Professor Alice Roberts - Origins of Us: Human Anatomy and Evolution

thank you all for coming to this Darwin Day event this is actually a confluence of three different events in effect so this is the eighth Darwin Day event we've had University of Birmingham the Darwin day initiative started in North America about 10 or 15 years ago as an idea of celebrating the life and legacy of Charles Darwin on his birthday or close to his birthday so Darwin's birthday is actually on Sunday but this was the closest working day that we could find over the course of the Darwin Davis who had in Birmingham we've covered all sorts of things the evolution of the human face evolution of genomes the evolution of biblical manuscripts we've had the Darwin correspondence project come and present to us we've covered a wide range of topics on the back of all that exciting stuff going on we've made a new appointment and this is Professor Alice Roberts I think she's going to feel a bit odd when I say that she said she would because this is a new new appointment just this month just a few days ago she started work here on the payroll at University of Birmingham I would now like to give the stage to Alice who's now going to give us a lecture to go with her series in our book called the origins of us over to you I'm absolutely delighted to be talking here at Birmingham University and now this is my university too and I'm really really pleased about that and delighted to be part of such a fantastic institution and thank you mark for inviting me to talk today which he actually signed me up to do before I signs if he's a favorite is a that I accepted the job I'm going to talk about origins of us and I'm going to draw on the television series but if you didn't see it it doesn't matter we'll be extending out from what we talked about on the on the television series but it was a fantastic opportunity for me as a physical anthropologist to go to some places which I never thought I get to go to that's one of the joys of doing television series like this but also to meet some fantastic experts in the field and to have time to really pick their brains which again is a an amazing opportunity and then to do that for a wider audience they bringing the kind of latest cutting-edge research in this area and to the widest possible audience which is great we are an incredibly successful species there is absolutely no doubt about that we can be philosophical about the effects that we're having on the world around us but there's there's there's no doubt that we are a successful species we have a population of something like seven billion we exist everywhere we thrive everywhere from the tropics to the Arctic but we're an African ape so how have we been able to do this how have we been so successful if we look at the other African Apes they don't live on all the continents of the world they don't make beautiful art and architecture they're not capable of the same things that we're capable of how are we so special now I the answers to that lie deep in our past in our evolutionary history I think if we go back in time we can get to a point where we were just another African ape so we go back that far to the stage of the last common ancestor with our places which are chimpanzees and this is I was lucky enough to meet some chimpanzees in Uganda last year based in the wild and also in a sanctuary as well where and I could play with them which was amazing and you suddenly realized how close you are to these creatures this is a four year old called nipper and he lived up to his name chimpanzees are our places living relatives and there are some similarities between us and there are some differences and superficially I think we noticed some very obvious differences which make us feel as they were very very different from them and they're covered in fur they run around on all fours they seem to be a world apart from us I think we like to think of ourselves as not just being another animal but being something rather special and but we are just another animal there's nipper again and there's some enormous ape next to me they're called Paul Jenkins one of the interesting things about asking this question and what is it that makes us human and taking this evolutionary approach to it is that we're going to find out things about ourselves but we're also going to understand more about our context we're going to understand more about how we fit into the great tree of life on the planet we're going to basically do the ultimates who do you think you are and trace your family tree back and back and back and understand where we fit it it's something which is incredibly intellectually satisfying I think you know we all we all ask that question who are we and we want to know more about it and and this is taking it right back into the past at Darwin and speaking on his birthday today I have to mention the great man Darwin thought that we were probably very closely related to African Apes and he thought that through observation of of the African Apes of gorillas and chimpanzees this is a direct quote from the descent of man in each great region of the world the living animals are closely related to the extinct species of the same region it's therefore probable that Africa was formerly inhabited by extinct Apes closely allied to the gorilla and a chimpanzee and as these two species are now man's nearest allies it's somewhat more probable that our early progenitors lived on the African continent then elsewhere now this now sayings you know you think well yeah that sounds reasonable of course it does but he's very carefully looking at gorillas and chimpanzees and deciding that they're closer to us than orangutans for instance in Asia and he's also saying this in a complete absence of any hominin fossils there are no fossils of human ancestors at the point in time when Charles Darwin makes this very prescient statement and of course he was right as he was about many things so we now have many many fossils but we also have other ways of knowing that we're very close to African Apes and that we are indeed an African ape ourselves I think that when you get up close and personal with with African Apes you realise that you look into their eyes you see something looking back at you that's perhaps a little bit more well or less other than other animals and I love this picture of a mother gorilla and a baby gorilla and it's just being a recent mother more recent ish and this this really kind of strikes a chord with me of course there are other ways less kind of perhaps sentimental ways of assessing that difference we can look at our genetic codes and if we look at the non-coding regions of our DNA we find that actually we are incredibly close to chimpanzees there's just about a 1.2 1.3 percent difference between us and chimpanzees and remarkably and this is something that we really didn't know until the genetics came along we are closer to chimpanzees than either of us is to gorillas and think because again if we just look at the superficial differences between the two of us well chimps and gorillas are hairy chimps and gorillas base knock a walk on the ground perhaps we think that they're more closely related they're kind of twin species and we're something off on a on a limb or perhaps each of us is equally related not at all and this is why people like Jared Diamond's well actually with the third chimpanzee you've got common chimps you've got bonobos and you've got us maybe we're not Homo sapiens at all maybe with Pan sapiens perhaps an alien coming in visiting earth with a bit more of an objective view than we have might say that and might get us to completely rewrite our classification systems we like to think of ourselves as being special so let's stick with Homo sapiens for now but keep this difference in mind this very small difference if you look at a chimp and human skeleton and you look at the entire skeleton they're very obviously different for different species but actually when you start looking at individual bones and there are areas where that difference disappears and I've always said I've never tried it when I was at Bristol because I thought it might be a little bit too naughty who knows maybe I'll try it at Birmingham I always said I could put a chimpanzee humorous a chimpanzee upper arm vein in a medical student spot exam their anatomy exams and they wouldn't notice that it wasn't human and that's not really saying anything about our medical students in the UK that's really saying something about how the chimpanzee humor er-2 human humor II okay that's just one banal from a similar one when we start to look at the rest of the skeleton we can see that there are quite significant differences between us and chimpanzees there's something going on in terms of limb proportions chimps have got very long arms and short legs it's kind of the other way in us so they we have retained quite long arms for a mammal and we've got ridiculously long legs things are going on in the pelvis look at that pelvis there it has very long thin iliac blades and these have got squashed down in us so there's all these kind of it's almost like you've taken the chimpanzee skeleton and morphed it but of course that's not right because chimpanzees aren't an ancestor chimpanzees are a cousin so we still don't know where we've come from we still don't know how much morphing has gone on maybe the last common ancestor look like us and it's chimpanzees that have changed think about that for instance I think we have these images and I'll head with the pit in there by popular popular imagery we'll all have seen that picture which I couldn't get clear copyright the ascent of man say that kind of linear idea of starting of something I'm gonna have to act it out because I haven't got a picture starting or something like a chimpanzee here and then you're gradually enhancing and becoming more and more human and then in the funny versions of it you punched a paper a computer or something the other end and but I think we I think we end up with this popular misconception that we've evolved from chimpanzees that can't be right chimpanzees and modern animals just as we are so we've built both evolved from a common ancestor and one of the really interesting areas of research at the moment is looking at what that common ancestor looks like and perhaps even those of us who had undertaken research in this area have had this kind of idea put into our heads that we find is actually quite difficult to get away from the idea that the last common ancestor must have been very chimpanzee like and we've evolved away from that and I'll explain what I mean by the clips I'm Anatomy in a minute some of the big differences between us and chimpanzees are in the shape of our spines we have this really beautiful shape in our spines a double S shape and this relates to the fact that we have stood up on two legs most of the most of the really big differences in our skeletons are relating to this they're relating to the fact that we are bipedal that's not to say chimpanzees aren't bipedal ever they're actually bipedal quite a lot of the time and perhaps I should say that we're habitually bipedal it's our locomotion of choice if you if we're asked to move from A to B what we tend to do is stand up and walk they're all run there if you ask a chimpanzee to do the same thing inevitably they'll drop down onto their hands and knock a walk across the floor but they can stand on two legs as well so when did this standing on two legs happen when when did this first start to appear when do when do we see that happening in our skeleton and well actually this very early fossil lacks a spine so we can't look at that spine and go oh well it's got the lovely SS shape that chimpanzees don't have but that we do have this is a fossil called to my or Sahir lunch procedure densest and was discovered in Chad in 2002 and it is just a skull so then perhaps you're left thinking how on earth can you tell from just a skull that this ape stood up and walked around on two legs I'm quite persuaded by this actually because it has to do with the position of the large hole underneath the skull where your spinal cord comes out and we don't like to cool things by an easily accessible English name in anatomy so we're not going to call it the large hole or call it frame and magnum and which means large hole and bit of Latin a Greek does help with monosomy because it's just it's all translated so what's interesting about to my is that his foramen magnum instead of being positioned right on the back of his skull here like a chimpanzee foramen magnum is then leading off into the spinal canal of the vertebral column like this at an angle which put head in the right position for walking along with all fours what we're seeing instead is that the Freya Magnum is down here so in fact this looks like it's the skull of something which has a skull balanced on an erect spine so he looks as though he probably was much more upright than a chimpanzee team'll is also really interesting because the evidence for being bipedal standing on two legs weight bearing on two legs pushing it back to almost the time of the split genetically from chimpanzees so this fossil dates to six to seven million years ago well we've got an estimate of the divergence from chimpanzees of somewhere between five and eight million years ago say pretty at the split to be very controversial I suppose we could say do we know if two minds really a hominin ancestor after all could he be a chimp ancestor it's an interesting suggestion another thing about to mine is that I think he dispels another myth another kind of common image that we have in our minds about human ancestors dropping down out of the tree using walking out across the Savannah and that's how you know it seems like such a nice just so story doesn't it you're climbing around in the trees and then you drop down and you stop walking on two legs there's a couple of things that don't quite ring true about that one of them is that Jim when chimpanzees drop out of the trees they don't walk on two legs there's nothing necessary about walking on two legs if you're going to walk along the ground not many animals do it think about it there's very few animals that walk around on two legs it's a stupid thing to do you're much more stable on four and if you you know if you haven't got if you're going to do two legs it helps to have a tail to balance on like a kangaroo and so it's a it's a very odd thing to do first of all the other thing is that actually it wasn't as though there was this big grassland environment for the to my to walk out into he didn't walk out into a savanna environment he was still living in quite a quite a wooded environment this is what he might have looked like this is one of the reconstructions from a Dueling Kindersley book on human evolution and which I was involved with it she's published in autumn last year and I was absolutely over the moon to have the kennis brothers working on it the kenny's brothers are fantastically creative pair of Dutch brothers who are paleo artists they bring ancient beasts to life and amongst the animals they bring to life ancient human ancestors and say they're basically making reconstruction based on casts of the original fossil material and then talking to the scientists trying to get an idea of the best possible way of reconstructing these ancient hominins so this is what to my might have looked like and he did not walk in a savanna environment another fossil which has kind of challenged that that kind of long-held idea about bipedal ISM evolving as human ancestors drops out of the trees and walked on the ground is this chap and you might have heard of him it's called Ardipithecus or Rd and these fossils date to 4.4 million years ago and they seem to show something quite interesting they seem to show a mixture of adaptations to walking on the ground but or say some adaptations which liquors they're doing quite a bit of walking in trees which seems like a seems like a slightly strange thing to do perhaps but it does seem that what we've got here is a creature which basically moved around in trees with an upright body say weight bearing on his feet and so then that becomes perhaps a precursor for weight bearing on your feet on the ground perhaps all he's doing in the trees is is walking effectively walking along branches and stabilizing himself with his hands what's really interesting about this is that there are modern Apes that do quite a bit of that and the most bipedal modern ape is also the most tree living the most arboreal it's the orangutan so now we're going away from the African Apes and looking at something which might be perhaps be a better model for what our ancestors look like than the extant than the living African Apes perhaps our ancestors were a little bit more like around new tangs in some way perhaps they were more bipedal and but not on the ground bipedal in the trees and this is based on research which has been carried out here at Birmingham University although I say it's been carried out here at Furman University we don't have many around tens here so students are research at the gang act of Borneo and looking at orangs in the in the field and looking really carefully at how they move around and why they do it because I think something that springs to mind immediately is why should why should this ain't be moving like that in the trees why isn't an orangutan dropping onto all fours and moving along branches on all fours why are they kind of standing and walking in trees what might be useful about that there must be something that's useful and eeveelution airily for that behavior to be there and it seems to be best of all it's difficult for a large body date to balance on the top of a branch it's actually much easier to stand on it and use your hands to balance and so you can get right out to the edges of trees and reach out for fruit on the thinnest branches by doing this so it's quite a useful way of edging right out to the edge of a tree and getting it with getting at that precious fruit it also means that actually you can get from one tree to the next tree without dropping onto the ground and again if you're a large bodied 8 that's quite an important thing to be able to do if you're going to spend most of your time in the trees and that's where you're getting your food then not dropping on to the ground is great it means that you are removing yourself from a risk of predators soon as you drop onto the ground then you could be eaten by something it's also you're also using less energy if you can basically walk from one tree into the next rather than climb down the tree walk across the ground climb up the next one that uses a lot more energy so maybe that's why our ancestors and we're doing this and as I say from RD it looks as they this this may be the origins of our walking on the ground I think it does make us make us wonder where they're actually some of the differences that we see our differences that have appeared in chimpanzees and have been conserved in us so maybe actually we're getting a very weird view of ourselves by comparing ourselves with gorillas and chimps and going ok when did we become different maybe that's not the question maybe we're looking at a last common ancestor which which which means that actually we've been quite conservative we've carried on doing the walking on two legs thing even if we've moved that onto the ground and it's the other two which have evolved in a different way and become knuckle walkers and actually when we look at the form of knuckle walking in gorillas and chimps it looks that much it looks that's different it's anatomically it's functionally different so perhaps they did independently evolved that way of walking around as we look at more fossils we've got a lot of fossils now of ancient hominins and we see more clues to becoming perhaps more and more adapted to moving around on two legs and moving around on two legs on the floor this is a reef amos fossil and this is Lucy so Lucy is an australopithecine dating to around 3 million years ago and she's got some adaptations in her skeleton which make us think that she's she's really kind of acquiring more adaptations to to walk you around on two legs her pelvis now looks much more human I know it still doesn't look quite human it still looks weird compared to the human pelvis but it doesn't have that great big long iliac blade that we saw in the chimpanzee for instance her legs have got a very definite angle femur so this thigh bone here is angled in towards the knee and there are some really beautiful fossils of just the knees of australopithecines which show us that their knees angled in and your knees are angled in everybody's knees angled in everybody has a little bit of not knees about them and it's all about bringing in your as having hips at the side and then bringing in your knees so that underneath your center of gravity and so then you have to have a little bit of an angle there and Lucy have got that she still got some what looked like adaptations to moving around in the trees in terms of the proportions of her limbs so she hasn't got terribly long legs and she's got quite long arms but actually a recently discovered skeleton which is called the big man Cardano mu another australopithecines and has got has got longer legs so perhaps we're getting a slightly different or slightly slightly strange idea of what these australopithecines looked like and indeed perhaps there was quite a lot of difference between the males and the females unfortunately Adana me doesn't have a skull so a few researchers say well we can't be sure that he's the same species but I think most researchers are happy that he is so when did long lengths appear then because one of the things we noticed bet you know the differences between ours and chimp skeletons is that we've got long legs and if we go back in time what we're seeing is ancestors with short legs well long legs really stride out onto the scene with this chap and I think this is probably my favorite hominin fossil he's a really beautifully preserved skeleton and I've lain him out here this is why we were filming origins of us in Kenya he's called an area kotomi boy I don't think he was called that when he was alive he died by the shores of a lake which is in a region which is now by the nari oka tamae River in Kenya it's also nice going to these places and meeting locals so I know that it is narrow kotomi and not as I used to say Neriah kata me and when we film this we filmed it with a little 5d camera a little Canon 5d camera positioned above it fantastic camera the 5d sir it takes HD video I don't think Canon realized it was going to be so popular as a as a as a film camera when they produced it but we filmed it looking down off the skeleton I laid the scale tonight what you couldn't see in the shots and the series was the tent the safari tent in the background where we disappear off and have cups of tea from time-slowing because that would let me to look forward to easy and the interesting thing about Nara kotomi boy is partly his long legs but also there's lots of other aspects of his skeleton which you can't really explain as adaptations to walking you look at his skeleton anew and and there are there are things about it the long legs perhaps you could explain as an adaptation to walking getting a nice pendulum effect going but there are other things including a strong nuchal ligament at the back of the at the back of the skull leading down onto the the neck vertebra the cervical vertebrae a long and flexible waist we haven't really seen that before and dropped down shoulders and his shoulders are sitting nice and low now Rob being up high and ready for moving in the trees as shoulders of drop down and and he also seems to have well-developed springs in his legs in the form of tendons we've got a very thick Achilles tendon compared with other Apes and it seems that this is developed by the time we get to an era cat Amy boy so this is the cover of nature based on the paper by Lieberman and bramble who put forward a very coherent argument that these adaptations in narrow Khatami boys skeleton and not about walking at all they're about running and it was amazing because I think we'd always thought about human evolution as being all about walking and suddenly there was this new form of locomotion that obviously we know about we know we can do it but from Dan's very careful analysis of the anatomy of living humans and of nagatomi boy and also of biomechanics so he was running humans on treadmills he was looking at which muscles are being used he was able to say look there's a whole suite of anatomical adaptations here that we can't explain just through walking it seems that running was a really really important thing for this young man and when I say young man he's a he's a strange he's a strange young man if I were to look at this skeleton in my lab and analyze him as a modern human I'd say he was a young teenager he's about five foot one and I'd be slightly worried about the way that his bones are developing and his teeth are developing because there seems to be a disparity between the age I'd get looking at his teeth and the age I'd get looking at his bones and actually if you if you look at him really carefully you say right--let's he we can't just use modern humans as a way of aging him we have to look at other primates as well let's look at chimpanzees and let's look at how they develop and he doesn't seem to be developing like chimpanzees either so he seems to have his own program of development perhaps that's not surprising you know he is another species he's Homer Augusta or African Homo erectus and but the best guess I think so far is that this is a boy who's eight which is really quite shocking yeah five foot one eight year old and so he was achieving maturity much earlier than we do and there's a big debate about whether or not there was an adolescence at this point chimpanzees don't really have an adolescent growth spurt in the same way that we do and it seems that Naracoorte a wee boy might not have had an adolescence as well anyway he is adapted to running look at his lovely long legs I think if you saw him walking around you wouldn't really bat nine it unless you were to get a really close look at his face he's got a bit of a small head his brain sizes only about 750 milliliters where is a most of us in here and you know getting up for one and a half liters you know we've got brain sizes almost twice the size of him so you might know it you might think his head looks a bit small say he's wearing a hat or something and space looks a bit we as well his teeth are a bit big but I'm in a distance walking along I think he would have looked like a modern human walking along in the distance he he's basically got our limb proportions it's quite amazing we just look at that skeleton as a as a whole and suddenly you're looking at something which is very different from those australopithecines very different from those kind of short legged long-armed creatures and this is a boy who as the cover of nature said was to run so this young man then was running out across the savanna there is a savanna now the savanna has expanded and in Eastern Africa we know that we know that from all sorts of Paleo climate investigations environmental sampling we also know it from the other animals that were around at the time we've got a big explosion in grazing animals so we're suddenly getting all those antelopes that we're kind of familiar with in the landscape of Africa appearing and expanding and now a kotomi boy is amongst this group of animals that is exploiting these new grasslands so he's running onto the grassland what is he doing it must be really important for him to be able to run onto these grasslands now this is another very powerful concept which is grit is the popular in the scientific imagination for decades the idea of man the hunter presumably this is what Narracott a me boy was doing running onto the savanna he was running down animals and probably throwing some stone tools at them because he had some stone tools by that point and when we look at hunter-gatherers today of course hunting is an important part of what they do hence the name hunter-gatherers so this idea that hunting is is there it's the kind of origin of our genus how Moe has been a very very powerful idea but when you look for the evidence of it there's very little evidence there we have some stone cutting tools by this point but we can't really tell what they were used for they could have been used for cutting anything and we can look at the scratches on them and people are starting to do that now but we're actually finding this it's very difficult to tell apart the scratches made by cutting something fibrous so a kind of fibrous plant material versus cutting meat so hopefully there'll be some new techniques at some point that we can use to say whether or not these things we use for for cutting me we can either tape analysis and I think that that's giving us an idea that in fact there is some more meat in the diet and but nevertheless at it I don't think it's is a date thing is as important to transition as we've always thought it was it's always been this idea that meat eating comes along that's what makes us human and I think that there's some really interesting ideas about what else is going on at this time as well because other things are changing so and if we look at teeth for instance and I just mentioned about the stone tools we get into the same problem with the teeth because if you're trying to look at you can look at the micro where scratches on teeth so you can make a cast of the teeth stick them under the microscope and analyze the tiny scratches on the surface of the teeth which basically record what you've eaten for the last couple of weeks and peter unger in the states has been doing this with a whole array of hominin teeth and coming up with some quite surprising findings one of which is that the another set of of hominins the the robust australopithecines these these massive jawed Nutcracker men probably weren't eating that many nuts and hard things they seemed to be needing grass and all meat and and that here again is the problem that meats and grass it'll leave a very very similar imprint on the teeth and what we do you find licking it and looking at the looking at Homo say Homo ergaster here now a cute AV boy again what we do find look at his teeth and is actually what seems to be happening with these early homo species is that they are eating a wide variety of things so we're getting some scratches some pits some kind of different patterns on the teeth so there seems to be an expansion in the variety of diet even if we can't put a finger on what exactly it is perhaps meat is a component there perhaps there also a variety of different plant foods this is Nyanza he's a had the hunter that I met last year in Tanzania now while he's out hunting and it's quite interesting when you meet hung together and men actually and talk to them about how often they bring in big game and I think that anthropologist was slightly waylaid by hunters telling them that they bring home massive antelopes all the time and it's a little bit asking somebody he's into fishing how do you know what have you caught what it was that big and it is a little bit like that because then when you talk to the women they go yeah well mostly it's rabbits and you get a slightly different idea so I think that I think there's some interviews with hunter-gatherers have given us some misconceptions about the importance of big-game hunting actually in human evolution as well while the answer this is not to say that we can't get any insights I mean obviously these people and modern people you know they're not proven then we're not looking through a window into the past they're more than people but perhaps they can give us some insights into how our ancestors lived they certainly would have lived as hunter-gatherers so we can perhaps get some ideas about the reality of that life from looking at and people like Nyanza and his and his family now while he's off hunting what we find is that the women at the group of the village are off collecting food and actually what you find I was very pleased about this was that if you add up the calories brought back by the men and the calories brought back by the women gessie brings back the most and a women know where to look the men are often slightly risky things or you know hunting things which are not necessarily going to lead to a successful kill the women are always successful they'll be relying on things like berries and fruits a lot of the time but actually they always have something they can fall back on because even if there aren't any fruits and berries to find they're always going to be things underground and this is an emerging idea that with it's actually one of the really important foods to hunter-gatherers and presumably one of the really important fees to our ancestors and really if we think about it carefully they're quite important to us today as well our tubers so we're not talking it's not the theory of then man the hunter it's the theory of woman the tuber gatherer I mean just think about the staples that we have today forget about all the cereals because we're not going to domesticate cereals for tens of thousands of years but think about other staple foods and potatoes form a really important part of our diets they're a good source of energy they're a good reliable source of feed and tubers underground storage organs and were probably an important source of food for our ancestors going back a very long time ago going out with the the women it's quite surprised at some of the tubers that we're finding actually they just I expect them to look like potatoes or sprays or sweet potatoes at least and a lot of them was just slightly expanded roots and so this is one here I think it's called aqua and it has a kind of that's that that's a chunk of it there so it kind of just looks like a tree branch but it's kind of a very thick root and you peel off the the outside cortex with your teeth and then you can chew this bit and you don't swallow it because it's really really fibrous there's actually delicious it tasted a little bit like chips nuts and I really liked it it was even nice and that brings me on to the issue of The Incredible Shrinking teeth so one of the one of the big things that we see happening in human evolution and one of the things that we really need to explain is why our teeth getting smaller over time so we can look at all those other aspects of our skeleton and and relate them to walking and in the trees walking on the ground running on the ground and but other things are going on in our heads we'll come to the most obvious one last but our teeth are getting smaller we have Incredible Shrinking teeth and a very very good idea about how this might have happened I think is something else that our ancestors did at some point it's really difficult to know when human ancestors controlled fire imagine trying to find archaeologically the traces of a campfire that somebody's made it's a really difficult thing to do the most likely thing is that that's going to get blown away and there won't be any traces of it left at all and it's also very difficult to discern the difference between fires that have been made and carefully controlled and wild fires you might just be looking at a lightning strike or something so it's actually very difficult and the most we've got compelling evidence for control fire by about half a million years ago and but Richard Wrangham is a researcher he thinks that actually there's pretty good evidence going back as far as an area kotomi boy and I think pretty much as soon as you've got fire which is going to be useful to you in lots of ways obviously keeping you warm at night as a way of defending ourselves against predators it's not going to be long until somebody sticks a bit of food in it and goes that tastes nice and cooking is more than just making food taste nice cooking does something really important for us cooking means that we get a lot more energy from our diet than we would do otherwise so Richard Wrangham zai dia is that cooking provides us with almost the same kind of boost as people used to put forward for the man the hunter idea that that meat would be the kind of thing which gave us a lot more energy and he's saying actually maybe we should be looking at cooking this could be much more important in terms of providing early human families with with lots of energy from their diet it means that you can move some of the work of digestion out of the body so you're effectively semi digesting your food outside and your body and then eating it so it means you're spending less energy on digesting it you can do other things you can do pounding of food that does a similar sort of thing and you're obviously physically digesting the food by pounding it but actually kicking is a really efficient way of maximizing the energy that you get from your food I think it's a I think it's a great theory so now instead of the idea of man the hunter going off and catching meat he's there but perhaps he's only bring back the occasional rabbit what we've got a women bringing in tubers and this idea of cooking that seems so unlikely in a way but this idea of cooking being quite an important part of our evolutionary heritage and all this extra energy that cooking is giving us will presumably mean that we could support bigger families and all that sort of thing but perhaps it also gives us the energy to help a bit of us grow because the other big thing that's happening is an expanding brain now now you Khatami boys brain is quite big when we look at earlier hominins earlier human ancestors at 750 milliliters it's almost twice the size of an Australopithecus teen brain which is about the same size as a chimp brain but having said that his body is much bigger so if we scale his brain to the size of his body there's not really that much grief in brain size because you expect an animal's brain to get bigger as their body size increases the really big expansion comes in fact after narak a tiny boy by the time we get to Homo heidelbergensis so relocated about 800,000 years ago that's when we see this really massive expansion in brain size and so maybe that's when we became master chefs who knows this is a slightly distorted argument or or idea that I've been presenting the idea that you could get more energy out or something and therefore you're going to grow a bit of your body that's not how evolution works and oK we've got to have the energy in our diets or through kicking to release a bit more energy in order to be able to support this very energy hungry organ the brain but one thing doesn't lead to another there has to be an evolutionary reason for growing that brain big there has to be a reason for the brain getting so big because it's a very demanding organ it wouldn't have grown bigger unless there was a really important advantage to us in having big brains and that has been something which is taxed pay anthropologists for decades and decades and I think still taxes everyone in the field how and why if we developed these enormous brains and you can come up with lots of ideas about it and you can say that oh well perhaps it's about cooperative hunting going back to the old man hunting is something about hunting it must be in there what Lions the cooperative hunters and you know dogs are cooperative hunters they don't have massive brains so that seems that seems frankly quite unlikely there are other ideas about a kind of feedback between beginning to make tools and then having to learn to make those tools and that's that kind of demand that that might place on your brain and maybe you need a bigger brain in order to and be able to create that kind of culture to create that technology and that's a you know that's a that's a very good idea I think and and we can test that but another thing is actually about our societies and the way we interact with each other and there's been some quite interesting research looking at the size of primate groups and actually other animal groups and also the complexity of those groups as well and there seems to be a very definite link between the size of group the complexity of group and brain size and we have big social groups and we incredibly complex social networks so maybe this is what is driving that massive brain size we're very good at keeping track of people in our social groups as well and working at what they're doing and what their intents are and we can see some of that in chimpanzee societies when you look at how they interact with each other politically but I think we do it even more we do that whole thing of we do some really complex things in everyday life of kind of working out what people are thinking so again I think you think something about her and she you think something about him and he thinks that about you and you can keep track of it through several people and there's there's an idea that Shakespeare is so successful because actually his plays are based on so much complexity and people knowing things about other people and we love that you know we thrive on it maybe that's what has fueled the expansion of our big brains and when our big brains come together and in these big groups there's there's a lot more going on than just politics we're able to bring ideas together we're able to express abstract ideas from deep in the recesses of our minds and share them with each other and build on them and create culture and we see a really interesting thing happening when population groups get dense enough throughout evolutionary history and an archaeological time and we seem to have an effect when a population gets to a certain size and density that you get explosions of of culture explosions of of ideas and there's a group in in London which have been looking at that and including mark Thomas not the comedian the the researcher and that's a really exciting idea because up until this point in time no not up until this point in time up until the invention of writing it's depended on one person speaking to another to share ideas when we get writing we can spread it more widely when you get the printing press you can spread it even more widely now we've got the Internet and the potential for ideas to grow and feed on each other I think is just huge at the moment say where we're kind of at the the at the very beginning of something in critics iting something that we couldn't have foreseen going back into it you should be passed as well these are some children learning from each other and they taught me some clapping games as well the importance of learning from each other and sharing ideas probably underlies the length of our lives as well we have very long lives and particularly women we live beyond our reproductive years and that's a very strange thing to do it's very odd for an animal to finish reproducing and then live for decades beyond that what is that about what could be the evolutionary function of living beyond the end of your reproductive years you should either carry on reproducing till you're dead or you should die at the same time as the menopause there's something going on which means that elderly people are valuable elderly people evolution is keeping people alive and that probably is down to sharing ideas and the fact that these older people in a population represent a repository of knowledge that the rest of the group can draw on so all sorts of things are shaped by our evolutionary journey we've seen our teeth being shaped by it our brains being shaped by it the shape of our bodies the way we move and even the length of our lives as well and hopefully at the end we've gained some deeper understanding of who we are as humans whilst at the same time acknowledging that we are animals and we are just another African ape I'd like to introduce you to some of these ancestors as we created by the wonderful kellys brothers and we'll just go through time and meet some or family on the way here's here the Kelly's brothers in their studio working away and building up the anatomical layers on a cast of a skull this is them this is a Neanderthal they're just doing their let's go back seven million years ago you've seen this character already this is to my so hero students this from Chad and then we've got Australopithecus africanus this is a two year old I love their reconstructions so many of these reconstructions of human ancestors are expressionless but here we're actually seeing a person we're seeing a little two-year-old gang ooh and this is the town baby and then we've got Australopithecus afarensis and this fossil from a group of fossils which has been called the first family and then we've got Homo habilis and Homo ergaster and Homo erectus this wonderful reconstruction of an East Asian ancient human Homo antecessor bein eight hundred thousand years ago and the undersell the old man of la Chapelle Oh son you could just imagine him speaking to I'm not sure what he would say or how he would say it another Homo sapiens and a homo sapiens lady from from Israel who probably dates to about a hundred thousand years ago by this time we're pretty much us thank you very much for coming along this afternoon and I must say thank you to everybody who worked on the series and all of all of the people on the production side of things but also all of our fantastic contributors experts in the field and also people people that we met like the Hadza and also thank you to DeLand Kindersley for letting me use it all the images from the book and to Adrian Alphonse Kennish who bring us face to face with our ancestors you

Channel: University of Birmingham

Views: 429,439

Rating: 4.6625972 out of 5

Keywords: professor, alice, roberts, public, engagement, science, university, birmingham, edgbaston, west, midlands, england, uk, great, read, at, grab, darwain, day, clinical, anatomist, author, broadcaster, origin, origins, us, human, anatomy, evolution

Id: x858bOny4Gw

Length: 50min 6sec (3006 seconds)

Published: Fri Jul 13 2012

Reddit Comments

[u/easilypersuadedsquid]

Alice Roberts, Professor of Public Engagement in Science at the University of Birmingham presents a lecture in association with the Great Read At Birmingham (GRAB) project.

Clinical anatomist, author and broadcaster Alice Roberts gave her lecture as part of the Darwin Day celebrations, with a focus on the anatomy and evolution of humans as a species.

'We are all members of a very special species. Whilst our anatomy and physiology is undoubtedly that of an ape, we have done things that no other ape can do, and become the most successful ape on the planet. Today, our global population numbers almost seven billion; we survive and thrive everywhere from the tropics to the Arctic.

So just what is it that makes us so special? In some ways we are so similar to our closest cousins, chimpanzees, but it's also clear that we are a world apart. But we can understand ourselves, how we got to where we are today, by going back into our deep past, to the time when we were just another African ape. And then tracing the small changes that over time, and unpredictably, led to us becoming human.

The answers to the question of 'what makes us human?' lie buried in the ground in the form of fossils and traces of our ancestors, but also lie deep within the form and function of our bodies.'

[u/Threctic]

Well, I looked into this lecture and honestly didn't expect much, but this was actually interesting! Taught me some new stuff I havn't heard of in pop-sciency articles, and it does kind of change your world view a bit.