Is Human Evolution Over? - Professor Steve Jones

what I want to explore is what can we say if anything about the future of the species to which meaning was going to belong how our sapiens given what we know about processes the evolutionary processes that caused that species to evolve well the notion of change in the future is really more or less universal you can see it again and again many of which it just models a decline but some are more optimistic and maybe the man who was most optimistic was Thomas More here who who wrote a book called utopian ok which means the real place a good place and he had a there's a map of utopia which looks to me a bit like the island whites which is which isn't to me on heaven on earth in particular but that's another story lots of yachts as we can see that and his utopia is interesting too beautifully written book of course is written in 1516 and what happens is that in you tasted utopia society changes chamber pots are made of gold ok because gold is a useful and easy malleable metal people who commit crimes are sent to hospital because there must be something wrong with them people who become ill or put in prison because they have look after themselves and these are these are all radical new ideas but what's interesting is that this is utopia of social and intellectual change but about a hundred years ago a bit more you'll see in a moment that's that notion in the future altered almost completely and now basically all our utopias utopias a physical change of evolution ok so here's one a nice utopian society I think that's from Star Trek I never really knows I've never seen Star Trek but what we've got on something like Star Trek and many other bits of science-fiction I don't know I don't read science fiction generally because it's all the same but science is always the same whatever it is you get these strange blobby mutant creatures biologically change creatures from that from outer space or even here on earth at some indeterminate time in the future but in fact so they changed biologically they have these brow ridges at gigantic is a bit like the Duke of Edinburgh and they changed biologically but if you look at the plots the stories of these new utopias modern utopias they aren't exactly the same as what we live in today there are the dystopian world in which we live there are tribes gangs there are Wars there are weapons there's a love interest kind of the quarrels all this kind of stuff so actually people have changed but society hasn't and that's a really big shift in the way perhaps that we see the future and I think we can trace that back to really the first modern work of science fiction in English which is written by this guy here not the gorilla but HG Wells and that's HG Wells who was a student at Imperial College so obviously it's obvious why he thought that everything was going to hell in a handcart but he photographed here in about 19 I was in about 1906 I think in the zoology Museum at University College London which is where I work in grant Museum which I recommend to you all it's a remarkable place and it's full of old fossils I take my lunch in the sea in a common room it is even full of old fossils and there he is standing there leaning on a gorilla with a human skull in his in his in his hand and he was very very interested in the biological future and he wrote really a magnificent book which is I'm sure you've already which is the time machine and there's a time machine and the time machine whoops what's going on there away a time machine technology the time machine the time machine is you know it's it's it's the first modern piece it's the first piece of science fiction reading in English Jules Verne and written you know the journey to the moon and so on but that's in French who doesn't count and the top machine it's a really a rather a good book and of course you all know the plot of the time machine it turns on somebody who invents a kind of bicycle upon which he can leap and cycle off into the future and this is rather unlikely there's a rather unlikely apparatus and he's missing off into the future and he starts he starts he starts off and zooms off in the future and lights and darks begin to blur into one and he stops at several thousand years in the future and he gets off his time machine and he finds himself in somewhere that at first sight looks a bit like a supposed Hampstead okay full of charming kindly people many of them vegetarians who didn't delightful post Georgian houses and a polite and loving to their partners and they're called the Eloi and this seems at first sight and ideal future so he's very happy about the future and he thinks well maybe I'll settled in this Camden in this in this Hampstead of the future but the Eloi since becomes clear have a terrible secret which they're very reluctant to divulge which is actually there exists another race of people called the Morlocks and the Morlocks from would find themselves today much more at home with Island which is in Camden Town rather than Hampstead and if you if you go down to Camden Town Hume station on a Saturday night you'll find yourself entirely surrounded by more logs he's telling these terrible fog at these terrible thuggish people who go around telling other others and fighting and vomiting and that kind of stuff and what his model is that they're happy human species has split into two ok there has been evolution into a charming and delightful form and into an evil and thuggish form and of course because he was a good and excellent novelist there is a twist in the tale which is that the rulers are these terrible Morlocks who only come out at night and roam the streets and the Eloi are their sheep and cattle there there are domestic animals which they slaughter and eat for dinner ok now that actually that's a good that's a good story but in fact it has a it has a clear tie with a lot of biological thinking at that time and I've treated always show this line much of which descends when this chap Francis cotton and golden was convinced that the future was black dark in me because he was sure from his very dubious researches the people of low quality well however you might want to define that we're having more children than people of high quality and so indeed the human race might indeed split into geniuses a book called hereditary genius group now which of course he included himself and Complete Idiot's and he was very concerned about this and you hate you this theme is still around you only have to to listen to two recent education separately to hear that that's true okay you know speaking of the man who passed the eleven plus I suppose he see myself as a genius and the eleven plus actually was set up kind of on that assumption too that there was a pool of hidden talent which wasn't being recognized that we had to nurture these supposed geniuses to make sure they don't just get wiped out by the idiots all right didn't all that much good okay and golden well it was quite blatant in his views that something had to be done and this is indeed where wills called his idea from as did many other people of that time George Bennett sure being one Mary Stopes being another one and all of them are convinced to eugenicist s-- they could they were convinced it was there it was their duty to ensure the future of the hips biological future of the human race by making sure that people have good quality repeat over reproduced of people of poor quality did not okay I met led to all kinds of disasters as of course we know one of the classic disasters which Colton was very much rotary he wrote I wrote a hair write a hair-raising paper which in nature which is called Africa for the Chinese and what he wanted all the Africans to disappear and because the useless and the Chinese actually different instead and this is an interesting diagram it's rather not very perfectly correct it shows the ability of different his suppose nobility of different human races inborn ability and it's actually it's ludicrous but it's an interesting diagram historically because it's the first ever use of what we call a histogram a graphic graphic display of some data or date data ish data and you can see as we put the various groups on the on the scale of nature this column that you're on the ancient Greeks were the smartest of all and that's okay because they're extinct and then we get to the English which understandably are of the living species other living groups are the best then we have the Asians and there's familiar dismal racism we still face today the Africans below them are the Australians with a considerable overlap with dogs etc I once showed this sign in Sydney shining this side in Sydney and it did not go down at all well I have to say of course there's absolutely no truth in that in that diagram but it shows the kind of mindset which was so very common to the typical time and it's a mindset which is an evolutionary mindset it comes from Darwin and Darwin himself gave his Jews being genius he would he didn't believe in this at all he said never say higher or lower I didn't see any direction to evolution either the humans or any other creature but what I'm gonna try and do in this talk is to describe - I'm sure you don't need the description what Darwin's theory of evolution actually is what it's raw material is and asked the question can we make any predictions about the future of evolution from what we know has gone on in the recent and perhaps even the distant past and my thesis is at least in part but at least in the sense which many people are most people think of evolution as some kind of progressive business of things things can only get better at least in that sense and mind you evolution is probably pretty much for the time being and in the developed world over and I hope I can persuade you that during the course of this lecture so let's remind ourselves about Darwinism and it's very simple Darwin described evolution in three words descent with modification reason we could rephrase that and three even shorter words genetics plus time it turns on differences inherited differences and they come from errors we now know of Oh done Darwin didn't that are called mutations ok mutations happen all the time as we will see in a moment then there are Darwin's descent with modification has a very clever add-on which is called natural selection inherited differences in the ability to copy genes and if you have a inherited mutation genetic variant that makes it more likely that you will survive find a mate and reproduce then that copy of the gene will get more common than because other people who don't have it don't do as well as you do see there's it it's kind of ok that's that's that's the other and the third morning she perhaps a bit less familiar his random change evolution by accident and in fact it was that which really stuck Darwin when he went around the world on HMS Beadle the first line of the Origin of Species is when well acting is naturist upon nature mister opponent HMS Beagle I noticed some peculiarities in the distribution of the animals and plants to South America and the peculiarity was that on the Galapagos there were fewer species of Canton animals than they were on the mainland ok so and that he thought had happened by accident only a few actually got there okay so that's the Darwinian mmm that's the Darwinian agenda and I want to explore each more of them variational which costume you tation natural selection and isolation and random change what's going to happen to them well let's talk first of all about mutation okay there's a rather less distinguished piece of science fiction where we have Bron Spain where the hell he was has written a book where there's x-rays and giant meat and rats run around striking tinha fear into the hands of the hearts of the citizens ok fair enough x-rays and so on certainly do cause maybe mutations and some chemicals and things of that kind that's certainly true but in the 1940s the very prehistory of genetics in fact there was a strong feeling that we were actually going to suffer a great increase in the mutation rate by virtue of radiation in particular to degree chemicals but mainly radiation and that led to perhaps the most cynical scientific experiment ever carried out which was the atom bombs on Hiroshima and Nagasaki now there were military reasons behind that but they were certainly seen as scientific experiments because there was a team of physicists waiting to go into the cities as soon as it as the Japanese had done had surrendered and also a team of geneticists and the genisis were strongly in the opinion that they would actually find a huge number of new mutations in the offspring of those who survived the bomb well the physics got in and they were astonished by the degree of damage this is the this is a picture of the Hiroshima bomb actually going off and within a few minutes what had been a thriving City looked like this and I've actually been there and it's rather a distressing place to go that's for sure and many people of course many thousands of people were killed at once many more thousands of people dying slowly and in agony over the next few weeks because they had radiation sickness the DNA and their body cells had been destroyed by the radiation from the bomb and so they could no longer pump water in and out and they died awful deaths as a result but the geneticists turn to see there's a woman who's been burned by the flash and will certainly die of radiation sickness the geneticist was sent in with the expectation that they would look at all the children of people who were irradiated and compare them to those who had been outside the city at the time of the bomb and this was called initially the ABC see the atomic bomb Control Commission and they found itself in this railway carriage which was parked outside the park turned on the mean in the ruins of Hiroshima well I'm not going to go into great length about it they actually they went on for 44 nearly 50 years they gave up in 1995 actually stopped in 1995 and in retrospect forgetting the ethical issues which of course very real in retrospect their task was hopeless because in 1945 when they went in we didn't know anything about your necks at all we didn't know what the human chromosome number was we didn't know how to look at genetic variation in proteins DNA was known to be the genetic material but we didn't know as the double helix so we were totally ignorant and it's not surprising that they really got very little out of it however towards the end of the process they began to get some rather more sophisticated techniques where they could look at a sample of blood proteins from the children whose parents had been in the bomb and it's and other children whose parents have been outside the city and survived and it was a huge task they looked at hundreds of thousands of millions of protein changes and in fact they found they found they found a total of 28 of them okay when you compare the children to the parents now annoyingly though I shouldn't say annoyingly perhaps reassuringly what actually happened was that that there was no effect they could find all the bombs at all over 28 about 14 but in the in the offspring of people who had been radiated and 14 or so one of the offspring of people who had not been irradiated so so far so bad but they did find one quite unexpected effect that actually 26 of the 28 new mutations were in the father rather than her mother and that's something that we now know and understand quite well which is that that males are the agents of many many mutations it's particularly true with older males here's a picture of one of them that's actually me 40 years ago collecting fruit flies at the California deserts and people tell me I have changed a bit since then I still have the moustache in the envelope somewhere I guess I should need it in case I should need it okay and that's the process of aging and the process of aging is a biological phenomenon it comes at least in part from damage to DNA to their Mason your own DNA which often manifests itself in things rather unfortunate things like this which is the rate of colon cancer in relation to age and colon cancer like many cancers or is it genetic disease of body cells so you can see that your body cells decay and degenerate with age and that's because they divided and divided and divided and divided that as you get older and older and more and more mistakes are made however it's goes worse than that my dear it's worse than that it's bigger it's worse than that because of the way the different ways in which sperm and egg are made okay now women make all their eggs before they're born and they they go through this process of critical meiosis of producing half the dose of DNA before they themselves are born quite a long time before they're born actually and then they just frozen at that moment until they reach maturity and then these eggs are released at at intervals throughout the reproductive life so in fact every egg that a woman passes on is separated by only about five or six cell divisions from the egg that made her okay however old she is her her eggs were all made at the same time before birth men are not like that we never rest even when we're giving lectures at Gresham College we make large numbers of sperm all right and every time that there's a that we make a sperm there's a chance of an error a cell division in cell division and the figures are quite starting if you look at the number of divisions between between a twenty-year-old father they're humble cell divisions between the sperm that made him and the sperm that he passes on therapy because it's divided divided divided divided there's been about 20 cell divisions or 25 cell divisions feel like you are the young father if you look on the other hand for a for a 28-year old father there have been something like 200 cell divisions and from a 60 year old father there would be 800 to a thousand cell divisions and heard from the sperm that made him to the sperm that he passes on and every one of those involves the chance of a mutation and indeed there are plenty of conditions where you look at the father's age you can see the father's agent on the horizontal axis there for a can drop lazier for example that's the picture of somebody with short arms and legs maribor below he was even asked his painting and a striking fit between the incidence of this new mutation and the age of the father and it's worth pointing out that nearly all children with with achondroplasia are born as new mutations to older fathers and the effect isn't small it's a multiplication of something like Oh probably 15 or 20 times compared to a young father and that's much much more than any radiation dose any radiation dose that we're doing not push the mutation rate up by 50 does would be instantly lethal so this is quite an important thing it's not just these are all skeletal mutations and nervous system mutations they all show the same effect but even even mutations and errors which lead to schizophrenia which mental dacosta's a mental disorder you see again the effect is really quite striking from a bird from goes up by about five times in fine father's over 50 compared to those under 25 so the effect is big so if you're worried about the future the mutation rate in the future you don't have to worry about chemicals in the water or radiation in the x-ray machine you have to worry about how many older fathers are there okay and what's surprising and counterintuitive is actually in the developed world now there are fewer older fathers than there might have been a century and more ago and that's because we might that seems odd because we're all used to the idea that perhaps in Dickensian times over earlier fathers started getting down to their paternal duties when there was sixteen or so which they probably did because you know the chances of staying alive weren't all that great so important to gather ye rosebuds while ye may as it were and that's true but now we don't do that perhaps kids do start having sex at that time but they use contraception so that there's a delay so that the average age of a father in Britain is now 28 okay rather than 16 so you might think Oh blimey him well that's that's but actually the shape of this curve is that it gets steeper and steeper and steeper with age so it's really old fathers that matter and the number of really old fathers has definitely gone down here we've got a fertility with age right number two there are children or fertility rate which is basically the number of children in France which is a fairly developed country okay in Pakistan which is rather less developed but still fairly affluent and Cameroon which is actually now getting quite but when this thing was made 10 years ago it wasn't so and actually what you can see this at the crucial group fathers of over 40 are much more common in places like Pakistan and Cameroon than they are in places like France because what we do in the developed world now is we start early and we stop early okay we have fewer children and we squeeze them into a narrow window so if anything the mutation rates are from going up as many people came to believe this if anything it's going going down okay so that's mutation so let's move on to the next part of the Darwin story which is natural selection now I always show these slides of natural selection so if you heard them before just fall into a quiet slumber but many people think that natural selection is somehow a complicated and baffling process but it isn't it's childishly simple inherited differences in the chances of reproduction and it's so from say as I often say it's designed without a designer it can make incredibly complicated objects with no forethought at all one of the standard idiot comments by creationists is look at the eye how could that extraordinary organ have evolved without somebody up there God designing it all and making sure it all fits together but you don't need to do that because you can generate the most astonishingly complex organs with very very simple systems now it's so I often think of natural selection as a factory a factory for making almost impossible things and strangely enough that was my first experience of natural selection I left school to train to become an engineer foolishly or a fitter or engineer and I went to work in the in the Yuma leave us leave it brothers soap factory and liverpool's left bank in the world Peninsula Port Sunlight and I worked him up normally the detergent shed and the way you make detergent then and now you take an enormous of that not quite as big as this room pretty big filled with a boiling chemical liquid and you push the liquid through a nozzle and it comes screaming out at tremendous noise and she's one of the reasons I'm deaf it comes screaming out and the breaks into a powder which falls and collected in the vapor which you around and condense the news again and in my day the nozzle looked like this this big simple construction constriction and it didn't work very well it's made great a different sizes it got blocked and most important it wore out very quickly and these things which were made of stainless steel were very expensive so the factory owners across the world hired intelligent designer as mathematicians to try and make it better without much success because the mathematics of shifting over phase transition as it's known shifting from a liquid into a powder vapor is not easy to understand so also that almost without realizing it these people these engineers move to a precise analogy of the Darwinian mechanism of inherited differences in reproduction what they did was to take these nozzles copy them you take them take one copy and change it slightly make it longer or shorter different place for the constriction and longer or shorter description scratches on the inside and maybe one of the ten copies they made did better so they took that one melted the other nine down it took that one and they made 10 more copies changed at random once again mutating once again and they went through that process again and again and as they went through their process something fairly remarkable began to happen you began to evolve an almost impossible nozzle through this process of natural selection and after only 45 generations we end up with this extraordinary thing which works probably a hundred times better than what went before okay nobody designed that nobody knows why it works better nobody needs to know why it works better it just works better that's evolution by natural selection and this approach is now widely used by engineers by computer scientists it's a standard approach in many many aspects of technology so as I say what evidence is there that this might have happened in humans well there's quite a lot and there's one classic case which you may know about so go through it very quickly which turns on the undoubted difference in appearance of humans across the world it's worth remembering what a collective a detection of arriviste s-- we all are we evolved emerge Africa nearly all of human history was in Africa and we didn't get into Europe in any numbers until about 80,000 years ago we didn't get into northern Europe permanently until about 12,000 years ago we didn't get into the Americas until about 20,000 years ago okay so we're a recent creature and of course moving out of Africa led to a totally different series of environmental challenges if you map that out one of the well-known challenges of course is in skin color and that's the that's the skin color map across the world and we know a lot about the genetics of it rather surprisingly you can find one of the genes involved in fish in zebrafish it was found that a thing called the golden zebrafish a zebrafish a widely used in biology because he could see them as they developed a transparent the golden a zebrafish is so called because it's got these black stripes which are filled with the pigment called melanin the golden one in the middle there as you can see has the stripes but they're not filled with black pigment so there's much they're more useful to doing biology on and if you look at below that you can see the grains of melanin in the wild-type and the the absence thereof in the in the in the in the in the mutant fish well once you've got the gene in fish you can look for it humans it's take you a second you just type it all you have to type this sequence in you type it into a thing called Swiss prompt which is database and it'll say whether you've got a that gene and B that mutant in humans the answer is yes you do and the distribution of the mutant is actually rather interesting because here are Isis book at the old world first and the in Europe and Africa here are Africans and nearly all Africans about the blue segment here which is the version that can make Melanie nearly all Europeans have got the yellow segment which is the version which cannot make Melanie so some time on the journey into Europe there was a mutation which was some reason was advantageous okay there's a spin on that story because if we look over in China and Japan and at Native Americans who are generally speaking what I colored they don't have much melanin in their skin but they've done it in a different way they've still got the African form of the mutation the blue but they've had a break in a second part of the melanin factory so that they failed to make Belleville in for a different reason so why is it so advantageous where there's natural selection pick that up well it's better to do as you may well know with vitamin balance if you don't have enough vitamin D you're in big trouble vitamin D which is an oily fish and stuff and liver and stuff like that is unusual among vitamins because you can make it yourself you have sunlight in your own skin all right and if you don't have it you have all kinds of problems you famously rickets soft bendy bones and if you were to go from here to bond Hill fields the cemetery just up the road there and dig up the many thousands of children's bones who were there probably from the 18th century probably 60 or 70% of them would have had rickets and what that would have been one reason they would have died because they were smoked coal they were wearing thick clothes there wasn't the habit of going into the Sun people bricked up their windows because of the window tax so rickets was really was really a real scourge and it's still a problem here's what actually happens if you don't have enough vitamin D all kinds of things go wrong osteoporosis muscle weakness heart problems schizophrenia depression it's a big big issue and in fact in some parts of the world Glasgow most of all there is a claim that there is a genuine shortage of rickets among German shows you vitamin D among the population simply because they've they maybe have light skins but they don't have much sunlight so the effect is quite striking here's the amount of vitamin D in Europeans European Americans in the dotted line and african-americans and you can see for both groups both the light color and the dark colored groups the incidence goes up of vitamin D in the summer that he goes down in the winter and in fact African Americans on the average only just managed to make enough vitamin D and in fact in Britain the group whose most at risk and it's a real issue a real problem or immigrant not necessarily immigrants but Asian Britons for women who tend to wear long all-encompassing clothing don't go outside very much never dream of sunbathing and also have a rather small amount of vitamin D and their diet so it's a real issue so any error or change which led to the ability to make vitamin D in other words losing your black pigment and gaining what gain becoming light in color would be very very rapidly favored and it was favored very quickly that leaves one question perhaps the most important question in today's biology which is what is the point at this mutant here okay yeah here preserve this is possibly our future prime minister god help us and you can see in here is classically an active and interested pose here and he's a blonde and he's a real blonde he's a blonde blonde that's for sure he's not a peroxide blonde and that's a real question what the hell is the point of blondes why are there we have blondes and the it's an extension of the of the white skin story because blondes historically were only found in northwest Europe that's they're impressed they ever got to be common okay and if you were to go to Scandinavia something like 80 percent of the genes would be for blonde hair now why is that it turns on an extension of the argument I just been giving you which is actually that farming didn't get up there until about about about 4,000 years old less ago and the farmers had a lousy diet they didn't have there yet porridge basically just like Scotland today and so they were really really in desperate need of vitamin D the reason that farming got up there was a reason you could grow crops up in the northwest of Europe and not at the same latitude in the center has to do with the Gulf Stream if you draw a line through Birmingham and I know many people have been tempted to do just that what you find is that north of that line in Central Europe you cannot grow crops seeds of the kind that the ancient farmers grew but in Western Europe you can and that's because of our friend the Gulf Stream that gives us an artificially warm climate in a spring and grains need a warm spring in order to germinate and so these people suffered a big problem they had the ability to grow grains but it rained all the time in the bringing it wasn't sunny there was no Sun at all there's no vitamin D in the diet they couldn't get it in sunlight so they became Boris's that's what so that's the origin of blondes I'm glad I got that straight for you but it's a classic example of natural selection at work and it's happened in the last few thousand years and I could multiply examples of that but I don't need to sure let me just give you one which is perhaps less familiar this is the evolution to of the ability to drink milk as an adult okay and what do you think about it it's very odd that many humans everybody in this room almost every in this room I'm sure would automatically I'm like we don't do it anymore but I used to have a glass of milk when I was an adult with no problems at all but for the great majority of the world's population its Chinese Japanese and so on and native Australian studies have native South Africans you give them a point of milk and they don't like it at all they get diarrhea they're bloated they burp okay and that makes sense because in nature adults don't get milk okay they get milk from their mothers but when they grow up that stops but in about 4,000 years ago we got began to get the origin of cattle that gave milk and I think you could see that the incidence of the ability to drink milk which is actually quite striking changes over Europe from about 90% in Scotland all the way down to about 40% in the south of Spain over a short distance fits exactly with the emergence of of Catalan milk drinking and this group here in in Nigerian around a group called the Fulani who independently took up no drinking from cattle and they to have that ability so it's a powerful process so the question then arises okay what's going to happen to it in the future well again to be sure that it seems pretty clear that it's lost much of its power as I said into a panic and as I said natural selection is it turns on inherited differences in reproduction and natural selection is a bit like the driving test it's got two papers it's got a theory paper okay which you have to pass and you've got a very ven you've got a really difficult practical I passed the theory paper because I'm still alive from other surprisingly so the first part is survival if you're going to reproduce you have to stay alive it does generally speaking help I find but I've failed the second paper because I have no children so you have to look at variation to measure the strength of natural selection variation in survival together with variation in the number of children that people have and if we look at those two we see some dramatic changes over the last few few centuries let's talk first about variation in survival this is a slider that I showed my first-year students on their first day you see elders to cheer them up I say these are the patterns of life or death in England and Wales over the last 400 years and in Shakespeare's time only one and three made it to be made it to be made it to be twenty-one Darwin's time of it before and - and now 99% - of course we have in those days in the early days we don't we died from external enemies things like cholera tuberculosis cold starvation violence all of which have been magically banished from this fair land needless to say we still have to die in the end and now we die of things like diabetes and heart disease which have a genetic component but that's a slightly different issue so that's um that's everything has changed now that's in England which is of course the high point of world civilization but in fact if you look at the patterns of mortality apart from better off apart from Africa now all these are Asia South America India and so on there's been a remarkable convergence across the world in mortality powers since from the 1950s to 2005 and they've got even closer now so that even in places like India which in the 1950s the mean mortality the mean age of death was 40 it's seventy and rapidly approaching seventy-five now that's all a good thing but what that tells us of course is that that removes some of the fuel of natural selection which is differences in ability to stay alive some of which no doubt were influenced by genes so that's the the convergence of world life expectancy so that part of the natural selection exam has become much easier we all stay alive long enough to reproduce the question is how many of us actually get around to it and reproduce that to is is a rather surprising result printing on both sides of the paper here's a picture of a family on holiday in Sweden in the 1960s gentlemen who's who's shown in a circle you may recognize he's no longer with us that's Osama bin Laden okay and Osama bin Laden was the son of a chap called Mohammed bin Laden it was very rich Mohammed bin Laden being a fillip regenitive kind of guy had 22 wives and 53 children and in the year or osama's birth he has six children and everybody in that picture is a Samus brother-sister half brother or half sister so there are some urban laden had a huge number of offspring Hammet bin Laden had a huge number but somehow it would few two didn't live up to his father now okay that's fine for Mohammed bin Laden but he had 22 wives that means that 21 poor sods didn't have any wives at all okay so there was a huge variation in male reproductive success and we can see evidence of that in the past what we can look we can from historical records and from inferences from buildings and that kind of stuff we can work out the range of reproductive success in hunter-gatherers people are herders and people who become farmers and then indeed become rich and powerful rulers and what we find is that as society gets more unequal some males in black do extraordinarily well and regularly might have among the Incas some of them might have had 350 children whereas in hunter-gatherer societies everybody has about the same number of children now in some ways of course we've all become hunter-gatherers again we go to Sainsbury's or Waitrose in your case and just say and we hunt and we gather on the shelves and we get what we need it takes us an hour a day or less if you can be bothered to to get a card or to deliver it okay so we're living a hunter-gatherer life and in fact what that has done is to make is to greatly reduce the variation in reproductive success particularly in males rather than women and their other than females but if you look at the genes across Europe and across the world you see some striking examples of successful men chief Genghis Khan and Genghis Khan had like oh man a particular Y chromosome and Genghis Khan was famous or notorious for his for his sexual proclivities and he had hundreds and hundreds of literally hundreds of mistresses and hundreds of possibly even thousands of children his sons did just the same because they were powerful cons to and in fact if you draw out the map of that what's called star cluster this group of white chromosomes which almost certainly descend from Genghis Khan with a few mutations if we draw the map of that of that of Aksum of that variant you can see that although across the Mongol Empire there were lots and lots of them there are probably a hundred million or more men in the world today who carry Genghis Khan's Y chromosome and it's kind of interesting you take the Hazara who would not in the area shown here as his empire but do believe themselves to be descendants of Genghis they're dead right they have Genghis his Y chromosome okay once again if Genghis Khan was fertilizing every woman in the landscape lots of men were not doing it so there was lots of variation in male mating success and in fact rather less variation in female vote mating success and that too has gone away we have the same kind of convergence that everybody has roughly the same number of children his fertility in Europe from 1980 to 2000 and certainly the average number of children because it's got less that's for sure okay but what's more interesting is the variation has gone - so in fact everybody now in Western Europe male and female has about two children - two children to point morning England 1.8 know about 6:00 in Italy so soon no more Italians but you know we've lost that part of the funeral selection - and what we can do we can actually put those figures together and we can say okay well let's cadets correct for the disappearance of differences in survival and for differences in fertility and we can work out a figure that's called the opportunity for natural selection how much of raw material is there in terms of differential reproductive success for selection to work on and it's changed and very very quickly here's the figures for the Gambia 1955 there's the figures it went up a bit as Gambia became more affluent but as The Gambia which we've been to which is a very civilized kind of country with a good educational system as that happened very quickly really within 25 years or 30 years the opportunity for summation the total variation in reproductive success just plummeted to half what it had been in 25 years and over longer periods it's done it's it's done much much more than that in India for example if you compare middle-class Indians with hill tribes and people who still kind of sort of live the kind of life which early farmers had the natural selection the raw material it's lost nine-tenths of its power so that you've got less mutations or less natural selection and let me move to the final part of the equation which is evolution at random which is perhaps a little bit less familiar but this is a diagram I show to my students well let's imagine we've got a bottle full of equal numbers of green and blue beads and we pour ten of them into a into a cup and by chance purely by chance we get seven blue ones and three so three green ones then they all reproduce and till we got back to the thousand or so 100 and so we had in the bottle regionally and in the next generation we've got 70 blue ones and thirty agreements so simply by virtue of going through bottleneck of a small number of people we've had a dramatic change in the genes and if that happens generation after generation after generation you very quickly get this phenomenon which is known as genetic drift and this these are three diagrams various generations repeating that experiment again and again with different sized samples very small samples of 20 samples of 200 samples of 2000 and you can see in small populations you get a very rapid divergence slower in medium-sized and very slow indeed in big populations and in fact of course humans have always been rare what we can do what I'm almost bought one of the most boring bits of research I've ever read has put all the mammals on a line and this gentleman he's a friend of mine so I shouldn't be rude about him he found two astonishment his astonishment that there are more mice in the world than there are elephants okay a big deal I hear you say and but you put everything on the line from little rolls which are the smallest to elephants which are the biggest and everything sits there that farm animals don't count it has to be wild they all sit on this line an uncannily straight line with one exception which is Homo sapiens we are ten thousand times more common than we ought to be in terms of our body size okay and that becomes from the population explosion that which happened with farming every one of you on the way to this talk saw more people than the average human being who was an together would have seen in his or her lifetimes so were used to thinking that we're a very abundant species but in fact we're not and we can historically we were not and we can see plenty of places where this random change in populations has had a big effect most of all of course on isolated populations in the middle of nowhere here's a famous one pinga lap finger lap the man who wrote all of us acts were a really good book called the called the island of the colorblind and Pingala has got a uniquely high frequency over there otherwise very very rare gene that's called achromatopsia which is basically first of all you're color blind and secondly and much worse you can't see in bright light so if you go out in daylight you're almost blind genetic phenomena and something like 60% of the population something probably half as many cases that are known in the world have got this problem so it's called the order of the color blind because everybody is learning to cope with this and they all live happily together but if you look at the pedigrees it turns out that every one of those individuals has indeed descended from one man who was one of the only three survivors of a gigantic typhoon which wiped they are unclean and about in about 1750 left he must have carried that gene hidden away and it's got very common purely at accident okay so in small populations it's actually very it's very it's very young it's a very powerful force but it's also quite powerful Oh what are we doing here okay it's quite powerful in bigger populations too particularly in populations where there are very different levels of success in having sex in reproduction by men and by women and we've seen some of these extraordinary figures like Genghis Khan but even in the modern world there are quite big differences from place to place in Finland Finland what we all know what timberlands like women are actually more variable in their sexual success that men are so they okay in Norway it's one in u.s. it's one point two men are a bit more variable in Britain I think it's about 1.1 but then we go into into into tribe tribes in South America and in and in and in Africa and you do get much more variation among men than in women well that's an interesting it has two interesting effects first of all it means that the population of male genes y chromosomes is smaller than the population of their own male version X chromosomes okay and that's because if males don't have any children they may as well be dead they failed me they failed the the test of natural selection and that tells us now this is rather an over complicated slide I'll try and talking away through what we could do is look at the amount of variation in the male chromosomes and the female chromosomes across the world and try to work out how big the bottlenecks were which we certainly went through as we left Africa to other places now this is really quite a complicated slide I should from making a copy of myself which is simpler but what we've got is the estimate of the bottleneck size of people in women in red and men in blue and we have an estimate of the smallest bottleneck and of the overall bottleneck over the whole of history but they just look at the smallest bottleneck at the bottom okay the whole of the population of Africa descends from 57 men and 32 women a small number of those got out to the central bit here 26 men and 15 women we move over towards India populations that are growing 1,000 sorry one thousand six just twenty six women and ten fifteen men India an enormous population explosion but huge sexual inequality just a few men with children twenty nine thousand five hundred women and one thousand and six hundred men and then over in the new world with costs from Siberia the founding population was 90 women and twenty-one men so it's a big big difference and that tells us something rather interesting rather aside in the biblical tale of Adam and Eve now these guys they originated that first and least original of all sin of having sex okay but and then they certainly existed in some sense there was an atom and there was a need for we can be completely sure they never met because they population size of the atoms the males was much less than the population size of the Eve's the females so we could draw a little diagram of that here we have a population of one two three four five six seven eight nine ten males which each generation only two or three males reproduce and there the black lines and the thin lines are made male lines that come to an end and we'll see if in one two three four generations we can get back to Adam now now let's do the eve and in a in Eve's or there are ten each generation more reproduced for three or four reproduce and in that case we have to go back one two three four five six seven eight nine ten generations to get to eat and in fact Adam the universal ancestor of the human race probably lived something like eighty thousand years ago okay so he was human Eve wasn't human he probably none of modern human she probably lived about 150,000 years ago and she was a homo erectus or be that as it may but it shows the subtlety of population bottlenecks they have quite a big big map but a big big effect and in fact where are we if we draw a map of the amount of genetic variation in human populations across the globe as we moved out from Africa into the focus the southern tip of South America and the distant islands of the Pacific you can see the over amount of overall amount of variation goes down so that in somewhere like the southern tip of South America we've only got a little bit more than half the variation in Africa ok and in Europe for intermediate and that just shows the power once again the power of bottlenecks and that too has actually changed quite striking me because you know history has always been made in bed but now the beds are actually getting much closer once we stay close to where we were born and populations could build their own art and identity and in fact people had a very small choice of who they could make with and if you had one very dramatic male and lots of females then basically perhaps only that men would have children but now of course we have what's the most important invention of all to an erosional biologists which is the bicycle you no longer have to marry the boy or the girl next door and get on your bicycle or your 747 and come to UCL you like and have a much bigger choice of partners so the inequality in male mating success comes out and the population size gets much bigger ok the but the effects of a bottleneck get much less and as populations begin to blend the population size gets bigger and bigger and the classic case has to do with one group were very interested in their own evolution who are African Americans and African Americans understandably feel that their past was stolen from them and they're very curious to know how much of they African and how much they how much are they European in ancestry and there's this rather dubious company 23andme I have rather mixed feelings about but they will do something that's called a stance Esther painting they'll take your set of chromosomes and throw one hundred dollars they'll tell you how many of your chromosomes come from Africa and this is one woman quite a lot of her Congress homes come from Africa how many come from Europe there's the black sessions how many come from Asia now Asia sings on but of course Native Americans are basically Asia and you see this is quite an odd mixed population so that the there has been effectively quite a large population size there because both Europeans and Africans slaves were mating of course it was the European men that took advantage of the African women but the effect is there and of course the effect is much much more real today in London which is probably the most sexually open city in the world if you take a teenager in London walking through the streets one of whose parents is an afro-caribbean for half of them the other parent would be white so there we've got almost a complete blending of two groups and they're in effect we've got a much bigger population of people who are mating a much less chance of these random bottlenecks through small groups they're only a few people succeeding in mating you can put figures on that to some degree by asking yourself a simple question how far apart was your birth place from that of your partner compared in in my case my wife was born in New York Manhattan I was boy I was born in West Wales so II that was about 3,000 miles apart compared to the distance apart where your parents were born and where your mother's mother was born your mother's father was born my parents were born three miles apart in West Wales I was lecturing to this two students and one arrogant it was sawn shoddy from the back and it shows I didn't work I didn't work out I didn't was and of course that effect that effect has now become absolutely the immense these are the flights from Heathrow I should have put Ryanair where the effect is even bigger of course you can you can now find a partner from across the globe so effectively the whole population that globe it's not quite one random mating population but it's rapidly getting that way so no more bottlenecks you can see it and I've shown this before here by looking at surnames which are localized here where the Joneses in 1881 and by 1998 we moved out carrying our genes with us and as you see we've reached into England you have to make 1% to get onto this map although we have not in fact made it either to Oxford or Cambridge but I don't care about that so that's what's happening we're moving into an era of unprecedented openness large population size so really all I can summarize this whole this whole tale is is that evolution has lost its power there are fewer mutations there is much less natural selection and there is effectively known population bottlenecks so that the Darwin machine has come in some senses to a stop so if you're worried about what utopia is going to look like you shouldn't worry because you're living in it now so I'll stop there thank you

Channel: Gresham College

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Keywords: gresham, gresham college, gresham college lecture, gresham lecture, science, biology, genetics, evolution, genes, humanity, genome, darwin, h g well, francis galton, boris johnson, genghis khan, blonde hair, Steve Jones (Author), Human Evolution (Literature Subject), Human (Quotation Subject), Professor (Job Title), Richard, Dawkins

Id: xBO2d39Tqgg

Length: 55min 57sec (3357 seconds)

Published: Wed Feb 18 2015