and you can also watch after words online. go to booktv.org and click on the book tv series and the topics list on the upper right side of the page. beth shapiro is next. her book how to clone a man that looks at climate change and migration patterns and the role they play in the extinction of mammoth. >> you may not be able to hear me. hello, everyone. thanks for joining us tonight. on behalf of the bookstore i'm delighted to welcome you to this event with beth shapiro and herbert how to clone a mammoth. this is one of the many events this spring. friday david roberts will join us in the store to introduced his new book the lost world of the old one discovery is in the ancient southwest and tickets are still available with david mcauliffe presented in the right brothers and the first terrorist church leader this month. to learn more, visit us online at harvard.com or pick up a player on your way out. can i talk will conclude with some questions after a book signing at the table. we have copies of "how to clone a mammoth." tonight is 20% off, part of part of how we say thanks for buying the book here at harvard book store. your purchases support the series and assure the independence bookstore. and finally, a quick reminder to silence our cell phones. we are pleased to have c-span book tv here taping this evenings event. during the q&a please were members you'll be recorded and maybe wait a moment for the microphone to come over to you. and so now i'm very pleased to introduce tonight's author. shapiro is a professor of psychology at the university of california santa cruz and the 2009 recipient of the macarthur award. the scientific articles have appeared in many publications including nature, science and molecular biology and evolution. tonight she will be presenting her book "how to clone a mammoth" national geographic.com calls it a sharp and an impeccably argued and scientific america right in this roadmap for the nation's discipline of extinction, shapiro examines not only how we can resurrect the long vanished species but also when we cannot and should not. we are pleased to host her here at harvard bookstore tonight. please join me in welcoming beth schapiro. [applause] >> thank you. thanks for inviting me you to you guys for coming. it's a beautiful day. i understand one of the first and what is going to be a wonderful spring and summer. thank you for spending an hour or so in here instead of out there where you should be because it is probably more entertaining to be outside than listening to me. one of the many hats i wear as a national geographic emerging exporter which is a silly thing. i'm not sure how i am emerging. i would like to look for the video that describes the work i do it at the fieldwork i do just to give you the taste of where we are so far. >> one, two three, four pieces. >> backbone. [inaudible] >> that water back there let's go home we better get out of here. it's the last part is a little silly but in my defense, that water is really gross. [laughter] what it is, this is near both in city and appears in the active class reminding in the gold mining where the snow melts and it's left to the stakeholding independents pumped up with high-pressure water hoses. it was saul and the exposure. let me wait a little bit. it melts a few more inches and then they wash those down. the goal is to get rid of all of the frozen dirt to get into the gravel underneath. but while they are doing that, hundreds if not thousands of these impeccably preserved pros "-end-quotes are uncovered uncovered and we come along and collect them. so i am a an evolutionary biologist were paleontologist on a molecular field and just. i've been called lots of different things. so what does a biologist want a frozen mammoth frozen mammoth bones recovered from the permafrost acts by a research is about climate change and how the communities adapt and respond to climate change. when we hear about climate change, we hear about things like changes in precipitation patterns and changes and storm patterns that we have some people in dire straits in different parts of the world and of course species that are potentially at the brink of extinction. when we read about this in the popular press often what we get our incredible doomsday scenarios. so as a biologist, one might wonder what we can do to actually stop this? i got ahead of myself a little bit. i've given this talk too many times. this is the hockey stick platts because it looks a little bit like a hockey stick. this is the end and then it comes up over here. what what what does this is the decline across the middle is in average global temperature about 1960 and then everything else is kind of wrote to that. so, over the last thousand years for the climate temperature was pretty stable. it may be declining a little bit and then in the last couple hundred years it increased by about 1.5 degrees. of course this can be extended and people are predicting much more rapid extensive increases in global climate. now this is not the first time in the earth's history however that we have seen a very rapid and large-scale change in the global temperature. if we extend this scale back to about 50,000 years ago moving forward to a thousand bc this right here. this isn't about the peak of the last ice age and he got 12,000 years ago as a transition into the interval that we are in today. and this particular transition right here around the last 4 degrees to the research that we are doing in dawson city is suggesting that this rapid increase probably happened over maybe a century or less. so, this is actually a past era covered equally rapid commit equally tumultuous climate change that should have affected plants and animals everywhere. so, my research tries to go back in time become a time can sample the sequences from the animals over space and over time and ask how did the species and communities respond to these past period of climate change with the hope of learning some things that we can then apply to make things more informed decisions about what we can do with the limited energy and resources that we have to deal with climate change in the present day. so the field i work in is called ancient dna. pretty self-explanatory. not older people be any of the stuff that's older like mammoth bones preserved in the permafrost. mostly it is a part of the world here that you can see spanning from the yukon territory across alaska and into siberia with this far part of siberia. this is just kind of a shallow sea and giving the ice ages when much of the water on the planet was taken up into making glaciers on top of the different continent to sea level was a lot lower than it is today and those white areas were exposed. they were exposed and they were incredibly rich grassland of support for the species. it is also an important corridor for the movement between the continent. camels and horses, for example moved from north america and asia. and the bison and humans moved from asia into north america. so, today this part of the world works like this. i'm actually in a helicopter whose shadow using on the ground taking this picture, and i will share you -- show you a beautiful image from the helicopter in a minute. but in the ice age coming up looks more like this where we have the mammoths and passed it on -- mastodon and the regular course like we see today and kind of weird things like lots of different species which is the funniest animal. anyway, this is the helicopter that we use to fly out in the particular expedition that we went on onto the north-central part of the tiger peninsula. and you can see that there are some windows missing in this helicopter here. that was actually particularly useful because after we got off into the air on about the third or fourth attempt of a french and the russian people who were in charge of the expedition decided that it might be nice to celebrate the success i would in a visitor. >> sitting on the site or side or gas tanks. it might have happened. so we fly out there and we stay in five-star accommodations. i'm not sure if you can see this. i took a picture kind of walking backwards and i'm focusing my camera so that you can see the depth of mosquitoes that we have to deal with what we are up in the hierarchy. we wander along the places where it is building. this is back in the yukon territory. you can see the water hoses and people are kind of standing around, picking up the bones as they wash out. so in that typical day it will take around five or maybe two dozen bags like this for bones that we've collected. most refined our bison and horses and care of you. if we get lucky because they are rarely find carnivores like wolves and bears maybe giant bears even in a different kind of lions. we take a chunk out of the bones of a regular thing desk only to get back to the lab, grind it up into a fine powder and extracted dna from it. than what we do is to correlate to the amount of diversity that we see genetic diversity that we see in the populations at any one point in time with how big the position is. lots of diversity and big populations. not very much diversity means small populations. then we can use this to decide and see when the populations are growing or shrinking, when they are moving across space, when a local population is extinct and replaced by something moving in from somewhere else. things like this that you can't necessarily see by counting and looking at the fossils themselves. we have learned a lot over the course of the last couple of decades where i group and other groups have been gathering this information and we see them peek around 40,000 years ago and then starts to decline after that and this is interesting because the major hypothesis of things that cause them to grow extinct or that he didn't like the ice age. it is bad for them or humans turned up and killed them all. if the decline began 40 to 45,000 years ago that was like 15,000 years before the peak of the last ice age ice age and 20,000 years before there were large numbers of people in north america which kind of goes through the early stages of the decline. they are increasing in population size and the landscape responding to the herbivore abundance and survived in the present day. they like to live where people don't which is a good trick. and why they went extinct. we get a lot of attention for the stuff that we publish in a nice high-profile journals and a lot of phone calls in the press and i'm always super excited to tell them what we've learned and how it can apply to the present conservation problems. how can we use this information in the present day but they only ask me one thing. and it's kind of annoying to be honest. the phrase that is given to describe this work right now is not extinction that we are stuck with at this point because it seems to have taken over the hash tag world of twitter. and we are kind of familiar because we were all there the last time we did it and we remember how that went. it all went particularly well. nothing went wrong. life didn't find a way as it was said. but we are not talking about dinosaurs now because we know we can't get dna from the dinosaurs there is no dna so we will never be able to clone a dinosaur. i am really sorry that we are going to talk about the mammoth. people kept asking me about the mammoth. now let's get down to it. firstly people think about is to clone the mammoth. but it isn't an ambiguous thing as a very scientific techniques. it's called a somatic cell nuclear transfer and this is the science word for cloning. we basically have two different types of cells. normally what happens when a new organism is formed is sperm and egg come together and it is a special kind of it can become every type in the body. hair cells, lung cells etc.. it already has a specific job and that is the only job is knows how to do. so the trick to the nuclear transfer is to convince them. every cell in the body creates a whole organism. the first example of the nuclear transfer and the most famous example is the experiment was done by the institute in scotland. anybody remember this lacks she was cloned using a memory cell, so that took a particular adult view and to be put into the dish. at the same time they get an egg cell from a different type of greed of the view and they believe the nuclear material. it sucks out of the nucleus including all of the dna from that exile. so they have an empty cell in some somatic cells and they do these things together and they zap them with a bit of electricity and they break open and vendor material, the nuclear material from the stressed-out cell dumps into the egg and then the protein can actually do a little bit of magic and cause that's how to do back to the capacity to become every type of cell in the body. then you have a surrogate mom and eventually the genetic clone of the donor of the mammary cells and not of the egg cell with a surrogate mom. this technology does work. it's not particularly efficient. it's one of nearly 300 different views that they attempted to use in the process, but it does work and it has been shown to work in a bunch of different species. how would it work? we go to the field of play and well preserved mammoth and remove the style and stress out in the dish. can we insert it into an egg cell and it it is this magical thing and can be implanted into his very good host and it has a baby and it grows up and we release it into the environment, straightforward. right. pretty easy. >> securely run into a stumbling block. we find some incredibly well preserved things in the arctic. this we found during dawson city 50 or 60000-years-old and here we have some really nice preserved mummies from siberia and a couple of years ago this individual was found in the new islands and this one was announced as having an even a little substance quit substance that was very similar to blood. they suggested that it was. i don't think it's been proven that it was but anyway, despite how well preserved none of them have any living cells and no one is ever going to find any mammoth remains that have any living cells. when an organism dies, the cells and the dna within ten begins to take a break away. first the action of enzymes in the body itself and then if it is a mommy maybe if he thought. lots of microbes and then it starts going down the dna so the radiation is for the radiation is no good answer cameras out the dna just like when we are alive they can't fix mistakes that are made by solar radiation. but things like water and oxygen hydrolysis. these are all chemical bombardments of the dna that just breaks it down into smaller and smaller pieces until eventually, there is nothing left. so you'll never find a mammoth that has a living selling and if we never find the living cell of a mammoth, we will never be able to clone a mammoth. [laughter] >> thank you for coming. [laughter] just kidding. so last week 18 of international researchers i think the league was from the national museum of sweden they announced that they had a complete genome of two different mammoths and so can be sure that the sequencing? shouldn't we sequence and start their? we have a whole list of letters that make up the dna. 4 billion of them intact. that's how big the genome is. and this provides an instruction manual for making the gene for making the proteins that make the mammoth look and act like a mammoth. so, let's go into the lab and a synthesized and to get these into the promised him somehow and then to the chromosomes into the south and then we can do this whole thing where we put it in and we go around here and then we have a mammoth. done, straightforward. the problem, several problems, let's just start here. they reported that he had a complete sequence and that's okay. that's kind of true. they kind of have a complete sequence. but it's not really complete in such a way that means that we could actually synthesized it in the lab. in fact, there isn't any vertebrate if you carry onto an organism that we have a complete genome sequence including humans. we do have most of the human genome sequence. we have a majority of the genome sequence that contains genes and that is the important thing we think. but there are perks of the human genome and every other that are made of these really tight we convinced most we bear the center and the end of the chromosome. there is no existing technology that allows us to get through that. so we couldn't actually going to the lab and sequence one end to the other even if we wanted to because they don't actually know the full sequence. we don't know how important it is to note the sequence. we don't believe it has any genes or what it does. we do think it has some important regulatory information utilities, etc., but we don't know. so there you go. the complete genome sequences and complete for humans. and it's even worse for mammoths. and there are a couple of reasons why it is really hard to generate the complete genome sequence for something that's been extinct for quite some time. but first this goes back to something i talked about. the sequences themselves are very short and very fragmented. just because of all of that bombardment and enzymes breaking it down from the microbes and the swale and the cost they chop it up into smaller and smaller pieces. if i were to extract from something modern i could get a very long lovely strands of the party streamer but we are talking about the ancient dna it is much more like confetti is not that looks as good as this. i couldn't actually find any images of confetti in the gutter today after the parade were after they were walking down the street. this isn't a good way. it's in terrible condition. also, the samples are full of all sorts of stuff and thought just mammoth dna. so if i were to take a piece of my here and extract dna. it would be my own dna. there's not much contamination in my hair or whatever. so i was involved in one of the team is the first used what we call the next-generation sequencing technology to extract dna from something and then to sequence anything and extract rather than target the specifics to the dna. we sequenced the dna from the the name of conferencing. that was like 40000-years-old. i can trim and exactly how old it was now. we did this approach called shotgun sequencing. what we ended up with is about 50% of what we recovered in the dna. the rest of it was stuff like soil that's probably more microbes that haven't been sequenced yet so we didn't know what it was. a little bit of contamination you see human and dog's. we often get human, dogs domestic cats can it get in the sequences gets in the sequences from the components despite we tried hard to keep them super clean. anyway, 50% is mammoth. at the time we were pretty bummed. without this isn't good how are we ever going to sequence the genome is all of all we are getting is 50% mammoth so it turns out later knowing more about this this is a very well preserved sample. the majority of samples that we extract from is something like five or 10% and that is from good places. if you sold the neanderthal that was assembled it was from a couple of different bones and none of those had more than 1% of neanderthal. the rest there just wasn't chemical contaminants that have to be thrown away. so, imagine that we have this kind of confetti mix or dirty confetti mix is really portable dna. we want to find maybe the purple one. so, how do we actually go about doing that? we have these sequences from living species basically as a scaffold which we can take these broken fragments and figure out where they go along the genome sequence. so if we want to map the fragments of views the human genome and what we end up with is a partial genome where we have mapped a look at stuff that's still going to have some holes that we can fill in. another slight challenge with this is that there have been some change like a duplication of the part of the chromosome or something that's different between an age elephant and a mammoth with its going to be like is having a book with missing pages. if we have the sequences but they are from a part that doesn't match, we would just assume they are microbial and throw them out and one might think that if we are interested in finding the parts in the genome that are different but these might be an important place to look. another problem is that having a sequence even if we could generate that hold long sequences of sequence isn't the same as having a living cell. we are getting better at stringing together to make long fragments that we don't know how to turn them into chromosomes yet in a way that would allow them to turn them on and off to something we would for two something we would want to be really don't fix those into cells. sequencing ourselves and where we are going to go i am afraid we are probably stuck in a first step, so that's not going to work. >> fortunately there is another way into this is a way that is probably going to be the path people follow that we are going to do something like bring bringing the extinct species or the trade back to life so that is to engineer ourselves. i mean something simple conceptually than cutting and pasting that if we want to change it to. pretty straightforward if you think about it. and we have a genome sequence so we can start looking through and find out where they look and mammoths look like something i'll something else and these two things were different from each other and then those are potential targets in places we might want to change in an elegant genome if we want to use that to create a mammoth. so imagine we had a little machine that we could program a specific place we wanted to change and we could give that little machine a little package into and the package is just a synthesized bit of mammoth dna. artificially created in the synthesized that matches the part of the genome of that that we want to swap out. we could then insert this little machine, this little package into the cells that will go out and find exactly the place, chop it out and stick that mammoth version into place. we have that machine and it's not a machine. it's actually an enzyme that bacteria is used to combat diseases and stop them from getting sick. this is probably something you've heard about recently in the news a couple of weeks ago there was a chinese used this for human embryos and it caused a bit of a stir. this is an incredibly powerful and easy to use technology that is being developed for the human genome engineering genetic diseases in mind not for the extinction obviously. but it is the type of technology that we would use. so this right here this big molecule that is our little machine. it's not really a machine. and this part of it is a part that recognizes the part of the dna that we want to change. we used to elephant dna into double mammoth dna that make the cut. now the cells don't like when the dna is broken so there are a couple of mechanisms to solve some evil to fix that. we want to harness its own repair machinery to stick the elephant version -- and getting my speech is confused to mistake the mammoth version in place of where the elephant version was independent wind up with an elephant that is a little bit of mammoth. so we know that they've been diverging for about 6 million years. the genomes are already nearly 99% identical. about the same amount of similarity as between us and the chimpanzees. so probably around a million or so differences. we can't right now target all. so probably what we will do is hone in on a few things that we think are really important. one of the first that anybody found to be different between elephants and mammoths position the globe in response of over targeting oxygen around the body. this is work that was done a few years ago and he found that comparing the sequence between the elephant in the mammoths there are only three differences between. so he took the cells and the cultures and made those three changes to measure the purpose of the three differences. what was different about the protein that had the mammoth version versus the one that had the elephant version. he found that the mammoth version was much better at carrying oxygen around a body at what temperatures. so come of this is a pretty good target for something to change if we want to take an elephant adapted and turn it into an arctic or at least have the rest of active mammoth. what else? is one around the corner that's been working on this question and compiling the list are different between elephants and mammoths and so far they have attempted to make 14 different spots. and they've been successful in doing all of it. so they've actually created one that is about 0.011% mammoth which is pretty cool. it is of course a far cry from having a living, breathing mammoth elephant hybrid but it is a secondary direction. so if we think hard plan we do see that we have the complete sequence and we do have the technology that we would need to edit and swap out the things we want to replace them with and then end than what we would have is an elephant so which would be alive which means we could go ahead and use the nuclear transfer to create a living and breathing animal. of course, the next step creating the living and breathing animal is actually pretty hard. in fact, this next step about which of which i like to call phase number two it may be harder than phase number one. when we hear that the extinction and the excitement generating the end of phase number one isn't venturing into all of the challenges are going to be once we move in to face number two. the first thing that we would have to do is find an appropriate surrogate host. for some this might be straightforward to the species being worked on to be resurrected. there are many living and although they couldn't use them in the surrogate host because they couldn't get them down from the ledges to the artificial they were able. they have living cells because they took a tissue sample from the last individual before she died so there is a little bit further ahead ahead than the cloning project then anyone in the mammoth project. but the evolutionary distance between the thing that you're trying to bring back and that is the potential host increases. we don't know how much will actually be tolerated and it's going to be different depending on what many are talking about. the other potential problem in the surrogacy is that there are some instances where the size difference between the thing that you're bringing back and the thing that is alive might actually be prohibitive. and i say here that i don't want to include a picture but i did include one because we are here. here we go. you thought it was good to be something gross committed in few there is a scale on the bottom that lived off the coast of california around the island and the commanders. they were hunted to death. so they might have been a source of food for travelers. this is an example of something where there is a technical problem that probably made the extinction not have enough waste if not innovation that allows us to have an outside the body of the living relative. another potential complication with the surrogacy is that we know now that we are more than the sum that make up our dna. in fact we are a combination of the sequence and the environment for which we are exposed. we know this is true by looking at identical. when they were when they look similar to each other but as they get older they diverge from each other both physically and the differences accumulate over time and by the time you have identical twins that are in their old age it is often hard to know that they are identical or even related and that is because of the differences in the environment that they are exposed and those began in the world. remember we are talking about a species that is 99% identical to this thing that's fair. it's developing inside of the mother elephant exposed to the four months and the elephants diet. how do we know that that isn't going to just ruin whatever changes we've made and it's not allowed them to be expressed? elephants often eat the dung of their mothers for the microbes. this newborn elephant mammoth hybrid that we have established in the microbial community and it's got it with got a quick two minute offense diet and live in and elephants community and it would eat whatever it is that elephants are fed in captivity. speaking of elephants in captivity, that brings us to what i think is the most serious challenge, but the imported and financial problem for all projects that is that there are ethical considerations for bringing these things back. we do know that they do not fare well in captivity and they failed to reproduce in the technology industry do they sometimes injure or kill their young in the psychological needs in captivity we shouldn't have been in captivity at all much less using them in the crazy experiments to bring back the hybrids. the other challenge is of course just like the technical challenges that depending on which species we are thinking about bringing back. but they are nonetheless extremely important to keep in mind. and of course it would be redness of me not to acknowledge that the world has changed a lot since many of these species went extinct and in many cases, there may be nowhere no where to put them without having a significant terrible effect on the ecosystem effects on the ecosystem and populations and species that are already there. at this picture for example as the east coast range of passenger pigeons have walked into the billions of individuals and went extinct 100 years ago. this is the candidate towards the extinction but what would we do if we brought them back to? it's 100 to 200 years ago when it arrived in these enormous flocks. so can we do to? dot get. but it's at a rapid pace and i have no doubt when someone does change the sequence is from one species to look more like something else. someone has written a book about this and i know i'm expected to have a concrete opinion about whether we should invade you have a concrete opinion if i don't know if i think it depends on which species we are talking about and there are a bunch of different species that have been proposed and are being worked on by the various groups. there's the passenger pigeon in a middle. there's also the frog, the american chestnut tree all sorts of different species and each one of them has a separate list a technical ethical challenges as he did in bringing them back. i honestly think that if we are going to use this technology to bring something back to the most fundamental question to answer before beginning any of this is why. why do we want to bring a species that has been extinct for a long time back to life? is there a compelling reason to do this and guilt which is the most commonly cited reason to do it to me isn't a compelling reason. there has to be a good reason in a real reason to go through the trouble of actually doing all of this work. and returning to the mammoth, i'm going to skip over the fact that it's technically not possible to bring it back to life and ethically is a terrible idea to bring in an effective way to talk about why i think it is kind of compelling to think about bringing mammoth back to life. the first is ecological. one reason to bring something back is that i reestablishing it in its natural habitat you can restore interactions between the species that used to exist but are gone and that has been overwhelmingly good positive effect on the entire community not just those that you are bringing back. there's a place in northeastern siberia that is aptly called the theme park that has been established where they started buying land near turkey and what he is doing is preparing a place for the return of the ice age animal including the mammoth. so far she has has by sending forces into the five different species not particularly patiently but waiting to come back. he has been performing some experiments to measure what their affect is on to ecosystem. here is a picture that they took an early spring and autumn on the side that's beside over here and on the other side of the fence he does so on the side without what you see is a fairly un- diverse state of grassland that can support a large number of herbivores. on the other side of the fence come you can't see it very well but there are lots of different species and there are tusks of green all over the place. this is very early spring. this is before the grass was able to make a comeback and yet there still is green and that means that by being on the landscape just by standing on the landscape and turning over the dirt and recycling nutrients and distributing they have created their own habitat. they've transformed this kind of tundra and not only are they doing well and thriving but they noticed other species that are endangered because they can't find enough to eat. it's such a rich habitat for them and he argues bringing back the mammoth might speed up the recovery of the ecosystem much like elephants play an important role in maintaining their own habitat. the second reason is more sentimental. a few of us can imagine a world without elephants. their habitat is declining and we are having trouble stopping them from being poached. elephants could disappear. every year there are fewer recorded. what if we could use the technology enough to bring in mammoths but to create an elephant that was capable of living somewhere cooler maybe in europe and north america or in a siberia where there's lots of space and people who want them. could we use this technology not to bring them back to life but to save elephants? we don't have to just think about elephants. what if we could use this technology as a tool in biodiversity conservation today? what if we could use this technology to take the black footed ferrets that are almost extinct in the central plains of the country right now now they are endangered and the disease is killing them. they went through the provision but there are those in the frozen zoo that were sampled and they are in museum collections that are thousands of tens of thousands of-years-old. we could go to these museums and find genes that increase the amount of diversity and use this technology from some of these existing black footed ferrets which evolution shaped that the decrease in the population size and extermination sites by humans they go away. we could use this technology not to do something crazy or bring back the species whose habitat no longer exists but as a powerful new weapon in our arsenal against the crisis we are experiencing today and that is the most compelling use of this technology. thank you. [applause] >> i am happy to answer any questions you might have about how crazy i am. [laughter] [inaudible] i haven't read it yet but [inaudible] my first example of that is the polar bear and the habitat is dissolving so the question come if you have something enough to do where would you put them on their habitat is gone and can you engineer a change in their genome to make them adapt to a different thing? >> this is a good question the polar and you've asked the right person because this is a major theme of research in my lab. polar bears are kind of a special case. pull their bears have almost no genetic diversity which is true but there's a sequence in the polar bear that is 100000-years-old and got polar bear so have almost no genetic diversity and the same amount as polar bears today so the lack of diversity isn't because of any recent decline or bottlenecks or climate change. they are a top predator that is very precisely adapted to the particular habitat and to absolutely right when that habitat disappears they don't have any diversity that would allow them to adapt to different habitat. but polar bears have an interesting strategy of dealing with this that we discovered recently and we discovered not only that it's happening right now but that every time it's happened in the past the same thing has happened. they breed with brown bears. they breed with brown bears and produce offspring that live as brown bears. but the polar bears are as discrete thing that would disappear into the idea is the engineering traits that allow them to survive in other environments isn't the same in the polar bears case because they will live in those environments. but absolutely the idea for the other species you have been targeted blade of diversity. can we increase the amount in the genetic booster shot if you want to get some adaptive flexibility. i think that is where this technology is probably more powerful. they have a new tool in the biodiversity conservation. spinning in terms of preserving diversity in the technology by what specific rubric would you define which species to bring back or maintain. >> even though we are changing certain species that are perishing. how much diversity is a good amount of diversity if we try to decide which species are a great age to conserve space on how much genetic diversity when we measure the genetic diversity the answer would be absolutely clear we would have to say that they have almost no genetic diversity compared to the rest so genetic diversity by itself is not a perfect measure of the population. to answer the question i think by species that might benefit the most from this technology have been through human induced population declines where they have recently purged diversity overall but as far as what diversity to introduce, we don't know. we are still at some of the stages where we have genomes we can compare or how they interact with each other are at the early stages of all of this but yet another technical challenge and standing in the way of actually applying this to a question nonetheless. it does have the potential to be useful and is something we should think about. >> your comments made me want to ask that in the recent issues of the population that would be the candidates of things were talking about. >> it would be great if we could find those that make them resistant. find some bats that are resistant and was part of the genome makes them resistant and transplant transplant is part and to those that are buying that would be fantastic in the application of the technology. i'm not saying that we have this. i'm just highlighting and that is a great one where we should push this along because it would be incredibly useful. >> the question is how do we date the bones that we have given this stuff that washes out of the sentiment. sometimes we get lucky and we actually find them in the context where there is frozen. sometimes we get even luckier and they are sitting in between the layers that have been dated and often we have to generate the dates on every single bone and we do that just using the carbon. this is a typical approach but does that mean that we are limited by the resolution that is within the last 50,000 years am and we know that we can get the dna from something much older than that. the oldest genome sequence but we have enabled so far is from a horse that we found in the klondike in one of these locations up north about it was founded in the association with a data of the volcanic ash layer around 700000-years-old so this is the 700000 euros horse and the only reason that it has any dna surviving its permafrost. it was deposited in husband throws in. if we look at them through time that is a significant challenge. a >> thank you very much for coming again. i booktv visited capitol hill to ask members of congress what they are reading this summer. this summer i reading a book this thick that i was given when i came to congress. virtually none of us have read it. it's jefferson's manual. so the rules of the house were written by thomas jefferson. he said what's my