Your inner Monkey

from the Badlands of Ethiopia to the coasts of Florida in the bones of ancient creatures and deep inside your own DNA lies an incredible story the story of your body and why you're built the way you are you are a cutie the shape of your hands your rich color vision the way you walk and even the structure of your brain then I find that language can all be traced back to ancient primates living in an ancient forest [Music] my name is Neil Shubin as an anatomist I look at human bodies differently for most people within us I see the ghosts of animals past distant ancestors who shaped our Anatomy in surprising ways prepare yourself for a trip back to an ancient world if you really want to know why you look the way you do it's time to meet your inner monkey [Music] if you go down to your local ice rink you might not expect to find evidence of your ancient evolutionary past but if you know how to look there's a story written in the bodies of these skaters and every one of us [Music] anyone who's fallen on the ayats knows there's one bit of your body you don't want to land on it's a remnant from a time when our ancestors who looked like monkeys complete with tails each of us have a vestige of our tail inside of us we call that the coccyx and that sits at the base of our spine when we fall on that it really can hurt and the coccyx is just the beginning inside all of us is a record of our ancient primate past what I like to call an inner monkey the way we see the world the way we walk and even the way we think can all be traced back to a time when our ancestors lived in the trees if you have a hard time believing we have an inner monkey try meeting modern-day monkeys face-to-face [Music] in a sense these guys squirrel monkeys are our distant cousins [Music] I mean it's hard not to look at these guys and feel a deep connection in a way that you don't feel the fish you look in their eyes [Music] when you see their hands see the little nails now they grab this little nut just like I'm holding it here I mean it's hard not to feel something powerful connecting you but the power of that is also scientific the power of that is in the anatomy of the bones and also in the fossils that show us the history we share with them we're primates monkeys and apes people but we're all part of the same branch of the Tree of Life and all primates are differ from other mammals in having certain features that other mammals don't have we have certain shaped to our skull our eyes stays forward we have a particular kind of hand that can grasp we share an evolutionary relationship with them to see what I mean imagine all life that has ever existed on a giant family tree from the first microscopic life billions of years ago to all animals alive today we didn't evolve from modern monkeys but if you trace our ancestry back in time eventually we reach a point where the human line and the lines of all primates meet this is where our story begins our common ancestor the ancestor of every monkey ape and human alive today so what did that common ancestor look like and how has it shaped our own bodies 1870 a surgeon from the Civil War has returned to his pre-war passion hunting fossils from the Wild West in Wyoming territory he finds a jawbone he thinks might belong to something like a small raccoon in fact he's found a creature that lived some 50 million years ago and occupied a place in our family tree very close to the first primates [Music] I've come to meet this creature called myth arctos and a scientist who knows every inch of its bones Jonathan Bloch this is a 50 million year old primate skeleton it gives us a window straight into the world of what the earliest primates would have been doing how they would have been interacting with their environment wow that's the middle this is the real deal that is absolutely exquisite [Music] like most modern monkeys Mathare 'kiss was a climber adapted to life in the trees the evolution of this creature and others like it had a huge impact on one of the features that most defines us our hands one of the things that's really nice about this hand is that we do have all of the bones preserve looks like a jigsaw puzzle you got to put it all together to see how that it's a three-dimensional jigsaw puzzle solve the puzzle of Mathare kisses hands you have to begin even further back in time over 365 million years ago ancient fish used their fins to crawl out of the scene [Music] those fins evolved into the feet of reptiles and later into the paws of mammals with short fingers that all pointed the same way and claws [Music] early primates like no Thark tiss took the mammalian hand to a whole new level one that seems very familiar to us when you actually articulate all of these bones what you see is that the thumb is divergent that is it forms an angle with the index finger and so that shows you that it could bring its thumb into opposition with the rest of the digits [Music] myth artists also has unusually long fingers and nails instead of claws this is one of the first times in the fossil record that we see a hand that looks like our own the hand of a primate it's a turning point in this story of the human body an anatomical change that would eventually let us shape the world around us [Music] so what were early primates doing with these new hands to find out I'm going up into the habitat where my ancient ancestors actually lived up in the trees thankfully I've got ropes minor monkeys not what needs to be okay [Laughter] little knotty up here just push your hand jammer a bit high so you can pull the rope through your crawl mm-hmm thank you Jim this is utterly wild I mean I was never a real climber as a kid and I have to admit I mean a little scared of heights and uncomfortable in trees but these creatures are so unbelievably agile all through here this is their home they are able to live on small branches big branches throughout the tree they can jump branch to branch you know when you're in the tree what you see is that the canopy is not one place there are lots of environments let sit niches up here and one special one is on the ends of the branches because it's there where the flowers and the fruits and the insects are so the rewards are great to get them we call it the fine branch niche and for the earliest primates being able to get out there would have been really important and that gives us a clue as to why their hands and feet evolved to be so different from what came before [Music] creatures with really short fingers and claws they're really great at crawling these big thick branches but not so much when you get to the ends of the branches that's because this sort of hand can't grasp lengthening the fingers and better still adding a divergent thumb means you can curl your fingers around even the thinnest branches rest them tight and remain stable we think that's why the hands and feet of early mammals changed what you end up with our primate hands wonderfully adapted to moving around the fine branches of trees [Music] embedded in our bodies is their distant past the hand I used to write with - the type of his computer to throw a baseball that hand has a long evolutionary history and one important point in that history was here in the trees on the fine branches that made a hand with longer fingers and a thumb [Music] life in the trees would lead to another critical change in our ancestors bodies a change deep within their eyes as they began to see the world in rich color I [Music] first got interested in the evolution of color vision back in 2009 I was watching my two kids Nathaniel and Hannah playing a game called hiss where they matched cards of a certain color to make a snake the thing you know about three and a half years old of a man and he should walk her right but he consistently lost anybody lose because he'd make mistakes with one kind of card which was purple and blue then we realized the thing else like the color blind in a sense he sees the world like early primates did before they evolved our rich color vision Nathaniel can only see a limited range of yellows and blues and can't tell the difference between reds greens and purples this means he's not so great at games like hiss but it doesn't affect his life much more than that and it certainly doesn't affect his ability to find food or to survive to adulthood that wasn't the case for our primate ancestors from leaves of years they'd been unable to tell the difference between fine shades of red and green then about 23 million years ago one group of primates evolved the ability to see many more colors now they could tell the difference between ripe red fruits and unripe green fruits and spot the most nutritious leaves in the evolutionary battle for survival this would have been a big advantage so what happened to the eyes of our ancestors how did our rich color vision of all [Music] to help me answer those questions I've come to Seattle to meet one of the world's experts on color vision Jayne Knights oh hey great to be in yeah the color lab well thank you I think we're off to a rock and start with these walls this is the color Club yes it is so what's the drill here Jay's been studying color vision for the last 25 years he combines cutting-edge genetics with studies on humans and other primates everything is cool about color it's a silent language that speaks to our emotions but it's just fascinating this is the place huh yep this is where we test color vision in the monkeys his work helped scientists figure out that most mammals including those primates see a limited range of colors this is Kramer hi Kramer and Kramer is red-green color blind but he has a good blue yellow color vision in order to train them we use the colors that they can't see so as you can see that here is this yellow blob against a gray background Kramer can see that as well as we can if they get it right they get a little reward and they also get a clicking sound oh he clearly who's trying to kiss it there [Music] you can see how good he is Kramer aces this first test you've done really well there Kramer but change the colors to red and green and it's a whole different ball game if you don't have any color vision this is completely invisible if you can't see red or green this just looks like a totally gray background most humans can clearly see this red blob can't Luckman son Nathaniel he can't tell the difference between reds and greens okay Cramer us star so why is this happening why doesn't Cramer see the world like we do Kramer's eyes like all eyes rely on special proteins called opsins to detect color they're held in thousands of special cells in the retina in the back of the eye Kramer's got two types of opsin each tuned to specific wavelengths of light signals from these options are then interpreted by the brain which allows us to perceive color but to see color like we do Kramer would need a third opsin tuned to different wavelengths of light we think our early primate ancestors were like Kramer they had just two options as well so how did they evolve a third opsin the answer is in our DNA [Music] each opsin is encoded by a single gene and when scientists compared these genes they found that the gene for the newer opsin sits right next to one of the old ones and significantly they are incredibly similar both facts are telltale clues as to how the extra gene evolved the old opsin gene must have been duplicated and one of these copies then acquired a small number of mutations that allowed it to detect different wavelengths of light but there's one more question could our rich color vision result from just duplicating a gene or would there have to be changes to the brain as well to find out jay has tried to replicate what happened in nature in his lab it's actually a great evolutionary question how did color vision evolve how can something so complicated evolve Jay implanted a third opsin gene from a human directly into the retinas of a color blind squirrel monkey called Sam what we did is really a test to see what's the minimal thing you could do in order to give an animal color vision the results were incredible like Kramer Sandies to fail this test now he can easily tell the difference between reds and greens Jay has recreated evolutionary history and given Sam human-like color vision you might think oh it would take him a long time to learn this new pattern in the brain as soon as that gene was turned on the animal began to make these discriminations that they couldn't make it before breehn was already ready somehow and so in one you know very short evolutionary stack that goes to this totally different world you go from just having strictly let's say five colors gray black white blue and yellow to hundreds of different colors that are all the blues and greens and purples and oranges one simple shift opens a whole universe of yeah that's the amazing thing it's like there's on something almost magical it's a multiplicative effect [Music] for the early primates that evolved this ability it was a huge advantage one that would eventually be passed on to us and color still plays a huge part in our lives today [Music] color helps us communicate attract attention and even express emotions [Music] we often take it for granted but it massively enriches our experience of the world but our focus on vision has come with some trade-offs namely our poor sense of smell like most humans I'm experiencing this wonderful Vista here with my eyes but the dogs experiencing this in a very different way this is a world of smells we think that a dogs sense of smell is anywhere from a thousand to a million times better than ours like many mammals it's his main way of understanding the world around him this fundamental difference in our sense of smell is also reflected in our DNA a dog has about a thousand genes that are devoted to detecting odors we have roughly the same number but about 600 of them don't work anymore they're relics it's a similar story in other primates with color vision these broken genes reveal another legacy of our primate past as our distant ancestors gained this wonderfully rich sense of color vision what happened was our sense of smell became less important and in the evolutionary world its use it or lose it and that's exactly what happened to her sense of smell it diminished over time so while we can thank Aaron or monkey for our wonderful color vision we can also blame it for our lousy sense of smell [Music] of course we humans have also made some radical changes to the ancient primate body plan unlike monkeys we stand up on our own two feet you know animals been walking on this planet for over 365 million years and for the most part that walking it's been on four legs walking on two legs is a fundamentally strange way to get around no other primate and very few other mammals move this way it's a change that had profound effects on the human body which begs the question how on earth did it happen [Applause] the best place in the world answer this question is in Africa a site where the Great Rift Valley cuts deep into ancient rocks exposing fossils from our distant past these are the remote Badlands of northern Ethiopia look at those Nazi funk funk funk just totally stretched out as a paleontologist that is what I dream about this is truly in the middle of nowhere I see the volcanic ash dropping out that's 3.4 million years old that is incredible my guide is Daniel Hanson one of the first people to hunt for fossils here back in the early seventies and a childhood hero of mine there's the camp there on the far side of the river right there yeah two of the most important fossils for understanding the origins of bipedalism have been found in this small region of Ethiopia Don's taking me to see where the first iconic fossil was found a 3.2 million year old human ancestor known as Lucy it was Sunday morning back in 1974 so I came up here looked at this had no idea what was waiting but it was right in this area right here what I saw was a fragment of bone and I looked at it and almost instantaneously said that's a hominid Wow Lucy made headlines around the world because although she looked like an ape she walked on two legs she was a biped at that stage the most ancient anyone had found once we broke that three million year barrier it was a whole new picture of what our earliest ancestors look like the board of the most exciting moments of my entire career since dawn first came here in the 70s scientists have organized expeditions here most years they found over 400 individual fossils from Lucy's species but it's Lucy I most want to meet our bones are some of the best evidence we have for what early bipeds look like now of course if this were all articulated properly you know the burger on top would see she'd be about three and a half feet tall you don't see this yeah you don't get that pierced the femur that's a laptop into the thigh bone and this one also mean when you put it all together now you have you know this is telling that people this is giving a hint of bipedal this certainly tells it was bipedal that kids in like that which is very characteristic our knees are close together they want to decide chimps come straight up having the upper and lower leg in a straight line is no good for a biped it makes for an awkward waddling gait Lucy's legs formed an angle her knees were closer together just like our own knees this positions the feet directly underneath the body making walking easier and more efficient sir Lucy walked much like us but she wasn't human she had many primitive features - this is a real mix you know there was a real big yeah it's amazing this is very primitive right ape-like very small break and very ape-like black woman's by people on bipedal and these hands would stretch down to about here so down yes the Nemo [Music] it's just so utterly fabulous isn't it interesting they had the pile of bones you put her here and all of a sudden could see that it was a living person she's beautiful yep thank you he named her after the people and the land behavior Australopithecus afarensis from the afar region so imagine if Lucy was here with us right now what does she look like well she'd be short the only about three and a half feet tall and the one thing that would be familiar to us she would be walking upright but with those long arms reaching almost down to her knees she's gonna have a very odd gait and as she got closer we'd see that she had a very ape-like thing I don't think you would see much of a glimmer of philosophical thoughts of your eyes I think in many ways she looked like the ape that stood up yeah you know that's amazing Lucy tells us that by 3.2 million years ago our ancestors had fully committed to walking on two legs what she can't tell us is how our ancestors first started walking upright to answer that question we need to meet a second iconic fossil found just 50 miles from the Lucy site this vasa called Ardipithecus has turned our ideas about how we became bipedal on their head [Music] I've come to Berkeley California to meet the guy who led the team that discovered Artie an old colleague of mine Tim white Tim's out in the field in Ethiopia most years and he documents his work meticulously with a video camera these rarely seen field tapes date from the early 90s what we wanted to do was to plumb the unknown to figure out what came before the Lucy species we just literally didn't know what we would find since 1992 the team has run annual expeditions to a remote site called the middle awash [Music] some of the rocks here were millions of years older than the nearby lucy site you see the two resistant bands up there on the hill they're digging into the lower pan but both of these are dated to 4.4 million this was really we nailed it so anything between that is 4.4 million years this band of ancient rock yielded some tantalizing fragments so they scoured this lair for months on end the breakthrough finally came in 1994 an Ethiopian graduate student johannes hailey Selassie found a fragment of Han bone in that same layer [Music] he picked up and said this looks like a hominid so we scraped and brushed that surface and we found some of these hominid and in foot bones in place and so we focused on that little hill and now we turn the video camera on and Doug oh wow this is the way we took it off virtually a millimeter at a time got to be really careful you know you scratch that you put your signature on it forever it comes to the mandible canines off on the left hand side right there here are the teeth coming out you know says appealing told us you're the first people in the entire planet to see that that's been buried for 4.4 million years [Music] this was a hugely significant find a new species of hominid at a critical moment in human evolution a time when our ancestors were just beginning to walk on two legs so while they were still in the field Tim wanted to collect as much information as he could about our DS world what we're out to do is to understand everything we can about that time slice and at 4.4 million years anything we learn is new and so that means bringing in sedimentology who understand what kind of a setting was at a river was it a floodplain bringing in paleontologists expert in the plants in the birds in the shrews wherever they found Artie's species they found woodland creatures parrots monkeys and peacocks as well as woodland plants it was a woodland not an open savanna setting now that's a woodland animals that runs counter to so much of what runs counter all the way back to the 1800s for over a hundred years there's been one named theory of how our ancestors started to walk on two legs the theory goes like this we started out as apes that lived in a trees we looked like chimpanzees and walked on all fours using the knuckles of our hands but the climate changed and only after forests had turned to savanna and did we start walking on two legs instead of four Artie tells a very different story she was already walking upright while living in the woodlands Artie's skeleton ran counter to the old theory - it was unlike anything anyone had seen before it took a team of experts for his teen years to fully piece her together so how do we know she was bipedal the man in charge of figuring out how already might have moved was anatomist Owen Lovejoy the critical thing in bipedality is the structure of the pelvis and at first when you look at this bone you might think that there's not much information here but actually there's an enormous amount of information that tells you a great deal about what the original bone looked like using information from this deformed bone the team was able to reconstruct Artie's entire pelvis this is a plastic structure is produced by a three-dimensional printer the top part of Artie's pelvis looks more human the hip bone is short and broad a key indicator of bipedalism but the lower half is much longer than a human pelvis more useful for climbing [Music] when you got to that detail you realized it was a mosaic of anatomy that had never been encountered before it suggests that already could walk on two legs but not as well as later hominids like Lucy and the rest of her Anatomy held surprises - neither Lucy nor humans have the ability to grasp with their big toe but this thing had full grasping ability so she has a grasping foot that can walk yes even the hands were a mosaic incredibly long fingers good for climbing but assured a human-like palm and the bones show none of the telltale signs that she walked on her knuckles like a chimpanzee so we now have a detailed picture of the crucial time when our ancestors had just started walking on two legs [Music] Artie was small around four feet tall a good climber she moved on all fours when in the trees but she walked upright when on the ground she blows the old theory of how we became bipedal out of the water not only did our ancestors start walking on two legs when still living in the woods they never looked or moved like our closest living relative the chimpanzee some scientists don't accept this interpretation they think already isn't a human ancestor at all but the relic of an extinct aide but Tim's spent years studying many specimens of Ardipithecus and he thinks the evidence is clear when we looked at the arti cranium we saw very small canines no other ape living or fossil has such reduced canines that's a good indicator she's come in our direction a bit go to the pelvis same thing a unique adaptation shared by humans and Lucy we're still not sure exactly why a woodland climber needed to walk on two legs but thanks to already we now have a snapshot of one of the most dramatic transformations in the history of our species the transition from walking on four legs to walking on two this major change to our ancestral body plan has serious consequences for us today [Music] these consequences can be seen within our own bodies and they're not all good this vault in the bowels of the Cleveland Museum of Natural History is the place to go if you want to find out what can go wrong with the human skeleton dr. Bruce Latimer is an anthropologist and anatomist there was a curator here for many years well this is the Hammond Tod collection which is the largest collection of its type in the world there are over 3,000 skeletons in this room in each one of these drawers is a complete human skeleton they come from unclaimed bodies at a Cleveland morgue dating from the early 1900's if you study these skeletons one thing becomes clear pretty quickly the human back goes wrong a lot there's an enormous amount of back problems the pain must have been phenomenal and you just see that all over this collection turns out our bad backs are an unwelcome inheritance from our inner monkey we took a skeleton like this that was essentially horizontal we stood it upright we've had to change essentially every bone to allow us to do that and we forced it into this new position we have a problem going from this kind of animal into that kind of animal and our main problem is balance on all fours the weight of our body hangs down from our spine but turn this body upright and the weight is all out front it puts us out of whack totally out of balance in order to balance we had to create this curve on your back and then your head would be back here wouldn't it so we had to create another curve here in the middle of your chest and then you're headed be sticking out in the front so we had to create another curve in your neck so we have this s-shaped curve in our spine and we expect that to hold us up that is an engineering nightmare our s-shaped spine is unique among mammals and it causes all sorts of problems the vertebrae that make up the bones of your back and the discs between them are put under a lot of pressure particularly the ones at the very apex of the biggest curve the thoracic vertebrae if you take those thoracic vertebra and you push on them from the ends too hard what happens is this you end up with called what's called a wedge fracture that curve has crunched it no other animal has anything even remotely like this it's a consequence of how we walk and it's not just fractured vertebrae from slipped discs to sciatica our spines go wrong in all kinds of ways 80% of all Americans will complain of back problems at some point in their lives our inner monkey has a lot to answer for [Music] but I don't want you to get the wrong idea standing up on two legs wasn't all bad or it never would have happened in the first place it freed our hands an anatomical change that combined with our amazing brains would eventually allow us to make tools and reshape the world around us this key moment in our evolutionary history is once again visible in the rocks of northern Ethiopia Lucy's from one part of it and we're going to another that's right we've just jumped about six or seven hundred thousand years in time and that is kind of mind-blowing yeah paleontologist bill Kimble has brought me to a site where you can find stone tools that are over 2 million years old if you know what you're looking for so what do I look for well you'll look for flakes on the ground low as that bone that is a piece of fossil bone and here's another one if I to look if I'm bone yeah yeah the important thing about tools is it's the hand and the brain right it's it's it's both together absolutely I don't get this at all yeah I know it looks like something from your driveway the tool Don's found was made by human ancestors called Homo habilis who lived a million years later than Lucy clearly some early human took a stone a hammer stone and struck it right there and go oh yeah that's right yeah feel that edge you could use it to strip off me or whatever so from this rock you could tell where they hid it how they hid it it's almost like a time machine you have it is it's a time machine that takes us back to a period when the faintest glimmer zuv what it means to be human are beginning to emerge use of the hand the cognition the repeated behavior to produce a stylized tool it's my blood Wow we look for tools I want to find a tool no that's natural no this one found one making tools takes excellent vision fine motor skills and a brain that can integrate the two we humans only have this sort of brain because it's been shaped by our ancient primate past [Music] monkey ape or human our brains share a basic architecture that's different from most other mammals we all have a special region involved with hand-eye coordination and a greatly expanded visual system with as much as 40% of the brain involved in seeing our inner monkey hasn't just shaped our bodies it's shaped our brains as well but if you look at the modern world around us and everything humans have been able to build from satellites to skyscrapers there's no doubt were more intelligent than monkeys so what changed what made our brains so different from those of other primates to the infant primate lab monkey place tomber Bakker studies monkeys in order to answer questions about our own brains he's going to show me an experiment that demonstrates an important difference between our brains and the brains of a monkey but the differences aren't what you might expect especially when we're young monkey on the sack monkey on the set Neil this is see I she's at three months old pigtailed macaque this experiment test something called object permanence in other words whether this monkey knows an object still exists when she can't see it it's a developmental milestone for both monkeys and humans you're going to put a piece of fruit on the toy itself you'll place it in the well she's looking at it there and you'll be back to complete and hide that toy okay three months old and already CI understands object permanence good I can even how are you you are a cutie Geneva is the same age as the baby monkey I'm going to do the exact same test on her under the expert eye of child development specialist Professor Susan speaker she needs to reach for him so that she's interested oh I think we got interest got it good you do yeah Oh Geneva you like those hello no Neil can you get them away oh I'm an expert at this kind of think that there thank you sorry Lou temporary yeah you are so good that way she's watching and she wonders what did you do now what toys I don't know where they went wow that is amazing it is incredible if it did if it's not there it doesn't exist that isn't easy so how come a baby monkey beats a baby human in this test these tests are showing us how rapidly a particular region of our brain is wiring up in development and it's showing us comparatively that we wire up much slower in this part of the brain than do monkeys compared to other primates we humans have an unusually long childhood even if you take the different lifespans into account this should be an evolutionary disadvantage but in fact it's one of our greatest strengths during childhood our brains are being shaped by our environment and by our experience [Music] extending this phase is thus longer to learn and pick up new skills some think that this is a key part of what makes us so smart but there are other factors too the brain is made up of vast networks of nerve cells called neurons that carry process and store information the part of the human brain responsible for higher thought the cortex contains more neurons than that of any other animal on the planet an astonishing 16 billion [Music] these neurons are organized in a uniquely powerful way they're unusually interconnected this means we can do things that other primates can't build complex tools compose symphonies and even investigate how our own brains work but before we get too carried away with our own cleverness I want to inject a bit of humility that means leaving monkeys behind and going back to where the series began my anatomy lab in Chicago and my favorite subject fish the brain of a fish and the brain of a human have more in common than you might think this is a trip to the beginning this is as basic as it gets we're going human fish represented by a cartilaginous fish a shark on the right and what you have is we see the muscles and nerves and organs inside the the shark head but importantly you see this yellow tissue this is the front end of the of the spinal cord it's the brain doesn't look like much but it's the shark brain this is the human brain this is where it all happens for us where our memories reside where our you know our fears our love's our hates it's all in here human brain really the surface level looks nothing like what's sitting inside the shark head yet when you know how to look you find a very profound similarity and that similarity lies in the overall architecture of the brain itself in the human we have a forebrain and that forebrain consists of this folded tissue here where much of our conscious thought happens then there's a midbrain this walnut-sized area in the middle and then a hind brain that's a fundamental division we see that in development and we see that based on where the nerves exit the brain well if you follow the similar nerves in a shark what you see is sharks to have that same structure a forebrain a midbrain and a hindbrain there's a fundamental architectural similarity among all brains the brains of people the brains of docks the brains of cats the brains of monkeys lizards frogs salamanders trout bass given sharks fish are similar each one of them has a forebrain and a midbrain and a hindbrain despite the fact but those brains are often very different in function and form but that's not the end of the story the fundamental architecture of our own brains can be traced back even further than fish to a surprisingly primitive animal that doesn't even really have a brain but I've got to find these tiny creatures first all right okay well we could stop trying to rattle dr. Spock thanks boss the squat let's give it good this is Peter Holland a world-renowned geneticist and head of zoology at Oxford University in England okay so what do I do now we pretty obvious because they'll start milk they'll really swim around the water makes the diggings finally carnage oh we got named whoa look a little guy go Hey just dip it in the water again you'll see it okay well they really click now you see it's beautiful look at that which is the front it doesn't look like much but this tiny creature called amphioxus has much to tell us about our own brands okay that ranks is cool okay so let's let's take a look at a couple of these so I brought this from the anatomy lab in Chicago this is a this is a human brain when I look at this I don't find any obvious similarities to that deep in the genes of this animal and the development of this animal and even the genes of us and the development of us there are the similarities no that is beautiful god they're so clear - you can see right through them you know it's amazing it MMP oxen the sand of the ocean floor filtering algae out of the water it's from an incredibly ancient group of animals we found fossils that look a lot like this in rocks that are over 500 million years old they are a window into what came before the first fish and crucially they don't have anything like what we'd call a brain the simple nerve cord that runs the length of their body ends with just a tiny swelling invisible to the naked eye if you look at the front end of this animal you don't see it all expanded into a large skull or brain region it's just pointed but if you look at the genetic makeup of these ancient creatures you find something truly remarkable to make the forebrain midbrain and hindbrain that we saw in our lab you need a series of control genes to tell the cells within the developing brain where they are they're like a zip code those same control genes that make our own brains are active in amphioxus but here they're simply building the primitive nerve cord and the tiny swelling at its front [Music] this means that the genetic roots of our complex primate brains existed in much simpler creatures that first arose over 500 million years ago I think it gives us a glimpse into where our brains came from into the basic organization of the brain of our ancestors I mean I find that mind-blowing it's just an exciting animal he knows you're talking about him he's going he's going you can see there's muscle blocks really working there yeah and I think we need a Luthor but we'll oh sorry he's going out Tiktaalik on land living yep he's done for the next transition exactly he's in the Devonian now [Music] the search for our inner fish has taken me from high in the Arctic here was the snout of exactly the creature we were looking for to the plains of Africa yeah I just want to run down here and start collecting fossils let's go as well as deep inside our own DNA and today we saw a little tiny worm living in the mud here in the bay that contains genes that we have that sculpt our own brains the organ that gives us many of our unique properties [Music] we've seen how our distant relatives from worms to fish from reptiles to early primates have defined our bodies at each new stage of our journey along the Tree of Life our our ancient animal ancestors have reconfigured what's gone before and that's how we ended up as the intelligent creatures with all our quirky flaws that dominate the planet today there's something incredibly profound and I think beautiful in the idea that inside every Oregon cell and gene of our body lie deep connections to the rest of life when our planet [Music] [Music] you

from the Badlands of Ethiopia to the coasts of Florida in the bones of ancient creatures and deep inside your own DNA lies an incredible story the story of your body and why you&#39;re built the way you are you are a cutie the shape of your hands your rich color vision the way you walk and even the structure of your brain then I find that language can all be traced back to ancient primates living in an ancient forest [Music] my name is Neil Shubin as an anatomist I look at human bodies differently for most people within us I see the ghosts of animals past distant ancestors who shaped our Anatomy in surprising ways prepare yourself for a trip back to an ancient world if you really want to know why you look the way you do it&#39;s time to meet your inner monkey [Music] if you go down to your local ice rink you might not expect to find evidence of your ancient evolutionary past but if you know how to look there&#39;s a story written in the bodies of these skaters and every one of us [Music] anyone who&#39;s fallen on the ayats knows there&#39;s one bit of your body you don&#39;t want to land on it&#39;s a remnant from a time when our ancestors who looked like monkeys complete with tails each of us have a vestige of our tail inside of us we call that the coccyx and that sits at the base of our spine when we fall on that it really can hurt and the coccyx is just the beginning inside all of us is a record of our ancient primate past what I like to call an inner monkey the way we see the world the way we walk and even the way we think can all be traced back to a time when our ancestors lived in the trees if you have a hard time believing we have an inner monkey try meeting modern-day monkeys face-to-face [Music] in a sense these guys squirrel monkeys are our distant cousins [Music] I mean it&#39;s hard not to look at these guys and feel a deep connection in a way that you don&#39;t feel the fish you look in their eyes [Music] when you see their hands see the little nails now they grab this little nut just like I&#39;m holding it here I mean it&#39;s hard not to feel something powerful connecting you but the power of that is also scientific the power of that is in the anatomy of the bones and also in the fossils that show us the history we share with them we&#39;re primates monkeys and apes people but we&#39;re all part of the same branch of the Tree of Life and all primates are differ from other mammals in having certain features that other mammals don&#39;t have we have certain shaped to our skull our eyes stays forward we have a particular kind of hand that can grasp we share an evolutionary relationship with them to see what I mean imagine all life that has ever existed on a giant family tree from the first microscopic life billions of years ago to all animals alive today we didn&#39;t evolve from modern monkeys but if you trace our ancestry back in time eventually we reach a point where the human line and the lines of all primates meet this is where our story begins our common ancestor the ancestor of every monkey ape and human alive today so what did that common ancestor look like and how has it shaped our own bodies 1870 a surgeon from the Civil War has returned to his pre-war passion hunting fossils from the Wild West in Wyoming territory he finds a jawbone he thinks might belong to something like a small raccoon in fact he&#39;s found a creature that lived some 50 million years ago and occupied a place in our family tree very close to the first primates [Music] I&#39;ve come to meet this creature called myth arctos and a scientist who knows every inch of its bones Jonathan Bloch this is a 50 million year old primate skeleton it gives us a window straight into the world of what the earliest primates would have been doing how they would have been interacting with their environment wow that&#39;s the middle this is the real deal that is absolutely exquisite [Music] like most modern monkeys Mathare &#39;kiss was a climber adapted to life in the trees the evolution of this creature and others like it had a huge impact on one of the features that most defines us our hands one of the things that&#39;s really nice about this hand is that we do have all of the bones preserve looks like a jigsaw puzzle you got to put it all together to see how that it&#39;s a three-dimensional jigsaw puzzle solve the puzzle of Mathare kisses hands you have to begin even further back in time over 365 million years ago ancient fish used their fins to crawl out of the scene [Music] those fins evolved into the feet of reptiles and later into the paws of mammals with short fingers that all pointed the same way and claws [Music] early primates like no Thark tiss took the mammalian hand to a whole new level one that seems very familiar to us when you actually articulate all of these bones what you see is that the thumb is divergent that is it forms an angle with the index finger and so that shows you that it could bring its thumb into opposition with the rest of the digits [Music] myth artists also has unusually long fingers and nails instead of claws this is one of the first times in the fossil record that we see a hand that looks like our own the hand of a primate it&#39;s a turning point in this story of the human body an anatomical change that would eventually let us shape the world around us [Music] so what were early primates doing with these new hands to find out I&#39;m going up into the habitat where my ancient ancestors actually lived up in the trees thankfully I&#39;ve got ropes minor monkeys not what needs to be okay [Laughter] little knotty up here just push your hand jammer a bit high so you can pull the rope through your crawl mm-hmm thank you Jim this is utterly wild I mean I was never a real climber as a kid and I have to admit I mean a little scared of heights and uncomfortable in trees but these creatures are so unbelievably agile all through here this is their home they are able to live on small branches big branches throughout the tree they can jump branch to branch you know when you&#39;re in the tree what you see is that the canopy is not one place there are lots of environments let sit niches up here and one special one is on the ends of the branches because it&#39;s there where the flowers and the fruits and the insects are so the rewards are great to get them we call it the fine branch niche and for the earliest primates being able to get out there would have been really important and that gives us a clue as to why their hands and feet evolved to be so different from what came before [Music] creatures with really short fingers and claws they&#39;re really great at crawling these big thick branches but not so much when you get to the ends of the branches that&#39;s because this sort of hand can&#39;t grasp lengthening the fingers and better still adding a divergent thumb means you can curl your fingers around even the thinnest branches rest them tight and remain stable we think that&#39;s why the hands and feet of early mammals changed what you end up with our primate hands wonderfully adapted to moving around the fine branches of trees [Music] embedded in our bodies is their distant past the hand I used to write with - the type of his computer to throw a baseball that hand has a long evolutionary history and one important point in that history was here in the trees on the fine branches that made a hand with longer fingers and a thumb [Music] life in the trees would lead to another critical change in our ancestors bodies a change deep within their eyes as they began to see the world in rich color I [Music] first got interested in the evolution of color vision back in 2009 I was watching my two kids Nathaniel and Hannah playing a game called hiss where they matched cards of a certain color to make a snake the thing you know about three and a half years old of a man and he should walk her right but he consistently lost anybody lose because he&#39;d make mistakes with one kind of card which was purple and blue then we realized the thing else like the color blind in a sense he sees the world like early primates did before they evolved our rich color vision Nathaniel can only see a limited range of yellows and blues and can&#39;t tell the difference between reds greens and purples this means he&#39;s not so great at games like hiss but it doesn&#39;t affect his life much more than that and it certainly doesn&#39;t affect his ability to find food or to survive to adulthood that wasn&#39;t the case for our primate ancestors from leaves of years they&#39;d been unable to tell the difference between fine shades of red and green then about 23 million years ago one group of primates evolved the ability to see many more colors now they could tell the difference between ripe red fruits and unripe green fruits and spot the most nutritious leaves in the evolutionary battle for survival this would have been a big advantage so what happened to the eyes of our ancestors how did our rich color vision of all [Music] to help me answer those questions I&#39;ve come to Seattle to meet one of the world&#39;s experts on color vision Jayne Knights oh hey great to be in yeah the color lab well thank you I think we&#39;re off to a rock and start with these walls this is the color Club yes it is so what&#39;s the drill here Jay&#39;s been studying color vision for the last 25 years he combines cutting-edge genetics with studies on humans and other primates everything is cool about color it&#39;s a silent language that speaks to our emotions but it&#39;s just fascinating this is the place huh yep this is where we test color vision in the monkeys his work helped scientists figure out that most mammals including those primates see a limited range of colors this is Kramer hi Kramer and Kramer is red-green color blind but he has a good blue yellow color vision in order to train them we use the colors that they can&#39;t see so as you can see that here is this yellow blob against a gray background Kramer can see that as well as we can if they get it right they get a little reward and they also get a clicking sound oh he clearly who&#39;s trying to kiss it there [Music] you can see how good he is Kramer aces this first test you&#39;ve done really well there Kramer but change the colors to red and green and it&#39;s a whole different ball game if you don&#39;t have any color vision this is completely invisible if you can&#39;t see red or green this just looks like a totally gray background most humans can clearly see this red blob can&#39;t Luckman son Nathaniel he can&#39;t tell the difference between reds and greens okay Cramer us star so why is this happening why doesn&#39;t Cramer see the world like we do Kramer&#39;s eyes like all eyes rely on special proteins called opsins to detect color they&#39;re held in thousands of special cells in the retina in the back of the eye Kramer&#39;s got two types of opsin each tuned to specific wavelengths of light signals from these options are then interpreted by the brain which allows us to perceive color but to see color like we do Kramer would need a third opsin tuned to different wavelengths of light we think our early primate ancestors were like Kramer they had just two options as well so how did they evolve a third opsin the answer is in our DNA [Music] each opsin is encoded by a single gene and when scientists compared these genes they found that the gene for the newer opsin sits right next to one of the old ones and significantly they are incredibly similar both facts are telltale clues as to how the extra gene evolved the old opsin gene must have been duplicated and one of these copies then acquired a small number of mutations that allowed it to detect different wavelengths of light but there&#39;s one more question could our rich color vision result from just duplicating a gene or would there have to be changes to the brain as well to find out jay has tried to replicate what happened in nature in his lab it&#39;s actually a great evolutionary question how did color vision evolve how can something so complicated evolve Jay implanted a third opsin gene from a human directly into the retinas of a color blind squirrel monkey called Sam what we did is really a test to see what&#39;s the minimal thing you could do in order to give an animal color vision the results were incredible like Kramer Sandies to fail this test now he can easily tell the difference between reds and greens Jay has recreated evolutionary history and given Sam human-like color vision you might think oh it would take him a long time to learn this new pattern in the brain as soon as that gene was turned on the animal began to make these discriminations that they couldn&#39;t make it before breehn was already ready somehow and so in one you know very short evolutionary stack that goes to this totally different world you go from just having strictly let&#39;s say five colors gray black white blue and yellow to hundreds of different colors that are all the blues and greens and purples and oranges one simple shift opens a whole universe of yeah that&#39;s the amazing thing it&#39;s like there&#39;s on something almost magical it&#39;s a multiplicative effect [Music] for the early primates that evolved this ability it was a huge advantage one that would eventually be passed on to us and color still plays a huge part in our lives today [Music] color helps us communicate attract attention and even express emotions [Music] we often take it for granted but it massively enriches our experience of the world but our focus on vision has come with some trade-offs namely our poor sense of smell like most humans I&#39;m experiencing this wonderful Vista here with my eyes but the dogs experiencing this in a very different way this is a world of smells we think that a dogs sense of smell is anywhere from a thousand to a million times better than ours like many mammals it&#39;s his main way of understanding the world around him this fundamental difference in our sense of smell is also reflected in our DNA a dog has about a thousand genes that are devoted to detecting odors we have roughly the same number but about 600 of them don&#39;t work anymore they&#39;re relics it&#39;s a similar story in other primates with color vision these broken genes reveal another legacy of our primate past as our distant ancestors gained this wonderfully rich sense of color vision what happened was our sense of smell became less important and in the evolutionary world its use it or lose it and that&#39;s exactly what happened to her sense of smell it diminished over time so while we can thank Aaron or monkey for our wonderful color vision we can also blame it for our lousy sense of smell [Music] of course we humans have also made some radical changes to the ancient primate body plan unlike monkeys we stand up on our own two feet you know animals been walking on this planet for over 365 million years and for the most part that walking it&#39;s been on four legs walking on two legs is a fundamentally strange way to get around no other primate and very few other mammals move this way it&#39;s a change that had profound effects on the human body which begs the question how on earth did it happen [Applause] the best place in the world answer this question is in Africa a site where the Great Rift Valley cuts deep into ancient rocks exposing fossils from our distant past these are the remote Badlands of northern Ethiopia look at those Nazi funk funk funk just totally stretched out as a paleontologist that is what I dream about this is truly in the middle of nowhere I see the volcanic ash dropping out that&#39;s 3.4 million years old that is incredible my guide is Daniel Hanson one of the first people to hunt for fossils here back in the early seventies and a childhood hero of mine there&#39;s the camp there on the far side of the river right there yeah two of the most important fossils for understanding the origins of bipedalism have been found in this small region of Ethiopia Don&#39;s taking me to see where the first iconic fossil was found a 3.2 million year old human ancestor known as Lucy it was Sunday morning back in 1974 so I came up here looked at this had no idea what was waiting but it was right in this area right here what I saw was a fragment of bone and I looked at it and almost instantaneously said that&#39;s a hominid Wow Lucy made headlines around the world because although she looked like an ape she walked on two legs she was a biped at that stage the most ancient anyone had found once we broke that three million year barrier it was a whole new picture of what our earliest ancestors look like the board of the most exciting moments of my entire career since dawn first came here in the 70s scientists have organized expeditions here most years they found over 400 individual fossils from Lucy&#39;s species but it&#39;s Lucy I most want to meet our bones are some of the best evidence we have for what early bipeds look like now of course if this were all articulated properly you know the burger on top would see she&#39;d be about three and a half feet tall you don&#39;t see this yeah you don&#39;t get that pierced the femur that&#39;s a laptop into the thigh bone and this one also mean when you put it all together now you have you know this is telling that people this is giving a hint of bipedal this certainly tells it was bipedal that kids in like that which is very characteristic our knees are close together they want to decide chimps come straight up having the upper and lower leg in a straight line is no good for a biped it makes for an awkward waddling gait Lucy&#39;s legs formed an angle her knees were closer together just like our own knees this positions the feet directly underneath the body making walking easier and more efficient sir Lucy walked much like us but she wasn&#39;t human she had many primitive features - this is a real mix you know there was a real big yeah it&#39;s amazing this is very primitive right ape-like very small break and very ape-like black woman&#39;s by people on bipedal and these hands would stretch down to about here so down yes the Nemo [Music] it&#39;s just so utterly fabulous isn&#39;t it interesting they had the pile of bones you put her here and all of a sudden could see that it was a living person she&#39;s beautiful yep thank you he named her after the people and the land behavior Australopithecus afarensis from the afar region so imagine if Lucy was here with us right now what does she look like well she&#39;d be short the only about three and a half feet tall and the one thing that would be familiar to us she would be walking upright but with those long arms reaching almost down to her knees she&#39;s gonna have a very odd gait and as she got closer we&#39;d see that she had a very ape-like thing I don&#39;t think you would see much of a glimmer of philosophical thoughts of your eyes I think in many ways she looked like the ape that stood up yeah you know that&#39;s amazing Lucy tells us that by 3.2 million years ago our ancestors had fully committed to walking on two legs what she can&#39;t tell us is how our ancestors first started walking upright to answer that question we need to meet a second iconic fossil found just 50 miles from the Lucy site this vasa called Ardipithecus has turned our ideas about how we became bipedal on their head [Music] I&#39;ve come to Berkeley California to meet the guy who led the team that discovered Artie an old colleague of mine Tim white Tim&#39;s out in the field in Ethiopia most years and he documents his work meticulously with a video camera these rarely seen field tapes date from the early 90s what we wanted to do was to plumb the unknown to figure out what came before the Lucy species we just literally didn&#39;t know what we would find since 1992 the team has run annual expeditions to a remote site called the middle awash [Music] some of the rocks here were millions of years older than the nearby lucy site you see the two resistant bands up there on the hill they&#39;re digging into the lower pan but both of these are dated to 4.4 million this was really we nailed it so anything between that is 4.4 million years this band of ancient rock yielded some tantalizing fragments so they scoured this lair for months on end the breakthrough finally came in 1994 an Ethiopian graduate student johannes hailey Selassie found a fragment of Han bone in that same layer [Music] he picked up and said this looks like a hominid so we scraped and brushed that surface and we found some of these hominid and in foot bones in place and so we focused on that little hill and now we turn the video camera on and Doug oh wow this is the way we took it off virtually a millimeter at a time got to be really careful you know you scratch that you put your signature on it forever it comes to the mandible canines off on the left hand side right there here are the teeth coming out you know says appealing told us you&#39;re the first people in the entire planet to see that that&#39;s been buried for 4.4 million years [Music] this was a hugely significant find a new species of hominid at a critical moment in human evolution a time when our ancestors were just beginning to walk on two legs so while they were still in the field Tim wanted to collect as much information as he could about our DS world what we&#39;re out to do is to understand everything we can about that time slice and at 4.4 million years anything we learn is new and so that means bringing in sedimentology who understand what kind of a setting was at a river was it a floodplain bringing in paleontologists expert in the plants in the birds in the shrews wherever they found Artie&#39;s species they found woodland creatures parrots monkeys and peacocks as well as woodland plants it was a woodland not an open savanna setting now that&#39;s a woodland animals that runs counter to so much of what runs counter all the way back to the 1800s for over a hundred years there&#39;s been one named theory of how our ancestors started to walk on two legs the theory goes like this we started out as apes that lived in a trees we looked like chimpanzees and walked on all fours using the knuckles of our hands but the climate changed and only after forests had turned to savanna and did we start walking on two legs instead of four Artie tells a very different story she was already walking upright while living in the woodlands Artie&#39;s skeleton ran counter to the old theory - it was unlike anything anyone had seen before it took a team of experts for his teen years to fully piece her together so how do we know she was bipedal the man in charge of figuring out how already might have moved was anatomist Owen Lovejoy the critical thing in bipedality is the structure of the pelvis and at first when you look at this bone you might think that there&#39;s not much information here but actually there&#39;s an enormous amount of information that tells you a great deal about what the original bone looked like using information from this deformed bone the team was able to reconstruct Artie&#39;s entire pelvis this is a plastic structure is produced by a three-dimensional printer the top part of Artie&#39;s pelvis looks more human the hip bone is short and broad a key indicator of bipedalism but the lower half is much longer than a human pelvis more useful for climbing [Music] when you got to that detail you realized it was a mosaic of anatomy that had never been encountered before it suggests that already could walk on two legs but not as well as later hominids like Lucy and the rest of her Anatomy held surprises - neither Lucy nor humans have the ability to grasp with their big toe but this thing had full grasping ability so she has a grasping foot that can walk yes even the hands were a mosaic incredibly long fingers good for climbing but assured a human-like palm and the bones show none of the telltale signs that she walked on her knuckles like a chimpanzee so we now have a detailed picture of the crucial time when our ancestors had just started walking on two legs [Music] Artie was small around four feet tall a good climber she moved on all fours when in the trees but she walked upright when on the ground she blows the old theory of how we became bipedal out of the water not only did our ancestors start walking on two legs when still living in the woods they never looked or moved like our closest living relative the chimpanzee some scientists don&#39;t accept this interpretation they think already isn&#39;t a human ancestor at all but the relic of an extinct aide but Tim&#39;s spent years studying many specimens of Ardipithecus and he thinks the evidence is clear when we looked at the arti cranium we saw very small canines no other ape living or fossil has such reduced canines that&#39;s a good indicator she&#39;s come in our direction a bit go to the pelvis same thing a unique adaptation shared by humans and Lucy we&#39;re still not sure exactly why a woodland climber needed to walk on two legs but thanks to already we now have a snapshot of one of the most dramatic transformations in the history of our species the transition from walking on four legs to walking on two this major change to our ancestral body plan has serious consequences for us today [Music] these consequences can be seen within our own bodies and they&#39;re not all good this vault in the bowels of the Cleveland Museum of Natural History is the place to go if you want to find out what can go wrong with the human skeleton dr. Bruce Latimer is an anthropologist and anatomist there was a curator here for many years well this is the Hammond Tod collection which is the largest collection of its type in the world there are over 3,000 skeletons in this room in each one of these drawers is a complete human skeleton they come from unclaimed bodies at a Cleveland morgue dating from the early 1900&#39;s if you study these skeletons one thing becomes clear pretty quickly the human back goes wrong a lot there&#39;s an enormous amount of back problems the pain must have been phenomenal and you just see that all over this collection turns out our bad backs are an unwelcome inheritance from our inner monkey we took a skeleton like this that was essentially horizontal we stood it upright we&#39;ve had to change essentially every bone to allow us to do that and we forced it into this new position we have a problem going from this kind of animal into that kind of animal and our main problem is balance on all fours the weight of our body hangs down from our spine but turn this body upright and the weight is all out front it puts us out of whack totally out of balance in order to balance we had to create this curve on your back and then your head would be back here wouldn&#39;t it so we had to create another curve here in the middle of your chest and then you&#39;re headed be sticking out in the front so we had to create another curve in your neck so we have this s-shaped curve in our spine and we expect that to hold us up that is an engineering nightmare our s-shaped spine is unique among mammals and it causes all sorts of problems the vertebrae that make up the bones of your back and the discs between them are put under a lot of pressure particularly the ones at the very apex of the biggest curve the thoracic vertebrae if you take those thoracic vertebra and you push on them from the ends too hard what happens is this you end up with called what&#39;s called a wedge fracture that curve has crunched it no other animal has anything even remotely like this it&#39;s a consequence of how we walk and it&#39;s not just fractured vertebrae from slipped discs to sciatica our spines go wrong in all kinds of ways 80% of all Americans will complain of back problems at some point in their lives our inner monkey has a lot to answer for [Music] but I don&#39;t want you to get the wrong idea standing up on two legs wasn&#39;t all bad or it never would have happened in the first place it freed our hands an anatomical change that combined with our amazing brains would eventually allow us to make tools and reshape the world around us this key moment in our evolutionary history is once again visible in the rocks of northern Ethiopia Lucy&#39;s from one part of it and we&#39;re going to another that&#39;s right we&#39;ve just jumped about six or seven hundred thousand years in time and that is kind of mind-blowing yeah paleontologist bill Kimble has brought me to a site where you can find stone tools that are over 2 million years old if you know what you&#39;re looking for so what do I look for well you&#39;ll look for flakes on the ground low as that bone that is a piece of fossil bone and here&#39;s another one if I to look if I&#39;m bone yeah yeah the important thing about tools is it&#39;s the hand and the brain right it&#39;s it&#39;s it&#39;s both together absolutely I don&#39;t get this at all yeah I know it looks like something from your driveway the tool Don&#39;s found was made by human ancestors called Homo habilis who lived a million years later than Lucy clearly some early human took a stone a hammer stone and struck it right there and go oh yeah that&#39;s right yeah feel that edge you could use it to strip off me or whatever so from this rock you could tell where they hid it how they hid it it&#39;s almost like a time machine you have it is it&#39;s a time machine that takes us back to a period when the faintest glimmer zuv what it means to be human are beginning to emerge use of the hand the cognition the repeated behavior to produce a stylized tool it&#39;s my blood Wow we look for tools I want to find a tool no that&#39;s natural no this one found one making tools takes excellent vision fine motor skills and a brain that can integrate the two we humans only have this sort of brain because it&#39;s been shaped by our ancient primate past [Music] monkey ape or human our brains share a basic architecture that&#39;s different from most other mammals we all have a special region involved with hand-eye coordination and a greatly expanded visual system with as much as 40% of the brain involved in seeing our inner monkey hasn&#39;t just shaped our bodies it&#39;s shaped our brains as well but if you look at the modern world around us and everything humans have been able to build from satellites to skyscrapers there&#39;s no doubt were more intelligent than monkeys so what changed what made our brains so different from those of other primates to the infant primate lab monkey place tomber Bakker studies monkeys in order to answer questions about our own brains he&#39;s going to show me an experiment that demonstrates an important difference between our brains and the brains of a monkey but the differences aren&#39;t what you might expect especially when we&#39;re young monkey on the sack monkey on the set Neil this is see I she&#39;s at three months old pigtailed macaque this experiment test something called object permanence in other words whether this monkey knows an object still exists when she can&#39;t see it it&#39;s a developmental milestone for both monkeys and humans you&#39;re going to put a piece of fruit on the toy itself you&#39;ll place it in the well she&#39;s looking at it there and you&#39;ll be back to complete and hide that toy okay three months old and already CI understands object permanence good I can even how are you you are a cutie Geneva is the same age as the baby monkey I&#39;m going to do the exact same test on her under the expert eye of child development specialist Professor Susan speaker she needs to reach for him so that she&#39;s interested oh I think we got interest got it good you do yeah Oh Geneva you like those hello no Neil can you get them away oh I&#39;m an expert at this kind of think that there thank you sorry Lou temporary yeah you are so good that way she&#39;s watching and she wonders what did you do now what toys I don&#39;t know where they went wow that is amazing it is incredible if it did if it&#39;s not there it doesn&#39;t exist that isn&#39;t easy so how come a baby monkey beats a baby human in this test these tests are showing us how rapidly a particular region of our brain is wiring up in development and it&#39;s showing us comparatively that we wire up much slower in this part of the brain than do monkeys compared to other primates we humans have an unusually long childhood even if you take the different lifespans into account this should be an evolutionary disadvantage but in fact it&#39;s one of our greatest strengths during childhood our brains are being shaped by our environment and by our experience [Music] extending this phase is thus longer to learn and pick up new skills some think that this is a key part of what makes us so smart but there are other factors too the brain is made up of vast networks of nerve cells called neurons that carry process and store information the part of the human brain responsible for higher thought the cortex contains more neurons than that of any other animal on the planet an astonishing 16 billion [Music] these neurons are organized in a uniquely powerful way they&#39;re unusually interconnected this means we can do things that other primates can&#39;t build complex tools compose symphonies and even investigate how our own brains work but before we get too carried away with our own cleverness I want to inject a bit of humility that means leaving monkeys behind and going back to where the series began my anatomy lab in Chicago and my favorite subject fish the brain of a fish and the brain of a human have more in common than you might think this is a trip to the beginning this is as basic as it gets we&#39;re going human fish represented by a cartilaginous fish a shark on the right and what you have is we see the muscles and nerves and organs inside the the shark head but importantly you see this yellow tissue this is the front end of the of the spinal cord it&#39;s the brain doesn&#39;t look like much but it&#39;s the shark brain this is the human brain this is where it all happens for us where our memories reside where our you know our fears our love&#39;s our hates it&#39;s all in here human brain really the surface level looks nothing like what&#39;s sitting inside the shark head yet when you know how to look you find a very profound similarity and that similarity lies in the overall architecture of the brain itself in the human we have a forebrain and that forebrain consists of this folded tissue here where much of our conscious thought happens then there&#39;s a midbrain this walnut-sized area in the middle and then a hind brain that&#39;s a fundamental division we see that in development and we see that based on where the nerves exit the brain well if you follow the similar nerves in a shark what you see is sharks to have that same structure a forebrain a midbrain and a hindbrain there&#39;s a fundamental architectural similarity among all brains the brains of people the brains of docks the brains of cats the brains of monkeys lizards frogs salamanders trout bass given sharks fish are similar each one of them has a forebrain and a midbrain and a hindbrain despite the fact but those brains are often very different in function and form but that&#39;s not the end of the story the fundamental architecture of our own brains can be traced back even further than fish to a surprisingly primitive animal that doesn&#39;t even really have a brain but I&#39;ve got to find these tiny creatures first all right okay well we could stop trying to rattle dr. Spock thanks boss the squat let&#39;s give it good this is Peter Holland a world-renowned geneticist and head of zoology at Oxford University in England okay so what do I do now we pretty obvious because they&#39;ll start milk they&#39;ll really swim around the water makes the diggings finally carnage oh we got named whoa look a little guy go Hey just dip it in the water again you&#39;ll see it okay well they really click now you see it&#39;s beautiful look at that which is the front it doesn&#39;t look like much but this tiny creature called amphioxus has much to tell us about our own brands okay that ranks is cool okay so let&#39;s let&#39;s take a look at a couple of these so I brought this from the anatomy lab in Chicago this is a this is a human brain when I look at this I don&#39;t find any obvious similarities to that deep in the genes of this animal and the development of this animal and even the genes of us and the development of us there are the similarities no that is beautiful god they&#39;re so clear - you can see right through them you know it&#39;s amazing it MMP oxen the sand of the ocean floor filtering algae out of the water it&#39;s from an incredibly ancient group of animals we found fossils that look a lot like this in rocks that are over 500 million years old they are a window into what came before the first fish and crucially they don&#39;t have anything like what we&#39;d call a brain the simple nerve cord that runs the length of their body ends with just a tiny swelling invisible to the naked eye if you look at the front end of this animal you don&#39;t see it all expanded into a large skull or brain region it&#39;s just pointed but if you look at the genetic makeup of these ancient creatures you find something truly remarkable to make the forebrain midbrain and hindbrain that we saw in our lab you need a series of control genes to tell the cells within the developing brain where they are they&#39;re like a zip code those same control genes that make our own brains are active in amphioxus but here they&#39;re simply building the primitive nerve cord and the tiny swelling at its front [Music] this means that the genetic roots of our complex primate brains existed in much simpler creatures that first arose over 500 million years ago I think it gives us a glimpse into where our brains came from into the basic organization of the brain of our ancestors I mean I find that mind-blowing it&#39;s just an exciting animal he knows you&#39;re talking about him he&#39;s going he&#39;s going you can see there&#39;s muscle blocks really working there yeah and I think we need a Luthor but we&#39;ll oh sorry he&#39;s going out Tiktaalik on land living yep he&#39;s done for the next transition exactly he&#39;s in the Devonian now [Music] the search for our inner fish has taken me from high in the Arctic here was the snout of exactly the creature we were looking for to the plains of Africa yeah I just want to run down here and start collecting fossils let&#39;s go as well as deep inside our own DNA and today we saw a little tiny worm living in the mud here in the bay that contains genes that we have that sculpt our own brains the organ that gives us many of our unique properties [Music] we&#39;ve seen how our distant relatives from worms to fish from reptiles to early primates have defined our bodies at each new stage of our journey along the Tree of Life our our ancient animal ancestors have reconfigured what&#39;s gone before and that&#39;s how we ended up as the intelligent creatures with all our quirky flaws that dominate the planet today there&#39;s something incredibly profound and I think beautiful in the idea that inside every Oregon cell and gene of our body lie deep connections to the rest of life when our planet [Music] [Music] you

Transcript for:Your inner Monkey

Transcript for:
Your inner Monkey