WEBVTT 00:00:05.166 --> 00:00:06.240 Alright! 00:00:06.240 --> 00:00:09.961 This is a sciene talk, so please block the exits, 00:00:09.961 --> 00:00:14.390 keep people from escaping and we'll see where we'll end up. 00:00:14.390 --> 00:00:17.849 My talk is about evolution and lots of things have been said about evolution, 00:00:17.849 --> 00:00:19.581 lots of things have been done. 00:00:19.581 --> 00:00:21.477 I want to make one disclaimer: 00:00:21.477 --> 00:00:26.426 I've only been given two and a half hours to talk about this by the organisers, 00:00:26.426 --> 00:00:31.868 so I have to give a short introduction to some aspects -- to a summary of evolution. 00:00:31.868 --> 00:00:34.001 I'm going to skip over things, going to simplify things, 00:00:34.001 --> 00:00:35.181 and you're going to have to live with it. 00:00:35.181 --> 00:00:39.775 But the points I'm making will hopefully make some sense. 00:00:39.775 --> 00:00:43.068 Evolution: everybody knows the theory 00:00:43.068 --> 00:00:45.505 or thinks that they know it. 00:00:45.505 --> 00:00:47.406 It's a work in progress; that's very important. 00:00:47.406 --> 00:00:48.767 There's many things we understand. 00:00:48.767 --> 00:00:51.228 There's many facts that tell us evolution is right. 00:00:51.228 --> 00:00:53.827 There's not a single scientist 00:00:53.827 --> 00:00:57.442 that really works by scientific methods, 00:00:57.442 --> 00:01:02.284 that looks at facts and uses theories that doubts the theory of evolution. 00:01:02.284 --> 00:01:06.546 That does not mean that the theory of evolution is there, that it's not changing. 00:01:06.546 --> 00:01:09.714 We always discover more and we need to adapt our theory. 00:01:09.714 --> 00:01:11.509 It's very important. Some people think 00:01:11.509 --> 00:01:13.704 that because we sometimes discover something 00:01:13.704 --> 00:01:15.849 and we need to make slight changes to our theory 00:01:15.849 --> 00:01:17.777 that the theory is not valid. 00:01:17.777 --> 00:01:20.847 And instead they come up with a theory for which there is no proof at all 00:01:20.847 --> 00:01:23.403 and they think that's a much better option. 00:01:23.403 --> 00:01:24.884 I don't think so. 00:01:24.884 --> 00:01:27.706 Alright! Let's start with this guy. 00:01:27.706 --> 00:01:32.059 As you can tell, very fashionable: French. 00:01:32.059 --> 00:01:33.582 Jean-Baptiste Lamarck. 00:01:33.582 --> 00:01:36.802 He was one of the first people to come up with a coherent theory of evolution. 00:01:36.802 --> 00:01:41.033 He's done many more things, but his theory is quite extraordinary. 00:01:41.033 --> 00:01:44.047 And one of the aspects of his theory is that 00:01:44.047 --> 00:01:48.917 he believed in the inheritence of acquired characteristics. 00:01:48.917 --> 00:01:50.298 What does he mean by that is 00:01:50.298 --> 00:01:52.232 that, well, look at these giraffes. 00:01:52.232 --> 00:01:56.041 It's a very easy way to explain this idea by Lamarck. 00:01:56.041 --> 00:01:59.264 Everybody knows that a giraffe has got a remarkably long neck. 00:01:59.264 --> 00:02:02.344 How does it get the long neck? Well -- 00:02:02.344 --> 00:02:05.578 it's trying to eat leaves on the tree. 00:02:05.578 --> 00:02:07.737 And it stretches it's neck. 00:02:07.737 --> 00:02:12.857 And therefore the little kiddy giraffes will have slightly longer necks. 00:02:12.857 --> 00:02:16.094 And again this repeats, and that's how the giraffe got a long neck. 00:02:16.094 --> 00:02:18.999 Seems a bit silly to us but it's actually a great idea. 00:02:18.999 --> 00:02:21.129 He was going with the data he had. 00:02:21.129 --> 00:02:26.377 Wonderful theory, except it's not right. 00:02:26.377 --> 00:02:28.097 In came Darwin. 00:02:28.097 --> 00:02:30.806 And enough has been said and done about Darwin 00:02:30.806 --> 00:02:32.501 over the last year especially. 00:02:32.501 --> 00:02:33.838 He's been great. 00:02:33.838 --> 00:02:36.665 One of the things that he did is 00:02:36.665 --> 00:02:38.873 he introduced two key concepts 00:02:38.873 --> 00:02:42.645 namely variation and selection. 00:02:42.645 --> 00:02:44.338 And with variation he just said: 00:02:44.338 --> 00:02:47.537 Well, these giraffes don't stretch their neck 00:02:47.537 --> 00:02:50.473 -- well maybe they do, but they are born with short and longer necks. 00:02:50.473 --> 00:02:54.711 There's just this natural variation amongst giraffes. 00:02:54.711 --> 00:02:58.856 And the lucky ones that have the long necks, can reach more leaves. 00:02:58.856 --> 00:03:02.139 And as you know, you only think about sex after you're not hungry anymore, 00:03:02.139 --> 00:03:05.359 so -- (Laughter) 00:03:05.359 --> 00:03:07.629 they're going to reproduce because they're not hungry anymore. 00:03:07.629 --> 00:03:11.909 They're going to get little giraffes with slightly longer necks 00:03:11.909 --> 00:03:13.701 and that's how evolution happens. 00:03:13.701 --> 00:03:16.295 So, this is the selection part 00:03:16.295 --> 00:03:17.801 and then there's natural variation. 00:03:17.801 --> 00:03:20.097 He didn't really say how the natural variation occured, 00:03:20.097 --> 00:03:22.404 he didn't really have answers to that. 00:03:22.404 --> 00:03:24.472 He thought about it a lot. 00:03:24.472 --> 00:03:26.590 But he really separated the two processes. 00:03:26.590 --> 00:03:28.361 This is also what made him so controversial, 00:03:28.361 --> 00:03:30.157 because it was very cruel, 00:03:30.157 --> 00:03:32.638 it's a very cruel way of having evolution. 00:03:32.638 --> 00:03:34.243 There's giraffes dying. 00:03:34.243 --> 00:03:38.437 There's poor giraffes with short necks dying here. 00:03:38.437 --> 00:03:39.365 Alright! 00:03:39.365 --> 00:03:41.965 And this fellow here looks very stern. 00:03:41.965 --> 00:03:44.483 He's German. (Laughter) 00:03:44.483 --> 00:03:47.546 August Weissmann, great great biologist. 00:03:47.546 --> 00:03:51.009 He really -- one of the things he did 00:03:51.009 --> 00:03:53.907 is really try to proof that variation and selection 00:03:53.907 --> 00:03:56.043 are completely independent. 00:03:56.043 --> 00:03:57.316 And one way he did this 00:03:57.316 --> 00:04:00.178 -- so he really sort of tried to kill the old idea by Lamarck 00:04:00.178 --> 00:04:05.400 that the length of the neck of the giraffe has really nothing to do 00:04:05.400 --> 00:04:07.603 with what it did in its lifetime 00:04:07.603 --> 00:04:10.555 and its stretching out for trees. 00:04:10.555 --> 00:04:11.643 So one of the things he did 00:04:11.643 --> 00:04:13.365 -- he's really very famous for this experiment, 00:04:13.365 --> 00:04:15.639 although it's not his best experiment -- 00:04:15.639 --> 00:04:17.447 he took mice as soon as they were born, 00:04:17.447 --> 00:04:20.822 cut off the tail then bred more mice 00:04:20.822 --> 00:04:22.313 as soon as the little mice were born 00:04:22.313 --> 00:04:24.748 cut off the tail again and just repeated this. 00:04:24.748 --> 00:04:26.347 And in the end what he noticed was 00:04:26.347 --> 00:04:28.660 that all these new mice, these little mice, 00:04:28.660 --> 00:04:31.106 even after he's done this for 30 generations 00:04:31.106 --> 00:04:35.592 still had tails that were just as long as the original mice. 00:04:35.592 --> 00:04:39.290 So it's a great way of disproving Lamarck. 00:04:39.290 --> 00:04:42.258 I would say, he should have relaxed, sit back, 00:04:42.258 --> 00:04:45.021 thought about looking at the Jewish male population 00:04:45.021 --> 00:04:50.965 and we wouldn't even had to do his experiment. (Laughter) 00:04:50.965 --> 00:04:57.004 So, he came up with a, I think, much more important finding, though. 00:04:57.004 --> 00:04:59.803 And really amazing work that he did. 00:04:59.803 --> 00:05:02.723 Where he actually said that, 00:05:02.723 --> 00:05:06.515 even early in our lives, and I'm talking about embryo's, 00:05:06.515 --> 00:05:08.144 what he called our germ cells, 00:05:08.144 --> 00:05:11.082 these are the cells that are used to reproduce, 00:05:11.082 --> 00:05:13.293 are separated from the rest of the embryo. 00:05:13.293 --> 00:05:15.964 You can see them here as little dots. 00:05:15.964 --> 00:05:19.494 And they separate and we all know where they end up in the end. 00:05:19.494 --> 00:05:21.352 And the strong point in that -- 00:05:21.352 --> 00:05:23.001 he was totally right about this -- 00:05:23.001 --> 00:05:25.133 and the strong point about this is that -- 00:05:25.133 --> 00:05:26.420 pretty much what he was saying is -- 00:05:26.420 --> 00:05:31.003 when the giraffe stretches its neck, it's not stretching its testicles. 00:05:31.003 --> 00:05:34.588 So how can this have any effect on your germ cells. 00:05:34.588 --> 00:05:36.374 It's a very strong point, then again, 00:05:36.374 --> 00:05:38.027 at least for complex organisms, 00:05:38.027 --> 00:05:41.093 he set apart variation and selection. 00:05:41.093 --> 00:05:43.302 The forces that will select you 00:05:43.302 --> 00:05:46.728 are independent of this variation that you have. 00:05:46.728 --> 00:05:47.930 Again a bit later 00:05:47.930 --> 00:05:52.397 these two fine gentlemen here, Luria and Delbrück, 00:05:52.397 --> 00:05:54.753 were working in Cold Spring Harbor in the U.S. 00:05:54.753 --> 00:05:59.960 where they were doing multiple amazing experiments 00:05:59.960 --> 00:06:02.435 and one of them got them the Nobel Prize. 00:06:02.435 --> 00:06:05.079 And they were working on this virus here, 00:06:05.079 --> 00:06:06.720 which looks a bit like a Moon lander 00:06:06.720 --> 00:06:08.784 but it's a little bit smaller than it. 00:06:08.784 --> 00:06:09.900 It's called a bacteriophage. 00:06:09.900 --> 00:06:11.547 This is good news for all of you. 00:06:11.547 --> 00:06:13.572 All of you non-scientists might not realize 00:06:13.572 --> 00:06:16.770 that these bacteria that make us sick 00:06:16.785 --> 00:06:19.590 they actually also get sick, they also have virus infections. 00:06:19.590 --> 00:06:23.767 The only organisms that gets away without being sick 00:06:23.767 --> 00:06:24.876 are the viruses themselves. 00:06:24.876 --> 00:06:27.059 But so, bacteria do get virus infections 00:06:27.059 --> 00:06:28.287 and they actually die from it 00:06:28.287 --> 00:06:30.270 and that's what these guys were studying. 00:06:30.270 --> 00:06:33.104 And they also wanted to look at this idea: 00:06:33.104 --> 00:06:35.739 is variation independent of selection. 00:06:35.739 --> 00:06:38.522 And they came up with a very smart experiment. 00:06:38.522 --> 00:06:42.717 What they did is, they said, "Well, let's start from one bacterial cell. 00:06:42.717 --> 00:06:45.593 And let's give it lot of food so it will make lots of little bacteria." 00:06:45.593 --> 00:06:46.912 And they always divide as you know, 00:06:46.912 --> 00:06:51.590 bacteria they grow or they multiply by just dividing themselves into two 00:06:51.590 --> 00:06:53.802 and they make clones of themselves, 00:06:53.802 --> 00:06:56.238 genetically identical, and so this is what happens. 00:06:56.238 --> 00:06:57.994 And they said -- 00:06:57.994 --> 00:07:00.807 so these are the bacteria here, always dividing -- 00:07:00.807 --> 00:07:04.079 and they said, "Well, at some point we're going to introduce a virus 00:07:04.079 --> 00:07:04.989 and we're going to see what happens." 00:07:04.989 --> 00:07:08.703 Because they've noted that when you introduce a virus to lots of bacteria 00:07:08.703 --> 00:07:12.282 there's always a few bacteria that manage to survive. 00:07:12.282 --> 00:07:18.821 They are genetically, because their little children bacteria are also surviving, 00:07:18.821 --> 00:07:20.631 so it's clearly a genetic trait 00:07:20.631 --> 00:07:23.394 something has happened to their DNA, to their genetic material. 00:07:23.394 --> 00:07:25.019 So something has happened. 00:07:25.019 --> 00:07:27.137 Some of these bacteria are resistant. 00:07:27.137 --> 00:07:28.649 And now the question is -- 00:07:28.649 --> 00:07:30.586 this variation, because that's what it is, 00:07:30.586 --> 00:07:35.811 does it occur before the bacteria are ever in contact with the virus? 00:07:35.811 --> 00:07:38.531 Or is it when we infect this culture, 00:07:38.531 --> 00:07:40.517 this hundred of millions of cells, 00:07:40.517 --> 00:07:43.805 that suddenly a few manage to become resistant? 00:07:43.805 --> 00:07:45.507 It's a very interesting question. 00:07:45.507 --> 00:07:47.336 And they were very smart. 00:07:47.336 --> 00:07:49.915 They said, "Well, supose there is a mechanism 00:07:49.915 --> 00:07:55.451 by which, when you infect the bacteria with the virus, 00:07:55.451 --> 00:07:58.326 it tries to become resistant some way. 00:07:58.326 --> 00:07:59.551 There's a mechanism. 00:07:59.551 --> 00:08:02.370 Then, if you do this to a hundred million cells, 00:08:02.370 --> 00:08:05.035 and you do it a few times to a hundred million cells, 00:08:05.035 --> 00:08:08.169 you sort of expect that a similar number of bacteria 00:08:08.169 --> 00:08:09.572 will always become resistant 00:08:09.572 --> 00:08:12.905 that manage to get there, right? The lucky few. 00:08:12.905 --> 00:08:17.458 Whereas, suppose that some bacteria become resistant 00:08:17.458 --> 00:08:20.417 while they're multiplying -- the blue dots here --, 00:08:20.417 --> 00:08:23.760 You can have vastly diferent numbers when you repeat this experiment. 00:08:23.760 --> 00:08:25.673 Because, what can happen is: 00:08:25.673 --> 00:08:30.943 here we have a bacterium that becomes resistant to the virus 00:08:30.943 --> 00:08:32.684 very late in the reproduction. 00:08:32.684 --> 00:08:34.570 And there's only one in this whole population 00:08:34.570 --> 00:08:37.009 that's resistant, that's not killed by the virus. 00:08:37.009 --> 00:08:40.212 Here though, you have what is called a jackpot event, 00:08:40.212 --> 00:08:43.772 and the name comes exactly from what you think it comes from. 00:08:43.772 --> 00:08:46.989 Very early in the reproduction of this first cell here 00:08:46.989 --> 00:08:48.592 one of two kids becomes -- 00:08:48.592 --> 00:08:51.506 or maybe the parent becomes resistant 00:08:51.506 --> 00:08:53.595 and it starts dividing. And now half of your culture -- 00:08:53.595 --> 00:08:55.600 but we're talking millions of cells here -- are resistant. 00:08:55.600 --> 00:08:57.517 So you have this huge variation. 00:08:57.517 --> 00:08:59.226 So they've done the experiment 00:08:59.226 --> 00:09:01.551 and what they found was this. 00:09:01.551 --> 00:09:02.996 And so they concluded: 00:09:02.996 --> 00:09:05.603 Clearly -- and they've shown this matematically -- 00:09:05.603 --> 00:09:08.387 clearly some bacteria in this population 00:09:08.387 --> 00:09:11.737 were resistant to a virus that they've never seen before. 00:09:11.737 --> 00:09:15.066 And again, variation must be independent of selection. 00:09:15.066 --> 00:09:17.438 Now, I would claim, and other people have claimed, 00:09:17.438 --> 00:09:22.291 that the experiment does contain a pretty serious flaw. 00:09:22.291 --> 00:09:24.731 And I'm not saying that they didn't deserve the Nobel Prize, 00:09:24.731 --> 00:09:27.986 at all, they definitely deserved it. 00:09:27.986 --> 00:09:30.749 But one problem with their experiment is clearly 00:09:30.749 --> 00:09:34.322 that, well, they introduce a deadly virus 00:09:34.322 --> 00:09:38.618 maybe the bacteria have a mechanism to develop resistance 00:09:38.618 --> 00:09:40.634 or tolerance to this virus, 00:09:40.634 --> 00:09:42.971 but not to one that kills them instantaneously. 00:09:42.971 --> 00:09:45.460 Maybe they should have used some milder stress, 00:09:45.460 --> 00:09:46.595 some milder selection. 00:09:46.595 --> 00:09:48.733 So that's the problem there. 00:09:48.733 --> 00:09:50.735 And then of course, later 00:09:50.735 --> 00:09:55.601 after Watson and Crick and Rosalind Franklin here 00:09:55.601 --> 00:09:57.267 discovered the structure of DNA 00:09:57.267 --> 00:10:00.442 and the whole molecular research started taking off 00:10:00.442 --> 00:10:03.382 we sort of put everything together of the evolution theory 00:10:03.382 --> 00:10:05.407 into what is called 'the new synthesis'. 00:10:05.407 --> 00:10:07.070 And that's sort of our current theory of evolution 00:10:07.070 --> 00:10:09.489 where you have changes in the DNA code 00:10:09.489 --> 00:10:11.705 that are more or less random, 00:10:11.705 --> 00:10:14.199 they are independent of selection 00:10:14.199 --> 00:10:15.736 and they give you diferences, 00:10:15.736 --> 00:10:17.836 that's what's causing all these differences between us 00:10:17.836 --> 00:10:22.593 and that's why some of us cannot get AIDS and most of us can. 00:10:22.593 --> 00:10:26.238 Which is true, by the way. 00:10:26.238 --> 00:10:29.351 And so this is pretty much our theory. 00:10:29.351 --> 00:10:34.055 Now, I don't want to end here. 00:10:34.055 --> 00:10:35.490 What we've seen is that 00:10:35.490 --> 00:10:37.870 more and more evidence is emerging that 00:10:37.870 --> 00:10:39.523 the story is a bit more complex. 00:10:39.523 --> 00:10:41.854 And maybe variation and selection 00:10:41.854 --> 00:10:48.268 are not so completely independent as some people believed. 00:10:48.268 --> 00:10:49.826 And I got to know about this 00:10:49.826 --> 00:10:51.827 while studying this year 00:10:51.827 --> 00:10:55.659 I did my PHD in a beer brewing lab. 00:10:55.659 --> 00:10:57.232 You know, it's one of the better places 00:10:57.232 --> 00:10:59.724 to start your research as a student. 00:10:59.724 --> 00:11:02.072 And I was stuying yeast cells, 00:11:02.072 --> 00:11:04.837 great genetic model organism by the way, 00:11:04.837 --> 00:11:06.346 so actually one of the frustrations I have 00:11:06.346 --> 00:11:09.331 is, try to be taking seriously by the people who need to fund you 00:11:09.331 --> 00:11:11.755 or at the conference, when you're working on beer. 00:11:11.755 --> 00:11:16.249 And you go like, "Trust me, I'm doing real serious genetic experimenting." 00:11:16.249 --> 00:11:19.268 Alright, so one of the things I was studying is 00:11:19.268 --> 00:11:21.259 yeast cells that are clumping together. 00:11:21.259 --> 00:11:22.320 It's called flocculation. 00:11:22.320 --> 00:11:24.744 So what you see here is a bunch of yeast cells 00:11:24.744 --> 00:11:29.049 that stick to each other and they settle out in this in this culture here. 00:11:29.049 --> 00:11:32.009 This is important for beer because it happens at the end of fermentation. 00:11:32.009 --> 00:11:35.007 This is what pretty much makes the difference between a clear beer, 00:11:35.007 --> 00:11:37.319 that doesn't have any yeast cells in it, 00:11:37.319 --> 00:11:41.176 and what we call a 'witbier' or a 'weizenbier' 00:11:41.176 --> 00:11:43.175 that has yeast cells still floating around in it. 00:11:43.175 --> 00:11:45.618 And we were trying to find the genetics of this. 00:11:45.618 --> 00:11:47.751 What we found is this one gene here 00:11:47.751 --> 00:11:50.287 flow one, which stands for flocculation one. 00:11:50.287 --> 00:11:54.017 It's a gene, and what is so special about this gene 00:11:54.017 --> 00:11:56.085 is that it contains a middle part 00:11:56.085 --> 00:11:57.613 that is extremely unstable. 00:11:57.613 --> 00:12:01.194 So this gene is of course made of DNA, like any gene. 00:12:01.194 --> 00:12:03.873 And the middle part of the DNA is extremely unstable. 00:12:03.873 --> 00:12:06.635 It changes much more than any other DNA. 00:12:06.635 --> 00:12:08.496 And what it is in particular 00:12:08.496 --> 00:12:11.712 is that it contains these things which are called 'tandem repeats'. 00:12:11.712 --> 00:12:15.889 It's pretty much a piece of DNA that's repeated time and time again. 00:12:15.889 --> 00:12:19.545 It's much longer than what you see here but you get the basic idea. 00:12:19.545 --> 00:12:20.937 And what makes it unstable is 00:12:20.937 --> 00:12:23.646 that the number of these repeats changes very quickly. 00:12:23.646 --> 00:12:25.346 Every time the DNA is copied 00:12:25.346 --> 00:12:30.055 you have a pretty high chance that the number will be different from what it was. 00:12:30.055 --> 00:12:32.043 This has been known for a long time 00:12:32.043 --> 00:12:35.700 except people don't really expected too much within genes. 00:12:35.700 --> 00:12:38.142 Usually you find these tandem repeats outside of genes. 00:12:38.142 --> 00:12:42.497 But here and in some other genes you find this. 00:12:42.497 --> 00:12:45.235 So, what you have here is a piece of DNA 00:12:45.235 --> 00:12:48.808 or a particular gene that's changing more rapidly than other genes. 00:12:48.808 --> 00:12:52.342 And in this case it means that flocculation is changing, 00:12:52.342 --> 00:12:56.442 so this characteristic of the yeast, this specific thing, 00:12:56.442 --> 00:12:58.010 compare it to a long neck, if you will, 00:12:58.010 --> 00:13:01.413 is changing more rapidly than some other properties of the yeast. 00:13:01.413 --> 00:13:06.147 Now if you think that this is 00:13:06.147 --> 00:13:08.409 -- well, this doesn't matter -- 00:13:08.409 --> 00:13:11.834 if you think that this is specific for yeast cells you are wrong. 00:13:11.834 --> 00:13:14.393 Pretty much around the same time we were publishing our story, 00:13:14.393 --> 00:13:17.221 there was a great story published about dogs. 00:13:17.221 --> 00:13:18.518 And I don't know if you've thought about this 00:13:18.518 --> 00:13:22.342 but dogs are some of the most variable creatures 00:13:22.342 --> 00:13:24.019 on the face of the Earth. 00:13:24.019 --> 00:13:26.428 Especially when it comes to their shape. 00:13:26.428 --> 00:13:27.843 Just look at, you know, 00:13:27.843 --> 00:13:31.536 this Chihuahua and this St. Bernard here. 00:13:31.536 --> 00:13:33.053 They're the same species. 00:13:33.053 --> 00:13:35.321 In principle. And I say 'in principle.' 00:13:35.321 --> 00:13:37.289 These things can breed. 00:13:37.289 --> 00:13:39.571 You just hope that the Chihuahua is not a female. 00:13:39.571 --> 00:13:43.300 (Laughter) 00:13:43.300 --> 00:13:47.412 Now, these are bred by humans. 00:13:47.412 --> 00:13:49.513 We have made these dogs by selection and whatever. 00:13:49.513 --> 00:13:52.040 But we didn't even use so much time for it. 00:13:52.040 --> 00:13:55.772 And in evolutionary terms these things are new. 00:13:55.772 --> 00:13:58.040 They are brand new and they were, sort of -- 00:13:58.040 --> 00:14:00.463 they developed in a very short time. 00:14:00.463 --> 00:14:02.414 And one of the things that was found 00:14:02.414 --> 00:14:05.545 is that one of the key regulators that regulates -- 00:14:05.545 --> 00:14:07.883 and again I'm talking about the gene -- 00:14:07.883 --> 00:14:14.056 it's a regulating gene and it regulates the shape of the skull. 00:14:14.059 --> 00:14:15.995 Basically the shape of the dog as well. 00:14:15.995 --> 00:14:18.716 And it also has this unstable tandem repeats in it. 00:14:18.716 --> 00:14:20.929 And what these researchers found is 00:14:20.929 --> 00:14:22.815 that there's a nice correlation between 00:14:22.815 --> 00:14:25.302 how many repeats you have in this gene 00:14:25.302 --> 00:14:28.049 and how curved your snout is 00:14:28.049 --> 00:14:30.998 or how long your snout is. 00:14:30.998 --> 00:14:34.818 And they also found that some other changes in another regulatory gene 00:14:34.818 --> 00:14:37.188 give you a sixth finger. 00:14:37.188 --> 00:14:41.118 Sort of this little extra thumb here. 00:14:41.118 --> 00:14:43.603 And, I didn't know this but this is a characteristic 00:14:43.603 --> 00:14:47.352 of a specific breed of Great Dane dogs. 00:14:47.352 --> 00:14:50.539 And that's why this actually happened. 00:14:50.539 --> 00:14:51.986 It sort of happened in a very short time 00:14:51.986 --> 00:14:55.423 and now people see this sixt claw, if you will, 00:14:55.423 --> 00:14:57.380 as a characteristic. 00:14:57.380 --> 00:15:00.299 So clearly it's not just happening in yeast. 00:15:00.299 --> 00:15:02.279 And there's more. 00:15:02.279 --> 00:15:04.863 One of the other things that people have known for a while 00:15:04.863 --> 00:15:06.250 and we are also researching 00:15:06.250 --> 00:15:07.814 is that the end of chromosomes 00:15:07.814 --> 00:15:10.391 -- chromosomes are basically packages of DNA, 00:15:10.391 --> 00:15:12.226 that's how our DNA sits in the cell -- 00:15:12.226 --> 00:15:14.622 well, the ends of chromosomes -- here, 00:15:14.622 --> 00:15:17.320 the very ends -- they change much more quickly. 00:15:17.320 --> 00:15:19.075 There's higher mutation rates. 00:15:19.075 --> 00:15:20.501 The DNA is not as stable. 00:15:20.501 --> 00:15:23.580 And so the genes that lie there, again, evolve. 00:15:23.580 --> 00:15:27.207 And if you're wondering in humans which genes are lying there. 00:15:27.207 --> 00:15:29.612 It's the genes that, for example, 00:15:29.612 --> 00:15:31.638 the genes that make us smell. 00:15:31.638 --> 00:15:33.600 And of course we have to recognize lots of different smells 00:15:33.600 --> 00:15:35.450 and these genes are copying themselves 00:15:35.450 --> 00:15:40.167 and they are changing very quickly. 00:15:40.167 --> 00:15:42.443 In plants: a whole different mechanism. 00:15:42.443 --> 00:15:43.872 And this is a bit more complicated. 00:15:43.872 --> 00:15:46.650 I will try to fly through it. 00:15:46.650 --> 00:15:48.869 There's this particular protein. 00:15:48.869 --> 00:15:51.276 And, this is a bit like your mother. 00:15:51.276 --> 00:15:53.021 This protein is the mother of the cell. 00:15:53.021 --> 00:15:54.861 It sort of checks all the other little proteins 00:15:54.861 --> 00:15:57.317 and it goes like, "Are you okay? 00:15:57.317 --> 00:15:59.942 You don't look very good. Here, here's your coat. 00:15:59.942 --> 00:16:01.731 You should behave this way, don't behave that way." 00:16:01.731 --> 00:16:03.738 It's sort of like a teacher mother. 00:16:03.738 --> 00:16:05.843 And, so the protein really takes care 00:16:05.843 --> 00:16:07.819 that even if there's small mutations, 00:16:07.819 --> 00:16:10.336 changes in other proteins, that they still behave right. 00:16:10.336 --> 00:16:13.059 And if they don't behave right, they get degraded. 00:16:13.059 --> 00:16:15.315 Now what you see is that, in times of stress 00:16:15.315 --> 00:16:17.226 -- and plants also have stress, 00:16:17.226 --> 00:16:20.349 stress is a biological word for selection. 00:16:20.349 --> 00:16:23.961 It means you're not adapted to a condition. 00:16:23.961 --> 00:16:27.457 It means that you feel the burden of evolution 00:16:27.457 --> 00:16:29.481 pressing down on you, pretty much. 00:16:29.481 --> 00:16:33.688 So, in times of stress, this protein, this function of the mother protein, 00:16:33.688 --> 00:16:36.157 gets dialed down a little bit. 00:16:36.157 --> 00:16:39.240 And suddenly these plants start disbehaving. 00:16:39.240 --> 00:16:40.710 You know, they become weird. 00:16:40.710 --> 00:16:43.939 And that's because some mutations that you previously couldn't see 00:16:43.939 --> 00:16:46.177 now suddenly emerge. 00:16:46.177 --> 00:16:48.269 And, although it's not proven, it seems like a likely theory 00:16:48.269 --> 00:16:50.260 that maybe this could serve as a mechanism 00:16:50.260 --> 00:16:52.222 to try and escape the stress. 00:16:52.222 --> 00:16:54.383 Because suddenly it's good to try and be different 00:16:54.383 --> 00:16:56.748 from what your mother was. 00:16:56.748 --> 00:16:58.859 And so maybe a few of these plants 00:16:58.859 --> 00:17:00.576 are better at surviving the stress. 00:17:00.576 --> 00:17:03.083 And they will cope. And maybe this mutation can get fixed. 00:17:03.083 --> 00:17:05.746 And this and that. 00:17:05.746 --> 00:17:09.649 Another thing, another example comes from bacteria. 00:17:09.649 --> 00:17:11.421 And I'm just skimming over it again, 00:17:11.421 --> 00:17:16.224 but bacteria -- in times of stress, again 00:17:16.224 --> 00:17:19.963 they activate -- and this is just to impress you 00:17:19.963 --> 00:17:22.633 it's not very important -- in times of stress 00:17:22.633 --> 00:17:27.535 what they do is, they activate a different protein to copy their DNA. 00:17:27.535 --> 00:17:30.253 And of course a protein to copy your DNA is a very important protein. 00:17:30.253 --> 00:17:31.998 Because it shouldn't make too many mistakes. 00:17:31.998 --> 00:17:34.983 Because that's how you get changes in DNA 00:17:34.983 --> 00:17:36.613 and that's how you get natural variation. 00:17:36.613 --> 00:17:39.227 So you need a little bit of them but you don't want to much of them 00:17:39.227 --> 00:17:42.298 because most of the variation is not good. 00:17:42.298 --> 00:17:45.867 It wouldn't be so great if a giraffe got a neck that was three times as long 00:17:45.867 --> 00:17:49.873 because the heart couldn't cope with it. 00:17:49.873 --> 00:17:51.824 But in times of stress, again 00:17:51.824 --> 00:17:54.885 it's obvious sometimes you need to chose between dying or gambling. 00:17:54.885 --> 00:17:56.454 And bacteria may be gambling. 00:17:56.454 --> 00:17:59.711 They activate this gene that's very sloppy. 00:17:59.711 --> 00:18:02.983 And so the DNA gets copied, but it has lots more changes in it. 00:18:02.983 --> 00:18:05.444 And maybe, although it's hard to prove it, 00:18:05.444 --> 00:18:09.358 maybe this is a strategy of bacteria to try and beat the selection, 00:18:09.358 --> 00:18:14.413 the evolutionary pressure that's pushing down on them. 00:18:14.413 --> 00:18:18.253 An even nicer example, I think, is the waterflea here. 00:18:18.253 --> 00:18:20.684 Again, it's pretty mysterious still. 00:18:20.684 --> 00:18:24.643 But waterfleas, swimming around, beautiful organisms, 00:18:24.643 --> 00:18:27.327 they have predators. And when they get -- you know, 00:18:27.327 --> 00:18:31.595 there's a family of waterfleas and dad gets eaten, 00:18:31.595 --> 00:18:34.057 there's some chemicals released in the water 00:18:34.057 --> 00:18:39.084 and it induces the formation of the stickle here, which is called a 'spina'. 00:18:39.084 --> 00:18:43.318 And the stickle makes the waterflea a little bit less attractive for predators. 00:18:43.318 --> 00:18:45.256 Now that's all great, thats not so special 00:18:45.256 --> 00:18:47.581 a chemical induces some morphological change. 00:18:47.581 --> 00:18:52.764 The weird thing is that the kids of this waterflea will also have the spina. 00:18:52.764 --> 00:18:54.601 Even if they've never seen a predator. 00:18:54.601 --> 00:18:56.408 Even if you take all the predators away. 00:18:56.408 --> 00:18:58.942 They will still have this for quite a while, 00:18:58.942 --> 00:19:00.790 for a few generations. 00:19:00.790 --> 00:19:03.706 So this comes very close to Lamarck, right? 00:19:03.706 --> 00:19:06.498 There is something happening in the course of the life of this organism. 00:19:06.498 --> 00:19:12.056 It changes something and it's giving that information to its kids. 00:19:12.056 --> 00:19:14.620 It's getting pretty close to Lamarck. 00:19:14.620 --> 00:19:20.001 So, this is, the conclusion of the talk -- and this is important -- 00:19:20.001 --> 00:19:24.288 does this mean that our theory of evolution really needs a major overhaul? 00:19:24.288 --> 00:19:25.445 I would say: not at all. 00:19:25.445 --> 00:19:28.465 And, people have often misunderstood 00:19:28.465 --> 00:19:30.290 I guess the things I have said and published. 00:19:30.290 --> 00:19:35.194 And it happened recently in this Flemish, or Dutch, magazine here, where I wrote a piece 00:19:35.194 --> 00:19:38.801 telling, or writing about the same things that I'm telling you now. 00:19:38.801 --> 00:19:40.898 And this is the cover they came up with. 00:19:40.898 --> 00:19:46.033 I wasn't so happy because it looks like I'm sort of sawing the ground under Darwin. 00:19:46.033 --> 00:19:47.449 No. 00:19:47.449 --> 00:19:49.578 Here, this is what Darwin wrote literally 00:19:49.578 --> 00:19:51.378 about variation and selection. 00:19:51.378 --> 00:19:53.326 He says, pretty much he says, 00:19:53.326 --> 00:19:58.293 I have spoken as if this natural variation was totally random in my book. 00:19:58.293 --> 00:20:01.081 Like it was just pure chance. 00:20:01.081 --> 00:20:04.341 But of course I didn't mean to imply that. 00:20:04.341 --> 00:20:06.400 It just means that I don't really know what's happening. 00:20:06.400 --> 00:20:08.956 And maybe there is a mechanism It's much more complex. 00:20:08.956 --> 00:20:11.292 Darwin was extremely clever. He thought about his theory. 00:20:11.292 --> 00:20:13.463 He knew exactly where the holes were 00:20:13.463 --> 00:20:17.167 and where he shouldn't really speak for one possibility or the other. 00:20:17.167 --> 00:20:18.578 So he actually incorporated -- 00:20:18.578 --> 00:20:22.462 it's only later that maybe we've gone a bit too far away from Lamarck. 00:20:22.462 --> 00:20:25.276 He didn't really dislike Lamarck's theory that much. 00:20:25.276 --> 00:20:29.279 Although, this is not to say that Lamarck's theory was right. 00:20:29.279 --> 00:20:32.000 I mean, I still think that it's mostly random 00:20:32.000 --> 00:20:34.545 but there's some small changes here and there 00:20:34.545 --> 00:20:37.738 that make it a little less random than completely random. 00:20:37.738 --> 00:20:40.951 So, what I'm saying is that through evolution, mechanisms 00:20:40.951 --> 00:20:47.722 have developed that make evolution not a complete chance. 00:20:47.722 --> 00:20:49.465 And then you might start wondering 00:20:49.465 --> 00:20:51.280 how can this be right. 00:20:51.280 --> 00:20:54.797 And there I would argue this just happens through the process of evolution. 00:20:54.797 --> 00:20:58.572 Suppose a gene becomes very unstable 00:20:58.572 --> 00:21:00.201 and it's a housekeeping gene 00:21:00.201 --> 00:21:02.476 it's a gene that doesn't need to change. 00:21:02.476 --> 00:21:04.980 Or it doesn't need to change as quickly. 00:21:04.980 --> 00:21:07.603 Or when it changes it's mostly detrimental. 00:21:07.603 --> 00:21:09.710 Now, if such a gene becomes unstable 00:21:09.710 --> 00:21:12.762 it's going to be a huge disadvantage for the organism that has it. 00:21:12.762 --> 00:21:14.748 And so it will be selected away. 00:21:14.748 --> 00:21:16.867 However, if a gene 00:21:16.867 --> 00:21:21.265 for example, a gene that makes your skull a bit more flexible, 00:21:21.265 --> 00:21:23.480 like in a giraffe, and maybe you can, you know, 00:21:23.480 --> 00:21:26.061 you get more giraffes with longer necks. 00:21:26.061 --> 00:21:29.132 If such a gene arises, by pure chance -- 00:21:29.132 --> 00:21:31.344 and this is pure chance. 00:21:31.344 --> 00:21:35.101 Maybe it becomes an advantage for the organism and it stays there. 00:21:35.104 --> 00:21:37.930 It stays unstable like it was. 00:21:37.930 --> 00:21:41.866 And maybe that's how these things have evolved. 00:21:41.866 --> 00:21:45.143 Now again, like I said, my work sometimes gets misinterpreted. 00:21:45.143 --> 00:21:48.052 Sometimes it's quite funny. Especially when it's the people 00:21:48.052 --> 00:21:52.496 that believe in creationism as a more intelligent design that take our work. 00:21:52.496 --> 00:21:54.800 This was [one of] the more funny things. 00:21:54.800 --> 00:21:57.607 This is a website called 'uncommon descent.' 00:21:57.607 --> 00:21:59.356 And if you think about it, you know, 00:21:59.356 --> 00:22:02.294 the title says it all. These people don't believe in the common descent, 00:22:02.294 --> 00:22:05.826 that's of course at core of our evolution theory. 00:22:05.826 --> 00:22:08.076 So we published a paper, 00:22:08.076 --> 00:22:12.815 a coleague in the U.S. -- when I was still working in the U.S. -- and I. 00:22:12.815 --> 00:22:17.650 And we were, again in this paper, it's a more in-depth discussion of what I'm telling you know, 00:22:17.650 --> 00:22:21.994 and we were aware of the fact that some people might misinterpret this. 00:22:21.994 --> 00:22:25.506 So, in the abstract, in the summary of the paper, 00:22:25.506 --> 00:22:28.220 which is pretty much the thing that everybody will read, 00:22:28.220 --> 00:22:34.297 we wrote, specifically, that our ideas do not go against Darwin. 00:22:34.297 --> 00:22:37.685 And then these guys here read the article, 00:22:37.685 --> 00:22:39.329 still wanted to use it for their ideas. 00:22:39.329 --> 00:22:45.062 And they said, "Well, to publish this in a reputed scientific journal 00:22:45.062 --> 00:22:48.815 the authors needed to write something that their ideas do not go against Darwin, 00:22:48.815 --> 00:22:50.117 but they don't mean it. 00:22:50.117 --> 00:22:54.301 It's just a secret handshake to get into this good journal." 00:22:54.301 --> 00:22:56.662 So that's the secret handshake here. 00:22:56.662 --> 00:22:57.903 So luckily there was -- 00:22:57.903 --> 00:23:01.780 oh, then it becomes quite funny because there's reactions on this forum 00:23:01.780 --> 00:23:08.236 of people, and, well, I can barely read it myself, but I'll try. 00:23:08.236 --> 00:23:11.068 So this is one of the people reacting to this, and he says -- 00:23:11.068 --> 00:23:14.303 they quote some of the parts that we write in the paper -- 00:23:14.303 --> 00:23:18.396 and he says like: "Error-prone DNA copying enzymes 00:23:18.396 --> 00:23:22.227 produce bursts of variability in times of stress. 00:23:22.227 --> 00:23:26.979 These mechanisms seem to tune the variability of a given characteristic 00:23:26.979 --> 00:23:30.479 to match the variability of the selection." 00:23:30.479 --> 00:23:32.842 That's something that we wrote. 00:23:32.842 --> 00:23:36.518 And he says, "Gee, it almost seems like a built-in response mechanism. 00:23:36.518 --> 00:23:41.350 Who would've thunk. Darwin is sooo dead!" That's what he writes. 00:23:41.350 --> 00:23:44.540 Anyway, so there's some people who did not misunderstand our paper 00:23:44.540 --> 00:23:46.096 and they reacted to this. 00:23:46.096 --> 00:23:47.502 And it's also fun to read this discussion 00:23:47.502 --> 00:23:50.821 because then the 'intelligent design' people get on. 00:23:50.821 --> 00:23:52.214 It's all one great family. 00:23:52.214 --> 00:23:54.755 It's kind of fun to have this -- I really like these discussions. 00:23:54.755 --> 00:23:59.183 I have nothing against people who come up with different theories. 00:23:59.183 --> 00:24:01.022 They're just wrong, but, you know, 00:24:01.022 --> 00:24:03.687 it makes it fun to discuss with them. 00:24:03.687 --> 00:24:07.298 Alright, this brings me to the acknowledgements. 00:24:07.298 --> 00:24:09.903 And I have to acknowledge pretty much all these people here, 00:24:09.903 --> 00:24:12.481 which are the people who are doing all the hard working in my lab, 00:24:12.481 --> 00:24:14.717 probably as we're speaking now they're getting more results 00:24:14.717 --> 00:24:19.299 so I can give another great talk and, you know, be the hero for this audience. 00:24:19.299 --> 00:24:22.273 They are chained to their benches. 00:24:22.273 --> 00:24:24.332 I have to remember to feed them tonight. 00:24:24.332 --> 00:24:27.906 But, they really are the heroes of the lab. 00:24:27.906 --> 00:24:29.307 And there are many more of them, of course, 00:24:29.307 --> 00:24:32.502 our group is definitely not the only one doing this work. 00:24:32.502 --> 00:24:35.224 For people who are scientists and want to know more about this 00:24:35.224 --> 00:24:36.751 these are some of the publications. 00:24:36.751 --> 00:24:40.172 This is the major one, where we really sort of discuss all these things. 00:24:40.172 --> 00:24:41.966 There's more information on the website. 00:24:41.966 --> 00:24:43.624 And this is very impotant as well, 00:24:43.624 --> 00:24:46.164 these are the people that are paying us. 00:24:46.164 --> 00:24:48.185 Well not me, but, more, the research. 00:24:48.185 --> 00:24:49.876 Thanks.