The First Human Ancestor To Stand On Two Legs | First Human | Timeline

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The First Human Ancestor To Stand On Two Legs | First Human | Timeline

the roots of the human race are shrouded in mystery lost in the depths of prehistoric time for although every school kid knows that we evolved from the AIDS the reality is that almost nothing is known about our earliest beginnings but in October of the year 2000 here in a remote corner of Kenya an extraordinary finding was made it was an instantaneous fantasy it was really the few seconds that followed we knew this is it this is going to change things this could be the oldest human ancestor ever discovered we know very little about this time period so no matter what it is very excited we may at last I found the animal and set us on a path to humanity it’s the only way we’re going to piece together our ancestry and understand where we came and this may be the eighth but learned to walk it is February 2001 and the news conference is called to announce an amazing discovery British French and Kenyan scientists have found what they claim is an ancient human ancestor an animal that may come from the mysterious point in our evolution when we descended from the trees if they are right then the implications are enormous nothing like this has ever been seen before Martin Pickford british-born geologists and paleontologists has been searching for fossils for over 30 years for him discovering what may be an early human ancestors the finds of our lifetimes being a scientist and I try and be a good scientist it’s an ongoing thing to make a really big breakthrough obviously doesn’t happen that frequently and when it does happen it’s it’s quite exciting resist sin Lou is a specialist in fossil morphology or the study of the shape of ancient skeletons she and Martin are based here at the French National Museum of Natural History one of the oldest museums of its type in the world by finding such significant bones they are on the brink of our revolutionary and controversial new theory of how we came to be it’s not an easy position but don’t forget that science don’t proceed or don’t get better with established IDs not just challenged the story starts some six months earlier here in the Chilean hills a remote rugged area of northeastern Kenya a part of Africa it’s often called the cradle of humanity Keep Calm Qi boy an experienced fossil hunter made an incredible fight now with a polo polo Hungarian am made able to I was slowly watching along the ground actually this ground was Wonder Stream yoga so as I looked closer I saw something that struck me nelly Borna a kangaroo a ma papa when I looked more closely and even turned it over I could see they were human teeth when I saw that my whole body was filled with excitement if I had jumped for joy I would have in the sky these fossilized teeth that looks strangely human at the start of something truly extraordinary kicked Elin was working for the community museums of Kenya an organization that has close ties with the French Museum Martin Pickford and Brigitte sanu traveled as quickly as they could from another dig in Uganda almost as soon as they arrived they were to make discoveries of their own discoveries

that would be more and more intriguing when I found it all you could see was the head like that the erosion had removed the sediment from around it and I picked it up and actually this bit stayed in the ground only the head came up but I could see this break here you see the crack so I dug carefully and I found this bit and then this bit was attached and then there was a third bit and then this unfortunately was missing at the lower end of the seam I was missing and that would have been beautiful to have that but unfortunately it’s not then we dug all this trench to looking for the rest of it but never got it what Martin had found was a femur or thighbone this to appear to be uncannily human might this be a hominid an early form of man there was still more to come Brigitte made another breakthrough when she found an upper arm bone or humerus I was working here English in the in the sand was lunch time we’re going back to the camp and sticking out of this area was a little piece of bone like that and I picked it up and it was obvious to me from the north where it was piece of the humerus and it took me about a week to stick all the pieces together within two weeks the count stood at 13 fossil fragments from five different individuals of a creature new to science what was really important was that they appeared to be far older than any comparable finder so old in fact that they could describe the very genesis of the human race the very roots of the family of man it stretches human history way back and we’re seeing the opening chapters of human origins here because the discovery was made in the year 2000 the press dubbed the find the Millennium man but its real name was hafta wait until later it’s now being christened scientifically as or arene to Gannon C’s owner in is a tuggin word for the original man and they have a legend in their mythology about the original inhabitant of this region and he’s called or arene so this name suggested to us by the local people and we thought it was quite a peasant name was Aurora in French is dawn and that was fairly appropriate unfortunately Aurora in Italian means hora which is it is not so good but on Orion is now the official scientific name for this species or the genus and then order into the menses for the species but were they jumping the gun was it really as old as we thought fossils are made when minerals replace organic matter taking on its shape literally turning the bone into stone carbon dating this material is impossible so how can they be sure of their age we can’t actually date the fossils directly themselves so what we can do is date the strata in which they occur and then extrapolate that date to the fossil the geology of this region helps the area is known as the Latino formation an ancient lake basin formed by a giant lava flow that poured from one of the massive volcanoes that are dotted around this part of Eastern Africa that lava flow is huge it extends for 50 or 60 kilometers north south and about 60 70 kilometers east west and it formed the floor of this Lake Basin where these sediments the look and information accumulated this lava is called track height above which the sediments were formed then a second flow of another lava battled created the icing on this geological layer cake the lavas can be dated so anything found in the middle such as Oran must come from a well-defined slice of prehistoric time so we’re it basically in a kind of sandwich with track at dated at six point two million years below and these basalt lavas at five point six five covering the sediment six million years even if only a rough date is an extraordinary age for hominids to understand why if a single modern human and place a parent behind them and then appear and behind that and so on and

only then does the true scale of the evolutionary process start to become clear generation after generation stretch into the past forming a queue of spectacular proportions the first of our kind and modern Homo sapiens are 100,000 years old and would be five thousand generations or about three miles down this line earlier species such as Homo habilis the first of our ancestors to use tools a much older at two million years or nearly sixty miles away but as we get further and further back in time the picture starts to become obscured and until recently the last known outpost was an animal that lived between three and four million years ago or a hundred and twenty miles into the past it goes by the tongue-twisting title of Australopithecus afarensis when the skeleton of this animal was first discovered it was given a rather more catchy name Lucy the man who found her was Don Johanson here was a specimen that opened up for for all of us but especially me an exceptional opportunity an opportunity to describe a new species of human ancestor not only was it an Associated skeleton bits of arms associated with bits of legs of pelvis part of the ribcage part of the skull a complete lower jaw but it was more than three million years old at the time Lucy was both a revelation and a sensation and to this day she is perhaps the most famous single skeleton in the world she has continued to play a very pivotal role in the profession as a benchmark by which other discoveries are judged but Lucy is a mere juvenile compared with the claims being made for Oran for if it is 6 million years old it would at last give us a glimpse into her most distant past this is a period of time from which we have three or four fossils that you could fit into the palm of your hand and anything that would be found in this time period of five six million years has to be important with so much at stake it’s crucial to refine the date of the find to do this the team have invited a group of scientists from the University of Chaumont in Japan to try to get a more precise figure for the sediments in which orang had laid for so long there are several methods one of which uses the way the Earth’s magnetic field changes over time first we measure the precise orientation of a sample using an extremely accurate compass it is then carefully marked before being taken away for analysis inside this rock tiny magnetic crystals form and as they do so they all point in the same direction and just the same way as the compass being used to mark them however every few hundred thousand years the Earth’s magnetic poles switch places South becomes north and north becomes south and this causes the crystals in the next layer of stone to form in the opposite direction over the millennia a unique magnetic fingerprint is left behind and this enables the rock to be dating the results will take some time but first there is one disturbing possibility I actually had nightmares for the next about two weeks thinking you know are these things really as old as six million years there has been history of discoveries in Kenya in particular but elsewhere in the world where the discoverers claimed they were very ancient and they turned out to be much younger because the site is a dried-up water course it could be that the bones have been simply washed therefore much younger rocks this would

treat the whole find in jeopardy the specter of displaced bones is one which haunts all fossil hunters but there is a way to be almost certain that the fossils do come from the sediments in which they were found that is to look at the huge variety of other creatures that accompanied millennium man’s remains in the Lucania formation where we found or in we also found other mammals such as elephants horses hippopotamus things and so on and by the evolutionary stage of those creatures those fossils we can also guess the age and as soon as we found ordering we looked around and found other fossils and we could say straightaway yeah this is late miocene in age so it’s got to be round about six million years the fossilized remains of these animals ancestors have already been accurately dated at other signs and by finding their remains here the indications for millenium man are good in addition all the fossils are encrusted with a coating that derives from freshwater algae so they are clearly from the same site but confirmation comes with the results from Japan millennium man is between 5.8 and 6.1 million years old this find has the potential to change much of what is known about how we came to exist you’re seeing a picture which nobody ever saw before previously the oldest known hominid was about 4.2 now we’re at 6 million I think most people who are not involved in the search for discovering these important fragments of our ancestry the thing that they don’t understand is how difficult it is how extraordinarily how remarkably difficult it is it makes looking for a needle in a haystack easy but when it pays off it has extraordinary consequences so what was this mysterious creature like and more importantly can we be certain that it really was our ancestor are we looking at an ape really literally an ape that stood up oran is so old that it poses a huge challenge for the scientists that found it because evolution on this scale is a staggeringly complex process Darwin’s theory is not about individuals but populations millions of individuals evolving over time the population split to form new species and be split again and again so putting anyone find in its correct place and this convoluted tree would seem impossible we’re really dealing with an infinitesimally small and we hope representatives part of the fossil record and trying to draw out details about human evolution from those few remains but are we talking about human evolution how can we tell given this incredibly complex picture the millenium man is related to us at all the further back we go the more difficult it becomes but there is one remarkable ability that modern humans possess a feature that distinguishes us from all other primates something so profound that it might show up even in our earliest ancestors we walk on two feet we are bipedal Brian Richmond is an expert in bipedalism in the university of illinois walking on two legs is a thing that defines the human family tree not the things we might think of like the ability to speak the ability to create art abstract thinking in the early fossil record we don’t see evidence of those things but we do see evidence that they’re walking upright so what we look for in the earliest human origins is evidence of this upright walking if Oren Walt’s bipedal II it is almost certainly our earliest ancestor

but because it’s six million years old that would also mean that bipedalism itself is far older than had ever been realized making the claim that any animal this age was walking upright is an incredibly important conclusion for paleoanthropology it’s a very important issue so we would like to have the entire skeleton or at least a good portion of the lower limb to be able to make this conclusion unfortunately for the Orang remains don’t have the knee joint the lack of this vital joint is a problem because the knee is the easiest way to tell if an animal walked on two legs or four because humans walk upright our knees are specially adapted to give us a smooth and efficient stride Apes on the other hand have their knees far apart and this difference between the two shows up in the shape of the bones if you’re imagining him standing there like I am now you’ve got your body weight coming down onto your hips it’s going down into your thigh bones which are angled into the knee bone the knee joint and then straight down to the floor and this is important because it makes for smooth walking rather than walking like a chimp with a lot of lateral movement human can walk with almost no movement in his hips so you’ve got the whole of your body weight coming down through two joints into the knees and straight down and for that to happen the sideburns have to be angled in humans this angle shows up when the knee joint is placed on a flat surface if the bone leans outwards as with this human bone the animal is certain to have walked on two feet of course this crucial test cannot be applied to Oren but there might be some clues in the bones they do possess the bone is very much a living tissue it’s very dynamic so in a bone there’s a little bit of a history of the activity of what happened in that animal and that’s what we’d like to get at in eventually is to look inside these bones for clues as to how these bones were loaded when the animals alive a tiny detail on the surface of the thigh bone may give a glimmer of hope this is a female of all rain and raise one picture which has been linked with by Buddhism if this groove here very well marked for one of the ligaments of one of the muscles which helps to keep the leg towards bring the legs towards the body this muscle runs from the back of the thigh bone connects to the front of the pelvis and a four-legged animal it has a straight path but in a biped the joint is extended so that the muscle becomes stretched and is wrapped around the neck of the femur forming a groove in the bone if that groove is present as it is in Aurora there is a suggestion there that the hip acted in a way very similar to our own meaning that this creature was bipedal but it can occur from time to time in other primates it’s seen sometimes in gorillas it seems sometimes in even new world monkeys so that there’s an indication there that this was a biped and we’re going to have to wait until more distinctive or diagnostic Anatomy is discovered finding just such a piece of diagnostic anatomy is extremely difficult but thanks to the extraordinary detail preserved in the six million year old fossils there is a way to discover the Millennium Mann was indeed our ancestor the secret is hidden in the neck of this one femur since we bear our weight on the hip joint that weight causes the neck to bend down creating stress on the top in the bottom of the neck but there’s also a muscle that pulls on this bone right here and that reduces the stress at the top but adds more stress at the bottom in a bipedal animal the underside of the neck becomes thicker to support the extra weight and this hidden feature can provide the conclusive evidence needed by the team so if a roarin has thick bone on the bottom and thin bone on the top and they would provide really good evidence that this thing walked on two legs that inside of the bone and that pattern tells us what the animal was

actually doing with its limbs while it was alive now we can’t see that with the fossil itself we’ll have to see x-rays or CT scans of the inside of the neck to be able to tell as part of the investigation the fossils are brought to a hospital in Toulouse and France here a CT or computer tomography scanner a device normally used diagnose illness will produce a three-dimensional x-ray image that shows their hidden structure these are consecutive slices through the top of the fossilized femur first they show the ball one which appears as a circle and then as we descend into the neck the amazing level of detail in this ancient thigh bone becomes a part every hole every ridge is there just as it was in the living creature the computer bill is a three-dimensional model of the finder which can then be sectioned to reveal the thickness of the bone and the crucial area the neck that took such a large load as the animal moves here at last is the vital evidence thicker bone on the underside of the neck there to support the weight on early humans as it worked on two feet or earnest is something apart from the eight walking running standing was a major part of the repertoire of this animal or this creature and it shows in the bones it was adapted for that kind of behavior and it shows that athletic adaptation in its bones it is likely them that or around two commences was a creature that is ancestral to each and every one the sixth film of modern humans on the planet today say hello to your grandparent with the discovery of millennium man scientists from the French National Museum of Natural History can at last get a glimpse of the species from which we are all likely to have to send it it’s about the size of a chimp modern chimpanzee but its legs were probably longer than the chimps legs if you see one walking around or in this environment you wouldn’t have said are there’s a man or a woman if there’s something a little bit like a human not really like a modern one piecing together an entire animal from just a few fragments of bone is an enormous challenge but the teeth are an excellent starting point Gary Schwartz is a specialist in ancient teeth at the George Washington University in the USA one of the really interesting things about teeth is that they are the only part of a skeletal system that comes into contact with the outside world on a daily basis now what’s interesting about the Aurora is the back teeth tend to have features that seem to resemble the modern human condition while the front teeth tend to have features which resemble modern chimpanzees in a six million year old animal scientists would expect all the teeth to be eight like and yet millennium man’s back teeth seem to be surprisingly similar to our own they are small like ours and the cat scan shows that they have thick enamel the tooth tough outer coating again just like us the shape of teeth tells you a lot about the food that that particular animal is eating an animal that eats mostly leaves tends to have teeth that are very sharp and crusted and those sharp crests tend to slice through the tough leafy material on the other hand animals that eat lots of tough hard nuts and seeds have low flat teeth which are used to pulverize and and crush those seeds millennium man’s teeth are of these low pulverizing type and so like us it was probably an omnivore eating whatever it

could find as it foraged for food nuts berries fruits and insects or probably the main ingredients of its diet given its similarity to humans it might also have eaten meat but what of its other behavior these discoveries of a roarin are are very fresh they’re very recent we don’t know much about the the broader picture in terms of how they lived and how they made their their living but I suspect they weren’t solitary creatures I suspect that they lived in some sort of a group probably in multi-male multi-female groups the evidence that they lived in mixed sex groups comes from the study of our modern cousins virtually every living primate displays a similar sort of social behavior and researchers are only just beginning to understand the complex societies formed by the higher Apes since it is so widespread there is no reason to suggest that this is a recent development and so orang was almost certainly a social beast even never had yet to develop in other ways this is certainly a long long time before the manufacture of stone tools which don’t really appear in the archaeological record till about 2.5 million years ago so these these are pre stone tool makers by a longshot and what is I think most important is is the evidence that comes from the associated animal fossils of a huge number of other fossils found near Oran most were of animals that live in forests Kolob ein monkeys and small deer seem to be particularly common and there was certainly plenty of water around – it’s the same old story you’ve got lots of impala and quite a little colobus monkeys so now you’ve got the referral he prefers rather well as hippos in this croc study and snails is freshwater snails here yeah but I think Western what because that I forget to cut expenses because back this paints a picture of an environment where trees played a major role and once again Oren’s remains can help us work out how it lived this humerus or arm bone shows that millenium man is a good climber the large flare at its lure in providing the attachment for the powerful arm muscles that a tree dwelling animal needs finger bone is curved feature that all modern Apes share because permanently curved hands are good for holding on the branches I suspect it might not have been unreasonable to think that they may have made nests and slept in the trees chimpanzees certainly do that and being off the ground would have added an additional element of safety Lauren would definitely have been on the lookout for predators because we have the evidence that sometimes the Predators want these shallow depressions of tooth marks probably from an ancient species of big cats it looks as the orange I’ll pray to some carnival on a reasonably regular basis we found the finger bones of a large carnivore which they’re slightly lighter than any fan one of the teeth one of the pecan SEO sickness which is the razor-like tooth that is used for searing the flesh the carnival like a leopard would fit the bill because it’s not only preying on ground animals like impalas but it’s also getting colobus monkeys from the trees and maybe are in from the freezer from the ground then bringing into a central place maybe to its favorite tree where it stores its prey UPS hanging hanging the prey up in the tree and that’s why there’s such a concentration now by gathering its prey to one particular place an ancient predator unwittingly provided us not only with the evidence

of our earliest known ancestor but also the answers to some of the toughest questions in all of evolutionary science high and wide and West that we descend from the trees the way in which we move our bodies standing and running on two feet has been one of our defining features since we descended from the tree but in fact by people ism is one of the most puzzling aspects of the human race by people ism is a very rare thing to see in mammals even in animals as a whole we know birds walk on two legs but there’s a very compelling reason they have wings and their upper limbs that are so specialized that they can’t use those limbs for weight support so they walk on two legs if humans had wings then we would either have the answer right there but we don’t so there must be some other very compelling reasons for humans to have begun walking on two legs the discovery of our antagonist or millennium man proves that this peculiar trait is almost twice as ancient as had been thought not only is it very rare it’s also very very old what advantage could this strange stance give an animal so that six million years later his descendants would still be moving in the same way one answer to this difficult problem uses a high technology field of research mark rebirth is an expert in robotics and his work gives him a unique insight into what might have caused millennium man to use to peace rather than for we’re very interested in the relationship between the robots we build and hand biology how people and animals work when they locomote and the relationship between those has two parts there’s what looking at the knowledge about animals tells us when we’re trying to design robots but there’s also an opportunity to use what we learn about building robots to help in understanding how people and animals work developed at the Massachusetts Institute of Technology in the USA Marc built some of the most extraordinary striving robots ever seen and what a variety of layouts some were bipedal while others were quadrupeds and this innovative technology hints at what may have driven evolution millions of years ago one of the things we found out is that it was much easier to build a robot with fewer legs than with more motion so a biped was much easier to develop and to make work than a quadruped n largely because the complexity of coordinating the legs was reduced the mechanical complexity was reduced by not having all the additional mechanisms and actuators a two-legged animals such as Oren has some clear advantages over a four-legged one with fewer limbs to control it can transport itself successfully yet use less of its body to achieve the task it also uses its natural instability to its advantage it’s highly maneuverable and extremely agile on top of this of course the animal is able to use its hands at all times it’s probably a combination of all these advantages that allowed millennium man to survive and pass his unique adaptation down to us but bipedalism brings a new set of problems an exceptional sense of balance becomes vital in order to achieve that you have to have a control system that can maintain its balance when just two feet are on the ground or one foot is on the ground and when it’s running when no feet are on the ground and so that’s a

big challenge so how did our ancestors learn to balance stand up what could have caused their bodies to change shape so dramatically that they could take advantage of the upright stance the conventional explanation centers on a huge environmental change that took place here in Africa deep in the past ten million years ago Equatorial Africa was covered with thick forests but then the land in the east began to rise due to tectonic activity in the Earth’s crust as the lands became higher rainfall in the region was reduced and the forests began to diet eventually becoming open savanna the old idea was the upright-walking must have appeared after the Savannah was formed a theory enshrined in perhaps the most famous image in the whole of science the ascent of man but now thanks to the discovery of orrorin we have the first direct evidence that this picture may be wrong the sort of classic image of a quadrupedal ape-like creature such as a chimp for example gradually becoming upright going through all the stages of torturing and hurry up to become fully upright I think that has to be thrown in the wastebasket I may be wrong but I I really think that that idea should be removed from the list of hypotheses about hominid origins orang doesn’t fit the old theory the fossil animals found with it so that far from being a creature of wide open spaces it still lived amongst the trees and we already know that it’s finger bones show that it was good at climbing one thing that’s emerging now and an Aurora in the discovery of Aurora really reinforces this is the idea that bipedalism is an adaptation that arose in a more forested environment and was a pre adaptation in many ways to when they did move out onto the savanna grasslands so how did it happen how could a tree dwelling creature develop what we now consider to be the most fundamental aspect of the human form how does an ape learn to walk Robin Crompton from the University of Liverpool is one of the few scientists in the world who is researching early human walking patterns by analyzing one particular modern primate he may have explained how an upright forest dwelling animal like orang came to evolve the subject of this research is one of the rarest animals in the world the orangutan for us being orangutan is a fascinating animal not only attractive but scientifically fascinating because in May of all the great apes be our best model for the origins of life or dowsing the name orangutan means forest man in Indonesian and while they don’t come from Africa and they are not our closest living relative they display behavior and adaptations that may hint at how we developed bipedalism here at Chester Zoo Robin has been using special high-speed video cameras to film these animals unique way of walking which unlike the chimpanzee is remarkably similar to ours weak hip joint is very extended that is good that goes behind the body and won’t search in handsy do that and this is linked to their behavior in the high levels of the forest canopy gathering gathering fruit and moving on fairly small vines and using their body rather like it’s almost like a spider to reach out for branches to reach out the food

in the wild these animals hardly ever come down to the ground preferring to spend almost all the time 60 meters up in the forest canopy yet they often support almost all their weight on their hind legs and their habitat Surprise them with the ideal environment in which to develop an acute sense of balance the trees are perhaps the ideal nursery for the evolution of Afyon walking because they enable an animal to bounce itself they can reach out in any direction everywhere although them above and side of them are fine branches which they can touch for me then the evidence is increasingly strong but bipedalism did not arise on the ground but arose in the trees a creature that is basically arboreal that needs to cross from patch of trees to 33:6 their bipedal they have an advantage they don’t have to change the body too much they come down to the ground their bodies are already upright from being in the trees they cross the ground upright and they climb up the next patch of trees to get food they don’t have to modify the body too much so rather than the traditional picture of evolution this would be more accurate our ancestors have been upright for well over six million years after all Horan must itself have evolved from an ape that was to some extent by people millenium man was an animal with a unique set of abilities it could climb in the trees like an orangutan but it could also walk on the ground like a human being a set of geological and evolutionary coincidences led to the prototype a human form which millions of years later would evolve again into modern man frustratingly the finer details of this extraordinary animal will not be known until more is fun however the team you are still looking they proceed regard to laburnum and cannon ah this canine tooth is just the latest piece of evidence of the ape that learned to walk [Applause] you you