>> jeremy desilva is an anthropologist at north or college and editor of a most interesting problem what darwin's descendents of man got right and wrong about have -- evolution and part of the research team that discovered two ancient members of the human family tree. he studied wild chimpanzees in western uganda and urban fossils throughout eastern and south africa from 1998 to 2003 and worked as an educator.

kate wong is senior editor at scientific american and has been writing about the evolution of humans and other organisms for "forbes" magazine since 1997 and is co-author of lucy's legacy the? for human origin. tonight they will be discussing jeremy jeremy desilva's new book "first steps" how upright walking made us human. he explores the history of the ability unique to humans to walk on two legs but he makes the case that bipedalism is crucial to allow for the evolution of humans despite the difficulties forever after. it praises the syllabus love of collaborating in examining bones first-hand and to turn anatomical evidence into the locus detailis of human afflictn

and his enthusiasm for research will leave the reader informed and up with different and pleased to turn things over to our speaker jeremy and kate. >> thank you. a appreciate the introduction. hi kate. >> hi jeremy. it's great to see you and thanks so much and to harvard bookstore. i'm delighted to pepper jeremy with questions about his new book which is about all the things that i get excited to write about so it's just really a pleasure to be here. i thought we could kick off the conversation by having you tell us why it sets us apart from mammals and other primates and we have bodies and large brains and language. why focus on bipedalism?

>> it's a great question. we have these differences but we have lots of similarities to our primate cousins. upright walking is one of those. mammals sprint and leap and walk and climb. your typical mammal runs on all fours thinking of cow dog sheet cat squirrel runs on all fours. people navigate and their extended hind limbs all the way. really a strange way to move and we kind of lose their mind. we videotape is happening in posted to youtube and it gets millions of hits. i was in researching this book i found examples of errors looking on two legs in a new jersey a bear named petals and it got

almost 5 million views m of a br walking on two legs in the jersey suburb. a gorilla in philadelphia started walking on two legs, occasionally. they got a video and ended up on the cbs news. something we do all the time, we then use the word pedestrian to describe something ordinary but when another animal does it it's remarkable but not only that i'm a paleontologist. a study fossils and what we can tell by going back in time to a common ancestor that we share with our cousins the further back we go we start to lose some of those unique characteristics like the large brain and evidence for language and the same happened more recently. the most ancient characteristic

we think about what their lineage is this ability to walk on twoac legs. notor only is it strange is a mammal but it's the most ancient thing that set her lineage off and what i argue in the book is that it was the key innovation that led to many of those other anatomical and behavioral changes that we assumed. >> that's a very interesting lens to which to view the entire evolution. this may sound like a question but think about this from a mechanic standpoint walking all the time we kind of take it for granted and we don't really think about it but what is special about it from the standpoint of -- can you describe the act of walking on two legs and what is unique

about it and how do you convey that? >> it's a balancing act moving on two legs. when i talk to my students i say imagine if i want you to design me a chair. you've probably designed with four legs and there may be clever students that use a barstool and make it out thede legs but if you make it out of two legs is not going to work. you will fall over. two legged locomotion is pretty unusual way for a mammal today. we can get into bird motion at some point and deep deepen the past we find evidence about dinosaurs and a crocodilian lineage but from a biomechanical standpoint this is about what we

canoi see and identify fossils s coming from things that move on two legs they have a specific individualhem these bones that aligned the joints and we that would prevent us from tipping over or we change the action of certain muscles so that those muscles would act in the way to prevent you from tipping over in onee of the classic examples is a bit joint. when you take a step and lift your upper leg you fall over and wanted chimpanzee walks and two legs that's exactly what they do. they wobble from side to side in humans we have an evolved pelvis where the muscle attachments here or on the side of the body and by being on the side we will contract that every time you take ade step. if you find this part of the

body it can tell you if something is moving on two legs. kate knows this very well. lucy sure enough has the hip joints arranged in a humanlike way. it's the only part of her we found we would be able to tell she was able to balance on a single leg and move around on two legs. really connecting it to -- it's not a great way to move around your world. we are incredibly unstable on our two legs. we fall a lot and that could be dangerous. 30th thousand americans die every year from falling in addition to that we are00 stunningly slow for a mammal. the fastest human as far as you

know that is ever lived in the fact that he's ran it 28 miles an hour in his 100 year -- in the 100-meter -- is 29 miles an h hour. it's half the speed of the galloping zebra half of the speed of the galloping antelope and half the speed of a lion and a leopard. evolving this form of locomotion madede us slow so it raises some interesting questions of in what ways is it beneficial in allowing us to overcome some of those now adaptations, this black of speed? >> and you anticipated my next question. which is why what sees

on the surface to be on the subpar way of getting around. i don't understand a lot of scholarship over many decades and people coming up with all kinds of ideas about why we did come to have this unusual locomotion and there are some really interesting ideas going back as far as darwin and i thought it would be fun to take a tour through some of those ideas if you wouldn't mind. >> it's one of those things where if there was another mammal that moved onto legs we would be able to test this more and look at science and say okay what does a this other mammal do and what is it eat and are its mating patterns and what are the ecologies bullets room which this form of locomotion is beneficial? when you're trying to figure out

il?something you want to look t in the natural world and see where else do we see examples like this in an if in fact we don't have other animals that walk around on two legs it's a very difficult problem to solve in one of the reasons we haven't solved it. you can go back to leimert and take itt up until 2021. people are still hypothesizing why bipedalism was so advantageous for ancestors. it goes back to leimert. leimert was interested in humans being able to stand and see off into the distance and without one if you look off into the distance the worst way way to give get a way from it would be bipedal lee some. bipedalism. there are ideas about of course

darwin saw the connection between k-9 teeth and bipedal lissome and tools. that becomes somewhat problematic although an interesting idea problematic because the timing. by the tee lissome that are six or 7 million years old and we don't have the tools until 3.3 million years where bipedal is reported to and there were wild ideas about displaying and showing off your body for selection and ideas that are more reasonable having to do with food sharing and if he can free the hands not to make tools

that together food there are some ideas that have been promoted where the females are gathering food and sharing it with others as nancy tanner's idea and lovejoy put that argument to males collecting it in sharing with potential sexual mates. it's idea that has had more lasting -- we are energetically very efficient and one of the best ways to explain that is herman ponce are and i talked about these ideas and he said in order to lose a pound of weight you have to walk 70 miles because we are too good at it. we are to energetically efficient so now you don't want to lose weight and early homonym

but if you need enough food to survive and maybe there's not a lot in the landscape those individuals are moving in a way that's energetically efficient might survive better. that's a possible idea as well. yeah there are lots and lots of hypotheses and we still don't have a handle on it and that's okay. they are going to be plenty of things like new discoveries that allow us to go back and revisit some of these ideas and the issue is not figuring out which one is right but to narrow that list down to the point that are clearly wrong. that's how science works by refuting ideas rather than improving them. >> right. we don't know yet why bipedalism evolved but we do have a lot more information about the

timeframe in which it evolved. maybe we could talk about some of the discoveries that have allowed you and your colleagues to start to piece together when this all happened and what bipedalism may have evolved from and where it took us. >> aa lot of folks will probably know about lucy from the 70s and lucy is a magnificent partial skeleton. a cast of her -- the original is in ethiopia of course but they were found in tanzania where i do my research as well. that pushed bipedalism back so those were markedly important

discovery showing bipedalism existed in 3.5 million yet the genetics and the common ancestry we share with chimpanzees were at six or 7 million the split between the two lineages is complete by 6 million years. that's a big gap, 3.5 million to 6 million what's going on in that timeframe? the last 20 years there have been remarkable wonderful important discoveries that have begin to piece that story together. one is a partial skeleton from ethiopia that 4.5 million years old it's known as already and arctic that the guest has some of these keen morphologies of the foot that would indicate at least it was occasionally able to move around on two legs on the ground but also has a big

grasping toe in the foot so it was an excellent tree climber with long fingers and a really good treat climber but when it came down to it they could actually move onto legs. so we have something that's bipedal and if you go further back than that the evidence becomes much more controversial and a little more difficult to interpret. this is a 5.5 million-year-old -- in ethiopia and it matches the shape especially the end of the bone of the human toe that would push off the ground when you are walking where's a chimpanzee to toe curves and the other direction for grabbing and this has the curvature to it that's more like an so it has an

angular way into it space. meaning it would probably have been able to push off from the ground. it's just the toe. it would be nice to have more. this is a beautiful femur from kenya that 6 million years old and what is unique about this one if you compare it to a chimpanzee the header at of the ball part of the joint is very similar to look how short the neck is on the champ and how long that neck is on this fossil. it's similar to what i was talkingre about earlier repositioning those hip muscles. by drawing those muscles farther from the hip you are making it more efficient and when you think of that anatomy there's evidence for bipedal locomotion. then if you go back even farther

to 7 million years there's this remarkable skull discovered in chad and is very controversial. the researchers who found it in first interpreted it argued that the hole at the base of the skull where the spinal cord would exit the brain was in a humanlike position and therefore this creature would have been able to hold itself up bright and walk on two legs. we don't walk with our heads like fossils from other parts of the bodies and there's a femur now that has been published by one team and another team hasn't. out and become two completely different conclusions on whether this is an upright walk or not. to me as you converge on the common ancestor of a chimpanzee you are going to get something that is not quite like any of

the living -- it's a fabulous combination and maybe a frustrating combination of anatomies that are difficult to interpret. kind of like what you might expect in a common ancestor. >> do you think the femur looks like that on the biped? >> i have not been able to -- you know i love to talk about fossils and this is not a fossil that i would be able to see myself and however they are even older fossils now. we don't have much from eight, nine or 10 million but there are new discoveries from a site in germany and journey might sound surprising to some of those

listening acres we've been talking about southern africa but in the mayan -- expanded around the mediterranean and were living in forests so we found fossils in spain france italy greece turkey and hungary. thisre new fossil from 11.5 million-year-old deposits and germany looks like an upright and it's an interesting find because it could imply and we are still trying to figure this out. it's one of the hottest topics right now is one of the body of form in bipedalism evolved? there are a lot of t-shirts coffee cups and bumper stickers that would suggest it was a chimpanzee that turned into a human and chimpanzees are not our ancestors. they are our cousins and the common ancestor isn't that we

come from but chimpanzees have the ball two. some of the fossils we are finding wero see those deposits that might indicate the common ancestor was more upright in the trees and knuckle walking could be a derived form of locomotion. plenty of my colleagues would disagree with that and think blogging is a form for which bipedalism involved -- evolved but they arere been compelling cases. >> it's a really revolutionary idea and it's fun to think about that. i peel is a mistake uniquely homonym trait and a new vs potentially a common it?

>> i don't think the timing is right and i think that genetic data shows very clearly when they were branching and having said that there big aero bars around these diversionshe state. but i think you raise an important point that our fields have always operated undert the assumption that if you find anything that shows characteristics of upright locomotion that it is automatically by definition the common then meaning it's an ancestor or extinct relative of us and would be more closely related to us than any of the. and i think that assumption is on the table as maybe not being 100% correct. if you had experimenting with

different forms of locomotion including upright navigating in the trees they might have some anatomies that look him little more humanlike. for instance that the nucleus tibia looks merriam -- very much like lucy's and i think that's telling us about leg positioning and not necessarily wait daring on a terrestrial bipedal leg but an animal that's in the trees and moving with hand assisted bipedalism. gibbons will do this and spider will do this but it would mean finding evidence for bipedalism may not he and not anymore to claim common in status. as we find more fossils five,

six, seven, eight or 10 million years we will see lots of experience going on -- experiments going on for bipedalism i do want to say attempted that may have evolved. it just was not an advantageous form of locomotion when the habitat changed. it will be fun. >> definitely. can we talk a little bit fossil records show us about the origin of bipedalism that you mention very briefly there other kinds of data that we can look at two study the emergence of this kind of locomotion and you mentioned a book of boys wanted to visit.

seems like one of the most iconic sites and even just thinking about it kind of gives me chills. there are is a very famous set of -- so you are seeing behavior of an anil. what does that tell us about the evolution of bipedalism at that point it time which was three to 6 million compared to what you know about going back to the new vs or something more recent? >> its bipedalism 2.0. those footprints. that place is magical. it is amazing and there are footprints in all these ash

deposits coming out of the hillsides and i like you said is fossilized bones and i love fossils. we can squeeze information out of them and tell stories about these bombs but fossils are live alive telling you about this moment in time in the life of the living breathing thinking individual who was a lot like us and a lot of the recent biomechanical work that's been done is telling a story of a human biped something that's moving a lot like us. it's crouched down bent hit the bent knee like a groucho marx walk or a chimpanzee. this is something that from a distance would look like you and

i walking. if you could put it on a treadmill you would pick up subtle differences and it's fun to think about. from the footprints and from the bones it looks like they are not pushing off the big toe quite as much as we do. their arches are flatterhe than ours are in their legs are shorter and they are maybe not extending it to have quite as much as we do when we walked that those differences are subtle. one of the really i think amazing discoveries in the last 10 years is that we often think of bipedal evolution in a linear way. talking about bipedalism 2.0 but what we see instead are different forms of idealism is evolving in different species of astor leviticus. the same time lucy and her

species were around and making those human footprints there is another species that had a divergent big toe in ethiopia not far from where lucy was found climbing trees and walking in abiah mechanically different kind of way. this is a fabulous discovery made in ethiopia and showed there were different forms of walking and coexisting. behind me this was discovered by lee burger and by his 9-year-old son in south africa. also in 2009 when they were published and made the discovery. i've see the foot in the leg of the skeleton and when i first heard working on it to me i just finished my ph.d. and studied the foot and ankle in the leg of

common noise and homonyms and i've seen the fossils with no functional variation until this. so different from anyone i'veve ever seen with its heal and its ankle and its knee and aspects of the hip and the lower back that we hypothesize that a walk in a very different way and what's neat is this. right up until -- and even on the doorstep of homo sapiens you have neanderthals in europe and the indonesian islands you have luzon's and this brand-new one. so there are all these different species and populations.

some of these we enter bread with and some of them i don't think we probably did but from the foot bone in the late loans it looks to me like many of them walked in abiah mechanically different ways in different ways of walking. i like to think about going back to any time period and seeing these different kinds of us in different species of our ancestors and they may look different and maybe eating different things that they would be walking in different ways. >> it's really wild to think about that degree of experimentation occurring from human evolution not just happened in "planet of the apes" but right up until virtually yesterday in geological terms. >> and it's amazing.

the story very much was homo erectus after homo sapiens and that'sda a we argued about were they different species or different part of our heritage? so to me studying upright walking it wasn't interesting. we had human evolved bipedal leaves him so let's go back to -- and now it's really interesting and there's a lot going on there. >> if we go back to prominence walking more or less like we do it's interesting that the oldest known stone tool for few hundred thousand years is younger than

those footprints. we are feeling a little bit closer to what darwin was talking about essentially, right?e and i'm just wondering how you see things aligning there? could it the bipedalism 2.0 is what frees the hands did start doing stuff like making stone tools? >> i think the possibility is back on the table and this was darwin's idea about bipedal origins and he incorporated brain size margin which we now know is not part of the story but it does indeed happen later but you are absolutely right. if you go back to the 1970s and the 1980s we had the oldest stone tools at 1.8 and it

looks like everyone was wrong. it looks like it was chronologically not aligning in their work tools in patagonia at 2.6 and 3.6 and we are getting closer. humanoid bipedalism got pushed back to a tibia discovered that was 2 million years old. i'd love to see what the rest of that creature looks like. honestly i was in it for my hopes thaty my expect tatian given how remarkable my colleagues are finding these fossils i would be out there looking for them but they are much better at finding them. when i think about the extraordinary discoveries in east africa in the last decade or so.

soso knowing more will be important but back to your point we now have reports of 3.3 million they are controversial but at the same time 3.3 million astor leviticus to meet the hate really i don't see any reason why they couldn't be making stone tools. they are walking like there is slight brain increase in their set new discovery on the basis of of the juvenile scale that shows they had slowed down raines and slowedve down bring groove is tied in mammals to learning them relied heavily on burning and this is a idea but also something that is heavily upon in the environment.

you want to speed it up rather than slowvi it down and there we plenty of carnivores and landscape that were more than happy to be in early -- so the fact that selection was favoring brainlo growth tells the story f heavy reliance on learningia and learning how to be learning how to make stone tools is also lays story of social buffering like how do you survive in a landscape like that and how do you avoid being picked off all the time? do you look out for each other and you have each other's backs. i think our sociology is built-in to bipedal locomotion. bipedal locomotion is not something that he is either superfast like an ostrich or his

super social and even compassionate. >> i thought that was a fascinating point that you made. you start out by talking about theoi early ideas about trucks d midi to violent behaviors and homonyms and the argument that actually it could never work if france has surged didn't did have the capacity for empathy and cooperate in. c i think so. i think the idea of uprightness using the hands not just for tools but for weapons is still part of the popular culture. we have all seen "2001: a space odyssey." they have the wielding of the

weapons and that has its intellectual roots back to raymond -- who discovered this wonderful little fossil. .. career and he discovered bones that were smashed and he formulated a hypothesis that the homonyms themselves had been doing this that we were the blood thirsty killer apes and is part of the popular culture even though we know now but those bones were smashed up because of hyenas but it is still part of how we think it is still part of how we think of ourselves. discovered in the 1970s by

richard and his team in kenya. this is a a leg bone, and upper leg bone, about 2 million years old. a little short of 2 million years. that's how we can tell from an upright walker by the cool thing about this a fossil amazing thing aboutha this fossil as it has a heel fracture. this bulge of bone sticking out of the inside of the femur is a healed fracture. think about breaking your femurr and 2 million years ago, no hospitals, no doctors note fire, note shelter and you break your leg but you heal? you survive? that cannot happen unless other and goes over helping you out. excited to million back to lucy's species there is a second skeleton, he is about

three and a half million years old. we think it is a larger mail. he has a healed ankle fracture. again he stepped in a hole, fell out of a tree, something happened at vargaspp ankle. if you are a zebra and break your ankle, that is not a good situation. but you're still able to get from point a to point b on your three legs. if you're a biped and you break your ankle you are already slow and i are hopping around the landscape i don't see how you're going to survive for this is a healed fracture so this individual did survive. it is connected these vulnerability as we have as bipeds, but than the fact that we have injuries that make us particularly feeble as bipeds. it's it is explainable only if we were, and continue to be

empathetic, compassionate, generous and prosocial with one another. >> host: fascinating. we have some questions are from the audience that she wants to put to you. we will turn it over to you. >> i thank you. i had not heard that with the healed ankle, that is amazing. i have no idea it went that far back. it was the discovery in 2010. look at the leaven years ago now, but still an indication of how rapidly my colleagues are fighting these fossils. print them out there and each of these fossils has this amazing story to tell why we are the way we are today.

it's easy for one to get overlooked. that was a cool off also did not the attention itil deserved. >> i am looking through these questions, i feel like the memory i have of it, the last i heard there is not evidence of that, anyway, sorry. that is awesome that is nice to know we can be nicer than we think it's very reassuring. we have a question, if you were able to change human anatomy to make a by pedal is an easier on us, what would you adjust? >> the foots, the foot is a disaster. [laughter] i study feet. the foot is sort of like

evolution's example of a good try. you did your best, but what happened here is you converted a grasping eight-foot into something that needs to be rigid. yes have moments of flexibility but then pushts off the ground in a rigid way. we have the same 26 bones and our foot that chimpanzees do. imagine you are trying to create something from scratch and it needs to contact the ground absorbed elastic energy and kick off the ground into your next step. you make it out of 26 parts? you would fail that engineering course it would not happen. look at this. now there you go. there was a foot from an ostrich. what has happened over the course of bird evolution as

the bones that make up their ankle and foot have fused together into a single rigid structure that is composed of instead of 26 bones it is about eight or so in the footig of an ostrich. this ends up looking a lot like the blade prosthetic that a lot of parent olympians will use and use with great effect and can run very fast. i would change the foot. the back is a bit of a mess as well. i work more on the foot that is the first place i would go. the knee is a disaster as well, we will stick with the foot.. >> branching off of that we have another question, is it possible for bipedal is him in

humans or anywhere else to evolve and improve anymore do wheat represents but this is going to be? is that even possible to speculate on? >> let's a great question is a thing i like to talk to my students about an speculate about. if you look at the place and see all these different body forms that existed i don't see the human body today, homo sabeans, is having some advantage over some of those others for example. looks the joints were smaller so maybe their home arranger is not as large. i certainly don't think we have reached some canticle of bipedal motion. i would much rather have a skeleton than an ostrich if i wanted to get from point a to point b on two legs or a t rex

for that matter. and even if you look back in the past, one of the fun things i got to research writing this book work by pedal animals that have long gone extinct. for instance there is a crocodile discovered in north carolina who is a paleontologist at north carolina g state. i'm sorry at that museum in north carolina. she reconstructed the gate is being up on two legs. at least occasionally. imagine a 9-foot tall crocodile up on two legs that could sprint. it is horrifying. and yet, what i find fascinating is that did not have evolutionary legs. what happened to crocodiles? they are on all fours. they are stealth hunters they

are hunters. being a bipedal was not successful ultimately, being quadra pedal was. the earliest dinosaurs were bipedal. okay a pad a source of brontosaurus and stegosaurus and triceratops assert quadrupeds from bipeds, bipedal is him seems to pop up occasionally, honestly failed. be a dead and lineage. you brought this up in the conversation but as a reminder, bipedal is him arose gradually, what is the time span, how many millions of years what is the time span and generally? >> we do not know it and

depends entirely with that common ancestor look like. if it was a knuckle walker, if knuckle walking is the ancestral trait and chimpanzees have retained it on their lineage, gorilla listed on their lineage, you have to have intense natural selection to go from a knuckle walking common ancestor to something that is not getting picked off by leopards because it's hunched over and could not movetl efficiently. in that circumstance i see this happening incredibly fast. or it happens incredibly slowly if the common ancestor is something that is imagined more like a large gibbon with shorter arms or a smaller new

getting apache or forest, it has to move across the landscape on its two legs that has a body form to do that. and so it is not a new it would be a very gradual our anatomies something that is a terrestrial biped. we have not even thought what that would be as a field. how do distinct between something on the ground versus something moving on two legs hand assisted where the trees are more compliance. the forces would be very different. you probably would not have to have those hip mechanics because you're holding your body with your hands. you are not going to have that public tilt problem. we have not really grappled with.

>> i would think just in contemplating these different scenarios it would be easy to fall into the trap about some of these. i don't know, maybe by the time you're in your position not. for the layman that would be a pretty easy trap to fall into. >> i think this probably happened gradually. i think there's probably not one explanation might bipedal is him was advent tatian it was a host of things in our efforts to search for the answer is probably wrongheaded. however, so yes you've got a population and a variation and there are certain individuals that move a bipedal eat more than others. they end up having more food

in more reproductive opportunities and off you go. we are just trying to figure out what it is to have more food and reproductive opportunities. there are other scholars who think this was more. set richard dawkins has written about this. he thanks bipedal is him emerged as a means, it was a cool thing to do. and that chimpanzees, gorillas and patiently move on two legs. if that became for some reason the fad and that population, then you could have more and more p individuals which is what we do. because the bone is plastic to an extent, you might get some of the anatomy that's really key not because you inherited them genetically but you acquired them through your life.

the best example is when you're born your femur is perfectly straight. as you start toddling around your femur begins to angle in and you become not need it. but we are not born that way. when you find a femur is don johansen did and it has an angle to it, it tells us this individual had to of walked on two legs. there is no other way to get that angle. there is a cool combination of anatomies you are born with an anatomies you acquire that blend together and your muscular skeletal system that allow you to walk on two legs. >> host: will thank you. [laughter] we have matthew asking, what circumstances are making it easier to find more fossils today? >> great question. like any science, you build on

the work of previous generations. there are lots of false starts that happened and mistakes that are made. you learn from the mistakes of predecessors. having said that there is lot a of technological advances that are happening. for instance in south africa one of my colleagues has been able to find as many fossil sites as he has is by using satellite imagery and looking at the clusters of trees. when you're on thes landscape walking it's really hard to see these t t caves. from the top down you can see them muchan better. that is one of the things that happening. i would also argue the decolonization has played a huge role in this and instead of doing parachuting science and dropping into these places

and spending a couple weeks and going back to the united states are back to western europe, a lot of this work incredible fossil discovery is being done by individuals that are from those countries. charles in tanzania, in kenya, and many, many other folks. so, kate i'm curious what you would think about that. why do you think we are getting this? >> the reasons you describe but i also wonder if there is a snowball effect. go into the cradle of humankind that was already supposedly really well explored and found these amazing things maybe we all need to go back to places we thought did not have any more

fossils for us a fresh eye and fresh outlook. >> i agree. i think that is true. that assumption that many of the great discoveries have already been m made. this last ten years i have been astounded by the numberr of fossils. it's not like were getting more of what we knew about. that is happening to some degree. but we are also finding, my colleagues are finding things i don't think any of us could predicted. i certainly would not have predicted these, any of them. it has been this really wonderful awakening i think in our field. and there is a humility that

there is a lot out there for us to discover. a lot of our ideas are going to end up being wrong. that is okay as long as we are following the evidence. then it is okay to have an idea based on the evidence you have and then oh, look at this new fossil, will greatly fossil. >> host: i think we can leave it there pretty think about at time, thanks to both of you so much jeremy and kate this is fantastic. thanks you for joining us. please learn more about this incredible book i've posted the link in the chat there's also a link up there to donate. thanks so much for tuning in. stay safe, have a lovely night and thanks to both of you. >> middle and high school

students, your opinion matters with c-span student video be part of the national conversation by creating a documentary that answers the question how does the federal government impact your life? your five -- six minute video will explore federal policy or program that affects you or your community. because $100,000 in total cash prizes and give a shot at the grand prize of $5000. entries for the competition will begin to be received wednesday, for tips and more information on how to get started, visit our website at student cam.org. ♪ ♪ >> brookins institute senior fellow jonathan rauch suggested cancel kultur social media disinformation are writing the truth. here's a portion of his discussion for. >> every society has have some

way to settle disagreements about facts. even if it's a very primitive culture you have to have some sense of what you believe for example about the weather. most cultures have belief about god and theology. a typical way to settle that over the millennia was for one group to dominate one group or spoon into and go towards each other. this typically how it was done in our society until comparatively recently. twenty-eight years ago i wrote a book which argued, talked about word knowledge comes from why free speech is important but what's also important to follow certain rules and figure out what's true and what is false. there's a lot of obligations and to submit our views and very open dynamic way, that is all true. but then something happened over the last ten and

especially the last five years. we began to see systematic and very attacks on the knowledge building community. not just from academics who said there is no such thing as truth and knowledge but also from social media, from controlling, from cancel culture. i began to really something was missing in my analysis and you named what it was. my effort is an effort to struggle james mattis into the world of philosophy of knowledge. and information science. this book is a way to figure out. what actually is the structure in society that allows us to convert just argument, disagreement, into objective knowledge. which is really what i mean by truth and the subtitle. we never get to final truth but it's truth is directional. it steers us in the direction of truth but any given day we have direct knowledge including the shot in my arm right now that's protecting me against covid.

this book is about the norms, structures with systematic, sophisticated and dangerous attacks on that system. >> to watch the rest of this program visit booktv.org. search for jonathan rauch or the title of his book the constitution of knowledge using the search box at the top of the page. >> obtaining a phd from physics and oxford an agent was a scientific challenge of our time. switch gears to computational biology but he worked at the institute using machine learning to decode dna and patient medical records. presenter based in london has appeared on discovery and the bbc. guiding us on a journey for the work being done to understand and combat the cause of