interesting book that i want to show right at the outset we're going to talk about it we can show it is called dominion and it's subtitled can call chair and can nature and culture coexist and it's a great pleasure to welcome him this punctuated equilibrium theory of evolution but you've been and you've been involved in these studies of evolution and then citing developments have been going on in terms of our understanding of that maybe you could share a little bit if you would your own background you've been applied to american museum to see what it tells us about the nature of the evolutionary process so the study my entire career trying to basically compare the facts of history on the one hand with what we have learned from geneticists and other forms of evolutionary  biologists what they have to say about the nature of the evolutionary process and see if we can put the facts of history make them resonate a little bit better with what we're saying about how the evolutionary process works or to try to bring them closer together the notion of punctuated equilibria was one sort of you know nineteenth century examples and understanding so what but the evolution of our understanding and the developments as you integrate genetic rampal to the work of louis leakey another thing that must have been an incredibly exciting time as more and more of the picture begins to difficulty this discern in absolute terms but it's getting clearer all the time and more interesting in the absolutely well part of my work has been on the actual facts of evolutionary history mention louis leakey louis leakey was of course really a pivotal pivotal figure in  in bringing zeroing in on the actual history of human evolution the other side of the coin that was how the evolutionary process works and usually the division of labor still seem to be as the genesis on one side who have a lot to tell us about how natural selection works is all very good work and the role of mutations and so forth in population size and we paleontologists are usually relegated to doing what you're thinking about with louis leakey which is to simply document the fact of evolution and its course of evolution but the more interesting thing to my mind is not just the facts of evolution and not just what the geneticists can tell us about natural selection is over trying to put those two things together to yield a really dynamic view of what the evolutionary process is understanding the whole process yeah exactly and making the process the theories or the statements about the process be responsible to the actual facts of history as far as we can determine them and also to be careful that our interpretations of history are consonant with what we know about the biology of the situation which in terms of human evolution we might even get into this i get to it in my book dominion absolutely some interpretations of human evolution just don't make any biological sense and so forth years old now but it was a scottish form of james hutton two hundred years ago realized that because of the processes of erosion and metamorphosis and so forth the just the normal processes of history is quite unlikely to find anything that goes back to the very very beginning so it's it's actually quite wonderful that we found in the cores of continents rocks that are about four billion years old and those are granite and so forth one very exciting aspect about this early history though is the soon as you get  astronomers i believe that the earth is a little bit younger than that maybe eleven billion i don't know what the status of that particular and then and then going through the process so we can begin to see the first beginnings of them you know whatever it was that led into life around three and a half billion years ago and well  thing is all we can say is the earliest rocks you might find fossils and you do so you don't know what that's not a matter of the origin of life and we have a very good idea and what we don't have one detail of the very good idea of how that amazing process began well  and these molecules are they a d n a that the we think i think rather overly simplistic leave that these molecules d n a and r n a are the things that cause the the formation of proteins and then the prote march off and they make up our bodies and they have the enzymes that run our bodies and so forth so it's like a one way street on the other hand it's been shown it was shown by stanley miller and i think fifty three running a very simple experiment at the university of chicago a protein chain store sort of semi proteins that are full functional proteins but their chains of amino acids will form just spontaneously like passing a spark through a cloud chamber with i guess methane and in a few other in the absence of oxygen you get these cha mechanisms where you get this reverse transcription going on i'm not sure where the theories are right now they're arguing where the proteins came before which are easier to form spontaneously than these macromolecules and heredity or more conven proliferation of of hard shelled creatures mostly animal creatures some of which are very difficult to interpret but some of them are very familiar to us or they're sort of primitive versions of things that are very very familiar to us and it was called the cam explosion and literally it took about ten million years for this thing to really get in place but that's a relatively brief span of time given the three billion years absolutely you know it's just bacteria and so the question always is what happened what caused this proliferation of different kinds of things and then i say different kinds of things i mean arthropods i work on trial about it's yes many people know fossils know what a trial by it is because they're complex and they look like well they're related to insects and crabs and shrimp and  years ago now that the rise in oxygen in the atmosphere or a reached a critical point so that there was enough dissolved oxygen in seawater to support more complex forms of life multicellular life even if they were rather small and first and this might have risen only one to two percent current level of saturation of oxygen in seawater but that was another support these more complex forms of life if that's correct or if it was something else that we can't quite detect what it was nonetheless the pattern looks like a real threshold it looks like you get to a point and bingo life can sort of take advantage of the situation it's very much a matter of if there's an opportunity nature's going to rush in the certainly biological nature is the whole story of this tree of life is going to rush in there and fill that vacuum and take it literally take advantage of the situation is an amazing story n n n n it also says that all these biochemical models are there underneath the organic i mean of this particular book dominion for stressing the importance of the says it all environment but you've already seen the example i gave you back five hundred thirty million years ago and that is of the physical harm by events ruling some sun happening there that either always major training was in geology or his major contribution to charles darwin where was the war would be for him where we have concerns of understanding even back to the greeks there was some sort of equations of evolution meaning simply that all the creatures on the face of the earth are descended from a single common ancestor that's sort of the baseline definition of evolution that notion was around what they gave us he was the one who convinced the western thinking world that life in fact has was that there were even the greeks some of the independent thinkers throughout the years have proposed that there's a relatedness to the creatures on the face of the earth so in other words that's the basic idea of evolution so darwin didn't wasn't the first to think about the fact there was a big tradition in france for about at least one hundred years prior to darwin thinking in precisely those terms but largely been on a subtly because of the the basic western cultural story about this which was a drive from genesis is that supernatural being god created everything the way we see it it was the sort of the fish in life there was a resistance i think more i think more even more telling resistance  accepting the notion of evolution because there was no way that people could see the apparent stability of form you know there's a separateness to to the species out there and how do you actually take that ad change from one natural selection came to him put together the ideas of thomas balthus about the can regulation of populations by natural phenomena like limitation of food and so forth with the notion that all organisms ten resemble their parents and that there variation in nature to came up with this mechanism of natural selection i mean basically the idea is that more organisms are born in each generation that can possibly survive and reproduce and so the telling example of that would be he was an example of elephants and i don't know if i can remember exactly from the origin but it would go something like this darwin said i don't remember our we don't know too much about the biology of breeding elephants but let us suppose you start with one pair fertile elephants and let them live to a ripe old age of sixty years i guess or reproductive age of sixty years and they start reproducing at the age of ten and each couple produces one offspring elephant every decade he said so that's six per everybody can survive and reproduce that's just the luck of the draw so it's nose creatures that are best suited to meeting the needs of the physical environment that they're that they're living in that are going to tend to survive they're going to leave more what we would now say leave more copies of their we keep learning so much already how could it work when they put these things together in the past without knowledge of all the things that we have now and it but it even so we had to want to keep your a paleontologist and this i idea of of the of the new species appearing in the origin of species that imperial observation which is that once a new species shows up in the fossil record you know you're out there driving around in your car and upstate new york where i was working in rocks that are about three hundred eighty million years old island and be able to segregate them into the different species it's not really very difficult it's just kind of obvious if you do that in the fossil record of some horizon it turns out that those individual groups that you identify all recognizable everybody goes out there knows what this thing is and it's common as dirt really is and you find them down there and near the bottom of the so called hamilton group of rocks and you find them at the time and you can tell apart at least we've actually my students and i and colleagues up at the university raja sort of a map of program on this now to look at as many of these different species as we can and we're finding time after time that you get a little bit of sort of variation as you go through time there's a little bit of sort of evolutionary change or whatever it is but by the time he gets in the top invariably this those species are still very much the same as they were at the over that long haul six million years and anything stunning now that's a long time for them to very good but he should have hinged as he see projected a his syllogism a sort of a if you if you see what's going on with breeders and you get it over a few generations a little bit of change in a particular desired direction but if you have millions of ecological level and what it really means is that if it ain't broke don't fix it and things are stable and as long as the habitats will change one thing that it was always assumed was that when when the environment changes for instance when the glaciers come gets cold for the glaciers start migrating from the south that the organisms that are able to adjust to this place by evolving for instance long coats of hair and so forth will do so and they will survive the alternative will be extinction and now we  know anybody who feels birds around here knows that mocking birds and tough to take mice and cardinals and so forth which are so common around here one hundred years ago they weren't found here the climate been warming up regularly whether it's global warming human caused or combination of some more natural event or whatever doing it and what's what we're seeing is a migration north of birds and plants and mammals and so forth and what happens is that when you change the environment  particularly temperature you get organisms species tracking yeah so instead of evolution doing a job making them adjust to the new conditions where you are right now they switch their geographic but even trees move because trees send out isolated example i was looking at showed that new species tend to appear relatively rapidly without a great deal of change for the parental species and if they get established then they'll live on side by side so what i was doing different ecological setting and then what happened was the seas withdrew from the continental interior so the other thing was extinct and once the seas came back to the continental interior we descended species bandspread so as a geographic ecological story of this evolution and that gave you a view in terms of the overall view of evolution itself and eight theory of evolution which would be applicable to evolution as a process right if speciation coupled with the tremendous conservatism stability of species once they're there that was the initial core idea but now i'm finding out that it's not just isolated lineages that are showing this but it's entire ecosystem doing this and now the model that we have is  starts to talk about the interplay between extinction on the one hand evolution on the other this hamilton for they keep talking about six or seven million years old or stability of three hundred different species meet in they persist and some of them drop out before they get to the end but  most of them get to the and then there's a turnover rapid turnover we don't even know what the environmental event back then was something happened what it was climate or what i don't i really don't know and only about twenty percent of the species get through  thing i mean that life to be a system i mean the that the earth system and the eco systems over here it is so amazing and in particular in terms of the universe and whether or not we can so easily like carl sagan and others say that there are other forms and you're not right said but that's extinctions can you read in the fossil record well actually if you look at any chart of geological time which all beginning geology students have to look at those divisions are all based on a rock record of extinction i see  get a clearer understanding agreement on that now raymond dart and his work and that kind of thing and you know we had peking man we had job a man we had you know neanderthal and that kind of thing but we're going to get a clearer idea now that we can begin to differentiate the know i think is quite defensible and your book has a great deal to do yeah you know what i try to do in there is to give an ecological interpretation of this as well as just sort of a historical litany his own point of the book is to say where are we right now and where are we going well see the juxtaposition of culture over biological solutions to problems with making a with them on what i mean by biological solution there's an adaptation if you're a fish swimming around and you have sharp teeth to eat other fish that's an monet thank you that's alright that's a political term which we now have of culture developed you can see piecemeal the way culture comes to override a purely biological approach that arse  are some of the sense that we begin to sell a story i think at a store i don't even go back all the way to lucy and tell that story particularly but i might just say very quickly it's again i see it's environmentally driven five million years ago the mediterranean dried up major rivers the dump into and out are not enough in rainfall in sufficient to keep even right now that water in the mediterranean so most of the water comes in from the atlantic and that's what happens and then when that closed off yeah that's the whole was a partial growth of savannah like conditions and the woodlands and tropical rainforest of eastern africa began to receive to some extent that's this is the time where just about the time snap and we see a reflection of this in the fossil record already it's again it's a complex pattern it's partly it's ecological migrations of species into new territories because the basic environment has changed and also there's an eating certainly vegetation as well living in small bands and local ecosystems probably without tools dark room and dark who's as you say was the first initial discoverer of this particular species when you get a complete reworking of the african ecosystem so a lot of species disappear a lot of new ones appear some of that is extinction and evolution on the other side some of it seems to be migrating in and out like i keep describing when the environments change what happened in this instance was you got the widespread appearance of a grasslands in savannah condition really sort of like old serengeti kind of conditions now started to take over eastern and southern africa so ecological is a very very different situation so that migration in about a species but also the true extinction of some species in the evolution of others probably through fragmentation of habitat the speciation mechanism that we were talking about just years there's five at least that they count down different species of these creatures and so like a lot a lot of specialists the fossil record show very rapid rates of evolution and very high rates of extinction because in a sense you're putting all your  stone tools show up in two and a half million years and that means quite it was obvious that some of our predecessors had with tools that don't make it at the fossil record but these are thrilling because you start finding these these crew choppers it's so cold to want choppers and there's the first sort of material evidence you can point to same thing culture is there yes it's beginning to inform the lives of exactly and that's the theme of your book that's right calls right so there's that still make really important yeah but they evolved in response to climate climatic event and it's not the last time that this actually happens getting close to the end the work line that we were like other species that we were victims of extinction climatic that's remarkable that these these creatures are out there are many ways i like that story that's still being debated whether those states are accurate and so for the story i'm telling it here i'll stick to it right now for simplicity is yes this homo erectus appeared in africa at one two point nine just under a million years ago in the teeth of the second glacial advance tough suckers yeah yeah so the story i've that i tell it here about that is that this is incredible because they had fire question of it not the not the second one so the story that the sort of the moral of the story is the same but it's even more remarkable as it was but it's unusual to see a species expanding its range like that yet securely in the face of the environmental archaic or is that an made a group or notion or and homo sapiens sapiens and and we want to get up to this genetic stuff you could mention that wilson's work out of berkeley and that kind of thing where that fits in and try to bring us up to the modern so skipping for a that we spread around the world as home or rectus and then went towards homo sapiens independently in each of several different areas africa itself europe through perhaps in the end it's all asia so that the you really have to strain at it increasingly now but there's no other example like this in the history of life where species will evolve spread out over the globe will evolve in concert in this gradual manner as the whole thing that punctuated equilibria understand of all of us if you look at the mitochondrial d n a it was an african woman who lived one hundred fifty one hundred seventy five thousand years ago whatever you think you are now there's a lot of criticism by geneticists of that particular study all i want to say is that it does happen to agree fairly well with w than that but how does that survive and everything else got bumped off of big mammals elsewhere the answer is that we are all there it's a remarkable you drive up to these animals in a in a jeep they don't pay attention you appear what the dinosaurs were that that prevalent as we are now but we're not two point seven and growing fast five point five point seven billion and that's a result of our cultural success and we can't continue it will be