Year of Darwin-Sean B. Carroll

hello welcome to another in the continuing series of Darwin Year events we're very happy to have Sean Carroll here with us for those of you who might be interested couple of his books are on sale in the lobby they're 1856 each I think a very good price and he'll be citing them afterward if anyone is inclined the Darwin year as some of you know is something we've been working on for quite a while we have neil greenspan with us who's the chair of the darwin committee and some of the other talks that are going to be coming up next week next Thursday we have Bob Richards from the University of Chicago talking about moral issues in in Darwin's view of life it should be very interesting he's actually giving two talks the main one is in the wolfstein building at 5:00 p.m. next Thursday and then on Friday at noon he is giving a more of a discussion about science and politics in the basement of Crawford in the Inamori center the week after that the Thursday at 6 p.m. I believe in stro soccer we have Judge John Jones who was the judge that officiated at in the Dover trial a couple years ago the creationism trial and that's these are all free and open to the public the following day we have a talk at 12:30 to 1:45 in Clark Hall in the Baker Nord Center sponsored by the religious studies department with one of the lawyers from that case and also the main journalist who covered Laurie Lebo who has a book out called the devil in Dover very interesting all of these I recommend and you can see more about the events that are coming up on the website which is WWE d u slash darwin we're very pleased that this event is co-sponsored by the college Scholars Program which is a very innovative undergraduate experience that first year students and sophomores can apply to be involved in do I recommend we have quite a number of students here who can talk to you about that and also co-sponsored by the sages program so let me introduce Joe Jyoti who will talk to you a little more one of our college scholars students hi as she said I'm Joe Julie Adi I'm in my fourth and now final semester with the college Scholars Program which if there are freshmen and sophomores out there and I imagine there are you should apply you get to design your own classes invite speakers that you think would be interesting among various other things in just a great sense of community so look for our events in the coming year because they'll be bountiful I think this event as Patricia said is part of the university's year-long celebration of Darwin and of evolution and Sean Carroll today is with us he's a member of the National Academy of Sciences and he most recently authored the making of the fittest which I believe is also the title of today's talk an investigator with the Howard Hughes Medical Institute at the University of Wisconsin Shawn's research has centered on the genes that control animal body patterns for instance butterfly wings and play major roles in the evolution of animal diversity in 1994 he was named by time as one of America's most promising leaders under 40 and his discoveries have been featured in Time US News and World Report the New York Times discovery Natural History among others so thanks Joe for the introduction thanks Patricia for organizing this and to Nick and the committee and I I wanted to say that you know and thanks to the college Scholars Program in the case community and the faculty who met with me already today I'm looking forward to this the whole visit my first visit to case not my first visit to Ohio by far I now will confess I grew up 100 miles west of here in the thriving metropolis of Toledo so there are certain traditions and things that I understand quite well anyway it's nice to visit it's nice to be back in Ohio it's nice to contribute a little bit to the discussion about evolution in my home state which can certainly use some help so so those animals they raise a lot of questions about evolution about how new capabilities evolve about genes and genomes and so my pleasure tonight is to update you on some of the great progress that's being made it has been made on understanding how evolution works how the fittest are made and to do so I'm going to show you some strange and wonderful and from here on out I promise entirely real creatures and the first of which I think is one of the most amazing animals I've ever learned about and to appreciate that we're going to have to go back in time to a voyage a long long time ago in the late 1920s of this ship the SS norwegia now this is a research vessel that was set out by the Norwegian government to the southern ocean the waters around Antarctic and it had several missions now one mission it had was to establish a shelter with some stash of provisions for shipwrecked sailors as you can tell from the waters that it's sailing in these are really rough waters lots and lots of ice lots of hazards to navigation and the Norwegian fleet was down there for various reasons I'll talk about in a second it's a second mission was to claim some territory some locale for the country of Norway and its third mission was research now the police they were aiming for was a pretty remote spot on this planet in fact maybe one of the most remote spots on the whole planet and it looks like this it's called Bouvet Island this is a photograph taken by one of the expedition members named Italy frost ed who was a zoology student and there was a tradition in the norwegian fleet that zoology students particularly right after graduation went out on various voyages and assisted the ship in all sorts of ways he was also ship photographer but also with their in this case with with the research mission now I said that Bouvet is a bit of a remote place let me show you how remote it is in this map this is it it's this little speck in the ocean and as you can see it's not a very hospitable place its ice-covered it's just a huge rock sticking up out of the ocean with very very thick snow and ice cover and these waters are very rough very stormy and very cold about 29 degrees fahrenheit in fact these waters around Bouvet so the crew of the Norwegian made their way to Bouvet Island in 1928 it was a bit of a hazardous journey all the way from Norway you can see that they had they went well south of the Cape of Good Hope they're far away from most landmarks that may be familiar far away from the tip of South America far away from the tip of Africa pretty far away from continental Antarctic Antarctica and a pretty good distance over a thousand miles from you might know about South Georgia island that's the island to which Shackleton rode to save the crew of the endurance in 1916 so rough waters far away well they succeeded in the first step of their mission this is the crew of the Norwich acclaiming Bouvet Island for the country of Norway okay so that was one of the first things they did there was a little spat with Britain over ownership but then Britain said you can have it so you know there's still to this day no no condo developments on Bouvet Island and it left rustic by the way that zoologist is just poking out here from the far left underneath that hat okay so with this I think I can't from the flag it looks like he's downwind of these guys which I think after that sail I don't think I would necessarily stand there anyway so they accomplished their first mission and then rustad that what they would do is around Bouvet is they would go out and circle the island they're making various maps and then Rusted would throw a net over over the side of the ship and trawl up whatever he could find he was just sort of taking an inventory of what was there in these waters you know when first the first ships that sailed to the Antarctic one thing they were surprised about was that these waters were so rich you might think that waters that were soaked and this sort of extreme climate were would be sort of depopulated but not at all it's a very very rich ecosystem and one day rust that pulled up an unusual-looking fish it looks like this now some of the hands on ship had seen this before and they had already dubbed it the ice fish and that was named for its very pale sort of almost translucent appearance but this odd-looking fish has this white face and large protruding jaw and pretty pale body it was it was pretty peculiar relative to other fish that Detlef had seen in his zoological studies but the story gets a little bit stranger when the Detlef brings the fish on board does what any good Norwegian should do he fillets it and he sees that the blood of the fish is entirely colorless so here's a modern version of what Detlef saw so if you put the blood of a fish of a nice fish in a tube and a centrifuge tube this is what you would see compared with other fish or even some of the what most fish you'd be familiar with but even some of the other fish that are in the southern water such as a typical rock cod now there was word got back to Norway in various ways about the so called bloodless fish but it was about 25 years until another Norwegian biologist Johan Rood couldn't stand this mystery anymore of what exactly this fish was travelled to the Antarctic set up or traveled east to the Southern Oceans set up a lab on the island of South Georgia gathered in some ice fish and did formal physiological and microscopic studies of these animals and what Ruud was able to confirm much to his astonishment astonishment is it in this blood of this fish there are no red blood cells whatsoever now that shocked rude because everything he had ever learned about vertebrates about backboned animals is that they all have red blood cells and we know that that red blood cell way of life has been going on for more than 500 million years on this planet so this was really quite surprising a bloodless fish a fish without any red blood cells whatsoever so what's going on well one thing we appreciate about that is that if you were to spin this blood down in a centrifuge and pack it so that you had the fluid on top and the cells at the bottom it's only about 1% cells by volume and they're all white cells the sort of cells that are evolved in host defense the rest is this really dilute plasma now reason that's that's such a shock is what we know about red blood cells so yes these are the only vertebrates with red blood cells and they then say only about 1% of their blood is cellular at all these other red-blooded fish cousins of theirs have about 15 to 18% red blood cells by volume and humans we have about 45% red blood cells by volume that's what we call hematocrit and anything less than 45% we refer to as anemia and anything significantly less than 45% is life-threatening so somehow these fish have gotten rid of red blood cells altogether they're not anemic I mean they just completely lack red blood cells so we got to start thinking what in the world would lead to such a condition what's going on well you got to think about where they live in the world as the first set of clues they live in the southern ocean which is as pretty cold water about 29 degrees Fahrenheit below the freezing temperature of fresh water and I don't know what Cleveland winters are they're not quite as harsh as Madison winters but you know in the wintertime we have to take certain precautions with our cars might even change the oil to reduce the viscosity of those fluids because they're harder to push in the cold so one possibility and one reasonable possibility here is it is it the thinning of the blood here is an adaptation to the cold a thinning out of the of the viscosity of the blood now these fish have other changes that are pretty obvious relative to their red blooded relatives they have bigger hearts they have and we think those big hearts are pumping a larger volume of blood I'll be very dilute blood and the concentration of oxygen in in their bloodstream that dilute plasma is the same as the ocean that surrounds them so they are pumping around a larger volume of oxygen that's just been taken in passively so as I said why on earth would they go to these measures what was going on in this part of the world that would lead to such a condition and to appreciate that we need to understand the environment which they live in the history of that environment and why they might have gone to these sorts of extremes so we know from the geologic record that 40 million years ago or so that South America and Antarctica were joined and beginning about 33 to 34 million years ago give or take a week they became separated and that opened up what's known as Drake's passage and that opening changed the pattern of currents around the Antarctic these continents move further away and isolated the Antarctic water since they became much cooler down towards 30 or 29 degrees Fahrenheit today from a starting temperature around 50 degrees Fahrenheit 30 to 40 million years ago so it's a pretty dramatic change in in ocean temperatures and what we know from from records from fossil records for example is that while there were 40 million years ago there were fish in this region that were like sharks and skates and flounders that sort of typical things those species are not in these waters today most of the species in the waters today are ice fish and their relatives so how do ice fish arise how can we learn something about exactly how it's gone through this process of adapting to these colder waters well as I said I brought up the fossil record the way we would normally do this as biologists to look at the origin of a group as we return to the fossil record but it turns out there is no fossil record of these fish and if we even had fossils it would be tough to tell from those fossils whether their blood was red or colorless when those changes took place so how can we peer more deeply into the origin of these species how can we peer into these this adaptation where can we look for clues but we don't have a fossil record but these days we have a whole new record of life and that's the DNA record in these species and in every organism is a vast record not only of the operating instructions that build that creature and run all of its functions but of its evolutionary past reveals how is it different from its ancestors or similar to its ancestors what has changed and we can now peer into that DNA record and very precisely pinpoint the meaningful changes that are involved in a whole host of adaptations so that DNA record of icefish reveals what in the course of evolution has been lost or modified or gained and what I want to do for just a couple minutes is show you some of the things that we can see in the DNA record of the ice fish that will make a whole lot of sense to you in terms of the way these animals live and I'll spend a good chunk of the rest of the talk showing you some other things in the DNA record of other species so I'm going to start out with a loss but it's a really dramatic and clear loss and it makes a lot of sense with what I told you so far so red blood is red because of the protein hemoglobin carries oxygen yours and my bloodstream and in fish that hemoglobin molecule is encoded by two genes that sit next to get next to each other just shown in this schematic one gene here with a little red candy stripe the other gene as as green if we go to this exact same position in the DNA of an ice fish we see that the green gene isn't there whatsoever it's gone and the striped gene is just a truncated remnant now we know where we are because there's enough resemblance in the text of the DNA between a red blooded species and the ice fish that we know we're looking at what used to be a globin gene but all that's there is a molecular remnant a molecular fossil eroding away the same sort of way that a fossil would erode when exposed to the elements it's decaying that there's still enough of the text left that we can tell that it used to be a good gene so that tells us a couple of things first of all it tells us that these fish these bloodless fish evolved from red blooded ancestors that makes a lot of sense but there's been a dramatic change in its content of globin genes they're gone gone for good okay so there here's a clear molecular signature a forensic signature in their DNA of their change to this red bloodless lifestyle now evolution isn't just about losses whatsoever it's also about inventions and there's been a lot of inventions in these fish I'm going to mention one of them so these fishes I told you live in waters that are about 29 degrees Fahrenheit that's really cold and would be really tough on most fish and they're one of the hazards of living in water that's that cold if you've seen pictures of either the Arctic or the Antarctic is there's a lot of ice floating around if you kind of look under the waters a lot of ice crystals a lot of love chunks around if these fish are just simply ingest a little bit of ice that could nucleate ice formation inside their stomachs and throughout their bodies and you know a fish stick right like that flash-frozen same with just making contact they have they have of course water in their in their body fluids it's still the same thing with making contact between their skin and ice right they would just you know you've sort of seen it all in the movies right the tongue stuck to the light pole in the wintertime right it would be the same sort of problem for these fish but they've come up with a terrific invention beginning about 40 years ago scientists at the University of Illinois we're studying the blood of ice fish relatives and they discovered that it contains its just chock-full of an antifreeze a very high concentration of a pretty peculiar looking family of proteins that we know from detailed biophysical studies prevents reduces the temperature at which ice crystals can grow so prevents the nucleation of ice crystals it's at very high concentrations in their bloodstream and these fish and an antifreeze containing fish dominate the ecosystem of the southern waters there are about 90% of the biomass of fish in southern waters are antifreeze containing fish so it's a very clear adaptation to these waters now what's really nifty in terms of the DNA record is that the same scientist the University of Illinois have looked at how are where did antifreeze genes come from and they've actually captured in the DNA record of antifreeze bearing fish really the origin of antifreeze in that we know that the antifreeze this really peculiar molecule that's encoded by a very repetitive stretch of DNA it arose as it broke off as a piece of code from another gene actually a digestive enzyme and that event has been captured in the DNA we can actually see a sort of a hybrid gene between the old gene the digestive enzyme and the new antifreeze so it's very clear in this case that something new was invented by using something old which is a general theme in evolution but in this case it's something really radically new a capacity that these animals never had that's enabled them to invade a habitat that's otherwise hostile to their kind so the sharks and the and the flounders and all that they're all gone but the southern fishery is dominated by these antifreeze containing fish so I tell you those couple stories to appreciate or to begin to appreciate how the DNA record contains a very precise exquisite record of things that have gone on in the past and still that are going on today that we can identify and understand the deepest level their meaning in terms of adaptation we can see how the fittest are made the genetic recipe for making organisms that have capabilities that other organisms don't so a lot of underscore tonight in my talk is a few general things about this DNA record it really reflects the general point that the earth and life evolved together and you'll see more examples of this if you start thinking about the habitats in which particular creatures are found there kela challenges presented by particular environmental conditions and the signature of how those organisms cope with that how they adapt to that is right there in their DNA record so we live on this changing earth and really the DNA record is a record of species keeping up with that changing earth these shifts in lifestyle are reflected in pertinent genes many many many other genes will show no changes whatsoever they're not they don't have to change to adapt to a new environment so lots of things stay the same but a particular subset of genes are evolving to adapt to new places and in the DNA record is vivid documentation of Darwin's principles of natural selection the reason why we're getting together here at case so many times this year is to talk about these ideas of Darwin and here we are almost 150 years later saying that what he inferred from the information he had available to him in the mid 19th century is well documented by a completely line a different and independent line of evidence he never could have imagined so since I brought up mr. Darwin in his principles of natural selection let's make sure we're all on the same page with what those principles are so this is a little bit of a lengthy passage out of the Origin of Species but it has all of the keywords in it and it's a it's worth going over so in is somewhat halting way Darwin wrote can it then be thought improbable that other variations useful in some way to each being in the great and complex battle of life so the key idea is there are that there's variation among organisms and they're engaged in a great and complex battle of life if you get nothing else if you want to know why the world changed with Darwin it's right there the Battle of life the most dramatic if you like philosophical change in the Darwinian view of the world from all predecessors was that not that the world was designed with all pieces in perfect harmony as you would sort of arrange pieces on a chessboard but that everything was engaged in a battle there was competition for resources predator and prey parasites and hosts vast waste famine death etc okay not the idealized world that that was largely driven by religious views from in all times preceding Darwin so this battle of life is what we're going to focus about okay so if these variations should sometimes useful variations should sometimes occur in the course of thousands of generations so vast amounts of time time was a key ingredient in Darwin's thinking and only I think because of his great geological orientation that Darwin have a grasp of time a much better grasp of time than other naturalist of his day so such do occur can we doubt remembering that many more individuals are born than could possibly survive that individuals having any advantage however slight over others would have the best chance of surviving appropriating your kind so what advantageous variations are there however and people often forget this part of Darwin's model on the other hand we may feel that sure that any variation in the least degree injurious would be rigidly destroyed so there's two processes going on the elimination of things that are injurious and the preservation of things that are favorable and it says preservation of favorable variations the rejection of injurious variations he calls natural selection let's look for evidence of this okay so let's talk about I'm going to focus entirely on this great and complex battle of life because it's very clear if my computer will move there we go it leaves a record in DNA and so what I want to focus on in the rest of my talk is a few highlights and I think some profound surprises from this massive DNA record of life and what I mean by massive as a working biologist it's transformed the world of biology in the last twenty years twenty years ago if you typed out all the DNA code that biologists around the world had ever deciphered and typed it into a normal-sized book it would fill about an average-sized novel if you were to do that exercise today and stack those books it would be more than six times the height of the Sears Tower in Chicago and growing by dozens of stories a year we have the complete DNA records of more than 800 species and that number is growing now at an enormous clip because all this technology is driven the cost of sequencing entire species genomes down to a pittance what used to cost hundreds of millions is now being done for a few thousand so biologists are mining this DNA record as never before so I could tell you lots of stories from this DNA record but unless you want to do an all-nighter I'm going to focus on one particular dimension and I'm going to just focus on the battle between seeing and not being seen it's a widespread one in the animal kingdom almost ubiquitous in the animal kingdom and I want to tell you some stories about evolution of this evolutionary game of hide-and-seek and some tricks that some hiders have come up with and some tricks that seekers have come up with to give you an appreciation for some of the insights we get by appreciating the DNA record so I'm going to start about on a battlefield it looks like this okay so here's a battlefield it's also known as the Pinacate lava flow of Arizona it's a beautiful place you see all the gorgeous swaro cacti of this part of Arizona this this battlefield extends into Mexico but the striking feature of this of course is the really dark soil and these dark outcrops in this part of the world in this part of Arizona there have been repeated bouts of lava flows and if you've been anywhere near Flagstaff or from the great near the Grand Canyon may have come across places like Sunset Crater etc you can just come around a turn all of a sudden there's this big craggy lava flow right in the middle of the desert and so several time there's been bursts of lava flows several times over the last million years in Arizona so if you want to see what one of those lava flows looks like sort of a cross and otherwise just brown rocky landscape there's one of these lava flows that decorate Arizona and these things can go on so they can be short they can go on sometimes for 30 or 40 miles outside of this region it's a really it's a really sandy rock scape and this area I'm showing you is the habitat for the Magnificent majestic and I think soon to be iconic pocket Mouse so these little creatures which are plentiful in the desert come in two flavors now I mentioned them as flavors because Michael Nachman my colleague at University Arizona who works on these has referred to them as the Snickers bars of the desert they are dinner for many things birds lizards snakes etc so they come in two flavors sandy and chocolate and what Michaels arranged here are some portraits of these mice on a couple of different backgrounds and you can see that the Sandy Mouse blends well with a sandy back colored background and the chocolate Mouse blends well with that lava rock background but this chocolate mouse sticks out on that sandy background and that sandy mouse ticks out on the lava background why does that matter well for 80 years naturalist have been studying yes 80 years 80 years Naturals have been studying these mice this is what biologists do okay it's a great calling it truly is I actually have been there to these sites with these mice and they are completely adorable and the sunsets are wonderful so I know why naturalist are out there studying these mice but why does this matter well the color-matching matters because naturalist know who these predators are and for example owls like these mice and if you're a dark mouse on a sandy background your dinner but if you're a Sandy Mouse and you happen to find yourself on a lava flow same deal so what we know from field studies of these mice is that the Predators are doing their job in sorting out the sandy color than the dark mice if you go to the lava flows today you'll find about 99% of the pocket mice you on the lava flows are dark and about 99 percent of the mice the pocket mice you find out in the open desert are sandy colored now the mice don't know which color they are okay they are all one species they interbreed okay and the genetics are such that for example sandy parents can still have dark-colored offspring but what we know is that there's different advantage whether or not being dark is good or bad depends upon where you live and whether or not being sandy is go to bed depends on on where you live but what makes this story I think a good tale and evolution or an especially good tale in evolutionary science is that we know precisely what makes for the difference between these two flavors of mice and it's one gene and just in case you happen to be quizzed on this you can earn a few extra points tomorrow I'll tell you who the gene is the genes called mc1r it's a coat color gene and we know precisely the changes in the DNA code of the mc1r gene that makes the difference between being sandy and dark so we know that there's one form of the gene that have a particular sequence and two copies of the gene your light colored and if you have an alternative form of the gene with mutation in it and you have either one copy of it or two copies of it your dark colored so we know precisely the mutation that has happened that makes the mice dark we know that ancestrally this population was sandy-colored and that at some point in the past the dark mutation arose and the dark mutation enabled those dark mice to invade the Lava habitat now why would that be important well it turns out that lava-rock as it breaks down a little bit is very very rich it provides a nice habitat for lots of plants these animals are seed gatherers so if they want to exploit the food resources that have popped up now on these on these lava outflows the dark mutation is advantageous remember whether the mutations advantageous or not is entirely conditional there's a connotation to the word mutation that mutation bad right mutation has changed something from what existed previously now in this case there's an advantageous mutation if you're invading the lava flows it's not an advantageous mutation if you're living out in the open desert so the fittest is a very conditional status mutation just generates variation whether or not those variants are favorite or not depends upon the conditions the organisms live in okay now get a little more feel for this this conditional nature of things as well as the DNA record that we can read I want to tell you another story the story in this case where the seeker has evolved a new trick I'm going to still stay with a with a model of rodents no I don't have a rodent fixation but biologists tend to study lots of small creatures because we can get them in large numbers and that helps to make substantial data sets this is a European vole not shown to scale this is more a Monty Python scaled vole so that you can see it because if I showed it to scale you wouldn't see it in green fields of Northern Europe so this vole lives in these lush fields of northern Europe but it is dinner for a particular bird the European Kestrel now the stories I said I'm gonna tell you about is I will tell you about the tricks the Kestrel has come up with now think about the challenge to a bird finding a little vole in a green field thick tall green grass now it's flying over it how does it know where to look how do you pick out a vole from that height well the important thing to appreciate is that these birds essentially all other birds have full color vision like us but the Kestrel has done something a little special with it I'll tell you about but I need to give you a little short digression about color vision a little quick little aside on color vision what we call full color vision is our ability to detect these various hues of light these various wavelengths of sunlight across what we humans call the spectrum of visible light and the way we detect that light are is a set of proteins and our retina called opsins so three options at us that I'm going to just refer to as the violet the green and the red opsin that are encoded by three separate genes and confer full color vision okay so these are sensitive to a spectrum of wavelengths and the integration of the information coming from all of our options is what we see as full color vision we have another option which is used in dim light and not going to talk about that tonight okay now what about full color vision well we have full color vision in humans our old-world primate relatives have full color vision birds have full color vision but other mammals are impoverished in this sense your dog does not have full color vision dolphins don't have color vision cats don't have color vision okay so mammals do not have full color vision we Old World primates have a volatile color vision and we know precisely why we have it it's because we have one extra gene involved in color vision detection that other mammals do not now just to think about why would color vision matter why in fact would color vision matter to our old-world primate ancestors and relatives well they give you a little feel for that I'm going to show you a film clip the film clip is from a red colobus monkey on the island of Zanzibar the Internet's a wonderful thing this is the only eight seconds I could find that would illustrate this point whatsoever I'm going to show it twice because it's it's not that easy to detect what I want to point out but I want what I want you to look at as I want you to look at the leaves that the monkey chooses to eat okay so I will show it twice here's our monkey here's our monkey and PowerPoint not starting come on monkey curse you Bill Gates there we go okay so watch watch how do you look you see that could you see the color of the leaves e8 okay we'll start this again not let's see all the green all those clean green leaves around him but look what he reaches for it could you see it the lighter colored leaves did you see that the yellow red leaves okay so if he didn't have full color vision he couldn't distinguish those red leaves from the green leaves and those red leaves are younger more nutritious and easier to digest so a lot of biologists think that this acquisition of color vision was an advantage when forging through the canopy in effect there are no old-world monkeys that are lacked this color vision so it was probably a pretty important competitive advantage okay so remember two days ago I was talking about the Kestrel follow me here okay that's your little aside on color vision and why it's important in primates let's go back to the stroll well the Kestrel has done something a little different what's going on in the Kestrel is that there's a mutation in the gene encoding its violent opsin that mutation which has been pinpointed changes the properties of the opsin so that now instead of detecting violet wavelengths of light it's now sensitive to the ultraviolet shifted its sensitivity to this end of the light spectrum to the ultraviolet now in you and I and many other creatures that would be a bad thing to change our perception of the world entirely but in the Kestrel it's a good thing and the reason why it's a good thing in the Kestrel is because vole urine reflects in the ultraviolet once again I want to point out to the students the glories of being a field biologist I'm going to preempt a question from the QA I don't know how they get the voles to pee in the cups but now the point now think about the challenge that that Kestrel faces being able to detect the reflectance of urine means that anywhere there's a concentration of voles on their trails around their burrows would be a visual signal that's the places that the bird should prowl for dinner so the Kestrel is picking out through the whole field the sign of the vole but again this mutation that's happened in the Kestrel good for the Kestrel wouldn't necessarily be good for other species again the fittest is a conditional thing so the two cases I told you about evolving genes I want to underscore a couple of points variations arise by random mutations the most common misunderstanding about the evolutionary process is what is random and what is not you'll often hear it said well it's a random process now mutations a random process mutation is blind these mutations arise at random in newborn in each time in each new offspring okay now why I had a little senior moment there for a second could come up with word mutations are happening all the time but they're happening at random sprinkled throughout the DNA it's the selective conditions it's the habitat it's the Predators its mates which determine which variants are favored which are the fittest so it's the interplay of this random process generating all sorts of variation and then this competitive process of sorting out the winners and the losers that's natural selection not random natural selection is not blind it's the key element so you might think this wondrous process of natural selection that once organism come up with a neat trick like full color vision they never get rid of it right that evolution would be a cumulative progressive process with each new trick being added on them and ascending the scale of life not at all and we can see this in the DNA record so to tell you about this I'm going to stay with the battle between seeing and not being seen released with color vision I'm going to switch the animals I'm going to talk about I'll talk about colorful fish those of you who like to keep tropical fish will appreciate that but most that shallow water fish like reef fish are often brightly colored and these shallow water fish often have full color vision because all the wavelengths of sunlight can penetrate shallow water okay and therefore they can go through all these fancy tricks of mating dances and camouflage etc so you see colorful fish at shallow depths but at greater depths something else is going on most wavelengths of light are being filtered out all you've got is really the deep blue so I'm going to show you a fish that lives it at great deeper depths and I want a student someone a senior or younger to identify this species of fish it's a pretty famous fish but this is some footage taken from a submersible there you go didn't take long so this is a coelacanth famous fish because it's a whole tribe of fish that's thought to be extinct until it was rediscovered in 1938 it's a really important fish in terms of understanding some of the things that have gone on with the evolution of paired fins and the origin of our walking limbs but these fish pretty much hang out in caves during the day and prowl the ocean floor at night eating crustacean and things like this so they're primarily living in a dark light environment and when we look and compare the genes in a coelacanth and in a shallow water fish we see a really distinct signal of how their lifestyle lifestyles have changed so if we take a look at something like a clownfish and we look at that violet opsin gene the same gene I was showing you for example it had changed in the Kestrel I'm just showing in a schematic here that that violet opsin gene is intact it's a perfectly intact piece of DNA code that makes a violet option that this fish uses in color vision but if we look at that exact same piece of DNA corresponding piece of DNA in a coelacanth it is shot full of holes there's four different mutations in that gene each one of which would the gene so it couldn't function so the coelacanth is carrying around in an activated violet opsin gene non-functional and really not any chance of regaining that function it's a molecular fossil now how can we rationalize that well it's living in deep water okay it only at best sees very dim blue light sort of blue shifted light okay these mutations have no effect on the performance of that fish so while the gene is there and has been there since the time of its ancestors this random process of mutation has been taking place but natural selection doesn't sweep these mutations away there's no disadvantage to these mutations now that same mutational process has been taking place in clownfish but they're not carrying any of those mutations they have to keep an intact gene so in this case what we thinks happen is that the shift to deeper water these fish living in deeper water has relaxed selection on the opposite so it's carrying around a fossil gene okay now that's a second fossil gene I told you about I told you about fossil globin genes and a nice fish fossil ops and jeans and a coelacanth or fossil genes just something that's you know peculiar to really strange animals that live in weird places not at all so before you get this sort of message let's look at something a little more cuddly let's look at a nocturnal owl monkey and what's the story here here's a strictly nocturnal animal beautiful big eyes seeing at night does not go off during the day you look at that exact same opsin gene shot to pieces now it's a different set of mutations in the coelacanth and that tells us that what happened in the owl monkey happened separately from what happened in the coelacanth they live in different places they have totally different evolutionary histories but it says that living in the dark relaxants selection on certain genes okay is that just true of all monkeys and coelacanths now here's another nocturnal primate beautiful little Bush baby you look at the violet opsin in this guy same story shot to pieces but different set of mutations than you see in the Alamo key or the coelacanth it's happened independently so what's that's telling us shift to a nocturnal lifestyle relaxes selection on daylight color vision genes okay so I'm going to test your sympathy and attraction to cuddly creatures with my third example so if shifting the deep water relaxes selection and some genes and shifting into the dark what about other habitats like living underground this is the subterranean blind mole rat but sure enough unlike rats that live above ground that have fully intact violet opsins the opposite of violet opsin gene in this animal is also a molecular fossil again a separate set of mutations then what happened in the other animals so what are what is this with fossil genes have i m-i again is this just a peculiarity of creatures that live in extreme habitats okay I'll show you the most peculiar animal of all plus you look in the human genome ballpark 20,000 maybe 22,000 genes at least 887 fossilized genes in you in me we're carrying around inactive genes no longer functioning okay 67 of those are still active in the chimp so that tells us they were fossilized in our lineage just from the split from between our lineage and chimps five million years ago so this is still going on we can talk about what the identity of some of those genes if you want in the qat you find fossilized genes in every organism baggage that they're carrying around if you want to look at the agents are still carrying around that they're no longer using for their current lifestyles well why is that significant well I think it's a little bit surprising there's a massive record of fossilized gene you can find them in everything well they tell us something about lifestyles of ancestors these genes were operating at some time in the past and ancestors for the coelacanth probably ancestors that lived in shallower water for the monkeys definitely ancestors that lived out in daylight and use those color vision genes to shop for food for the rat for their above-ground ancestors that's for sure but perhaps most importantly this is exactly what you should expect to see happen in the absence of natural selection if selections relaxed if organisms are now living in a different place from their ancestors it's a different regime a different selective regime and now those genes are not useful they don't affect performance they don't affect fertility they don't affect survival so they start to accumulate mutations use-it-or-lose-it there's a rule they demonstrate that evolution at this level is it's not a progressive process some information gets irretrievably lost we've lost hundreds and hundreds of functional genes that existed in some of our mammalian ancestors primate ancestors dozens of genes that existed in our common ancestor with chimpanzees and I think they're they're a good hint that diversity is not a matter of design this is exactly what we'd expect to have happen under a random mutational process and so I would pose the question you know what designer would design all these non-functional jeans at a minimum a designer with a great sense of humor there's something else about the fossil jeans that I want to just emphasize for a couple minutes I told you about the same Jean the violet opsin gene being fossilized in these different species in different parts of the world live in different sorts of habitats raises the possibility that maybe this process of evolution is a bit more predictable a bit more reproducible than you might have imagined you bet it is we couldn't tell this before the DNA record just looking at organisms from the outside you can't look at that monkey and know it doesn't have a functional violet opsin gene that it can't see in color you'd have to do deeper investigation you can't just look from the outside but in the DNA record we're looking right at the recipe that encodes all of the properties of that organism well what can we see go to some other animals how about the snow geese if you look at the white and melanic forms of these snow geese you can map the difference between these forms once again to that gene mc1r the coat color gene of the pocket mice that causes the alternative forms of the pocket mice is at work and causing the alternative plumage forms of these geese same gene is involved in the orange versus the black phase of Jaguars mutations in the same gene cause this difference I can go on and I'll give you one more example same situation in the Arctic skewer this is the melanic in the lighter form of the Arctic skewer and what's interesting here is the same mutations at the exact same pieces of nucleotide position same places in the DNA text have taken place in this bird has happened in the pocket mice different points in time different places in the world entirely different histories yeah we're coming up with lots and lots and lots of cases of the same event happening again and again and again so I'm going to close this riff with just one more example one of my favorite examples I told you a while ago about these fish living in the southern ocean that have to protect themselves from the icy waters with antifreeze now what about the northern ocean what about the Arctic did those fish have antifreeze you bet they do but here's the killer a very similar antifreeze chemically speaking was invented about ten million years apart from the Antarctic fish we can date these events again using the DNA record it's we it's clear from the exact DNA code of that antifreeze that it has a completely different origin from the Antarctic antifreeze they come up with similar similar chemical solutions but there are certain signatures that tell us these were independent solutions so again similar challenge living in cold water similar solution independent paths so evolution does repeat itself similar selective conditions favor similar genetic variations in different species at different times in different parts of the world something we couldn't say till we looked at the DNA but wow what a nice confirmation this whole idea of mutation and selection working together to shape biological diversity so evolution is far more reproducible and therefore far more predictable than we thought I pretty much guarantee it go find nocturnal animals you're going to find changes that have taken place in them that reflect that lifestyle find things that live in hot springs you'll find things that reflect that lifestyle okay find things that live in deep water or shallow water you're going to find things that reflect that lifestyle scripted in their DNA so biologists have come across this record as I say the access and the volume of this record is really very very recent and so um you can if you see the gray in there I'm old enough to appreciate that this is I think a second golden age at safety say the first Golden Age of evolutionary science was the discovery of evolution by the geologists paleontologists and naturalist of the mid 19th century then seeing it in all its rich workings in the depth and detail and conviction that we can now is fantastic and you can see this reflected and some of our some of the popular press here's Time magazine from a little while ago talking about how we became human and that now that we have the DNA records of chimpanzees and macaques and gorillas and humans and soon Neanderthals the quest is on to find the meaningful changes that explain how humans are different from other species or the same different from Neanderthals or the same it's a great time to be an evolutionary biologist golden opportunity but I would be remiss not to point out that this golden age also has is occurring at least I would say at a at a parallel Dark Age I've been carrying this slide around for a couple of years with me I have to update the story just keeps getting better and it's not hard to collect these quotes from some of the country's highest offices from from elected officials I was in Tennessee not too long ago and I came across this quote I love this one we've hunted for almost a hundred and fifty years and not found supporting evidence speaking of evolution who is the we and you know while the we in this case this the person speaking it turns out was a state representative named Raymond Finney I didn't know who this was it was a a state legislature and so you know go to Google type in Raymond Finney you know why wouldn't he have found any evidence got my answer so it's striking almost incomprehensible to those of us in the scientific community that a time when the evidence is raining upon us when we are drinking this information like we're drinking out of a fire hose that you continue to see these utterances from from public officials so there's a big disconnect between knowledge hard established knowledge and this knowledge I've been telling you about from the DNA record remember the role of DNA keep in mind the role of DNA in our society today we use DNA in every courthouse to convict and exonerate criminals to put some to death we use DNA to determine paternity we use DNA in every clinic as a diagnostic and a prognostic tool society likes DNA most of the leading shows on TV CSI whatever they're up to now okay viewers are getting the message that DNA is a crime solving tool that's a lot better than fingerprints or eyewitness testimony etc so we love DNA and it's practical implications but evidently not its philosophical ones so we need to catch up and there's a lot of information out there a lot of stories being cracked every day about the evolutionary history of life on Earth as it's documented there so now what do some people say how should we approach this cultural problem it's not a scientific problem it's a cultural problem some people say well there's alternative scientific theories what alternative scientific theory okay let's talk about one of the examples I showed you what would be an alternative interpretation okay given everything we know about mutation which has been studied at the biochemical level for 50 years that can be quantified by the exact tools of molecular biology we know the rate of mutation we know the pattern of mutation do you want if you want to come up with alternative scientific theory for let's say the kestrel well if I was to translate what the intelligent designer say this is it now I want to be clear here yes this is I don't mean I'm not mocking god I'm mocking those who would invoke God when I think God would have better things to do okay millions of species on this planet and I would also say just there's theological I'm not a theologian but I can tell there's a theological question or problem posed by this which is what would God have against voles right okay and this is actually something that Darwin recognized okay that I mean it in battles there are kind of winners and losers why would you equip the predator with the machinery to make the prey okay you got the point all right so what do we do about this in a there's only one way to characterize quote the scientific argument of intelligent design which is miracles not mutation okay that's not science okay Kestrel did not need a miracle okay I know miracles the Red Sox winning the World Series twice winning it once was a where achill I don't even know if there's a word for winning it twice and I'm sorry I know it came at Cleveland's expense I'm really sorry okay I was not met you know not meant to inflict any more pain although the Governor of Wisconsin asked me to thank you for CC Sabathia okay okay so so what are we going to do okay we just all we can do is we can just keep talking about the science and sharing it and I think the power of the DNA record is that these are really crystalline examples of how evolution works with unimpeachable evidence of exactly what has happened in terms of the origin of adaptations and most of the examples I showed you tonight if not all of them they're not in textbooks okay yet they will be we just have a whole new amount of whole new body of information to bring to students from K through 12 right up through the college level so they can see evolution for themselves we can teach it in a much more tangible way I think then we were equipped to do just even a decade ago thank you son so we have some time for questions Joe and Jeff will man the microphones if you have a question just to put your hand up or stand up and then I'll give the microphone to you see we have a couple already thanks Patricia sure so one out one I'll talk about it's in human lineage and not chimps is if you look at things like macaques and gorillas and things like that you know they have a really big mandible really big lower jaw and they chew pretty rough food and there's a big muscle coming down from the top of the skull that moves that really heavy mandible that muscle is almost gone in humans and the making of that muscle involves a particular protein if you know about myosins and muscles there's a particular muscle specific myosin in this temporalis muscle and the gene for that in humans is a fossil the reason why that's pretty interesting is that first of all it's a clear change of our musculoskeletal arrangement from from other apes but functional morphologist think that by not having that big muscle you have to have a pretty thick skull to anchor that muscle on the side of the head so by eating more refined foods and having a more slender jaw and not anchoring that muscle might have opened up a little room for the skull to thin out a bit may even make a little more room up top for a little grain gray matter so there may be a little linkage there between diet and some of the sort of release of potential for for evolution of a larger brain and so very clear signature in the absence of that gene if we go a little further back in time it's a difference between a major set of differences between ourselves and lots of other mammals come that is is a clear signature in genes involved in the sense of smell so the largest gene family in mammals are smell receptors so mouse has over a thousand of these genes and if you sort of think about a mouse's lifestyle and lots of other mammals going around the ground interpreting its world by what it can smell okay either smelling food or smelling mates so finding its way home whatever it might be so sense of smell really important if you look at that same family of genes in humans over half of them are fossilized genes hundreds of fossilized smell receptors so we have junked a lot of our capacity for detecting odors you can also find some other fossilized genes in the machinery that's involved in sort of processing smells and even in some of the anatomy in our nasal structures that is volved in detecting smells that's that has atrophied so there's a clear signature in our DNA that we have evolved from sort of a smell oriented lifestyle and I and there's good evidence or a good I would say correlative evidence that that may be a reflection of our color vision based lifestyle so we are using color vision to find food to find our way in the world to remember where we are to see mates etc we're not relying on the sense of smell as much so the shift in lifestyle maybe a color vision lifestyle relaxing a more smell driven lifestyle and the correlative evidence that supports that which i think is really cool I told you that Old World primates are the only ones with color vision but I was telling a neat lie the neat lie is that howler monkeys in the new world have independently evolved full color vision and when you look at their smell receptors they're shot the heck okay so it looks like we've run the experiment twice once in Africa once in Central America that evolution of color vision is associated with a relaxation on the preservation of the olfactory system other question dr. Francis here last week and he was telling us about these common variations that seem to underlie a lot of human diseases and I was just wanting if you comment maybe as to why some of these common variants that are Dilla tereus were able to reach such high prevalences in humans and why they weren't really selected against yeah so it's a great question how much of what we did he talked about cystic fibrosis by chance because this is Francis Collins yeah okay because he discovered the cystic fibrosis genes it did so did he talk about that specifically just I don't repeat him okay so there's various idea so cystic fibrosis I'll give you that example I'll shift to a couple more cystic fibrosis the prevalence of that disease and the underlying mutation is higher in the human population then you would think given that it affects survival okay so biologists thought about why might that exist well it might exist at high frequency if it conveys some other sort of advantage and the overproduction of mucus I think which is one of the manifestations of cystic fibrosis that might have been protective at times when humans were being exposed to certain types of pathogens but the other idea is the cystic fibrosis protein out there on the cell may have actually been a receptor for a nasty pathogen and that to escape essentially being a victim of that pathogen mutations and cystic fibrosis protein could have been selected for the thinking they're really parallels what's absolutely clear in the case of sickle cell anemia or the sickle cell mutation and malaria now most of you are nodding because you saw this in the you got this in high school you might have gotten this in college the story is pretty rich it's the sort of thing where everyone many people are familiar with this story but it turns out many few people are familiar with who actually discovered it I could take a few minutes and tell you I'll wrap that up quickly but here's here's the salient features of sickle cell are that sickle cell the key discovery about sickle cell was as Tony Allison the discoverer who was a Kenyan born individual who then trained at Oxford for medical school as he went across his native Kenya in East Africa he noticed it remarkable changes in the frequency of the sickle cell trait as he went from area to area so in certain places he could find in a frequency of 40 percent other places virtually not there and these were not that far apart in places like Kenya and Uganda Tanzania and then he figured out these were often the high frequencies were in low-lying moist areas and not in the more arid mountain country and he thought well wait a second that's those are the real malarial zones so what if sickle cell provides some some protection to malaria so he put that all together in 1954 it's really the first time any genetic variant and a selective advantage was was connected where we knew the molecular basis of it that was a change in hemoglobin and it's sort of the first molecular model of natural selection and I tell you that story because Tony Allison hasn't gotten credit nearly as much credit as she got any figure that out in 1954 so that's sort of a model that if selected pressure is strong enough that a mutation that would have that would have some fitness consequences in some setting if it provides enough of a benefit it can increase in frequency I remember homozygous individuals people carry two copies of the sickle cell mutation there the full brunt of the disease and those children for example will die young so the advantage is in is in Chile and this is especially the advantage is very pronounced in children by the way really in the first four years of age it's the advantage wanes as you get older because your natural immune system becomes more important than the sickle cell fate trait but in young kids with one copy of sickle cell this is an advantage so that's why sickle cells at high frequency in certain parts of Africa and in southern Europe and southern India and I just want to while I'm rambling about this that sickle cell mutation by the way has arisen at least five times in human history again it's another case of the repetition of evolution that that mutation arose separately at three different parts of Africa separately in southern Europe and separately in in southern India we can tell that from again the forensic DNA record so that advant agent and those are all malarial zones historically intense malarial zones and a it's a case where similar selected conditions have favored a similar selected variant so people are trying to figure out whether certain things that are running around modern human populations right now might be due to plagues other epidemics that might have happened any time in the last several thousand years there's a lot of thinking of Middle Ages in bubonic plague and who might have survived that and why they might have survived that but those are I think I hope I'm being fair I think those are largely hypotheses and not as as solidly established as the malarial sickle-cell wake that makes sense okay yeah I have a question about your examples in the DNA record would it be fair to say that all those examples are evidence of microevolution and is there any way of showing in the DNA record macro-evolution sure now the distinction between micro and macro-evolution just so we are operating on the same definitional terms macro-evolution traditionally means evolutionary changes at the species level and higher so I'm showing you differences that exist between sometimes within a population or between species so kestrels have some things that other birds don't that certain mutations have happened in certain species and not I've shown you these examples because in 45 minutes or so they're the they're sort of the crystal and simplest examples I can talk about if you want to think about more complex traits pieces of anatomy body patterns things that involve multiple genes traits that were assembled over many many evolutionary steps that's the general realm of an area called evolutionary developmental biology or evo-devo which I'm active in and we could talk about that a little bit but they're they're hard stories to get across in a few minutes so we have lots and lots of stories of mapping of tracing differences that have evolved over many steps between species at higher taxonomic levels so and when we look at the DNA record and this is the key question about micro and macro as its ever related to any kind of debate is whether or not you need any special mechanisms to explain evolution at higher levels not at all same stuff going on at the DNA level that I just showed you just given more time or more genetic inputs more stuff happens cumulatively over time to explain say if you want explain the difference we know a butterfly and a beetle well that's tons and tons and tons of difference that added up you want explain the difference between two butterflies it's fewer differences and that's all we're really talking about is sort of the accumulated differences and the accumulated amount of time is that a feel for the so the message I really want to give you without giving a lot of molecular details is that nothing we don't need any additional genetic mechanisms nothing special to explain changes at higher levels than what we see going on right outside our window in in species we can monitor today there's a question in the far back right um I don't it just seems almost a little too lucky that I mean - I couldn't hear that work you lucky lucky yeah add that um something that codes for a digestive enzyme would undergo mutations and become antifreeze like even over thousands of generations how does that happen I mean why wouldn't it become something like an extra fin or something I mean that might all good advantageous well there's actually sexually some rationale there this was a digestive enzyme and we know that antifreeze is put out by the same organ that makes that digestive enzyme so one thing when we trace innovations like this we often find that the innovation is built upon some foundation that was already there so rather than coming up with antifreeze from scratch antifreeze came up with because it turns out that if you just express a little piece which is a peptide essentially a small little chunk of protein it has and if you can synthesize the same little chunks in the laboratory it has this freeze protection property now if this mutation arises in a gene that's that's already being exported into the digestive tract then you're going to put you're going to get this any freeze property of this mutation into the digestive tract so as we reconstruct the path when you take her with a digestive enzyme you don't get a new fin you get a new protein that has different properties than the old protein but in this case is being dumped into the same place okay then you need more steps to get that protein put out into the bloodstream but we know that that's some of the rationale we think that the first place in antifreeze evolved was in protecting the digestive tract from the ingestion of ice crystals and now it makes sense it came free of all from a digestive enzyme so you get the sense of that so when it I know what you mean by it sort of sounds lucky and I don't know that I mean antifreezes to my knowledge so far have been invented this antifreeze has been invented twice in fish but I've got to tell you that most many many things living in extreme environments have invented their own type of antifreeze it's it's not uncommon the proteins that are in your lenses of your eyes that are called crystallins have been invented many many many times in the history of the evolution of eyes in the animal kingdom so it turns out that inventing things that have these properties maybe depress the the ability of ice to form remember these aren't these aren't magic antifreezes ice just forms at about a degree in a hat degree maybe two degrees lower than without it so that's the margin that that invention has given these fish relative to other fish but these of these and other proteins it looks like lots and lots of proteins can be used as the the major protein in our in eye lenses it doesn't really matter just as long as it's something that's fairly clear and fairly stable and maybe is a little bit protective in terms of UV irradiation and things like this so there may be many paths to get these sorts of properties it's not a rare rare rare rare perfect recipe it's something that is imperfect at first but as soon as you have any advantage to that natural selection takes over and can perfect what was you know an initially mediocre invention yeah about switches sure in a detail you might want to consult the rest of the audience whether they want me to go into detail about genetic switches okay so all these stories I've told you about involve what we call the coding part of the genome that DNA DNA and us for example if you take all the DNA s 3,000 billion base 3 billion base pairs only about one and a half percent of our DNA encodes proteins which are the molecules that do work in our bodies about another three percent of our DNA carries the instructions or is involved in the process of determining where our genes are used and how much of each protein we make okay so by there's a huge part in biology of regulation making the right thing in the right amount at the right time in the right place and the general way we describe this material for turning genes on and off in the right place and the right time our genetic switches which are pieces of non-coding DNA that act sort of like a light switch that when they are occupied or not occupied by various sets of proteins determine whether or not a gene is on or off now the reason why switches are important maybe that's why the context you're you're raising it is that evolution can happen in switches and in fact my own work has been involved in exploring how genetic switches play a pivotal role in the evolution of form so I showed you these examples that I'll just sort of cut many of them were alcohol them sort of physiological though it's what exactly what what wavelengths of light are detected by the eye or changes in proteins involved in respiration like globin etc if when you're dealing with for example you know whether you make fins or hands or hands that have three fingers or two fingers or five fingers and things like this these are matters of the evolution of form and those changes take place by changing the program of development what happens in a developing embryo and the genes involved in building bodies specifying where the bone and the cartilage and the muscles and and go and how big things get and the exact fine sculpting of pattern all those processes going on development are highly regulated highly Cory choreographed and we now have 20-25 examples of where differences in form between species can be mapped to evolutionary changes in the sequences of genetic switches is that enough detail okay so there's a big chunk of the genome involved in evolution that I didn't emphasize today but for eighteen how much is it outside eighteen fifty six for eighteen fifty six I'd say that was a shameful luck stirring of my books but I don't feel any shame so the book endless forms most beautiful emphasizes the evolution of form and the book the making of the fittest if you happen to read it will emphasize that sort of examples you heard about tonight but many many many many more they work out to maybe a dime for example hey I got a kid in college too anyway so the evolution of form if you if you want to know I'm only trying to emphasize the some distinctions between the evolution of form and the evolution of sort of the fine tuning of body physiology because probably some of the capabilities that most interests about humans our big brains our ability to have this conversation the exact human form standing upright dexterity in our hands things like this these are changes in the regulation regulatory processes of development that evolve between us and chimpanzees and we're trying to we the collective scientific community is trying to map out some of those so there's going to be a lot more stories coming from that other part of the DNA record the regulatory part of the DNA that you'll hear more about we should have another round of applause and go to the book signing afterwards thanks very much and I'll hang on and answer questions as long as people want outside

Channel: Case Western Reserve University

Views: 18,092

Rating: 4.8373985 out of 5

Keywords: Darwin, Carroll, MediaVision, evolution, Case

Id: iL25Spo3YTE

Length: 79min 34sec (4774 seconds)

Published: Tue Sep 23 2008