[00:21.40]What if an alien biologist from outer space visited Earth?
[00:27.03]Imagine he was looking for the most intelligent of our planet's tens of millions of species.
[00:35.31]He'd probably start with the apes.
[00:40.31]They all seem pretty smart.
[00:42.58]A chimpanzee can do most of the things a two and a half year old human child can.
[00:56.30]If he compared their DNA, our alien investigator would discover they're almost identical.
[01:14.72]Biologically, he wouldn't hesitate to classify us humans as just another kind of chimp.
[01:25.16]But if he'd stayed and watched the way humans live and behave,
[01:29.33]he'd soon have seen a huge gulf between our capabilities
[01:33.03]and those of all the other apes.
[01:37.27]He'd have seen billions and billions of us dominating the Earth.
[01:43.64]How did that happen
[01:45.85]How did we, Homo sapiens, become so different?
[02:10.70]In this programme we're going to take a five million year journey
[02:15.01]from tree living apes to modern man.
[02:20.98]We're going to meet our closest living relatives and discover how we used our hands to get ahead.
[02:35.33]Following in our ancestors' footsteps,
[02:37.70]we're going to see how we came up against some very serious design flaws.
[02:45.21]Why giving birth is so hard for us.
[02:54.21]Why for so many years we could do little more than grunt
[03:01.66]and how talking is worth risking our lives for.
[03:07.73]When we open our mouths to speak there's a chance we could choke.
[03:23.88]We'll find out how the human race almost became extinct.
[03:29.98]...and what it was that saved us
[03:42.46]And we'll be looking into the future -
[03:44.77]when by taking control of our evolution we may be able to create perfect humans.
[03:50.50]And even defy the ageing process.
[04:04.92]Both man and animal. The hairless ape.
[04:09.79]Yet we're so different from all other animals on the planet.
[04:17.03]Where did we come from?
[04:30.44]For thousands of years we turned to the supernatural for the answer.
[04:39.25]But there is another scientific explanation -
[04:42.46]that we gradually evolved into what we are now over millions of years.
[04:53.10]The big clues to our past come from chimpanzees -
[04:56.34]our closest living relatives.
[05:04.21]All these chimps have been rescued from the bush-meat trade in Cameroon.
[05:13.79]They're now looked after by Dieudonne here - who has a very special relationship with them.
[05:29.87]The more we study chimps the more we realize just how much we have in common.
[05:41.42]The evidence that shows we really are descending from a chimp
[05:46.29]like ancestor is deep within the workings of our bodies.
[05:48.62]In our genes. 99% of our genes are exactly the same as theirs.
[05:56.76]What's the story in that 1% difference that's taken us from ape to man.
[06:07.51]In the beginning it had nothing to do with brainpower.
[06:15.15]Between 4 and 5 million years ago
[06:17.65]our ancestors started to spend more time on the ground.
[06:23.29]Two very different strategies emerged.
[06:30.30]walking on their knuckles as a way of getting around.
[06:36.27]Their hands stayed thick and solid to bear their weight.
[06:45.21]We took a more radical approach, the first step in our journey was just that.
[06:54.22]We stood up - on two legs.
[07:01.39]Since then we've never looked back.
[07:24.28]But our brains weren't as big as they are today.
[07:33.76]5 million years ago they were much smaller, the same size as the chimps.
[07:47.57]So why was walking upright such a crucial step?
[07:53.78]By putting all our weight on our feet we freed up our hands to do other things.
[08:02.02]The chimps here have been playing with Dieudonne's shoelaces for years.
[08:17.27]There seems to be an element of competition.
[08:25.25]The chimps never give up.
[08:31.28]They tie themselves in knots trying to get it right.
[08:41.63]However hard they practice though they can't compete with us.
[08:49.87]As we all know learning to tie your shoelaces is more complicated than it looks -
[08:54.77]and chimps just don't have what it takes,
[08:58.45]a delicate precision grip between finger and thumb.
[09:07.42]Our thumbs are longer and more flexible than those of chimps.
[09:11.83]So our hands have become precision instruments
[09:14.33]which we can use in an extraordinary variety of ways.
[09:41.22]Our ancestors didn't acquire this new anatomy overnight
[09:44.99]it also took an important change
[09:46.59]in the climate to make this evolutionary leap away from the chimps.
[09:54.33]It was then that we parted company.
[09:57.14]The chimps stayed in the trees.
[09:59.07]While we walked out onto the newly formed African savannah.
[10:06.71]The climate change suited our ancestors very well.
[10:10.58]Over the next few million years, it got drier and drier -
[10:14.29]completely transforming the landscape from thick forest into open plains.
[10:21.09]As our ancestors used their hands more and more for holding things
[10:25.40]it led us to the next big landmark on our journey.
[10:31.20]The creation of tools.
[10:34.31]Some of the earliest have been found in caves just like this.
[10:44.42]All these tools were very simple...
[10:47.05]and also very similar.
[10:53.13]This was state of the art technology 2 and a half million years ago.
[10:58.50]It's actually a kind of Ape mans' penknife.
[11:01.80]This cutting edge almost matches that of steel.
[11:07.21]The basic design didn't change for a million years,
[11:10.64]so around 5000 generations of hominids would have handled tools just like these.
[11:18.55]It's remarkable when you think how much modern technology,
[11:22.09]like the mobile phone has moved on in just the last 10 years.
[11:26.69]Today one person could have owned all these different types of phones.
[11:32.97]But that didn't mean that the ancient tool users were standing still.
[11:37.80]Once we'd left the trees for the plains, we had a new challenge to face.
[11:42.94]We were not alone.
[11:49.22]Taking a walk on the savannah on your own is asking for trouble,
[11:53.79]and it gets more dangerous the darker it becomes.
[12:02.26]Because this is the domain of the big cats.
[12:12.34]At night baboons try to find a hiding place.
[12:15.64]They stick close together and, if they can, take refuge in a tree.
[12:20.61]But when they hear a leopard coming they still panic-
[12:23.88]because they can't see well at night.
[12:29.56]The leopard aims to terrorize the troop into breaking ranks.
[12:33.76]Once separated from the rest, a baboon's a sitting target.
[13:01.19]Imagine what it would have been like for our ancestors out here,
[13:04.49]24 hours a day, trying to keep their families safe from wild animals.
[13:11.80]This is no place for a soft, defenseless human to be out late on their own.
[13:18.34]And there's solid evidence to show we humans really were under attack.
[13:23.74]Again the clues lie deep in ancient caves.
[13:35.22]Ape man skulls have been found with holes in them
[13:38.83]that exactly match the teeth of leopard, hyena and saber toothed tiger.
[13:55.98]One cave contained the remains of over 300 baboons and 150 ape men.
[14:02.65]Between one and three million years ago
[14:04.78]our ancestors were being torn apart and...
[14:07.12]eaten by big cats.
[14:24.37]Even by day, life here is no walk in the Park.
[14:27.87]But at least baboons like us can see much better in the daylight.
[14:38.28]They live in large troops, which means many pairs of eyes to spot a threat -
[14:42.99]and more combined force to fight off a predator.
[15:00.24]Safety in numbers gives baboons surprising confidence
[15:08.15]In fact they're downright cocky!
[15:20.29]For our ancestors too,
[15:21.73]sticking together was the best way to avoid ending up as cat food.
[15:27.13]The communal life created new challenges -
[15:29.64]and forced us to really start using our brains.
[15:34.91]Living together brings a whole new element - a social life.
[15:41.28]But the bigger your group, the bigger your social problems can be.
[15:50.09]You need a bigger brain to cope.
[15:55.73]In a group, working at friendships and alliances is crucial.
[15:59.93]You need to remember who's who and what's what?
[16:11.18]You need to be a diplomat
[16:12.81]so you don't get on the wrong side of those with more powerful weapons than you.
[16:22.19]A single social gaffe could be disastrous.
[17:04.16]As we too began to live in larger groups for safety,
[17:07.50]so our brains evolved to cope.
[17:10.10]And our brains continued to get bigger - almost four times bigger -
[17:14.31]so our skulls had to get larger too.
[17:20.15]And this gave us our next challenge.
[17:23.95]Because being the 2 legged brain boxes of the savannah
[17:27.22]now gave us a problem our four-legged friends didn't have.
[17:38.87]Because they walk on all fours, they can afford to have wide hips.
[17:46.97]That makes giving birth quick and easy, important with so many predators around.
[17:59.95]Although the baby wildebeest is big,
[18:02.09]its brain and skull are quite small in relation to its body size.
[18:06.19]So it can slip out easily.
[18:23.11]But for humans, birth is where we pay the price for our big brain.
[18:30.48]If we move from the Kenyan plains to the city of Nairobi
[18:33.85]and look at the physique of modern woman we can see why.
[18:44.23]The best design for walking upright is a slender body with narrow hips.
[18:52.34]But narrow hips are the worst possible design for giving birth to big brained humans.
[18:58.51]This was perhaps the biggest stumbling block we humans faced in our whole journey of life.
[19:03.65]We were stuck!
[19:07.35]Until evolution came up with a surprising solution.
[19:15.13]Unlike almost all other mammals, our skull isn't fully formed at birth.
[19:20.47]A human baby's head is soft and pliable
[19:23.20]allowing it to pass down the narrow birth canal.
[19:36.05]Woah, that's well done.
[19:38.15]During the first 12 months of life,
[19:40.12]the bony skull plates gradually fuse together to protect the brain,
[19:44.92]in effect we're all born premature!
[19:54.17]So for the first few months, a human baby is extremely vulnerable,
[19:58.30]requiring constant care.
[20:00.37]But the pay-off - a giant brain -
[20:02.81]far outweighs the risk - another biological problem solved.
[20:12.49]So 300,000 years ago big brained man, homo sapiens arrived.
[20:22.40]We can see the evidence f our greater intelligence in the new technology
[20:26.40]that early ape-men never had.
[20:33.17]A more sophisticated tool kit.
[20:40.18]Which includes spear points
[20:42.05]as well as a variety of scrapers and cutters for butchering meat.
[21:00.07]Found alongside those tools was a simple lump of rock
[21:04.34]that would lead to the great masterpieces of the future.
[21:14.25]It's ochre - crumbly iron oxide.
[21:18.08]This piece was found in Blombos Cave,
[21:20.49]near Cape Town in South Africa and is at least 70,000 years old.
[21:27.19]What's amazing is that it's engraved.
[21:29.96]This abstract etching is the first recorded work of art.
[21:34.57]It marks the roots of what we now call culture or civilization.
[21:41.37]And this pigs jaw bone might even offer a clue to when religion first began.
[21:47.88]It was discovered in the same grave as an early human
[21:51.72]and it's dated at more than a hundred thousand years old.
[21:55.62]It's the earliest evidence of ritual burial.
[22:00.49]The act of carefully burying a body with other objects suggests that
[22:05.20]those people believed that death wasn't the end.
[22:08.73]That the spirit lived on.
[22:12.44]Art and religion set us apart from the rest of the animal kingdom
[22:16.44]and led to our great civilizations.
[22:57.32]Many scientists believe that the trigger for these extraordinary breakthroughs
[23:01.55]was something we all take for granted.
[23:07.16]This is where the main palm Sunday procession took place.
[23:10.73]From fossils scientists know that our voice box - or larynx -
[23:15.30]was much higher up in our ancestors than it is today.
[23:25.14]It's still in this position in the chimps and other apes.
[23:32.49]If this was still the same for us apart from the odd grunt
[23:36.12]or two we wouldn't have the power of speech.
[23:41.13]But around 200,000 years ago,
[23:43.36]our larynx dropped to where it is today, allowing us to make more complex sounds.
[23:51.47]This is when we started to talk.
[23:54.71]But why is talking so important to the story of the human race?
[24:03.55]You can find a clue back in West Africa.
[24:11.79]These chimps are collecting nuts to eat.
[24:28.11]They have to use a rock to crack open the shells.
[24:36.52]And they pick up these skills by copying.
[25:03.28]The young ones learn by watching their mothers closely.
[25:11.68]In Britain children also gather nuts, but not to eat, to play with.
[25:24.20]These are chestnuts or conkers.
[25:31.30]Like the chimps,
[25:32.34]the younger children learn by copying the older ones,
[25:35.34]handing down skills across the generations.
[25:46.55]The difference is, that it can take a young chimp
[25:49.09]six years to perfect its nut-cracking technique.
[26:09.14]We humans on the other hand can use a short cut.
[26:12.98]That's a nice little conker.
[26:14.35]Don't eat it though.
[26:15.38]Go and put it in the pile.
[26:20.15]We can teach even very young children simply by talking to them.
[26:25.59]- Are you opening them with your heels. - Yes
[26:28.06]Are you. Much easier to do it like that isn't it.
[26:34.30]So they can learn a new technique for opening the conkers instantly.
[26:47.95]And with language we continue to learn new tricks all our lives.
[26:55.59]By a hundred thousand years ago we were solving problems by talking together.
[27:00.76]We were using our big brains to communicate with each other as never before.
[27:08.80]But talking gave us another biological problem, and this one still hasn't been solved.
[27:15.57]Let's look at the chimps in Cameroon again.
[27:30.19]Chimps breathe mostly through their nose and hardly ever through their mouth.
[27:34.96]They use their mouths almost entirely for feeding.
[27:37.83]So air goes down one way, food another.
[27:47.21]For humans though it's a different story.
[27:54.31]Remember how as a child you were told not to talk with your mouth full?
[27:58.25]Well, there's a very good reason for this.
[28:07.63]To talk, we have to breathe through our mouths as well.
[28:11.10]So we use the same opening for talking, eating, drinking and breathing.
[28:16.80]Children sing Happy Birthday
[28:29.48]Usually this works out fine.
[28:31.75]But sometimes, things go down the wrong way.
[28:35.69]Sometimes with tragic results.
[28:41.03]Normally when we swallow, a flap of cartilage covers the windpipe -
[28:45.13]so the food goes straight down to the stomach.
[28:50.54]But with our larynx now in its lower position,
[28:52.97]just occasionally food falls in and down the windpipe -
[28:56.98]where it blocks the airway to the lungs, making us choke.
[29:08.02]Every year in Britain alone, around 200 people choke to death.
[29:14.26]Talking has been so critical to our evolution that it's even worth risking death for.
[29:30.61]At this point in our journey,
[29:32.18]it had been four million years since we'd split from the apes.
[29:36.55]What happened to us during that time?
[29:39.32]Biological evolution -
[29:40.89]that is, the physical changes to our bodies had worked some slow
[29:44.76]but crucial changes in us.
[29:47.46]First, around four to five million years ago, we stood up on two legs and walked.
[29:59.04]Then it was another three million years before we started getting clever with our hands.
[30:07.08]It wasn't until over a million years later that our brains got as big as they are today.
[30:13.52]And for all this time,
[30:14.59]our only form of conversation was probably just grunting!
[30:23.00]It wasn't until very recently along life's journey -
[30:25.80]around 200,000 years ago that our larynx began to drop.
[30:30.24]Which gave us the power of real language.
[30:33.87]Melee sync comments rugby players
[30:40.31]Now that we could talk - our cultural evolution could take off too.
[30:46.45]Cultural evolution was a brand new trend.
[30:49.25]It isn't based on genes like biological evolution -
[30:52.39]it's about the sharing of ideas.
[30:58.63]Talking allowed knowledge to be passed around quickly,
[31:02.20]it was one of the greatest revolutions in the Journey of Life
[31:05.50]that set us on the path to world dominance.
[31:11.48]But perhaps the greatest drama in the story of the human race was yet to come.
[31:16.98]75,000 years ago,
[31:19.15]when modern, talking humans were thriving here in Africa disaster struck.
[31:29.29]On the other side of the world in Sumatra a volcano called Toba erupted.
[31:57.99]It blasted vast clouds of ash and sulphur dioxide right across the planet blocking out the sun.
[32:08.40]It triggered a six-year global winter which blighted the entire world.
[32:30.42]In Africa, over 6,000 kilometers away, drought and famine followed.
[32:38.33]Millions of animals died - the animals we humans depended on for meat.
[32:47.47]Those early homo sapiens must have been decimated too.
[32:53.78]Because of one freak act of nature, our ancestors nearly became extinct.
[32:59.62]DNA evidence suggests that perhaps as few as a thousand people were left.
[33:04.42]Which could mean that all six billion of us alive on earth today
[33:08.69]are descended from those one thousand survivors in Africa.
[33:20.07]How did we survive?
[33:22.74]Scientists now believe what really may have saved us
[33:25.58]from extinction was working together -
[33:34.62]To get some idea of what life must have been like after Toba blew its top,
[33:38.99]you can go to the Kalahari desert today.
[33:41.69]It's one of the harshest places anywhere in the world.
[33:45.86]But even here there is water and food if you know where to look.
[33:55.04]The Zhuang people of northern Namibia are mainly hunter gatherers.
[34:01.68]How do they cope with living in such heat and drought?
[34:18.70]Most importantly, they never remain isolated as a single band for long.
[34:23.30]They regularly walk for two to three days across the desert
[34:26.57]to visit different family groups.
[34:42.22]It may have been months since they last saw each other.
[35:20.33]Once here, the highlight of the visit is swapping gifts.
[35:27.47]They do it not only to cement the bonds of friendship,
[35:30.34]but also to secure cooperation and the sharing of ideas.
[35:37.21]And out here,
[35:38.41]what your neighbors tell you could well save your life.
[35:45.35]They may know where the best water sources are or good fruiting trees
[35:49.75]or new hunting grounds, and of course they can tell you the gossip.
[35:57.03]Without this regular exchange of knowledge,
[35:59.16]different villages would become isolated and without outside help,
[36:03.47]even die out.
[36:06.54]It's now thought it was our ability to talk and help each other in a hostile world
[36:10.91]that saved us from extinction after Toba erupted.
[36:18.42]It's encouraging to think that the very existence of the human race
[36:22.09]owes more to cooperation, than to conflict.
[36:34.10]Gradually the world recovered and small bands of pioneering humans
[36:38.47]started to leave Africa and travel to the far corners of the earth.
[36:54.29]By now, we humans weren't just talking and sharing ideas,
[36:58.26]we were working together as never before
[37:01.09]and cultural evolution was going on all around the globe.
[37:13.64]Although telling other people what you know through speech is still vital to man today.
[37:18.61]There's only so much knowledge any individual can store in the memory.
[37:23.48]Yeah I don't know whether there's one up there.
[37:27.12]So it's not by the lecky up by that way is it?
[37:31.19]Oh yeah down there yeah.
[37:32.29]See that red building.
[37:33.46]And no one person can know everything.
[37:44.17]Excuse me mate can you tell me the way to library please.
[37:46.77]Yeah go round here,
[37:47.91]up the top of Park Street, round the triangle up...
[37:50.41]If someone dies without passing on their ideas and culture,
[37:54.58]those ideas are lost - forever.
[38:01.65]Unless of course they've been written down.
[38:07.16]The answer was for us to start preserving our ideas and knowledge -
[38:18.07]Cultural evolution could now accelerate further.
[38:30.95]Writing meant successive generations could build on what had gone before.
[38:47.17]No one could remember how to make a space rocket,
[38:50.44]but once it's written down that information is accessible to many others.
[38:58.44]For 2,500 years, we saved our precious culture in our books.
[39:06.62]But the amount of knowledge accessible through a computer
[39:09.59]adds up to all the books,
[39:11.06]in all the libraries, in all the world.
[39:17.36]In the age of the internet anyone, anywhere can tap into this vast central fund.
[39:27.64]Back in the forest reserve in Cameroon,
[39:29.87]Dieudonne can search the web and get hold of the same information
[39:33.65]as anyone at a computer anywhere else on earth.
[39:45.66]And it's fast!
[39:48.76]A picture can be sent halfway round the world in seconds.
[39:52.33]Never before have ideas spread so widely so quickly,
[39:56.13]whether for business, education or purely for pleasure.
[40:01.44]Computers are now the core of modern culture.
[40:06.38]But without writing and without this power to store knowledge -
[40:09.91]where would we be?
[40:12.85]The answer is here - still in the Stone Age.
[40:20.66]If you could use a time machine to bring a Stone Age baby
[40:24.06]forward from 35,000 years ago and educate it here in our modern world,
[40:29.77]it could do anything -
[40:31.37]become an airline pilot, doctor - even president!
[40:35.97]By the Stone Age, people were just as intelligent as us.
[40:43.01]And if a 21st century baby was sent back 35,000 years.
[40:48.09]It would be no more advanced than the people who lived then.
[40:51.56]Strip away our technology, and underneath we're all still cave men!
[40:57.60]That's because our genes haven't changed since the Stone Age -
[41:01.70]both babies would have the same genetic make-up.
[41:06.47]But, just suppose both babies were unlucky,
[41:10.07]and were born with a serious genetic disease.
[41:13.38]In the past, this baby would have died,
[41:16.45]his defective gene would not have been passed on.
[41:19.52]It was, after all, survival of the fittest.
[41:26.06]Today, though, modern medicine is so advanced that
[41:29.13]many of us can live on despite our problem genes.
[41:41.27]Whereas in the past we wouldn't have survived.
[41:47.31]And that's affecting human evolution as a whole.
[41:50.92]Now, without the force of natural selection,
[41:53.28]those problem genes will become more and more widespread.
[42:06.33]Fortunately though our most important evolutionary strong point,
[42:10.27]our big brain, may have come up with a solution.
[42:16.47]In as little as 10 years from now,
[42:18.54]we may be able to alter our children's genes before they're born.
[42:25.72]We now know which genes are involved in some five thousand illnesses.
[42:32.36]Scientists believe they'll soon be able to manipulate these genes
[42:35.99]in a fertilized embryo.
[42:45.04]So for the first time in our evolutionary history our children,
[42:48.41]and their children could be free of genetic illness and disease.
[42:57.75]And remember, cultural evolution works faster and faster.
[43:13.16]Once scientists have the power to cure these illnesses,
[43:16.30]what else may they do with that knowledge in years to come?
[43:22.14]Imagine a world where the same technology could enhance our children's looks.
[43:26.88]Could we soon be ordering up designer babies?
[43:29.55]So the first thing to think about,
[43:30.78]have you thought about what kind of skin color you'd like?
[43:32.48]Could we choose the perfect features for our child?
[43:37.09]Every detail - from skin tone
[43:40.73]Have you thought about the color of the eyes?
[43:42.89]Yes my husband and I...
[43:44.06]to eye color.
[43:45.60]Can we have blue?
[43:47.17]And have you thought about the features of the face?
[43:50.03]No more nose jobs
[43:51.27]Have you thought about the mouth, the shape of the mouth?
[43:52.77]And no more plastic surgery.
[43:54.47]Yes quite full lips I think.
[44:00.41]Yep happy with that.
[44:01.38]Yeah that's fantastic.
[44:02.45]And what about their brain power?
[44:04.18]And there she is,
[44:05.08]she looks like she's going to be a beautiful girl.
[44:06.35]Our offspring could turn out much more intelligent than us,
[44:20.03]Child geniuses could soon become the norm.
[44:24.74]The only other thing is intelligence.
[44:28.11]Our children would be academically successful at a much earlier age.
[44:37.45]And make complex modern technology look like child's play.
[44:46.52]Some scientists even predict that by 2020
[44:49.89]we'll be able to manipulate the genes that control ageing.
[44:54.37]While we age normally over our 3 score and 10 years.
[44:58.00]Our children could reach 200 years and still keep their youthful good looks.
[45:12.88]We've come a long way from the chimps.
[45:15.49]Amazing considering there's only that crucial one per cent difference in our genes.
[45:26.70]Our journey of life has certainly been a rocky ride!
[45:30.37]Until now our evolution was a Game of chance -
[45:33.47]that we survived at all is something of a miracle.
[45:41.28]No one can really know for sure how much further away from chimps we'll go.
[45:46.52]The difference is that now the choice is ours.
[46:09.17]So what might that space age biologist find if he came back to Earth in the future?
[46:18.95]If he examined apes again, he might get quite a surprise.
[46:29.66]Before, he was comparing us humans with chimps.
[46:40.87]But if he now looked at the chimps.
[46:45.28]And at the average un-modified person of today.
[46:48.91]Then at the new super homo sapiens of the future.
[46:52.85]He might well see a greater difference between me present day human and the superhuman
[46:58.92]than he previously saw between the present day human and the chimps.
[47:05.16]For the first time in the history of life we can control our own evolution.
[47:11.20]Whether we choose to or not,
[47:13.07]we now have the knowledge and power to determine our biological future.
[47:18.21]Our own Journey of Life.
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