 All right, so welcome to the middle third of Biology 1B. In this section, we'll be covering evolution. Basically, I can't cover the entire field in one third of a course. 13 lectures is the number of lectures we'll have. But I will try to hit the highlights some of the more interesting aspects of evolution that are of the most relevance to the general public, for instance, in medicine. So a little bit about the course. First of all, the instructor, that's me. My name is John Holsenbeck. Well, I guess you see it over there. No, you don't. That's unusual, isn't it? I guess you can look at it on the screen as well, but I'll let them sort that out. So I thought my name was on the screen too, but evidently not. My name is John Holsenbeck. Like I said, you'll have me for the next 13 lectures. I do have office hours, and they're going to be held directly after the lecture. So they're going to be Monday, Wednesday, and Friday, from 9 to 10 AM. And the room is 2013, 2013 BLSB. If you don't know where that is, it's just down on the north side of the building. That said, you can also drop by my office. So if you can't make it to my office hours, you can either email me, and we can try to schedule an appointment, but better yet, if you're on this side of campus and you have a question, you can drop by my office, which is 4161 BLSB. And obviously, if you just drop by, there's not a guaranteed chance I'll be there. But there is a chance, like a 90% chance, that I'll be in my office. So you can just roll the dice and see what happens. Now there's another thing I should mention, and it's because I think there's a temptation to email questions to me, which is fine. That's why I'm here. So you can always email questions to me, but you have to realize that some questions require a long response, right? And so the last thing I wanna do is spend an hour at the computer typing in a long detailed response to some question you have. So a lot of times I might ask you to just come by my office hours, and we'll discuss it then. It's much more efficient to do it in office hours or just in person talking than to actually write out an email, okay? So some questions, obviously, I can't answer quickly, I will, but if it's gonna require a lot of time writing a response or writing an answer to the question, then I'm gonna ask you to just come by. And that's just because I've got things to do with my life as well besides spend all day typing emails to you, okay? But it's nothing personal, that's what I wanna say. Okay, so what are we gonna be covering? We are gonna be talking about evolution. The syllabus is now online. So if you go to the course website, you'll see the syllabus. Like I said, 13 lectures we'll be talking about population genetics, that's sort of the mathy part of evolution. We've given examples of natural selection. We'll be talking about the evolutionary advantage of sex, sexual selection, species, and how species form, phylogenies, which is how you reconstruct the history of life. We'll talk a little bit about the fossil record. And the very last lecture I'll talk about human evolution or actually I won't, I'm gonna have a guest lecture for the very last lecture, okay? So that will be announced at the time. So I'll be out of town, but the last lecture will be on human evolution. What else do I need to say? Oh, in terms of what you're required to know on my exam, so it's cut to the chase, sort of speak. So everything I say and everything is in my notes you're responsible for. Now the book, you're aware that this book has the large Campbell, what is it, 9th edition. That is, in the syllabus I give chapters that you might read and think of that as background or supporting material. If it's in the book, but I don't say it in lecture or it's not in my notes, then you're not responsible for it. If I say it in lecture or it's in my notes, then you are responsible for it, it's that simple. So I know there's a, you know, inevitably somebody will ask me, do we have to know this? And the answer is if I said it or it's in my notes, you do, okay? Now the format, of course, the midterm exam will have I think what is it, 30, 33 questions on it. And that will be on November 5th from 6 to 7 p.m. And then the final, there will be a portion of the final that will be my question. So there'll be 17 questions on the final that will be from me, okay? I'm thinking what you'll see is a disproportionate number of questions on the final from the third section, the plant biology section of this file 1b, because that last section doesn't have midterm. So they have, you know, the final will have like a midterm from the last section plus 17 questions from the last section, plus 17 questions from me and 17 questions from Dr. Shable who did the ecology. Is that clear? Okay. Are there any questions about sort of the organization of what we're gonna do here for 13 elections? And it's pretty simple. I come up here, I talk and you guys, you know, absorb the information and then you regurgitate it on a test, but hopefully you'll remember a lot of it 20 years from now, okay? Now a little bit, I don't wanna talk about myself too much, but I think I should mention a few things. I actually went to Cal, you know, I graduated, ooh, go Bears. So I graduated in 1988, which is, you know, a long time ago to you guys. It doesn't seem that long ago to me, but I know it's a long time. I actually was in this class in 1986. So it was a much different format. The room was much shabbier back then because they renovated the building between 1986 and now. But I did take the course. I think I'm the only instructor to teach Bio 1b who's ever taken the course in the past. That's a first. There is a chance that Dr. Fine, if he ever, he's in our department, if he ever teaches the ecology section, he also took Bio 1b. He hasn't taught Bio 1b yet. So I'm the first and so for the only person that's ever taken the course. And it's sort of, I've taught this for three times now. And it's, I should also say, like a lot of my family members went to Cal as well. My mom did. My sister was a year behind me. So we're big Cal fans. And I never actually, you know, go to football games. I never actually had the opportunity to go to a baseball game. It looks like I never will now. But, you know, I do try to go to, I do try to go to the sports and I do enjoy that. Actually, you know, go to the football games. I alternate children. You know, my wife doesn't like to go to them. She went to another university, but I do take kids to the game. So anyways, a little bit about Bio 1b. I taught it three times. And the first time, especially when I was teaching it, I was thinking, well, what did I learn in Bio 1b? I was actually trying to think back to my lectures in Bio 1b. And the remarkable fact is that I couldn't remember anything from Bio 1b. Not one thing. I couldn't even remember who instructed Bio 1b. And you have to remember, I'm now colleagues with these people, right? They're in my department. So I can't even remember the person that did it. And so, it's a little bit disconcerting because I was thinking, well, if I can't remember, and I'm actually an evolutionary biologist, what can I expect from the students who are taking it, many of whom will go off to medical school and make a lot more money than I ever have a chance to make? And so, my goal here is to at least leave you with an impression of what the basic facts of evolution are, what the process is, and hopefully a general sense of the interesting things that are going on in the field. And it is an interesting field. It's an intellectually important field. It's the only field that ties all of biology together. Now, this is one of the remarkable things about biology. I mean, from your perspective, it probably seems like a lot of memorization, right? You go through molecular cell biology and there's a lot of things to remember. I mean, the mechanisms you learn about how cells work, they're like Rube-Goldberg contraptions, right? And evolution is kind of unique because it's the only real conceptual part of all biology. This is the part that ties it all together. This is why it makes sense. This is why we have Rube-Goldberg contraptions that run cells. It's the evolution, the natural selection, the fact that we're not the result, and organisms aren't the result of a design process. It's a process of natural selection. And natural selection works with a variation that's currently in the population, as you'll find out. So anyways, I couldn't remember much. I could actually remember as an aside, I don't want to reminisce too much, but I do remember one thing from Bio1. I also don't remember a lot from 1A, but I do remember one laboratory, and they don't do this laboratory anymore, but at the time what they did is some physiology lab, and you take a rat, and they're looking at respiration of rats, and you put the rat into a little chamber, and you measure how fast he's using up oxygen. And then the idea was you immerse the chamber into cold, like an ice water. The rat's fine, but he's now colder, and of course his respiration picks up because he's burning energy more quickly. That's the experiment. In the RTA, you can imagine in a course like that, you're working with live rats, and the first thing they do is animal care, and the TA's going over how you have to treat the animals kindly, and if anybody abuses the rat, you're gonna get an F on this lab, and it's just threatening us, and then she's talking to us how to handle the rat. So she says, don't worry, these things are harmless, but you need to handle them carefully. So she reaches into this cage, and it's one of these cages that, I don't know if you've seen these sort of rat cages, but has the lid comes up, right? She lifts up the lid and goes in to grab the rat, and the rat bites her right here in between her thumb and her first index finger, and we're all like this, and she's shaking her hand trying to get the rat off, and the rat's sort of with her, she finally grabs the rat and throws it into the cage, and you can see the rat sort of bounces up and comes back down, she slams the cage down, and she's holding her hand, and she's looking at us as just one second, and she runs out of the room, and that was it, and we're all thinking, my God, we have to deal with these killer rats, and there was a lot of debate among, at least my lab group, you divide them into lab groups, but who was actually gonna touch the rat, and all our members, I didn't have to touch the rat. But anyways, that's the only thing I remember. I don't want you guys to have experiences like that in the evolution section, but I do want you to remember something, okay? So that's the course. Oh, and the last thing, I mean, it is an important field. It's become more important remarkably, so that it's hard to believe that a field that started 150 years ago is becoming more and more relevant, and one of the main reasons it's become more relevant isn't just because of antibiotic resistance and the medical relevance of evolution, but it's the field that can actually make sense of genomic sequence data, so I don't know if you've heard this, but it's becoming quite easy to sequence human genomes and genomes of any organism or critter you can think of, and evolution turns out had the tools, the statistical tools sitting there, and their toolkit that we've been using for years to do these types of analyses, so it's actually becoming more relevant, not less relevant, okay? So it's a remarkable fact about the field is that it's actually something that you probably should know something about, and my only fear is that I'm not the most dynamic lecturer in the world, so I want to convey my enthusiasm, but I know I don't really have the personality to do it, but you have to sort of believe me that, when I say that, at least inside me, I'm sort of bubbling with enthusiasm about the field. Okay, so I really don't see the point of having this here, okay? I mean, presumably you can see me, you don't have to see me twice, I'm sorry? Technical difficulties, yeah, okay. I did mirror the window earlier, but we'll do it again. All right, no more, all right, we're fine. Okay, so we're back in business. Okay, well in case you don't know, that's Charles Darwin. You'll learn a lot more about him in the first few lectures, but I want to start off with an example of evolution, and I'm gonna ask you back there, if you have a pointer, that's one thing I just forgot to get a pointer, it's not really important right now, but this is one of my heroes, this is Alexander Fleming. Does anybody know what Alexander Fleming's important for, or known for? Penicillin, he discovered penicillin, right? And so this is Alexander Fleming, you got the Nobel Prize in 1945 for his discovery, and you have to, he was basically a research doctor at St. Mary's Hospital in London, okay, and he was in World War II, in World War I rather, which of course went from 1914 to 1918, and in those days, and actually all the wars previous to the First World War, the main cause of death, thank you so much. The main cause of death in wars wasn't so much being shot, right, which of course is a bummer, but that wasn't the main cause of death, it's like you're in the camp and you come down with some disease and you die, that's the world in the Civil War, that's where most of the people died, and a die of wounds suffered in battle, they died in camp from pneumonia or tuberculosis or some bacterial disease, okay, and of course this was also true in World War I, a little bit less true than it was earlier because at least they knew what caused disease by then, but a lot of the wounds that people suffered at that time would become septicemic, right, you'd have blood poisoning essentially, and you've heard of gangrene, that's another type of septicinium. So Alexander Fleming was interested in trying to prevent deaths through bacterial infections, he was in 1922, he discovered lysozyme, which is an enzyme that lices bacteria, so he was the discoverer of lysozyme, so he'd been doing this for a while, and in 1928, he sort of fortuitously discovered penicillin, and the story's kind of interesting because what he was doing, let's see, so this is his lab, he's sitting in his lab, and you can sort of see these circular objects, these little disks, these are called plates, and a lot of people that work with bacteria, they grow the bacteria on these little plates, let's see if I've got it, here's an example of a plate right here, so here's the plate, it's the little dish, and what you do is you pour into this dish a jelly-like substance, jello-like substance, I should say, that's full of nutrients, it's called luria broth, and it's an agar-type substance, you put agar in there to solidify the luria broth, and the bacteria love this stuff, and so what you do is you basically pour this gel into the bottom of the dish, and then you spread, and there's technique to this, but you spread a thin layer of bacteria across this gel, and you put them in an incubator, and the bacteria, of course, do what bacteria do, they divide and grow, and after maybe a day, or maybe even less than a day, you'll get what they call a bacterial lawn, but basically the plate becomes opaque, that's because there's a layer of bacteria now growing evenly across the surface of the plate. So he was working with staphylococcus, with a type of bacteria, he was plating them out on these plates, and he went off to, on some family vacation, he had a bunch of these plates stacked on his lab desk, he comes back, and if you've worked in a lab, or some of you will eventually work in a lab that deals with bacteria, I'm sure, they become contaminated, like fungus or molds will land on these plates, and they ruin the plate, so usually you throw them out, right? Shoot, these are all ruined. What he did is he came back, and he noticed there was a fungus growing on one of them, the penicillin fungus, and around the fungus on the plate, they had this nice lawn over here, but there was this zone of inhibition where no bacteria were growing, and of course the guy had a train mind, he was looking for things like that would inhibit the growth of bacteria, so it wasn't as fortuitous, but he was prepared for the discovery in a sense, right? And so he said, there's something in the mold that's inhibiting the growth of bacteria, and so he spent the next 12 years basically exploring this, trying to isolate what it was in the fungus that was in the mold that was actually inhibiting the growth, and they finally got some help from chemists who actually isolated the penicillin and also were able to synthesize it, right? And so basically by World War II, which is 1939 for us, 1941 to 45, penicillin was starting to be grown, or manufactured on sort of an industrial basis, and it saved tons of lives, and some of the early reports of the act of penicillin, the first antibiotic were almost miraculous. People near death, they gave them penicillin, they almost literally hopped out of their beds, but it was almost that traumatic, right? It was just, it was a miracle drug, and so basically from the start of the development of antibiotics, modern antibiotics like penicillin, is they've called the 50 years after that, golden age of medicine, prevented millions of deaths. I mean, there's probably a good fraction of us in this room who wouldn't be here without these modern antibiotics. You know, our parents or we would have died, or our grandparents would have died of some bacterial infection, many of them would, okay? So this is an example of the plate. This has given you, oh, so if 19, say 28 to 1940 sort of represents the beginning of the antibiotic era, 1947 was the first year in which they'd noticed bacteria that were resistant to penicillin. So the bacteria responded almost immediately. So before they had antibiotics like penicillin, there was some fraction, some very small fraction of the bacteria were resistant to it, and after it was started to be used in a clinical basis, you saw more and more bacteria becoming resistant to it. This is an example of evolution. It's not a change in a single bacterium, it's a change in the population in general. So you started to see the bacteria respond, evolve to the use of antibiotics, and so the medical community responded like you might think they would. They developed new antibiotics. So for instance, I can't see like I used to be able to, this is pretty pathetic. So you saw immunoglycosides introduced in the 1950s and 60s. Cephalosporin was another one that came around tetracycline. They started to introduce all sorts of new antibiotics that attack the bacteria in different ways. Some of them, for instance, would inhibit the translation machinery, this machinery that makes proteins. Others would inhibit DNA synthesis, for instance, some act on the GI race, which uncoils the DNA during replication. So there are all sorts of ways that these different antibiotics would attack the bacteria, but the bacteria, there would always be some fraction, some small number that would be resistant for able to evade that antibiotic. And of course, when you then have a lot of antibiotics and use the fraction or the frequency of those particular bacteria would increase in the bacterial population. That's evolution. So these are examples of resistance. Of course, you need to think about resistance as not being your resistant or not. It's sort of a continuous scale. You can be more or less resistant. So what you're seeing here are plates, and what they've done is they've taken a small piece of paper, filter paper, usually impregnated it with, soaked it in an antibiotic, and then they set that onto the plate. And so what you can see is the zone of inhibition around the little piece of filter paper. And of course, what you have to imagine is happening is the antibiotic is leaching out of the filter paper and there's a gradient going out. So it's probably most concentrated at the filter paper and less concentrated as it goes out. And at some point, the bacteria can handle the amount of antibiotic and at some point, they can't. So the smaller the hole, the smaller this hole is, the more resistant the bacteria are. So for instance, these holes are smaller than these, so these bacteria are probably more resistant to whatever the antibiotic is than these are. Because you can actually measure resistance, right? How much of a particular antibiotic do we need before we kill the bacteria? All right, so that's basically what I just said. So this is an example. So antibiotic resistance is an example of evolution. It's a fact. In that sense, evolution is a fact. We can see, for instance, evolution happening today, not only in the bacteria, but in other species as well. And we have a fossil record that shows us that species that lived in the past look different than they do today. So things have changed over time. And that's all evolution is, is change over time. And that's the necessary part of any theory of evolution is recognizing that things have changed over time. Now the real question is why? And Darwin, Charles Darwin is a certifiable great man. And the reason is he's supplied the why. I'll talk a lot more about his theory and about his life in this lecture, but the basic reason Darwin is a famous person is because he provides the mechanism to explain why we have evolution occurring. He provided the mechanism that explains antibiotic resistance. And so these are just some pictures of Darwin through time. Most of the time you see him sort of represented as a fairly in his later years. The photo I showed you in the very beginning was this one, or from his, I think he died in 1882 or 1883. But there he is as a young man, sort of a very angry young father, I suppose. And he had a lot of children, so I have two kids I can imagine, multiply that by four and you get scowls. And then he was buried. You can actually find him today in Westminster Abbey. So he was very near Isaac Newton. So he's a very, he's of that caliber of a scientist. So a little bit about Darwin. There's a, one thing I forgot to mention in terms of how the course is organized is that these, these are keynote presentations. I'll have them saved as PDFs. Those will be available after the lecture. And then I also have notes that I use, fairly detailed notes. I will also post these as a PDF, right? But after the lecture. So you'll be able to, man, I know you go, you wanna write down a lot of information, but a lot of it will be written down again in these notes. Anyways, a little bit about, about his life. Well, actually I think I wanna back up a little bit. Let's go turn the lights on. I have to remember how to do this. There we go. Blank the screen. Perfect. So a little bit more about the idea of what a successful theory of evolution requires. So I already mentioned the fact. All right, now, this is not something that's original to Darwin. The idea that things change over time is not original to Darwin. There's actually pre-Darwinian ideas that, that species change through time. Okay, in fact, I list some of them, but the Comte Befum, he's a French scientist. He had an idea, he wasn't a, he was a creationist, but he, this is the 1700s of course, but he did speculate on the idea that things changed over time. There was Darwin's grandfather, Erasmus Darwin. He was sort of a philosopher and doctor, but he had this idea that all life sprang from one species, right? Now he didn't have any mechanism in his writing that's so flowery that it's hard to actually interpret, but it looks as if he had an idea of evolution. And then of course you've all heard of Lamarck, sort of your high school biology textbooks, favorite whipping voice, sort of speak. Mostly because he's, you know, they kind of use him as an example of a wrong theory, right? Well, it turns out that some of his theory was right. Things do change over time, right? So he accepted the idea of evolution. He saw that, look, things do change over time. His mechanism was what was wrong. So he had this idea that organisms through use or disuse of some part of their body could change that trait over time, over their lifetime, and then pass it on to their offspring. Now of course we know that's not true. There's no mechanism that allows you to, for instance, if you're an athlete and your training, your child isn't gonna inherit your robust physique, say, unless they train as well, right? That's not something that's passed on directly, okay? And so basically what we know today is that individuals don't change over time, their genetics don't. It's just a species that change over time. So anyway, so Lamar had some ideas about evolution as well. It just turns out his mechanism was wrong. The other part of a successful theory of evolution is to think about what the pattern of evolution might be. So this is describing what we see. Is it a gradual pattern of change, or is it an abrupt pattern of change? So for instance, you can think of where there's a, so if we make a little graph here, here's our graph, maybe we'll have our trait that we're interested in measuring on our x-axis and we'll have time on our y. So one pattern of change can be something slow and gradual. The trait changes over time in a slow, gradual way. And this was the pattern that Darwin argued very strongly for, okay? Another possible pattern would be one of more abrupt change. The trait more or less doesn't change for a while then you have a period of very abrupt change and then it doesn't change again very much. That's a different pattern of evolution. It's still evolution, but it's not a slow, gradual pattern. Now there's still debate among evolutionary biologists about what exactly the pattern of evolution is. And what's not fair is you often see critics of evolution point to the debate within the field about the pattern and as I'll talk about in the second of process of evolution as an argument that the fact of evolution must be wrong as well. That's not fair, right? Nobody, no scientist or very few scientists debate the fact of evolution. It's an accepted theory. It's accepted fact in the field of biology. What people debate about why we actually have a field of evolutionary biologists, why people like me can actually be employed is because there is active research on the pattern and the processes of evolution. So that's a little bit on the pattern of evolution. Darwin did have something to say about the pattern. He argued that it was slow and gradual, but he could have been wrong in many instances. And then we have the process or the mechanism of evolution. And this is where Darwin made the major contribution. As I said, he wasn't original about arguing that evolution occurred, although he gave lots more evidence that it did, or about the pattern, but it's mostly the process. He described a unique process that we'll describe in great detail and that process is called natural selection. Natural selection, so you guys in the front here can see it. This is his mechanism for evolution. Now of course, we will talk about some other mechanisms that cause change through time as well, but this is the mechanism that can cause adaptation. It can cause creatures to be adapted to their environment. It's the only mechanism we know of that has that property. Again, we will be talking about that in great detail. So how did Darwin come up with this? Oh, and I should say one last thing about a theory. So I think you can look at the, I mean, this is just my own thoughts on this, but I think you can look at the fact and the pattern of evolution without, you can just document. You just look in the fossil record. You can look at the organisms around us and you can actually document change through time and you can even document the pattern. If that was all there was to the field, I would argue that I wouldn't be in it, frankly. It would be rather uninteresting. It'd be a little bit like stamp collecting. Well, I saw this here and I saw that there. What really makes the field of evolutionary biology and science is that we can actually attach a process to things that occurred in the past. When we see change through time, we can say, well, we understand the natural selection is working today and we can actually measure its effects today and we can say, and this process must have worked in the past as well. So in order to explain past events in a mechanistic way, you have to make a very important assumption. It's one that you probably don't have a problem with, but it's an important assumption. So we might as well stay explicitly. It's not controversial, but the assumption is that the processes we see working today also acted in the past. That's all there is to it. It's such an important concept that it has its own name, and it's a long imposing name, but here it is, uniformitarianism. So uniform materialism. So I think I have it spelled correctly. Once again, it's just the idea that the processes we see working today also acted in the past. So if we can see natural selection, for instance, operating in the past, the same process must have worked today. If we can see natural selection working today, we can extend that process and say it also worked in the past. Now this is an assumption that actually underlies several historical sciences. So for instance, geology also makes a uniformitarianism assumption. It's the basic idea is if we see processes acting to erode rocks or form rocks today, that those processes worked in the past. We see earthquakes fracture the crust. We see sedimentation occur in river basins and lakes in the deep sea. We see wind and water erosion working today. Those processes worked in the past as well. It's not a controversial assumption. It also underlies astronomy. There's a really good course on campus at the top of Filippenko. It's a kind of introduction to astronomy. I wish he was teaching when I was undergrad here. But basically it's the same argument. When we see the light from stars, the light we see isn't, it traveled a long way, sometimes billions of years. So the things we see working around us in the heavens, those are things that occurred deep in the past. So in order to explain how these stars are moving around, we use physics, right? We understand how planets and stars move based on things you would learn in physics A and 8B. Once again, it's the idea that the processes we see working today also worked in the past and other places as well. It's not a controversial assumption. Now that's not to say, so uniformitarianism, so we might consider the alternative first of all. So what is the alternative to uniformitarianism? Of course it's the idea that processes we see today didn't work in the past, that something else happened, in which of course completely, if we believe that, then there's no way you can actually go ahead and apply these processes into the past. We would have no way of doing science in that case. And I would argue that that type of assumption does have a name, it's called magic, right? Or supernaturalism. But the idea that without that assumption, if you're gonna willy-nilly substitute new processes and say that they worked in the past and we can't do science, okay? So that's a sort of a ground state. We can't even have a conversation unless we can kind of agree on some of these assumptions. Now, if you believe uniformitarianism, it doesn't necessarily mean that all the changes are slower gradual. So uniformitarianism does not equal slow gradual and continuous change. There's lots of perfectly natural processes that are abrupt. So for instance, in geology, it's the 100, so-called 100 year, or 1,000 year floods, right? Those are abrupt things that occur over the course of a few days, but infrequently. In fact, they're very important in formation of rocks. If you look at rocks up until dinner, up in the hills here, what you see are the rock layers are mostly formed in, not gradually, but every 1,000 years or so. The sedimentation occurs in abrupt instances. And then most of the time in a section of rock, if you look at a section of rock that's exposed along like Claremont Avenue, and you look up, most of the time isn't in the rock, it's in the layers between the rocks, if that makes sense. So you don't have to, or the volcanoes, that's also an abrupt change, or asteroids hitting the earth. We think that actually, we think that asteroids hitting the earth have had a large impact on life. Those are definitely not slow gradual things, thank goodness. There are things that happen once very occasionally and they have a big effect. They're definitely abrupt. So the dozen uniformitarianism does not equal slow gradual change. And uniformitarianism doesn't imply that the rules governing the change of the past and present are perfectly understood or predictable. So for instance, there's lots of things about, there's a physics department here because there's lots of unknown physics. There's a chemistry department here because there's lots of unknown things about chemistry. People are actively working on these fields. So we don't know everything, there isn't a done to know about everything. That's why we're still have science departments. And so just because we don't understand everything doesn't mean we can't actually use this uniformitarianism assumption. Or it doesn't mean that we can perfectly predict what happens. So for instance, a really good example is the weather. We think weather patterns are caused by physics and chemistry, things we understand, right? But that doesn't mean that the weather is predictable. It means that you can only, it's such a complicated system that there's always some degree of uncertainty about what the weather is gonna be tomorrow. And in fact, weathermen with all their information can only do a little bit better than this very simple prediction scheme which is tomorrow's weather will look like today, which is pretty remarkable, right? If you have a scheme which says tomorrow's weather will be like today's weather, you'll be right quite frequently. And then if you're a weatherman and you go to college and learn all about weather, you can only do like 5% better than that, okay? Which is pretty, that doesn't mean that we say, well it's supernatural. It means that we just don't understand the system well enough to explain it with perfection, right? There's always some amount of random chance or stochasticity in some systems. And it's the same for evolution, geology and these other historical fields. So that's all I wanted to say about the field. That's what you understand that there's a fact and pattern and process of evolution. These are the successful components of a theory. So when we discuss the field, you might think about what parts are the pattern, which are the processes that are causing the pattern. And I would argue that in order to actually attach a process to things that occurred in the past, we have to make this uniform tering assumption, okay? And it's an assumption that's not unique to evolutionary biology that's shared among several historical sciences. Are there any questions about that? Okay, so let's go back to Darwin. I want to talk a little bit about, so usually I don't have such problems with this. At least in the past I haven't. So this is, here we're back in business. All right, so we talked about Darwin. So I want to talk a little bit about his life. He was kind of a remarkable story. We won't be talking about Darwin the entire 13 lectures, only this lecture and part of the next one. But the story is what a privilege. He was born February 12th, 1809. That's the easy date to remember because it's the same day and year as Abraham Lincoln. Two pretty famous people on the same day and the same year. Obviously different backgrounds there. He was born in England. His father was a doctor. His grandfather, as I said, was a doctor. He was slated to become a doctor as well. There's a lot of pressure you might imagine in the family to become a doctor like his father and grandfather who were both very successful. They're well-to-do. They were not hurting for money at all. In fact, I don't think he ever needed to work in his life. Basically he basically had a trust fund and then when his father died he inherited all the money. So he never had to work a day in his life. This is very common of scientists of that era. It wasn't a profession back then. It was something that gentlemen did. People that had means of support and so they could go ahead and pursue science on their own. What science didn't start as a field until the late 1800s when you actually had professional scientists. Anyways, he was slated to become a doctor. I believe the first university he went to was in Scotland. And you have to remember this is before the days of knocking people out and doing surgery while you're knocked out. He basically witnessed a surgery on a child and decided, okay, I'm not doing this. And so he decided he didn't want to become a doctor. He transferred to Cambridge University and he was slated to go into become basically a pastor in a church. That was sort of another respectable way to go if you have a respectable profession for a very wealthy people. But at the same time he was a very avid naturalist. So naturalism or being a naturalist was a very popular hobby like collecting beetles and birds eggs and being a bird. These were all very popular hobbies back in the Victorian era of England. And he was a very enthusiastic bug collector for instance. He was really into beetles especially. And he was also very much drawn to the courses he took with his botany professor and the geology professor, the fellow named Lyle. Charles Lyle was the professor of geology. He was actually the one who argued for uniformitarianism in geology. So you can imagine Darwin was probably exposed this idea very early. And he was also exposed to the idea at the time that the earth was much older than people thought. So by the 1830s, 1820s, when he was going to college, the idea that the earth was maybe tens, what they thought were tens of millions or maybe 100 million years old. Of course we know it's much older now but was sort of gaining popularity. So people realized the earth was old. So he knew the earth was old that they had. He was exposed to uniformitarianism assumption and he went on lots of field trips with his botany professor. And when he graduated, he was presented with the opportunity of a lifetime. So instead of going into a seminary, he was given the opportunity to go on around the world trip with the Royal Navy as the naturalists. So what the Royal Navy was doing at the time is to prevent ships becoming shipwrecked. They were doing very good job of trying to map out the coasts of different parts that hadn't been mapped out before. So what they would do is they load up a ship with what are, we're called chronometers. Everybody know what a chronometer is? It's a very accurate watch, right? And it helps you measure longitude accurately. So they send out these ships with lots of chronometers and they would do very careful mappings of the position of the coastal parts of like different parts of the world and also soundings, how deep the water was at different points. So basically making detailed maps for mariners, okay? So he was given an opportunity to go on one of these on the HMS Beagle and his role on board was as the ship's naturalist. And the real purpose was to give the captain somebody to talk to during dinner because the captain was a gentleman. He needed a gentleman to talk to over dinner. And so Darwin fit the bill. He had an interview with the captain, Captain Fitzroy. Fitzroy liked it. There was this idea, there was this field at the time which was very popular was what is this? Physiognomy, which was the basically trying to assess people's characters by looking at the bumps on their heads. And evidently, Fitzroy was a real adherent to this. And he looked at Darwin. He thought he had good bumps on the head so you're in, okay? So Darwin was in, he went off on this cruise. He was seasick the entire time. It was a five year cruise, right? It was a five year voyage. So from 1831, 1830 to 1835, 36. And most of the time was spent along the east coast of South America doing these mappings, all right? But whenever they would come along the coast, he would go inland and he did lots of collecting. So he would send these to you package, he would prepare skins, he'd send all sorts of specimens back to London where there are curators at the museums there who would receive the packages and sometimes got quite excited about what he was finding. He found, for instance, one of the, he found lots of fossils in South America here in the Galapagos Islands, which are now part of Ecuador, I think they were then too. He spent quite a bit of time going from island to island. So here is the Galapagos Islands. Now the Galapagos Islands, you may have heard of the Galapagos Islands in conjunction with Darwin's name, right? Cause he spent a lot of time here and he referred back to his time, the collections he made on the Galapagos Islands over and over again. But at the time when he was going through the Galapagos, he didn't have the theory of evolution in his head. He didn't have the mechanism of evolution in his head. He was just collecting. And in fact, a lot of the collections, I mean, if you were really thought of the islands as being super important, you probably would have labeled all the specimens by which island you collected it from. He had to kind of reconstruct which islands he collected things from after the fact. So anyways, he was on the Galapagos Islands and of course, if you go to the Galapagos, there's all sorts of pretty cool organisms. You have these giant tortoises. I love tortoises. I've got one in my backyard, not one is this big, but he's big. But you know, you saw the Galapagos tortoises and one thing they learned, for instance, by some of the locals is that some of these locals claimed that if you gave them a tortoise shell, they could identify what island it was from because the tortoise shells varied from one island to the next. Then you have these weird marine iguanas. Here's some land iguanas. You have, you've probably heard of the Darwin finches. He thought they were mockingbirds, but it turns out the islands have a radiation of so-called radiation of finch well over a dozen species. And of course, I think when they were at the islands, it was pretty common in those days to grab a couple tortoises. And these guys lived for a long time, even without food, and you basically turn them upside down on the ship and then you have food a month, your fresh meat in a month from now. It's kind of sad. That's why there's so few around now. Anyway, so he went on this voyage, eventually returned home. He married his second cousin, I believe. This woman, I don't know if you've ever heard of Wedgwood pottery. Some of you may have. It's a very famous pottery. It's a fine china. But anyways, he married a Wedgwood, his cousin, and so his wife was pretty well off as well, and they had lots of kids, and they settled in down. Here's his house. And still there, it's a sort of museum nowadays. There's his house. And he started up some, at this point he'd given up going into the seminary. He settled down to doing science. He started up lots of notebooks. So he called one notebook, which he started around shortly after he got back from this voyage, the transmutation of species. So somewhere in the early, in the late 1830s, he started to get his ideas on evolution, and he started to accumulate evidence for the theory of natural selection from 1836 to 1859, 20 years. He was very conservative. He didn't want to break this idea without lots of evidence. And frankly, he was a little bit concerned about what would happen to his reputation if he let this idea up. So he spent a long time amassing evidence, and then it was 1859, or actually 1858, where he had to publish. What happened is he got this letter from a naturalist, this guy Wallace, who was out in the South Pacific collecting specimens, and Wallace had a completely different background. He was a naturalist and collected butterflies to sell. He actually had to make a living as a naturalist. And he wrote this very short paper and said to Darwin, could you please present this at the Royal Society, because I've got this idea about how species change. And Darwin read this, and he realized that Wallace had written a better abstract of his idea of evolution through natural selection than he could have written. He said, oh shoot, there were a couple of his friends, including Lyle and Henslow, the botany professor, that he had told these ideas to, and they said, look, what we'll do is we'll read both papers side by side in 1858. So the two papers were read at the Royal Society, and interestingly, they had no effect on anybody. In fact, the president at the Royal Society that year said it's too bad, no really big breakthroughs came through this year. That's 1858. But basically, Darwin had the fire lit under him, sort of speak, and he wrote what he called a short abstract of his ideas, and that's what you see as the origin of species. He's actually intended to write, if you can believe it, an even thicker book. Outlining his ideas on evolution through natural selection. And I believe this might be a good place to start. What we'll do is stop, rather. What I'll do is I'll discuss the theory in great detail and what Darwin said in the next lecture, and good luck on your midterm.