Como nos Tornamos Humanos - Ep. 3/3 (Documentário-2009)

[Music] humans without a doubt the smartest animal on earth yet we're unmistakably tied to our AP Origins millions of years ago we were Apes living ape lives in Africa so how did we get from that to this what happened what set us on the path to humanity the questions are huge but at last there are answers more than 6 million years ago we took the first step to separate from the Apes since then there have been at least 20 types of human ancestor in our family tree some of them were on their way to being

us others were evolutionary dead ends as recently as 50,000 years ago there were probably four different kinds of humans living at the same time yet today we are a species alone why did we survive and all the others disappear new discoveries are Shining Light on the final stages of our Evolution we're finding out where where our species Homo sapiens came from the genetic record shows us that all modern humans are descended from a small population of approximately 600 breeding individuals and we are discovering how they spread through the world pushing out other ancient humans like

the Neanderthal neanderthals were very successful humans they have lived in Europe for maybe 300 400,000 years but eventually they were replaced by modern humans but why were they replaced by modern humans The Mystery of the Neanderthal disappearance is finally being solved as the secrets of their genetic code are unlocked we're discovering exactly what made them different from us and how we're unique so join us as we explore the origins of our own species find out one where the last humans standing right now on Nova [Music] imagine a world with only a tiny number of us

in it perhaps just a few thousand a recently evolved species we are completely at the mercy of the Natural Forces around us 140,000 years ago Homo sapiens teetered on the brink of Extinction new discoveries are revealing how from these humble beginnings we took over the planet eventually replacing other ancient humans who were already living there Homo erectus and the Neanderthals humans have a very intensive way of using the environment humans move into the Middle East the homorectus starts going extinct when humans move into Europe the Neanderthals go for almost 400,000 years the Neanderthals lived in

Ice Age Europe superb Hunters they had brains bigger than ours and a record of survival twice as long they were the most advanced humans on Earth until we arve and then they vanished why finally we're unearthing the answers the the remains of a 100,000 yearold child are revealing what we had that they didn't essential to figure out what are the differences between the neand and us to to figure out what is special about us was it some new physical ability or was it a new way of thinking these questions go to the heart of what

makes us human to answer them we must travel back in time to the beginning of our human story imagine the entire span of recorded human history taking us back to the Egyptian pyramids 5,000 years ago double it 10,000 years ago when plants were domesticated and agriculture begins double it again to the time when Ice Age Hunters paint stunning images on Cave walls and keep doubling six more times and we are finally entering the world of homo erectus the remarkable ancestor who pioneered what it means to be [Music] human Homo erectus appeared on the African plains

almost 2 million years ago they were the first ancestors who had B bodies like ours they were hunter gatherers and Tool makers beings who lived in social groups and cared for each other the most famous Homo erectus is the fossil called turab [Music] boy well tab boy and his ancestors they represent a threshold they represent that that point in our Evolution when we were we weren't quite fully a human but we were no longer an ape paleo artist Victor deck specializes in creating scientifically based sculptures of ancient humans from their fossil remains as he reconstructs

turab boy's head aplike features emerge heavy brow ridges a protruding lower face a skull still smaller than our own but despite these differences turab boy is definitely starting to look like a human being and behind those eyes his mind was becoming human too I suspect that complex feelings and and behaviors had their Beginnings with tabo's kind and that what it is to truly be a human had its bubblings at that point it was probably Homo erectus almost 2 million years ago who first started to leave Africa ever since Africa has been the engine of our

Evolution pumping out wave after wave ancient humans who populated Europe and Asia settling in far off places they developed in their own special Wes an early wave gave rise in Indonesia to the extraordinary Hobbit perhaps a type of dwarf Homo erectus another wave took Homo erectus all the way to China where fossil remains have been dated to over 700,000 years ago soon after another wave left Africa this time heading for Europe This was the species that would one day give rise to the Neanderthals ever since the first skull was discovered in heidleberg Germany they have

been called homo heidelbergensis but almost nothing was known about them until one extraordinary find was made at aera in Northern Spain these Rolling Hills have turned out to be an archaeological goal mine when a railway was built over a 100 years ago it cut right through the hills archaeologists later discovered this had exposed over a million years of ancient human habitation including the oldest human remains in Europe nearby on the crest of one of the hills they also found the entrance to some caves to explore them took years but it has been worth it they

have discovered a Labyrinth of Chambers and corridors reaching far inside the hills at the end of the labyrinth is one of the most inaccessible archaeological sites in the world a treasure Grove of human fossils they call the pit of [Music] Bones this is the entrance to the whole system the pit itself is very far from here it is a long way and in some places they have to crawl it's a difficult place to work today today it takes half an hour of walking crawling and scrambling in the dark to reach the 50-ft vertical shaft that

drops into the pit but it took almost 10 years for the sight to give up its secrets we started to find a small pieces of human bones difficult to recognize at the beginning because they were very fragmentary but so many tiny fragments made them think they were on to something big even without talking each other we started to think that maybe there were down there skeletons as bone after bone came out of the pit they realized they had not one but many complete skeletons we have around 30 complete skeletons half a million years old and

this is absolutely unique these are the skeletons of the ancestors called homo H highle bensis one of the earliest to populate Europe but why were so many complete skeletons collected in one place Juan Louise AR swaga believes they were put there intentionally by their kin half a million years ago the pit of Bones now deep under ground had an opening to the surface perhaps homo H highle bensis dropped the bodies into the pit in a sort of primitive [Music] burial and there is evidence it may have been ceremonial along with the bones Juan Lise found

a single artifact a hand axe made of pink quartz a mineral which must have been brought from a long way away the team called it Excalibur after King Arthur's famous sword they believe it was an offer the first symbol ever found if this is right here were beings with complex Minds capable of symbolism and belief the half a million years ago in these European populations there was planning there was Consciousness there was a human mind and uh there was also symbolic Behavior we used to think these qualities belonged only to us homo sapi that the

earliest evidence for them was in the painted caves of Southern France just 30,000 years ago but the extraordinary finds at atera may have pushed the beginnings of that mental Evolution back almost half a million years homo heidelbergensis would continue to evolve eventually becoming the species who would populate Europe the Neanderthals of all ancient humans the Neanderthals were the closest to us their brains were slightly larger than ours their short heavys set bodies helped them survive repeated ice ages they were Hunters living off the big game that roam the edges of the great ice sheets covering

Europe and Central Asia when the and fossils were first discovered Darwin had yet to publish his theory of evolution the idea that modern humans had descended from more primitive forms would generate Furious controversy this is the skull of Angus 2 it is the first nandal fossil ever found on Earth it was discovered at the end of 1829 but back then people were not happy with the idea that this could be a human being like us many claimed that the Neanderthals were just diseased misshapen humans then as evolutionary ideas took hold people wondered if they were

the missing link between us and the Apes if we go back to the the beginning of the 20th century nandor were seen as sort of apik creatures but since then hundreds of fossil fines have revealed their physical similarities to us after the the 70s uh there was a so-called Rehabilitation of the nandor so we tend to see them in in a more human way but did they think and act like us today the remains of a young boy who died 100,000 years ago are helping research penetrate the mysteries of the Neanderthal mine the M Valley

in [Music] Belgium it was caves and rock shelters here that gave up the very first Neanderthal fossils 150 years ago today they are revealing deeper secrets of the Neanderthal world [Music] for over 20 years Michel Tusa and Dominic Balon have been Excavating a cave called [Music] sadina 1 mm at a time they've been sifting through the debris that once filled the cave their painstaking work paid off I've had the chance to be present when one of my students have discovered the ne child and when we have come there and see that this piece well we

were so surprised we couldn't believe what they uncovered was the Jawbone of a young boy 100,000 years old nearby they found more fragments and teeth until they had almost a complete mouth since then they've been trying to reconstruct the life the boy from slad they know the woodlands and caves of the MS Valley were his home he probably lived here with his extended [Music] family already he would have been learning from his father the skills to become a hunter but what else can we infer about his way of life his bones are full of Clues

and new techniques are allowing scientists to decipher them Michelle is taking a piece of the jaw to one of the few places in the world where the test SE needs can be done [Music] the max plank Institute in lepic Germany is one of the world's foremost centers for human evolutionary studies here the jaw bone of the child from scladina is put through a high-powered CT scan this allows researchers to peer into the internal structure of the teeth and Bone so this is the the mandible that was scanned yesterday the scan mandible and we have built

up what we call a surface model which is basically a virtual representation of the mandible in a computer we can separate all the teeth from the bone in the specimen the features that we can explore show us how uh nandal are similar to us in in many aspects but also how they are different the teeth of children are among the most prized of all archaeological finds because only they can tell us how fast those children were growing up if we look at the pattern of eruption of the te the scladina child by Modern Standard should

be about 11 or 12 years old the second m is is almost completely erupted uh but when we look at the internal structures of the enamel and Dentin it has been shown that it's it's in fact much younger we know that this child died around 8 years old although the boy from sadina would have looked like us he probably grew up much more quickly that means he had much less time for brain development and learning but is it safe to assume the Neanderthals were less intelligent than we are the crucial evidence comes from skulls endocasts

Impressions taken from the inside of Neanderthal skull have revealed brains with many similarities to ours when we look at the neandertal endocast we find a frontal LOE that we can't really differentiate from Modern Homo sapiens the brokest caps that have to do with the motor control motor aspects of speech are thoroughly human in terms of their form so if the front of the Neanderthal brain is similar to ours what about the rest of [Music] it today scientists like Catarina havarti are trying to measure fossil skulls with new precision [Music] she uses a special instrument to

digitize the skulls and create perfect three-dimensional [Music] images we've known for a long time that nanital look different from modern humans ever since they were first discovered and described but the question then becomes what does this difference actually mean this is a digitized 3D image of our own skull with its characteristic High Dome by contrast the Neanderthal skull is low and elongated possibly indicating a different brain shape the parts of the Neanderthal brain called the parietal and temporal loaves may have been slightly smaller that small difference could have had a large impact on their mental

ability there are regions of the prial loes and the temporal loes that are very important in cognition particularly in terms of language in memory and remembering spatial locations the reduced size of those regions of Neanderthal brains might be a sign of limited thinking Powers but the boy from scad's Jawbone has more to tell us about other limitations back at the max plank Institute Mike Richards is delving even deeper into the micro structure of the bone to find out about his diet the food we eat leaves a chemical signature in our bodies these signatures are incorporated

into the protein of our bones so what we do is get the bone and we take that protein out and measure those signatures we can work backwards and say this is the food that this human ate over their lifetime he's discovering that neanderthals were almost exclusively meat eaters although there were many fruits berries and Ed roots in their environment we don't see any evidence that plant protein was at all important in their diet and it doesn't look like they had marine food at all they were hunting large herbivores like bison or reindeer and things like

that they were carnivores with a diet closer to that of a predator like a wolf than a human and they showed few signs of change no matter where they live so far we' measured the type specimen from Germany that the Neals from sadina Neals from France and Croatia over about 100,000 years and in every case in all these different environments the Neals do same thing so the bones of the boy from scladina and his people are revealing important Clues to Neanderthal Behavior they did one thing hunting large game and they just kept on doing it

for hundreds of thousands of years their technology tells a similar story Nal technology is is quick and dirty it's simple there's very few tools that nals made that one can't copy in a few seconds or even minutes although they hunted large animals they didn't have throwing Spears or arrows none of the the stone tools that the Nars made are the size and shape sufficient to be a projectile point they're all too big which suggests they're either knives or tips of trusting Spears that meant Neanderthal Hunters had to get close to their prey to kill them

which made hunting a risky business most Neanderthal male skeletons have multiple fractures Neanderthal lines were tough and they were short [Music] their skeletons tell us that very few lived beyond the age of 30 but as a species the Neanderthals were long lived they lasted for almost 400,000 years that's twice as long as we have but one day their time on Earth would come to an end by 25,000 years ago they vanish from the fossil record so what happened to find out we have to return to Africa the Great Rift Valley the stage on which so

much of human evolution has played [Music] out it was here millions of years ago that nature began its Grand experiment with creatures like Lucy who walked upright it was here just over a million years ago that turab boy and his kind with their bigger brains and bodies formed the first hunter gatherer society and it was here about 200,000 years ago that the skulls of a new species start to be found the last human to evolve Homo sapiens they are still not completely us their brow ridges are a little heavier their faces a little bigger and

their technology is still simple you have stone tools made by nals and stone tools made by Homo sapiens and they're identical you can't tell which one made the stone tools cuz they're making the same kinds of tools so what changed what made us into the versatile beings we are today all the evidence points to climate appe we enter one of the longest coldest glacial stages on record around 200,000 years ago vast ice sheets descend in Africa Mega droughts turn much of the continent into a desert and so basically you've got this double whammy of climatic

challenges slamming the African population and the people dwindle geneticist Spencer Wells believes that ancient population crashes have left a footprint in our genes it's called the bottleneck effect humans although on the surface we seem to be so different from each other actually have remarkably little genetic diversity were 99.9% identical you look at other Apes like chimps or G gorillas or ruttin they have between four and 10 times as much diversity at the DNA level the lack of diversity in human DNA is a clue to a crisis that may have wiped out whole populations reason that

we have so little diversity at the genetic level is because we lost it at some point imagine that this bottle of jelly beans is the initial population you've got so much diversity in here what happens during a bottleneck when you go through the bottleneck only a few of the lineages survive so that's the drop in population size right there everyone alive today is a descendant of these individuals and you can see that we're missing many of the colors that you see in the initial population that's how a bottleneck works and everybody alive today is a

descendant of that small number of individuals who made it through the bottleneck ancient climate data shows that around 140,000 years ago most of tropical Africa became uninhabitable our ancestors were forced to seek refuge on coasts and Highlands it looks like four to six potential locations in Africa that would still be supportive of Hunter gather populations despite the refuges there is evidence our our ancestors were pushed to the brink of Extinction the genetic record shows us that all modern humans are descended from a small population of approximately 600 breeding individuals there's disagreement about the numbers and

timing but it does seem that all people on Earth are descended from a very small original population in Africa Curtis Marian believes they live on the south African Coastal and that it was life by the sea that forced them to [Music] change at Pinnacle Point South Africa he has found caves used by early Homo sapiens ancestors during the mega drought period they're full of clues that hint at new ways of thinking and behaving here he has found some of the earliest evidence that humans were living off the sea this darkish material here is is ash

from a fireplace and the vast majority of this material is is burnt shell so clearly there was quite a bit of uh of cooking of shellfish that was taking place at this this exact spot 76,000 years ago somebody had a a nice shellfish dinner there he here was a population that was broadening its diet away from meat requiring Ingenuity unknown among earlier ancestors you go out to collect shellfish at the wrong time you're dead you have to be able to time your access to the coastline so that you are here when the tides are right

to collect those shellfish the best time to collect shellfish is at extreme low time and to predict those it helps to understand the cycles of the Moon those are the times that you want to be collecting shellfish all the shellfish are exposed so this water which you see here is out there at that point where that rock is so the smart Coastal Hunter gather knows how to use the moon to signal to them when to come to the coastline to collect the shellfish the people of Pinnacle Point were not just harvesting shellfish they were also

hunting on the planes behind the coast and Gathering berries and Roots their way of life reflected a new versatility the systematic use of coastal resources does suggest a a cognitive complexity our ancestors occupied these caves for over 100 40,000 years leaving behind an amazing record of their transformation this site documents a change in the way that people made stone tools at the bottom of the sequence they made stone tools with this rough Quartzsite material and then right at about 71,000 years ago which occurs just about there in the sequence they make a shift to making

stone tools on this silr in the form of long thin blades before flaking it the people here were heating this material in the fire and through heating it improved its fakability and that was at about 71,000 years ago about 40,000 years older than that has been found anywhere else in the world the technology of our ancestors was expanding from the single allpurpose hand ax to a variety of lighter specialized tools then they started to make these kinds of things they made tools with special little points for Perforating tasks like this they made others with special

little chisel ends for carving tasks specialized tools allowed our ancestors to get more out of their environment but this wasn't the only change at this point we begin to see people treating stone tools as symbols they're making them more complex than they need to be to accomplish a particular cutting task so at this point stone tools are no longer just tools for cutting things they're instruments of of carrying social information about their owners a new type of symbolic Consciousness was emerging the first evidence of decorative art made from a naturally occurring mineral called red ochre

has been found at blombos another cave along the South African Coast while we were Excavating more or less in this area you can see over here we found a chunk of ochre and when we brushed up the surface of the ochre uh we realized that there was actually a design on the one side and once we looked at it in more detail held it up to the light uh we could see a cross-hatch pattern that had lines zigzagged across the surface of this flat ground surface um and also had lines across the top through the

middle and along the bottom and you can imagine there was enormous excitement because we did not expect to find um something that might represent a symbolic image uh in these 75,000 level so uh this really was an enormous an enormous surprise forness at blombos they've also found shells with holes drilled in them believed to have been used for necklaces so our ancestors were now wearing ornaments and probably painting their bodies as well for me what is really important is here for the first time really ever we have evidence that people can store information outside of

the human brain [Music] it is the birth of a new type of human culture more complex but easier to pass on from generation to generation 60,000 years ago our ancestors emerged with new technology and new culture thousands of years of drought had forced them to change they were ready to explore the world as the climate improved they started to stream Out of [Music] Africa they might have been surprised to discover continents already populated by other humans remnants of earlier more primitive migrations as they moved into Asia they might have come across Homo erectus or the

tiny Hobbit there's no evidence for such a meeting but there is one encounter we can be more certain about as a separate waves slowly move through the Middle East into Europe they must have met the Neanderthals what were those meetings like for many years scientists speculated that early Homo sapiens populations absorbed the Neanderthals through interbreeding if they did there would be traces of Neanderthal DNA in our genes today but there was no way to detect Neanderthal DNA until researchers at the max plank Institute set out on a daring scientific Odyssey the quest to sequence the

Neanderthal genome the human genome contains approximately 3 billion chemical bases the A's T's C's and G's that make up our gen mapping that was hard [Music] enough the idea of mapping the Genome of a long extinct species seemed seemed Pure Fantasy but that didn't stop Santi Pabo from dreaming about it the first problem was to get DNA from Neanderthal bones over 30,000 years old in most cases DNA degrades steadily over time leaving only minute fragments my group is involved since over 20 years now in developing techniques to retrieve ancient DNA from fossils and old bones

and of course always a dream was to do the neandertal our closest relative but finally taking great care not to contaminate it with their own they isolated the first piece of Neanderthal DNA spon's dream is now a reality he and his team have made a draft of the entire neand Thal genome now scientists all over the world can compare key parts of it to the human genome and one such comparison is already giving us deeper insight into the Neanderthal brain the gene called Fox P2 it's the only Gene we know of today that's involved in

speech and language development in humans we know that because if one copy is lost in a human due to a mutation who have a severe speech problem when first discovered Fox P2 created a lot of excitement although many animals have the fox P2 Gene the human version is unique some thought it was the gene for language we now know that complex traits like language are controlled by many gen yet researchers are agree the human version of fox P2 is closely tied to some of the basic motor skills necessary for speech and the big question was

of course is that shared with neander TOS or not and when we now look at it in the neander tall indeed it looks to be identical with us it's tantalizing evidence that despite their mental limitations the boy from scladina and his people may have been able to speak if we share the capacity for language with the Neanderthals could we both have inherited it from the same Source a common ancestor who gave rise to both species who was it with a technique called the molecular clock scientists can now find out that's because DNA mutated Ates or

changes at a surprisingly regular rate by counting the differences in the genetic code of Neanderthal and ourselves simply comparing the A's T's C's and G's in our DNA scientists can calculate how long the two species have been diverging we can then estimate when there was a common ancestral population where some individuals went on to become modern humans some went on to become the under tals is in the order of say 300,000 400,000 years ago the timing points straight to the Intriguing ancestors who left Africa half a million years ago and buried their dead in the

hills of Northern Spain leaving a distinctive pink hand ax at the spot [Music] this is homo heidle bensis who we now know is our ancestor [Music] too in Europe they evolved into the Neanderthal in Africa groups that had not yet migrated evolved into Homo sapiens so DNA is revealing we share a common ancestor with the Neanderthals but do we carry some vestage of Neanderthal DNA in our genes proof that we absorb them by Inner breeding some people claim that there are some hybrids of neand and modern humans in the in the genetical record we don't

see clear evidence of that the big story is that they were nandor they were replaced by other people and and and after a rather short time we don't see any trace of the in Europe and certainly today we don't see really traces of neand genes with no evidence of inner breeding it now seems more likely that as our population grew we simply pushed the Neanderthals out of their environments humans have a very intensive way of using the environment we seem to have the ability to pump out lots of babies and our babies seem to have

a high probability of surviving so population growth is a really important part of the of the human adaptation the arrival of homo sapiens was not the only thing the Neanderthals had to contend with Europe was gripped by wild climate swings the Neanderthals were already struggling to survive probably the density of Neanderthals in the in the landscape uh was very low and there was a good reason for that Neanderthal technology was limited and their energy needs were huge they had this big body this big brain living in a rather cold environment so we we have estimates

of their uh energy consumption every day it's about 5,000 kilo calories it's about what what someone racing the tour def France is spending every [Music] day but with Slimmer taller IES modern humans had lower energy demands and an Ever improving toolkit they now developed yet another breakthrough technology projectile weapons throwing Spears these are two very different kinds of Spears these are the big heavy wooden Spears that deander TS and their ancestors used these are the lighter bone tip Spears that homo sapiens used these weapons have different kind of per performance characteristics the the heavy Spears

are effective but they're effective at a very short range and they're heavy you can only carry so many of them in one hand the bone tip Spears are lighter they're more durable they have a longer effective range in essence the the bone tip Spears that our ancestors use allow them to hunt a wider range of animals more safely and therefore to have a broader ecological niche these big heavy spe Spears with their you know their weight their relatively short range it's like hunting with a pistol whereas using these things is like hunting with a semi-automatic

rifle one has more than one shot one has greater range it's a more effective weapon throwing Spears allowed our ancestors to go after a wider range of game with less risk to themselves the modern humans have this trend of intensifying their exploitation of the environment to sort of squeezing out everything possible from the environment that Trend already established in Africa would become more pronounced as our ancestors spread around the world archaeologists have been able to track their movements by the extinctions of large animals in Europe and Asia the arrival of homo sapiens coincides with the

disappearing of the hairy Mammoth the Cav Line and other large mammal in Australia most animals weighing over 100 lb vanish within a few thousand years of our arrival the effects of homo sapiens on large animal communities become more profound As you move further and further from Africa so very few major extinctions in Africa a few of them few extinctions associated with Homo sapiens moving into Eurasia and then when they hit when they hit Australia in the new world it's a wipe out the Neanderthals were just one of many species that disappeared when we arrived gradually

they were pushed into marginal areas of Europe their last Refuge seems to have been the Rock of Gibralter 28,000 years ago then they vanished leaving no Legacy but their fossilized bones for the first time there was only one type of human on the planet but these species it covered the whole planet it went to places where other hominines lived LED them to Extinction actually they went to Australia they went to Americas they went to the moon and they will go to Mars and and this is very peculiar because the way these species intensify its exploitation

of the environment is really unique in the beginning climate upheavals made us what we are they taught us a new inventiveness which has led to a Cascade of technological advances but exactly what made us different is still an enigma soon we'll discover the genetic changes unique to our species but genes are only part of what makes us special the other part is that mysterious creation unique to humans culture Homo sapiens is the most adaptable species in the human career meaning that no matter what happens in the world we have a way of adapting to it

today that way is called culture if glaciers came to Arizona where I live we wouldn't be growing thick fur and thick skin we would be building more fireplaces and heating systems culture is the storehouse of our complex ways of thinking and perceiving and we pass it on to our children as surely as we pass on our genes the ways in which cultural Evolution and genetic Evolution interact will be at the Forefront of the research search of tomorrow because one thing is for sure evolution is not stopping rate of evolution and the genomic level has increased

over the last 10,000 years and it probably will continue over the next few thousand years where it will take us nobody knows but we're still a young species there is a long future ah [Applause] [Music] this Nova program is available on DVD and Blu-ray at shoppbs.org or call 1800 playay PBS see [Music] [Music]