 Well, welcome, everybody, for the third session of this meeting on synthetic biology. So I'm the chairperson of the third session. Actually, I know very few people here, because I, myself, I'm neither a mathematician nor a biologist in the strict sense. Actually, I am an evolutionary biologist. And it's actually, it was already a great pleasure to hear that evolution pops up in some of the discussions before. So I'll use the few minutes that I can use as the chairperson of this session to try to explain to you why synthetic biology could be interesting for also for people in my background, and it's ecology and evolutionary biology. Oh, sorry, is it better? OK, so I'm going to try to explain how synthetic biology can be interesting for also for people in my area of evolutionary biologists. So we're now here on a meeting on synthetic biology. So most people think of it in terms of Frankensteinian science. So actually, one of them, this is an image of a salamander larvae which has, they gave another eye. So it's not evolutionary, but it's synthetic. They've implanted another eye, and these salamanders can actually do very well with it. The other thing is real, but it's not science. It's art. It's an artist from Australia who has implanted an ear in his arm, and he wants actually to put a microphone in it to do some art things. But so for most people, when you talk about synthetic biology, that's what they tend to think about, you know, sort of scientists, the mad scientists interfering with things that they shouldn't interfere with. But anyway, I think that the whole aim of this meeting is to show that it's a respectable science and that we can actually use it for many ways. Of course, we have had already an engineering point of view where we can actually use all sorts of insights to design, modify natural systems in order to do things that we want them to do. I want to stress here that we actually also can use, we could use, synthetic biology to gain insight in how things are. So I'm an evolutionary biologist, and much of my day-to-day work is to deal with mathematical models that try to predict the outcome of evolution. And it turns out that most of this rest on hypothesis that we make about trade-offs between trades that individuals have. And the oldest examples actually date from the 60s of the previous century where people were asking themselves what makes that some organisms are generalists that live in the whole environment, whereas other organisms are specialists. They specialize on special types of environments. And it turns out that the end result depends on basically what is possible for the organism. If you can have two types of environments, and you can measure the fitness, the degree of adaptiveness to these different types of environments, and you can make a line where all the maximum fitnesses that the individual is able to attain. So it can choose a point somewhere on this line, and it's this trade-off shape that determines what's basically what's possible for this organism. Well, it turns out that the end result, the evolutionary end result depends very much on the shape of this line. So here, in this case, you can have a shape which is concave, but you can also have a shape which is more convex. And it turns out that the end result, the evolutionary end result is here sort of represented by the blue dots is a generalist population if this trade-off shape is convex, whereas you get two specializing populations if the trade-off shape is concave. So this gives us an insight, as an evolutionary biologist, this gives us an insight of what might be the conditions that favor a specialization of organisms. But now you want to test this kind of prediction. And then you're going into the field, my colleague's going to the field, and they say, well, let's try to see what is the shape of this trade-off function. But if you do this, this is typically what you get. Either you have one single population and you get sort of a cloud around the single population of journalists, but it's very difficult to gain insight in what precisely determines the shape. It's this indicative of a convex shape or a concave. And similarly for the concave, in this case, you have two distinct populations. And we have actually very little information about what might be the trade-off shape in between. Now, people have already started doing things like genetic engineering to gain insights in this kind of question. And you can take a bacterium and you can think with its basic physiology. I don't know the precise details, but it means that if you interfere with the production of the expression of different genes, you can switch on different types of responses in the bacterium. I think this is E. coli. And by interfering with this, you can actually sort of make the organism. You can create many different strains where the expression levels of these genes are modified. And you can quite neatly trace out the shape of these trade-off functions. So I think synthetic biology could be used to get this even further and to make us address questions like biology, evolutionary biology, but it's actually possible. So this is one of the questions, I think, that we should add to this list that Victor already wrote on the Blackboard earlier on. And then if we know what is possible, we also have to work out why it isn't there already. And I think this is also a question that arose more or less during the discussion earlier today. So I think this is a very short outline of why synthetic biology could be of interest for people in my area, evolutionary biology. But it really means that we should address questions like dealing with evolution. So my session, during this session, actually also because of the chairperson of tomorrow comes our chairperson next morning as well. My session of these two sessions continue on the theme of what you can do if you change the genetic code. And there's actually an evolutionary biology that has a related question that pops up all over the place. And that's actually why actually do organisms use a common code. If you think about it, it's not so obvious at all. Of course, we have seen the dogma, the famous dogma already a couple of times today, which says, well, you have DNA. And then everything follows from this. But actually, lots and lots of research nowadays shows that this dogma is not so infallible as it has sheen. Of course, we know about reverse transcriptase for a long time. But nowadays, lots of genetic information is actually not coded in DNA, but in epigenes. So there are modifications, short-term modifications of DNA. And these have a much more fluid way of encoding information. And so it really means that genes are not so universal as is often thought. And I stumbled on a question like this already a long time ago when we were doing a model on the evolution of information used in a population. And it turns out that you have a system that will evolve to use a single way of encoding information only if the members of this population are not too much in conflict. If the members of the population are in conflict, actually what you have is that the whole thing becomes unstable. And you get cyclic evolution or chaotic evolution where you have different types of encoding that evolve. And in human populations, you can already see this that here we are all very nice people, so we don't have much conflict here, so we can manage all speaking English. But if you go to the market or some other economically important area, you will discover that people tend to speak in code where they try to convey some of the information to have to try to address sent information only to particular people and not allow everybody to hear. So in this case, common code will not evolve. And actually, there are some examples in biology where the common code is actually aborted, for instance, where populations interact with parasites and viruses and things. So you can actually arrive at the situation where the whole information use breaks down. So there's the second case. So we were talking, discussing standards earlier on. Actually, I think there should be also a reason. We should also be aware that there's an advantage of having a standard, but it can also be an inconvenience. But you always have to worry about where you are. You always have to worry about the costs and benefits of standardizing and efficient communication. OK, so that was actually what I had to say today. So I'll now leave the floor to Floyd-Rome's work was all going to talk about semi-synthetic organisms that I wrote.