 All right. I mean, the t-shirt's appropriate for the class, I thought, so. So, I want to start off this lecture with a question. So, the last lecture used a lot of, you know, PowerPoint or keynote instead of the usual chalkboard. How many people prefer that versus the chalkboard? So, if you prefer the keynote, chalkboard? Oh, yikes. Okay. It's kind of ironic that it takes a lot more time to prepare the keynote presentation than to just do something from the chalkboard. So, I think in the future, I'll, I think it probably slows me down a bit. So, I give you a lot more information more quickly if I do things in the PowerPoint. So, I think I'll try to cool it for the rest of the semester on that. And in the future, I probably won't do it. Okay. But you're going to have to live with it just a little bit longer. And what I want to do is finish up the lecture I started last time, which was how the evolution of helpful behaviors occurs. And just to remind you, we talked about, we discussed a number of different types of interactions between organisms where both interactors, the donor and the recipient benefit, that's called mutualism, that's easy to explain, predation or where one benefits the other doesn't, that's easy to explain. But these cases where the donor doesn't have, doesn't appear to have any advantage in the interaction, that is that they suffer a cost, those were difficult to explain. That is to say, how do we explain altruistic or helpful behavior? And there are two explanations just to remind you. The first explanation is that it's not really that helpful because ultimately the donor will benefit, that's called reciprocal altruism. It's just you don't get a benefit immediately, you get one down the road. The other explanation I wanted to give, or I did give, is called kin selection, this is Bill Hamilton's idea. And the basic idea is that you're helping close relatives. And in that case, you're helping, I don't like that at all, there's some benefit that the recipient gets called B and there's some cost to you, which we call C. But the point here is that the individuals you're helping, the individuals who get the benefit are related to you by some factor R. And Bill Hamilton said that if the relatedness times the benefit minus the cost to you is greater than zero, then an imaginary gene that causes you to act in an altruistic way towards close relatives could spread through a population. So the population, the math works is what I'm saying. And it's easy to see, but basically he introduced this idea of what we call inclusive fitness. This is the idea that your fitness can be calculated as adding two parts together. The first part is the usual fitness, that is the number of kids you have, the number of offspring you have. But it's also can be calculated by including the offspring of your close relatives. So the offspring of your close relatives don't count for as much as one of your offspring do, but they do count as sort of a devalued child as far as you're concerned. So you can increase your fitness in two ways, that is by having more kids, or by having your close relatives have more kids, that's the point. So that is what this statement says right here. So this is sort of in words yikes, this isn't working by the way. The pointer isn't working. So that's what this statement is saying. I just said that. It's a little bit about relatedness as something I covered last time, but we can calculate our relatedness as the probability that two alleles sampled at the same gene are identical by descent, that is they can trace themselves to the same copy in the parents, or somewhere down the line in your grandparents or great-grandparents. And so for full Sibs, there's two ways that a brother and a sister, for instance, can share a gene, that is they can share the gene through the mother or through the father. So there's two separate paths that you need to consider when you calculate the relatedness. For a half Sib, on the other hand, you're only through the shared parent, the mother or the father. So there's only one path to consider. And half Sibs are related to one another by half as much as full Sibs are. Now you're not going to be responsible for how to calculate relatedness. I'm hoping this is an intuitive idea to you, though. So use sociality is a form of altruism which has these following broad characteristics. So first of all, you have a you typically have this overlap in generations between the parents and the offspring. That is to say you don't have all of the individuals of some cohort dying off at the same time and then having a new generation being formed. You have overlap in the parents and the offspring, kind of like we do, right? You have cooperative brood care and it's often, you have these specialized casts of non-reproductive individuals. So think of worker beings, for instance. Or cast of ants which forego reproduction to help maintain or grow the hive or the nest. Why do these individuals forego reproduction? That seems like the ultimate that is the ultimate form of altruism, right? Where you completely forego your own reproduction to help out others. How can that form of altruism arise? Here's an example of an altruistic or of a youth social insect. These are leaf cutting ants where you have these little ants go out into the forest and they forage for leaves and they bring back these leaves to the nest and then they have other workers in the nest that chew up the leaves and they cultivate a fungus. And ultimately what they do is they eat the fungus. So these are really cool insects. They're kind of like little farmers, if you will. Now the interesting thing about a lot of the youth social insects like the bees and the wasps or bees and insects or bees and ants, I'm sorry, is that they have a special form of sex determination called haplodiploid. Now in this form of sex determination females form from fertilized eggs. So they're diploid. And so of course if you're forming from a fertilized egg you have a mom and a dad. On the other hand the brothers, the males are formed from unfertilized eggs. They're haploid. They have one copy of each chromosome. Were you able to get me a pointer by any chance it works? Oh okay, well I guess I wasn't pushing the button correctly. I thought I knew that. So let's look at how these sisters are related to one another. Now normally of course full sips would be related to one another by a factor of one half. But the point here is that the chromosome that they might share from their father has to be the same chromosome because dad only has one chromosome to give. So when you trace the path through the mom it's the usual one where you go one half of a factor up times one half of a factor down. So that's one quarter. Plus going to the father it's a one half times a one. They have to share that chromosome because dad only has one chromosome to give. So in the end sisters are related to one another by kind of this elevated fraction three quarters. So they're much more closer related to each other than normally full sips would be related to one another. Now I can go through the other calculations but sisters and brothers are related to one another by a factor of one quarter, a relatedness of one quarter. And mothers are related to their sons and daughters in the usual way. So parents like for instance I'm related to both my children, my son and my daughter by a factor of one half. Okay there I'm equally related to both my children. And that's the case for these you social insects as well, the haplodiploid insects as well, where the mother-daughter relationship and the mother-son relationship is the usual one one half to one half. So just realize in terms of what I want you to take away from this figure, realize that mothers are related to the children in the usual way equally related to sons and daughters but the offspring have this asymmetry in their relatedness. The sisters are related to one another by a factor of three quarters. They're very highly related to one another whereas they're much less related to their brothers. And that's unusual. And I should also say to you that it's the sisters that are the form that cast the workers in these you social insects. So there's a couple of interesting things that come out of here. So first of all, first of all I want to mention that people believe that a large reason why you can have sociality evolve in these insects is because of this unusually high R among the females. That is to say that when R is bigger, that it's easier to satisfy this inequality. True? It may not be the only reason but they think it's a very important contributing factor and you'll see that in you social mammals which don't have this haplodiploidy sex-determining mechanism, it's also the case that the workers are very highly related to one another. I'll get to that in a bit. So that's the first thing I want to mention. High R means that this inequality is easier to satisfy and that's probably contributed to the evolution of you sociality. There's also some interesting predictions that the unequal relationship between brothers and sisters has and what the queen which is the reproductive individual in one of these nests has. So remember the queen, the one that's the reproductive individual, the mother of all the insects in the, of all the offspring in the hive has the equal relationship to sons and daughters. So she should favor based on this equal relationship between sons and daughters and equal investment in sons and daughters as well. That's to say she should favor the same number of males and females to be reproduced in the hive. The workers however which are all females should favor an unequal sex ratio. They should favor a ratio of three females to every one male because they're three times more related to their sisters than they are to their brothers. So you get this sort of parent offspring conflict, not the type of parent offspring conflict you may have undergone with your parents as teenagers, but one where you really are investing different amounts, really do favor investing different amounts in brothers and sisters, males and females in the hive. Once again the queen and equal investment in males and females because she's equally related to both and the workers which are all females preferring unequal investment in females and males. In fact they should favor a three to one investment ratio because they're three times more related to their sisters than they are to their brothers. And the question is what do you actually see in these, in these hives, in these you social groups? Do you see an unequal investment or do you see an equal investment? That's been examined a couple of different times. So this is just restating what I said that the queen favors the one to one investment and the females, the workers in the hive favor a three to one investment. So this has been investigated a number of times. Trivers like, oh gosh, 35 years ago almost. Trivers and Hare actually found this expected three to one investment ratio meaning the workers are actually controlling the investment in males and females in these nests. And Mueller who's at University of Texas now also showed that the worker hymenopterans can alter their investment colony, their investment in their colony mates depending on the relatedness. That is to say, what happens when, so let's say you have a queen and then she founds the nest and all the workers, all the offspring are founded from that one queen. They're all sons and daughters of that one queen. What happens when that queen dies? What happens is one of the female workers, they're all sexually competent. They can in principle become sexually reproductive. One of them becomes sexually reproductive. So now she's the queen. What this means is that all the workers around now aren't helping out their sisters and brothers, they're helping out their nieces and nephews which have a much different relatedness, much lower relatedness. So they should now start to favor a more equal investment in males and females. Once you have a new queen the relatedness between males and females, brothers and sisters, becomes more equal. You're helping raise nieces and nephews which are related to you by, in these cases, a factor of about 0.37. And so you should see a change in the investment strategy in these nests where the queen is actually one of the sisters. And they find that's what Mueller found. They found that you can actually, that the workers actually can control their investment and change the ratio of males and females in these colonies. So the point here is that relatedness can explain a lot in terms of the investment strategies that you see in these nests. And that's the only point I really want you to remember. That when you're equally related to some other individual you should favor an equal investment. Evolution predicts that you should favor an equal investment in males and females. And when it's not equal then you should have an unequal investment. And that's exactly what you can see in these social groups of insects. Now before I go on to the topic for today, I want to give one more example of eusociality and that's in these naked mole rats. These are mammals, believe it or not. They're moles so they burrow underground. Here's the version of the naked mole rat that my daughter has, the little stuffed animal. But they basically, these are mammals that live underground in groups of about 200 individuals. And just like in these eusocial insects where you have sort of a queen bee that does all the reproduction, you have breeding restricted just a single queen into just a couple kings. That is to say males that mate with the female and are the fathers of all the offspring in this group. And these other individuals in this group of 200 are non-reproductive. They act kind of like worker bees. They go gather food, they defend the nest, they extend the nest burrowing and so forth. They're diploid like all mammals. They have the same sex determining mechanism that we have. But it turns out that these individuals are highly inbred. And so the relatedness among very highly inbred organisms is unusually high. And in this case the relatedness is .81, which is even higher than you have between females, your sisters in a eusocial haploid diploid group. And this is basically one of the explanations for why you have this high relatedness. 85% of all the matings are between parents and their offspring, or between full sips. So when you have that type of reproduction you get very high relatedness values. The main point here again is that in these groups where you see altruistic behavior evolving, it appears to be associated with a very high R relatedness. Meaning that once again this inequality is easier to satisfy. Now that is all I wanted to say for the first lecture. Let's go ahead, that's kind of gross. I'll blanket since it's so gross. So that was a lot of material to get in the lecture and a half. So remember we talked about sexual selection and we talked about the evolution of altruistic behavior in the lecture and a half. That was like I said a lot of material. The main points I want you to remember from sexual selection is the explanation for that. You either have the dimorphism in males and females is caused by either competition among males for access to females or the females choose. You should understand why females might be the choosy sex. That is to say it's this anisogamy rearing its head. And you might think about some of the reasons or understand some of the reasons why the females may, on what basis females might choose a mate. So for instance one explanation I gave is that some direct benefit the males bring such as food or a good nesting site or the good genes hypothesis. That is to say the males have some genetic quality that the females are looking for. Those were the explanations I gave there. Then in terms of the evolution of helpful behaviors we talked about reciprocal altruism and we talked about kin selection. You should understand what those are and be able to give an example of each. If you can do that I would be a very happy person. You would be too because you will have done well on the exam. The next half lecture and lecture are going to be covering what I think is a quite interesting area of evolutionary biology and that is how species form. If you look at the diversity of life today we have millions and millions of species. Yet all organisms on earth are related to one another through some common ancestor. Which means that if you go back in time further and further there must have been one species billions of years ago that gave rise to all of organisms on earth today. The process, this branching process by which we increase diversity, this branching process the branches, the splitting events are caused by what we call speciation. Of course the thing that prunes away diversity is when species go extinct and we have lots of examples of extinction as well. Over time the rate at which species form has been greater than the rate at which species die out so that's why we have so much diversity on earth today. That's why we have so many different kinds of species around. The second lecture I want to talk about the process of speciation and as I'll discuss in that lecture it's all about turning off gene flow between populations. Once you turn off gene flow between populations then the populations can evolve independently. And we'll talk about genetic mechanisms for example that prevent species from coming back together and forming one species again later in time. But today what I want to do is I want to spend most of my time discussing what is a species in the first place. So two questions, what is a species and secondly how species form. Let me see if I can find some better chalk. Once again this is today's lecture and we'll postpone discussing this until Wednesday. So what is a species? So there's a number of definitions that we can use. Sometimes they're called species concepts or definitions. We're only going to discuss two. There's quite a few and remarkably there's more debate about what a species is among evolutionaryologists than you'd expect. Now it turns out even though there's a large number of species concepts or definitions usually it doesn't matter. Usually all of these different methods or concepts agree on saying for instance that humans and chimps are two different species. There's no debate among anybody about in some cases. But it's the cases where species are recently formed. That is to say the speciation event that led to the two different species we see today occurred recently at a time say maybe a couple hundred thousand years ago where it's more difficult to distinguish the species and these different species concepts often disagree which is what you'd expect. When things are very closely related to one another, when the speciation event that led to the two species occurred very recently, the species are very similar to one another and it becomes difficult to distinguish them. Now given enough time of course they'll differentiate more and it would become easier for future biologists to distinguish the two species. But there's lots of species today alive that it's difficult to distinguish them and it becomes a problem of expertise. But I'm going to discuss two species concepts. The first species concept is the one you probably think of. And what I'm going to do to describe the species concept is imagine the following scenario where you go out to nature and you grab individuals and you measure the individuals for some number of traits. That is to say things you can see on the organism. Maybe you go to the gophers and you measure their weight and their length for instance. Or maybe you go to gophers and you measure some features of their bones. The length of the femur or whatever. So what we have is we're going to just to simplify this we're only going to imagine two traits. You have trait one and you have trait two. And when you measure one individual it's going to fall somewhere on this xy plot and then you go and you measure another individual, another individual. What you would find is clusters of individuals. Some individuals have similar values for the two traits and others have different but similar values for these traits. Many people would go out into nature and say well all the individuals that cluster here they're going to be called species one. And the individuals over here we're going to call species two. So this is the morphological species concept and it's often abbreviated the MSC for morphological species concept. That is to say just to repeat you've distinguished different species based on the morphology and specifically you look for gaps like this in the morphology between different groups of organisms. Now when you identify species of course you need to give them a name and in principle it shouldn't matter what we name the species. But among scientists there is a convention we follow and that is to use a Latin binomial system for naming species. That is to say every species gets two names, a genus name and a species name and when you write these things that when you write a genus and species name down in a newspaper article or in a scientific paper the genus name should always be capitalized and the species name should always be lowercase. In principle you should also italicize the species in the olden days since I can't actually write italics printing you would underline it if you were doing it on a typewriter say. But if you ever see a newspaper article where the species name is capitalized you know that they actually not a biologist because they inappropriately capitalized the species name. It was every species gets a genus and species name and in our case for instance this would be Homo sapiens would be the genus and species for humans. Now what are some of the problems with the morphological species concept? One problem is what traits are important. So a lot of species where there is variation among individuals within the species for different traits. And for instance if you were to look at those traits you might actually call things different species that really aren't. So for instance in humans I can look out in the audience I see a lot of people with dark hair and I see some people with blonde hair and we can say well there is a difference. So if I make a plot, since we're only looking at one axis we'll say here's a hair color and a frequency and I would say well there's a lot of people with blonde hair and there's some people with dark hair why don't I call those two different species. We all know of course that would be a silly thing to do that there's other distinguishing features that might be more important to look at among individuals and that we would classify all the individuals in this room as members of a single species. But the point here is that it's a judgment call about which traits are important and which aren't. And it's often a matter of expertise on the part of the biologist. That's one thing I want to point out. Sexual dimorphism can also be problematic in some cases. And here I want to give you this example which I think is really neat. So here's an example of a highly sexually dimorphic species. These are insects of the order strepsiptera. I will just give you let's say EG strepsiptera. Remember that I just said that they're an order to themselves so these are of the same classification level as beetles and bees and wasps and true bugs and so forth. But they're very little, not much is known about their biologist. There's only a couple hundred species of these critters known and what you see up here on the top left is a wasp that has been what they call stylopized. It's been parasitized by a female of the species. And what happens is the female is a larvae sort of gloms onto the side and they burrow into this poor wasp and then the female strepsipterin takes over the entire abdominal cavity of the wasp. And basically the female gets all her nutrients from her hosts. So if you look at these things, at the females at least, the females if we were to dissect the female out of this wasp, they look like an undifferentiated bag. That's all they really look like. And you can see that these little extrusions in the abdominal cavity of the wasp. This is just one part of the strepsipterin female that's emerging outside. And what happens is that occasionally she, young, emerge from openings here and basically the young are either going to be males or females. If it's a female basically they hang around looking for another wasp or insect to glom onto and parasitize. And if it's a male, the male emerges. And the male remarkably lives only for a few hours. They have non-functioning mouth parts. They don't have a digestive system believe it or not. Imagine that being an organism without functioning mouth parts. So they don't feed obviously. They live only for a few hours. And their mission in those two hours is to find a female and mate before he dies. That's all they do. And I know a little bit about the biology of these guys because I really think they're cool. But if you look here they have these, the males have these antennae. And if you look at them under like very high magnification you can see these antennae have what look like lots of receptors which are probably for pheromones. People don't know for sure but they think that the females release pheromones and the males are attracted to them. Anyway, so these are really cool organisms. Now there's the male I said it looks kind of fly like they're called twisted wing flies by the way if that's a common name. There's a male the female like I said looks like an undifferentiated bag. Remarkably trained biologists, people who are experts in this group cannot match the males and the females of the same species together. The males and the females have no characteristics in common. So how can you actually match them up? So sexual dimorphism this is an example of very extreme sexual dimorphism but this is an example where even identifying males and females and placing them in the same species can be problematic. In this particular case what do people do? Well they're starting to resort to genetics so they're starting to sequence DNA and look for match up males and females based on how similar their DNA is which is remarkable that you'd ever have to even resort to such an extreme measure to match up males and females for the same species. We don't have that problem in our species even though we're dimorphic. So that's one example of a problem and the other is polymorphism. So polymorphism means many that's the poly and morph is form in many forms. And there are species where like us that are polymorphic for various traits. So here's an interesting example. Here's an example from a butterfly of the genus species Estrapi's folderotter and all the adults look like this. They're monomorphic. There's only one form for the adults. They're very kind of pretty blue patch here and black wings. The larvae however look like this for the species. The larvae are highly polymorphic. So here's 10 different polymorphisms that you can find that are all named in this one species. So the point here is that if you were to base your species names in this particular species, this particular butterfly species based on the polymorphism you see in the larvae you would say that you have 10 different species. Whereas you only see one adult form. Now in this particular case it turns out biologists think that these different larval forms, the polymorphism you see in the larvae aren't important and that we really only have one species. But it does point out a problem with the morphological species concept is how do you decide that the polymorphisms you see among the larvae aren't important. And just to contrast that example here's sparrows. These are adult sparrows of different species and to my eye at least, an amount of trained ornithologist by any means, but to my eye the forms you see here the variation you see among these different species of sparrow look like smaller differences than you see among the differences in the larvae in the butterfly example. But in this case the differences among the adults are significant and people do classify these as different species. Are there any questions so far? Now it's often the case that the morphological species concept is the only one that can be applied in a situation. So for instance paleontologists, people that study fossils, they're forced to use the morphological species concept. But there's one other species concept that I want to discuss and that is the biological species concept or the BSC. In a way the biological species concept is letting the organisms themselves decide who's in the same species and who isn't. The biological species concept is the idea that individuals are the same species if they freely interbreed with one another under natural conditions. Now the freely interbreeding part can usually be tested or can often be tested experimentally. That is to say you take two flies of different sexes and put them in a fruit bottle and you ask whether or not they can mate and the offspring are fertile. If that's the case then they can clearly interbreed with one another. That's not always the case. Sometimes organisms can mate and form offspring but those offspring might be infertile or sometimes the offspring will, you might have an egg form but they won't develop into an adult. So they can't form offspring. But there are often cases where you can actually test that. If I put a male of this so-called species with a female of this other potential species do they breed and form fertile offspring? Yes or no? The other part of this definition isn't as easy to determine. Can they do this under natural conditions? So this consideration is one where you have to think about the plausibility that these individuals are going to find one another in nature. Now there are some cases where that might not be so problematic. So you can imagine for instance say a bird species here's Asia and on this side we'll put North America so you can imagine let's say a bird species that lives along the west coast of North America and along the coastal region of Asia say you might even in the laboratory do these things and put them in a zoo. You can take males and females from these two species, this hypothetical example put them in a zoo and ask whether they produce fertile offspring. The answer may be yes. But then the question becomes do they do that under natural conditions? Realizing that there's a very large ocean that separates North America and Asia. So do they do that under natural conditions? The answer may be no. Maybe these guys don't migrate. Maybe they can't fly 5,000 miles. In which case you might, even though they might form fertile offspring, you might still decide to call them different species because they don't do that under natural conditions. But keep that in mind. Like I said there's this from our perspective this biological species concept is going to be considered the correct species concept. I'm saying this with the realization that lots of my colleagues across the world would probably be shouting at me right now because they might have a biological concept for species that's quite different. But we're going to consider the correct species and I think it's the most useful for a couple reasons. It's one that allows, like I said, the organisms themselves to determine what species they're from. But secondly it's going to be important for our next lecture when we talk about how species form. And remember I said species formation is about cutting off gene flow, migration. So if these arrows represent potential migration or gene flow between these populations, the formation of species is all about preventing gene flow or having gene flow being turned off between different populations. In that sense the biological, you're preventing mating or interbreeding between the organisms, between the groups, between the populations. And from this perspective the biological species concept is the most useful in my opinion for understanding how species form. Of that said, although it's, we're going to be termed, for the purposes of this class we're going to be considering the correct species concept. It's not always universally applicable. So again let's imagine this poor paleontologist who sees a new form, a new species, potential species in the fossil record. They're not in a situation where you can actually test the biological species concept. So I'll tell you right now, I haven't actually tried this but I'm almost certain this would be the case. You take a box right, there's your box and you put two different fossils into that box and you wait and you're not going to get little fossil offspring. That's a guarantee. I'm almost certain of that. I've never done it myself but I'm almost certain. You can't do these experiments in things that can't reproduce obviously. And often it's the case that you can't, some species are very difficult to rear in the lab for instance or even keep alive in the lab so obviously it'd be very difficult to test whether or not they can interbreed with one another in laboratory conditions at least in those situations. Under the biological species concept even if the species to our eye look the same, even if there's no morphological differences that we can distinguish, if the individuals recognize each other as being different species then we call them different species. So remember once again the biological species concept doesn't mean that you can actually distinguish them morphologically as long as the organisms can do it then they're different species even if we can't distinguish them. And there are some examples for instance in Drosophila of flies where it's incredibly difficult to distinguish among different species. Usually the most of the morphology is identical and the only way you can really distinguish between the species is if you're an expert on the morphology it's usually the penis of the flies that allows you to determine whether or not they're different species or not. That's the most rapidly evolving part of the morphology in many flies it turns out. But for almost anybody else it's very, any human that is it's very difficult to tell the difference and of course the flies have no problem determining whether they're different species or not. Let's go look at some examples here. Here's an example where morphologically you have different populations that look as if they're different species but we have one species. This is an example of what's called a ring species and it's a genus of salamander of Instantina which was studied for ages by a fellow who's still in the museum here called David Wake. He's a very famous herpetologist. He's retired now but for much of his career he studied these California salamanders and these salamanders have a range that goes all the way from San Diego along the coastal range and then along the Sierra Nevadas. And the interesting thing about these salamanders is each population often has what looks like a different form. So in this figure here you see here's the salamander that you find here, here's the salamander you find here along the array, here's one you find up here in the Bay Area and so forth. To my eye and to many, historically to many herpetologist's eyes they look like different species and originally they were classified as such. But it turns out that if you look and ask the question well how about these, the population here can it interbreed with a population here? And the answer is yes. There's free interbreeding between these populations here and then you can ask the question how about the individuals here? But can the population here interbreed with a population here? And the answer is yes. There's free interbreeding here. There's free interbreeding among the populations all along this ring except when you come to this gap. And it turns out if you take the individuals here and ask can they interbreed with the population here it turns out they can't. So this is a ring species you have gene flow all along this ring but the gene flow is small enough that by the time you get to the very end of the ring the populations are different enough that they can't interbreed. In this case they're all classified as being one species even though they have this situation where at the end of the rings the individuals, the populations can't interbreed. Really cool example. Here's an example where in baboons where originally there were five different species of baboons in Africa and they all have different forms so you can actually easily distinguish these different forms and like I said they were originally given different species names. But when people looked at these populations in more detail they realized that the adjacent populations were freely interbreeding with one another. And so they reclassified the baboons to be all members of one species and then they gave, sometimes you actually see this, you have the genus name, the species name and sometimes you'll have a subspecies name appended. So what happened here was that what was originally a different species they gave them different subspecies names and one question that comes up which is mostly just a note keeping, notebook keeping type of problem which is you had five species before now we have one name what name do we use? And one possibility is just use a brand new name, a name that hasn't been used. But what the usual solution is is you use the oldest name, the name that was first applied to any of the five species and that's the one that wins. Usually that's what they do in these cases where you reclassify the organisms. One of the points here is that people can change their mind in this business of naming species. As we get more information as people realize that even though they had different forms that the species just turned out to be polymorphic, the forms weren't important. They weren't important to the baboons at least because they didn't care, they would be interbreeding one group to another. The scientists are always willing to change their minds if they get enough evidence. Now as evolutionary biologist species are interesting for a number of reasons, the main one being that we understand how species form, we learn a lot about how the diversity on life was created. But there's legal reasons why species and this game of naming species can become quite important. And that has to do with a law that was passed in 1973 called the Endangered Species Act. This law, the intent is quite good I think. So the idea here is that if the species is in danger of going extinct that land is set aside or its habitat is protected. You're not allowed to mess with the population in such a way that you might endanger its chances of survival. Now the intent like I said is good but often it's a case that the Endangered Species Act conflicts with economic activity. And this is an example of just that. This is the Larkspur, the baker's Larkspur, it's a plant that lives up near Point Reyes, because a flowering plant that lives near Point Reyes. And there's a very, I mean historically the population was quite big but even in 1942 when it was first described, the person who described the species noted that its population was getting smaller and smaller, the number of individuals was getting smaller and smaller, mostly because of farming activity. And so now there's only a couple populations of these things around. In fact almost all of them were wiped out recently by road crew construction work. They just sort of accidentally guys with bulldozers who were working along the road accidentally wiped out almost all the species. They didn't do it intentionally of course. But in this particular case there was a housing development that was proposed to go into their native habitat. People filed a lawsuit saying no you can't do that because this is the only habitat for this Larkspur. The point being here that there was a conflict between the economic activity that would have brought jobs, construction jobs for instance, and protecting the last population of these Larkspur. So it's often the case that as a society we have to make a decision about which way we go. Do we protect the species or do we allow economic activity to go unabated? And I'm not going to tell you which way to go on that. Here's an example that I thought was pretty cool. Because I was only very peripherally involved as the office mate of the person who was involved in this. So as a graduate student my office mate was this fellow Paul Chippendale. And Paul worked on this species of salamander of the genus Eurecia that lives in Central Texas. So it lives along in streams in Central Texas and also lives in caves. So he did a lot of caveings, belunking, looking for these salamanders. It's a neotinic salamander meaning that it still has gills as an adult. We won't be talking about that. So you can see these gills. And part of his dissertation was doing a population genetic survey of all these salamanders in Central Texas. And he discovered in the course of doing this that there were some genetically isolated populations. Populations that looked like they were different species. And in some of these cases he was able to associate these different populations and these different species with morphological differences. But for the most part these Eurecia, even of different species, looked very, very similar to one another. So it's very difficult to distinguish among the different species. Unless you're an expert like Paul. Now it came up to be quite interesting because one of these species that he discovered had one population that happened to live in this pool. Now how many of you in Austin, Texas, know what this pool is? Anybody know what this pool is? It's a really neat part of Austin. This is called Barton Springs. It's almost in the downtown area of Austin. And a lot of people come here, especially during the hot season, which is of course most of the year in Austin. And they swim. It's basically a creek that was dammed up, forming this pool and you can see there's like a diving board and people often hang out in the grass and they swim. It's a great place. But the salamanders lived, I think actually one of the populations was right here underneath the diving board because I remember helping Paul collect these things and you could get a lot of them right there. Normally not a problem. It's just a pool and the people swimming around in the pool didn't really disrupt the population at all. But the problem was this. A lot of people would be swimming laps in this pool or they're swimming in this pool and they complained to the lifeguard saying, look I was swimming here and there was like, you know, some grass or whatever in the bottom of the pool. I mean this is a natural spring. So of course there's plants and stuff growing on the bottom of this. So what they did to satisfy these complaints is occasionally maybe once a week they drained this pool, that is to say open the dam, let the water flow out and then they power wash the limestone that formed the bait that was along the bottom here, getting rid of all the weeds. And of course that was great because nobody then had the icky weeds along their feet when they were swimming. But it wasn't so good for the salamanders. Basically when they live along the little grass parts of the streambed. So they were really disrupting the population. So there was this movement called the Save Our Springs movement in Austin and basically trying to save the habitat for the salamander. And the solution was actually quite simple and not disruptive in any way. They just decided not to power wash the streambed. And so now if you swim in Barton Springs occasionally you'll find at the bottom the pool weeds and stuff that you might find in any natural pool. But the salamanders are happy. But this is an example where human activity was actually encroaching on the only population of a unique species of salamander. In this case the solution was quite simple. That's all I want to say.