling with [Music] creatures but there's not much here beside a few patches of algae there's only one explanation the sun it blasts the surface with deadly radiation the complex life we've seen in the ocean wouldn't stand a chance on land but 50 km up where the Rays enter the Earth's atmosphere something strange is happening when oxygen meets the sun's radiation the oxygen is turning into another kind of gas called ozone this is forming a blanket around the planet this ozone layer is absorbing the sun's lethal radiation over 120 million years it's getting thicker stopping more and more radiation from reaching the Earth's surface without the ozone layer life on land simply wouldn't exist now shielded from from radiation conditions are perfect for life to take hold on land look there those small Mossy lumps are our first land [Music] plants and they're pumping out even more oxygen levels are rocketing 375 million years ago one day scientists will make a remarkable Discovery here in what will be a remote Valley on Canada's ellere Island [Music] they will discover the fossilized remains of this strange fish called a [Music] talic its neck is mobile allowing it to raise itself up [Music] it's using its fins to support itself as if they're legs and move out of the water [Applause] over 15 million years these creatures called tetrapods evolve they grow stronger Limbs and spend more time out of the water until 360 million years ago they make the land their home it's from a creature like this that all four-legged vertebrates will evolve dinosaurs birds mammals and eventually you and [Music] me everywhere we look there are mosses and ferns some at least 30 m tall it's a seed the first we've seen until now plants reproduced using spores single- celled particles that need plenty of water to survive and [Music] grow but this seed is kilometers from water and flying even further Inland to survive this embryonic plant must have its own onboard food and water supply so unlike a Spore this SE seed can survive far from water for months even [Music] years our Tiny Seed is now a mighty treel likee plant one of a vast Forest stretching far inland The Humble seed is spreading life across the planet and all these trees and plants are pumping out even more [Music] oxygen we could stand here and take a breath we could live here right now we've come a long way from a lump of burning Rock and dust to a blue blue green ball bursting with life but humans won't walk across this landscape for another 360 million years what was that it's a dragonfly a dragonfly the size of an eagle this giant is called megura what were once legs have evolved into Wings extending the dragonfly's hunting territory over a vast area there are millipedes cockroaches spiders all sorts of bugs down there these creatures called arthropods were among the very first to set foot on land they've been around for hundreds of millions of years already they look almost identical to the bugs that invade our homes except for one big difference like meura they're monsters 360 million years ago we've stumbled into a Lost World of Giants where millipedes are 2 m long and scorpions the size of wolves all the oxygen in the atmosphere allows their respiratory systems to be more efficient freeing up space for their bodies to [Music] grow and over there a lizard-like creature called [Music] hylonomus the creatures we've seen so far laid their eggs in the water but these eggs contain all the water and nutrients the developing hylonomus needs the babies are growing in their own selfcontained Pond the egg is a major evolutionary breakthrough now animals can leave the water behind and conquer the land [Music] this baby hylonomus will lead the advance it's a new kind of creature a [Music] reptile in inevitably with life comes death there's so much dead plant matter it builds up and decays into dense soggy layers over hundreds of millions of years rocks will cover these layers heat from the Earth's core and pressure from the overlying rocks will transform the layers of dead plants into seams of coal [Applause] each lump of coal we burn today to warm our homes and fire our power stations is made of plants that died 300 million years [Music] ago amidst the Decay hidden from sight life is stirring soon seeds will germinate plants will grow and this Wasteland will live again life seems to have conquered the planet [Music] 250 million years ago a herd of creatures graze the Siberian Plains they're not dinosaurs they won't set foot on the earth for at least another 20 million years but they are big evolution has taken a huge leap forwards the small lizards we saw earlier are now giant reptiles these are scutosaurus the distant relatives of turtles they're Plante eaters and if the Plante eaters look this tough the carnivores must be seriously [Music] mean it's a gorgonopsid the largest killer on the plan planet right now we're meters away from a perfectly engineered prehistoric killing machine its saber teeth have wounded the scaur [Music] it's watching as its prey grows weak from blood loss it's backing off something strange is happening the ground is getting hot [Music] there must be enormous pressure beneath the surface [Music] there's lava but this isn't one single volcano the entire landscape is erupting a massive plume of mantle is rising up from deep inside the earth pushing molten rock out through fissures in the Earth's crust [Music] the Lush Paradise is becoming a lifeless hell [Applause] [Music] [Music] on the other side of the continent it's as if nothing happened snow but the temperature is about 20° C it's not snow it's Ash Fallout from the eruptions some 16,000 km away this ash is burning suffocating and the animals are dying 250 million years ago the largest mass extinction of all time is underway the atmosphere is full of sulfur dioxide from the eruptions as it rains the gas is turning to sulfuric acid burning everything it falls on at first it seemed like this was a local disaster now it's gone Global all that volcanic activity is pushing up carbon dioxide levels the atmosphere is getting hotter water evaporates vegetation is dying we thought life had finally found a foothold now it looks like we were [Music] wrong there's nowhere left to hide on land life is running out of [Music] options this can't be right the oceans are turning pink and the plants the trilobites the Predators everything's gone everything except for this pink algae the new new hotter atmosphere must have heated the oceans and stripped them of [Music] oxygen now nothing can survive in the stagnant water except algae the Siberian eruptions are transforming the entire planet nothing not even the deepest ocean floor is beyond their reach if the sea is heating up there could be another problem look there bubbles they're escaping from vast pockets of methane gas beneath the seabed methane is a greenhouse gas at least 20 times deadlier than carbon dioxide until now the gas has been frozen now with the sea temperature rising it's beginning to melt [Music] it's seeping up through the seabed bubbling up through the water and escaping into the [Music] atmosphere this powerful gas is pushing up temperatures even further up to 40° C 6° hotter than before the Siberian eruptions now even the creatures that have made it this far are doomed it's 500,000 years since the eruptions first began and all this time for half a million years the lava has been pouring out by now it covers an area the size of the United States with a layer of molten rock nearly 6 km deep 95% of all life has been wiped out only a handful of creatures have survived so far by burrowing underground and eating anything the mass extinction has reset the evolutionary clock 250 million years ago we're back where we started on a lifeless Planet almost it's 50 million years since virtually all life on Earth was wiped out and the planet has been transformed it's now 200 million years ago and there's just one supercontinent called Pangia stretching from pole to [Music] pole after the trauma of the mass extinction the planet is healing temperatures are stabilizing the acid rain is neutralizing and vegetation returning and with 95% of all life on Earth wiped out the field is open for a new species to emerge one that will dominate the planet like no other before or since the dinosaurs these dinosaurs are called Amur like all dinosaurs they've evolved from the handful of reptiles that survived the mass extinction at 4 and 1/2 M tall their size makes them slow and vulnerable a [Applause] Dilophosaurus two of [Applause] them they're small and fast [Applause] [Applause] theasaurus is too big a meal for one Dilophosaurus but not for [Music] two the dinosaurs have conquered the Earth but no species con tame this Restless volatile planet [Music] the Earth's crust is thinning here it's releasing lava shaking with earthquakes as though it's being stretched by some unseen force and the same thing is happening all the way down what will be North America's Eastern seaboard the Earth's plates are on the move again 190 million years ago the great supercontinent of Pangia is breaking up a vast chunk of land has broken away and formed a new ocean called the teus over what will one day be the Middle East currents are pushing nutrients up into the coastal Waters and the nutrients attract fish in their [Music] millions and with so much life comes death dead fish and planks and carpet the ocean floor over the next 10 million years layers of rock will bury and heat the dead [Music] creatures ancient fish and Plankton will become [Music] oil every lead of gas in our cars every piece of plastic on the planet the paint on our walls the carpet under our feet even the soap we wash with all originated this way [Music] 180 million years ago and further west the North American Plate is still moving away from the European and Asian plate it's happening slowly at about 2 and 1/2 CM each year the same speed as our fingernails grow but hit fast forward Ward and we can see a new ocean forming right beneath us and new continents Montreal is moving away from mares New York from West Africa the world as we know it is taking shape the chasm between the two continents fills to create a vast ocean the Atlantic and there in the middle a volcano we've seen plates move before we know it's caused by currents deep beneath the earth's crust this process is happening down there right now the entire sea floor has been torn in two and pushed up into a ridge of mountains and volcanoes it's growing higher than the Himalayas and longer than the Rockies the water's hot here molten lava is forcing its way out from deep inside the Earth [Music] as the lava cools it creates volcanic mountains and new ocean floor over millions of years this process pushes the plates and Pangia apart and rearranges our world [Music] [Music] it's this geological activity that makes the Earth Restless creative unique and every time the planet reinvents itself the things that live on it must adapt and evolve things like these their [Music] iosaur their reptile ancestors lived on land but as the planet changed so did they they grew fins and moved into the newly formed Atlantic Ocean this one is 6 M long and fast it travels at about 40 km an hour it's the ocean's fastest creature the most efficient predator and it's ruled the Earth's oceans for 50 million [Music] years but now there's a new Contender for the crown a [Music] pliosaur longer than a bus as heavy as a truck its jaws are immense eight times more powerful than a great white sharks and its teeth at least 30 cm long the earth and the creatures that live on it has changed beyond recognition this was once Solid Ground now it's the Atlantic Ocean it was on this very spot that we stood and watched amasa graze and dilophosaurs stalk their prey the dinosaurs world may be different but they're as dominant as ever they appear [Music] Invincible 65 million years ago they're one of the plan planet's most successful species they've survived volcanic eruptions earthquakes entire continent splitting in two the dinosaurs have thrived for 165 million years but nothing is Invincible it's a mammal and it's evolved from the small number of mammals that survived the mass extinction 185 million years ago it's also prey for the dinosaurs this is why most mammals live in the trees or underground and venture out at night mammals are no threat to the dinosaurs nothing can challenge their dominance nothing on Earth it's a lump of Space Rock a large [Music] one this asteroid is about 10 km [Music] across bigger than Mount [Music] [Music] Everest it's heading for the Gulf of Mexico just off the Yucatan Peninsula everything's happening so fast blink and we'd miss the impact unless we slow down time it's a split second that will change the world forever even now at the moment of impact the asteroids back Edge is still up here at nearly 11,000 M the same height as a commercial aircraft flies the asteroid strikes with such immense force it destroys everything it hits even the asteroid itself instantly vaporizes [Applause] the impact is unleashing the energy of millions of nuclear [Applause] weapons nowhere is safe not even up here some of these Boulders are as big as entire city blocks it's the blast wave racing out from the Impact Zone like Shel from an exploding bomb w [Music] minutes after impact thousands of kilometers from where the asteroid struck the Earth is under attack from every direction Boulders are raining [Music] down earthquakes shaking the ground and tsunamis battering the coasts but the onslaught has only just begun the plume of molten rock and dust is spreading out and engulfing the planet the entire sky is acting like a giant sunlamp the earth's surface is now 275° C vegetation is spontaneously igniting even months after the impact smoke and Ash are still blocking out the sun with no sunlight plants are dying and the animals that eat them are starving against this Onslaught it's hard to see how anything could survive 65 million years ago the dinosaurs have been blasted stoned and burnt alive the dinosaur's 165 milliony year reign is over but the dinosaur's demise is an opportunity for another species [Music] mammals by living underground they've avoided the Heat and the fires and by eating anything and everything they're thriving while more selective eaters are [Music] dying these are the unlikely inheritors of the dinosaur's crown [Music] and as one story ends another begins could this be our chance our time will the next chapter belong to us [Music] the dinosaurs are long dead the planet is peaceful in this new world our mammal ancestors are evolving [Music] [Music] this Lake 47 million years ago in what will one day be Germany should be the perfect place to spot [Music] [Music] them this isn't like the mammals we saw earlier its eyes and brain are bigger this is darwinius melay or AA she looks nothing like us but fossil evidence from our own time tells us these creatures could evolve into monies apes and eventually [Music] humans we're looking back through 47 million years of evolution to what may be one of our earliest known ancestors the lake sits on a volcanic crater it's beling out noxious gas now the lake that killed her will preserve her in its oxygen depleted depths one day when the water has gone and AA is fossilized in stone we her descendants will discover her and recognize in this primitive primate what could be the very beginnings of Our Own Story the story of human [Music] life we're closer to understanding how everything we've seen from Ocean bacteria through walking fish and Subterranean rodents leads to us and to understanding how our planet was [Music] made 47 million years ago and the atmosphere is much like our own the temperature is 24° cius and a day lasts just under 24 hours the Earth we're looking at now is almost identical to the planet we call home almost the Earth's plates are moving again carrying the continents on their backs this time India is moving north towards [Music] Asia the Indian and Asian plates are locked in a Titanic struggle [Music] neither plate is winning both plates are beginning to buckle what was once ocean floor is contorting upwards along a 2400 km crumple Zone a vast mountain range Rises up 1,500 M 4500 m now over 8,000 [Music] M these are the [Music] Himalayas and there it is the highest mountain of all Mount [Music] Everest its Summit reaches up into the Earth's jet stream at the same altitude as airliners fly [Music] when the snow on the Peaks melts it feeds Great Rivers the Ganges indis yansi and yellow [Music] Rivers the Himalayas are like a vast water tower one day their Rivers will supply water for almost half the world's [Music] [Music] population 20 million years ago this is our planet with every continent every ocean just as we know it except there's one thing missing us the human [Music] race for humans to evolve something somewhere down there has to [Music] change along Africa's East Coast between the plates that make up the Earth's crust a great rift is opening up 4 million years ago the rift stretches nearly 6,000 km along its Edge mountains are growing stop there it looks like an ape not a human they might stay in these trees forever but their world is changing the growing mountains must be acting like a wall of rock stopping moisture from the Indian Ocean passing over the land it's getting hotter and drier the Lush rainforest is becoming arid Savannah the new hotter climate is destroying the creatures habitat it's forcing them to to search further a field for food to stop dragging their Knuckles on the ground like apes to stand up and walk on two feet it's the most important step in the human story this mountain range along Africa's East Coast could be the reason we walk on two feet it seems incredible the random movement of two plates may have kickstarted a chain of events that will lead to the first humans [Music] a man and child it could be a scene from our own time but it's 1 and 1/2 million years ago these are an early species of human called Homo [Music] erectus and these are the first ever Footprints like our own our journey is nearly complete but our ancestors still have to make their own Journey Out of Africa [Music] the climate is changing again 70,000 years ago sea levels are falling the gap between Africa and Arabia is shrinking down to just 13 [Music] km the Red Sea is narrow enough and shallow enough for this small group to cross out of Africa there another later species of human called Homo sapiens they've made it across scientists believe every man woman and child outside of Africa is descended from these 200 or so individuals over time our ancestors multiply and spread out to India onto Asia and into [Music] Europe but while humans head north a giant wall of ice is spreading South it looks like once again our planet and the things that live live on it are about to go head to-head Europe 40,000 years ago our Homo sapiens ancestors are arriving only to find a world that's changing fast it's getting colder it should be the height of Summer but the plants are frostbitten the rivers are Frozen now natural changes in the Earth's orbit CO2 levels and the flow of warm water around the planet are conspiring to lower the Earth's temperature the earth and its inhabitants is entering an Ice Age just look at these glaciers as high as skyscrapers they're creeping over the Northern Hemisphere at 30 cm a day slow and Powerful they sculpt the landscape as they move over it gouging out great depressions the planet will never look the same again now around 20,000 years ago they're grinding to a halt much of the northern hemisphere is covered by ice sheets up to 2 and 1/2 km thick with trillions of liters of water locked up as ice sea levels have [Music] fallen 20,000 years ago a strip of land has emerged from the ocean between Siberia and Alaska it's a bridge between two vast continents a Gateway taking humans from Asia to a new world America it's the last great continent to be colonized the last great human migration and somewhere down there are the first [Music] Americans now 14,000 years ago the changes that triggered the ice age must be going into reverse as the ice Retreats it's revealing a very different northern hemisphere the glaciers gouged out huge depressions now they're filling with water to become North America's Great Lakes [Music] 6,000 years ago the ice Retreats back to the poles [Music] after a 4 and a half billion year Journey we've made it we're back home this is our world our time now for the first time we can piece together our planet's incredible story we can understand how and why everything we see around us is here today [Applause] from the skies above us to water the essential ingredient for Life the ground beneath our [Music] feet and life the spectacular result of a random chain of catastrophes and coincidences [Music] each Triumph each disaster is a step on the trail that leads to here to each and every one of us right [Music] now but Earth's story doesn't end [Music] here a lot has happened but there more to come the Earth will live for at least another 4 and2 billion years everything we've seen on our journey is only half the story just imagine what wonders what Terrors what strange creatures lie ahead for our Restless Creative Planet [Music] the next chapter of Earth's story is still to be written [Music] [Applause] [Music]