TEDxNUS - Debunking myths about evolution - John van Wyhe

can you hear me yeah okay yeah today I want to talk about Darwin and evolution and evolution is one of the most important ideas in the history of science and unfortunately most of what most people have heard about Charles Darwin and discovery evolution is completely wrong and that's not good enough I study Darwin in the history of biology and history of evolution and it is one of my passions to try and share what I know because the discovery and the unmet the the unveiling of evolutionism is an incredible story it's a part of all of us it's our story every one of us it's where we come from and what we are and not understanding that and not knowing anything about it I think is a shame so I'll start with Darwin and how evolution was discovered this is Charles Darwin as a young man and information online until 1882 but before I want to move on to what Darwin actually found out there's a little bit of historical context or background that you must have in order to understand what Darwin did because the story I'm about to tell you is usually told a completely different way and it could be be wrong which is something like this until Darwin published his origin of species in 1859 everyone thought the world was 6,000 years old and that a supernatural being had created every species on the earth at one time that's false that is not true that was not the state of scientific knowledge when Darwin came along and if you tell the story in that incorrect way it's very difficult to understand how Darwin could have possibly done what he did technical difficulties anyway and that the main point is that the size of the community oh gosh there we go the scientific community before Darwin all religious men not evolutionists not atheists had already figured out of the preceding decades that the earth is unbelievably ancient countless millions of years none of them accepted that over six thousand years old unanimously accepted the world was very very ancient this was obvious to them after decades of studying the actual fabric of the earth itself the rocks layer or layer were discovered named categorized there were eras of life worthy where the deposition was stack on top with other layers that have been folded eroded away others deposited on top on and on and on furthermore they found that sedimentary rocks containing fossil creatures showed not only that they were living things on the earth that are now gone extinct things that no longer live in the world today which was a big puzzle for a while don't people to want to accept that how could anything be created it no longer exists but anyway they found that the fossil record was progressive and the most ancient rocks were the most primitive living things and that is he moved through time up towards the present creatures more and more similar to those alive today or present so these two foot points are universally accepted before D'Arnot the board is unbelievably ancient and the history of life on Earth has been a progressive story there was not evidence for evolution for these pre-darwinian scientists and other ways of explaining it that they had been for example a series of creation events and that's why the fossil record looked the way it did anyway the Piranha makes what halfway to go on already with pre-darwinian science this is a these are two contemporary views of the progressive nature of the fossil record okay Charles Darwin sailed around the world on board HMS Beagle of surveying a vessel the point of the voyage was to make maps not to carry Charles Darwin around in fact it's very often said nowadays that DOM wasn't really the naturalist on the Beagle but in fact the ships did the captain's companion I think that's wrong down really was the naturalist on the ship and furthermore if he was supposed to be the captain's companion he was a really bad one because he only spent 20% of the time on the ship the rest of the time he was on land mostly in South America being an actress now when he didn't so he had one of these notebooks in his pocket recording his scientific observations and also some sketches a darn famously couldn't draw to save his life but I will show you just this one sketch which is very special in my opinion because it is the only known self-portrait of Charles Darwin there he is in only time the great man ever drew himself okay so the Beagle sails to the darkest islands the most famous part of the Beagle voyage many people think Darwin just sailed to the Galapagos Islands and when there would happen to he had some sort of Eureka moment when he saw the beaks of these finches and got the idea for evolution that's completely wrong not only to Darwin not get the idea of evolution from the scene these ventures but when he was in the Galapagos Islands he didn't even know they were all finches here there were loads of different kinds of birds they vary a lot it's only when he got home they're an expert on earth all just told him that they were finished but these birds he did notice at the time the mockingbirds he noticed that on one Island the birds stood like this and the next Island they look different and he noted that at the time and it's these birds that the basis of his first recorded doubting about species staying the same over time I don't know if you can read this this patient is on a theological notes or he says if this is true about those mocking birds being different on different islands he says if there is the slightest foundation for these remotes the zoology of archipelagos will be well worth examining for such facts would undermine the stability of species under - varied species well what was only actually when Darwin came home then he came up with this theory to explain all this and he was asked in later years what was it that made him come up with his theory he never he didn't say it was the glass person of inches he always named three kinds of evidence number one the discovery of extinct fossil mammals in South America that were puzzlingly similar even related to things that only live in South America today there are many examples this is just one they lifted on with its bony external covering and the armadillo also with a bony armor on the outside just to make this point bit clearer imagine down is aware of the fact that these extinct things have only been found in this small part of the entire world which is also incidentally the only place that these relatives or parent relatives are found why should that be why should there be this similarity in the rock in this in the same place of similar creatures happening over time next was the puzzle of geographical distribution there were many examples I will just use this one of the rares or ostriches there were two species Darwin found a new one why should it be that these very very similar species there were they look like cousins why should they have ranges that are but right a next one to another why should their ranges be right next to each other similar species right next to each other the environment didn't seem to make that necessary next the third thing he listed third of three was the Galapagos Islands oh there they are 600 miles off the coast of South America Darwin as a geologist could see that these were volcanic rocks that had erupted out of the ocean originally bare naked and lifeless so where are all the living things on these islands come from well as a naturalist who is just spent the last few years in South America it was absolutely obvious to him that these creatures had come from South America they were obviously South American kinds of things and not things that was for some reason created to go with volcanic islands with volcanic rocks which is what the existing theory of the day would have predicted that living things were why some means created to suit the environment they lived in which is why for example when earlier eras of life without have been swept away perhaps they thought the earth had changed so much that the earlier species who were fixed within certain limits beyond which they could not change when the environment change too much for them they died out and some miraculous process created new life that fitted the new environment well here is a new environment but creatures living there are not created for volcanic islands they're creatures like those in South America how did they get there well one theory was it they had all migrated independently each from South America to each individual Island now Darwin can see that that's an absurd hypothesis it's not it's just ridiculous I think that everyone one of these birds or weeds had gone all the way from South America only to one Island that can't be so instead he thought so I think I deserve somebody in the air with the laser pointer instead much simpler to think that a single migration process happened to the islands of the Galapagos from South America and then once in the islands to migrate to other islands is a much simpler more likely process but somewhere in there the only way this is recognizable of course was that they were different species on the different islands so Darwin could see from all three of these kinds of information that clearly species must change over time and the Galapagos was a particularly clear case so it was only when he got back to London and put all of the pieces together they began to create his theory of evolution by branching descent that is living species like the finches or the mockingbirds are related to one another along a branching genealogical tree family tree of life this is one of the earliest ones in his notebooks well while he was trying to explain how can this be how can living things change and more importantly how can they become adapted to their particular environments how can the mistletoe become adapted to feed on the SAP of certain trees and require certain kinds of birds to eat their seeds to deposit them on other trees such a complex relationship couldn't be explained by any of the other scientific theories that have been put forward such as by Lamarck or the author of the vestiges that there was some sort of inherent law of progress that made things move forwards up some sort of cosmic scale that couldn't explain such complex ecological relationships for down and then you happen to read the theorists Thomas Malthus about the idea of geometrical population growth and this is what really gave down the key Malthus was writing by human populations but doan consider this fit the entire natural world that any species that you choose whether it be an orchid peas sardines anything are reproducing at a rate that within a few hundred generations would utterly cover the globe but they don't the only reason that can be is that almost all of them are being killed crushed devoured starved eaten etc therefore don't thought what is it about the few who don't get consumed only a few make it through this gauntlet of death and those few are the ones that pass on their their likeness to future generations what was it about these to find the clue that down studied domestication how is that human breeders and farmers are able to create particular breeds with particular properties this is one example from one of Donald's books one of my favorites this is a kind of chicken called the Polish farm fancy breed that people made it's not a natural naturally-occurring breed like to call it a punch chicken because as is huge tress and breeders made this by always choosing the one with it that had slightly bigger naturally slightly bigger crest slightly bigger feathers here's a real one seeing it a look at what this actually that was actually my own chicken until she was naturally selected by Foxy nice eggs - he also studied pigeons now all the different kinds of pigeon breeds they still exist today many of you back then thought that each one was descended from its own wild ancestor which conveniently didn't exist or had gone extinct Darwin explained no it must be that all of these different breeds are actually derived from the wild rock pigeon that's the kind that's filling every square and city in the world today that's the wild rock pigeon coincidentally the reason why our squares and cities are covered those today is we don't need them anymore but a hundred years ago there were no pigeon tomorrow we don't need them anymore we have life a food so I'm stuck again so Darwin realized that selection a version of the breeders selection was the key that through the ever running process of unbelievable overproduction seeds eggs pollen small squirrels whatever it is being produced in incredible numbers all of them slightly varying slightly different never the same just like us and in the complex circumstances of life anything that makes a difference to any of them actually getting through the gauntlet which Darwin called natural selection which is actually not a thing but a name for this broad basket of different kinds of causes and effects and complexities that lead to something getting killed off or not anything that leads one to have an edge to make it through it's likely to be passed on to its offspring and that tiny bit of change that little bit of a bigger feather which a breeder can see and select is the same kind of thing would happen in natural selection and then you have to exercise the power of the ancient earth the ancient age of the earth but the power of endless time these tiny cumulation of tiny changes can accumulate to create every species alive in the world today every beautiful and complex form that is found that has ever been found so Darwin after working for 20 years on this theory and by the way it's another myth that Darwin was afraid to tell anyone what he believed he told on basically all of his family friends neighbors and colleagues that he believed in evolution during this long period of time and then in the end he was prompted by another great naturalist Alfred Russel Wallace was actually here in Singapore and I'm sort of starting up a new project called Wallace online now your than us Wallace came up with almost the same idea and sent an essay to Darwin why did he send it to Darwin because he knew Darwin was working on the speech question and wallace was planning some day when he got back to write a book on the subject you know that Darwin had the same idea but he didn't know Don was almost finished with his book Don was pretty surprised but it turned out to be pretty much the same idea and so that the Darwin as a gentleman handed the essay over to his colleagues who decided to publish extracts from Darwin and Wallace his essay together at the same same time in a joint publication this prompted down to bring out of course his most famous book the Origin of Species published in 1859 and it's very often believed that when Darwin's book was published there was a great public outcry and outrage it was a huge conflict of science and religion not really yes there was a lot of controversy yeah there's a lot of name-calling but actually the reaction was quite different than what most of us now think of it and this is one of the most important messages I want to leave you with and that is that within 20 years of the publication of the Origin of Species the scientific debate about evolution was over over it was done the international scientific community had accepted that evolution is true by the 1870s and moved on so if you've heard as I'm sure everyone listening to me has that evolution is somehow controversial well no it hasn't been since 1870s there are more recent controversies but those have erupted in the 20th century this is a new movement not a still ongoing problem or debate or question with Darwin ever since the beginning it's a new movement when down by the time Darwin died in 1882 it was clearly remembered as one of the greatest scientists who had ever lived that's the way people describe it this is the last line of the Origin of Species which is quite wedding there is grandeur in this view of life with its several powers having been originally breathed into a few forms or into one and that whilst this planet has gone cycling on according to the fixed law of gravity from so simple a beginning endless forms most beautiful and most wonderful have been and are being evolved and and and so it that was how his memory was was placed after he died if you'd like to know more about Darwin his complete works are available for free on Darwin on line thanks very much

Channel: TEDx Talks

Views: 325,813

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Keywords: tedxnus, Evolution, ted talks, ted, ted talk, tedx talk, theory, van Wyhe, Charles Darwin, tedx, tedx talks, ted x

Id: KvpQ5Lyah50

Length: 18min 52sec (1132 seconds)

Published: Mon Mar 07 2011