Cladistics

by Jason Amores Sumpter
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Hello, everyone. In this lesson, we're going to be talking about the different relationships between organisms that you can discover inside of filo genetic trees. Okay, so first off, we're going to go over a generalized term called Cledus Ticks. Claude ist ICS is going to be a field of study inside of biology and inside of genetics and Klytus sticks is going to be a type of classifications based on shared characteristics between common ancestors. And it's going to be utilized for hypothesis, hypothesizing evolutionary relationships between different organisms and it is going to it is now incorporating things like genetics, shared genetic characteristics, shared genetic code and different things like that. And this is one of the main ways that we create file a genie's Klytus sticks and the shared characteristics and genetics between organisms. Now clouded sticks is going to be based off. This word called Played. Ah, played. You are gonna need to know this. I remember being tested on what ACL aid was and what the different types of groups inside of Fila genies were. And the Clague is going to be a group of organisms based on a common ancestor and its descendants, so ACL aid is the ancestor and all of the organisms that evolved from that ancestor. And that is going to be a group. A particular group that you confined within a file, a genie. So, for example, this biology that we have done here, let's say that we're looking at this particular ancestor. Well, this would be a played because it has the ancestor and all of the different organisms that evolved from that ancestor. So that is a played Now there are going to be different types of groups that you confined within a file a genie. And I have seen it many times. Your professor might say, Look at this file a genie and which of these groups is para file, eh, Tik? And you're gonna have to know what that is. Okay, so let's talk about monofilament first, because it is pretty much the easiest to understand. And why is that? Well, it's pretty much the same thing as it played. A monofilament ick group of organisms inside of a file. A genie is the ancestral species and all of its descendants so realize that that is the same thing as it played. They're the exact same thing. A monofilament group and it played are going to be the same thing. Now how do you remember what monofilament means? I'm not sure if this helps everyone, but this usually helps me if I know what the words mean. If I know the basis of the words where the words come from, it usually helps me to remember them. So mono means what? Whenever you're thinking about numbers or you're thinking about groups, mono means Onley or alone. So mono means the Onley ancestor, and it's on Lee descendants. So on Lee, the ancestor and its descendants, so mono means Onley, ancestor and descendant. I'm not sure if that helps everyone, but it does help me. So Onley ancestor plus descendants, not anybody else. Nobody else could be in this group. It's a very closed off special group. You can on Lee be the ancestor or the descendants to be in this group. Nobody else is allowed in. It's like a special club, so that's going to be mono politic Now. There's also pair of politic, a pair of Pillette ick group inside of a file. A genie is going to be the ancestral species, and some but not all of the descendants. So some of the descendants have been left out. For whatever reason, maybe the scientists was only really interested in looking at a certain number of organisms. And those organisms make up a pair of fileting group because all of the descendants were not included. So what does Pere mean? Pera is going to mean near so Pera means near or close to. So it's nearly complete. The group is nearly complete, but not all of the organisms not all of the descendants are within this group. This is why this group is para file a tick and not monofilament IQ. Now which of the groups are going to be para file etiquette? Well, a great example of a para fi led a group is going to be this blue one soap era biologic. And that is because you can see that the common ancestor is down here. And here's a descendant. So lemmerz air A descendant, um lorises, air descendant of that ancestor Tar Sears are a descendant of the ancestor. But all of these guys are descendants as well, but they were not included in this blue group. So this blue group is para file, eh? Tik? Okay, so that is a great example of a parafoil ethic group. Now, I didn't go over it, but just realized that this yellow group is mono file A tick, right? Or a played. Okay. And why is that? Because see that this is the common ancestor, and every single one of its descendants is included in this yellow group. So this is a great example of ACL aid or a monofilament ick group, an ancestor and its descendants. And that's all nobody else on Lee, the ancestor and the descendants, while the para fi led a group is the ancestor and nearly all of the descendants, but not all of them. Okay. All right. So now the last one that we have is not super commonly used, but I have seen it before. Monopolistic and para file, Eric or definitely the mawr important wants to know. But your professor might want you to know Pol if I let it. But it's not as common. Polypill, eh Tik is going to include variously distant related species, but not their common ancestor. So basically what you can think of this as is What does Polly mean? Polly is the opposite of mono. Mono means one or Onley. One Polly means many. So basically, this is going to be many different organisms that aren't really related to each other. So many different organisms, but their ancestor is not included. So a great example of polypill etiquette is going to be right here. Polly, by letting so you can see that the lorises and the tar Sears do have a common in ancestor way back here. But it's not included in the Red Group. The only thing that is included, or the Loris is, and the Tarsus years, which does not include their common ancestor. So this includes distantly related species, because Lorises Antar Sears are pretty distantly related, but not their common ancestor. So basically, polypill Eric means many different organisms without the common ancestor. But again, like I said, polypill, Eric isn't used as often. So you probably don't have to know that one definitely no played monofilament and para file letting those are very important. Okay. All right, so now let's go down, and we're gonna talk about another. We're going to reference another file. A genie. Sorry about that. Okay, So we're going to talk about an out group. What is an out group? Well, an out group is going to be something you use when you are studying the evolutionary relationships between organisms and you need something to compare it to. An out group is going to be a monofilament group. Remember what that means, the ancestor and all of its descendants, and it's going to serve as a reference point for the groups being studied. So the opposite of the out group is the in group, and the in group is going to be your group of interest. Whatever you are studying, maybe you study frogs and your out group is going to be, I don't know, some sort of fish. Okay, so you have an in group that's going to be the one that you are particularly interested in, the one you are studying the evolutionary relationships off, and then you're gonna have an out group which is gonna be a modified leading group of organisms that aren't really related, maybe very distantly related to your group of interest, and you're going to use that group as a reference point. Now we're going to talk about two other things that you can see or you confined inside of file a genetic trees and that's going to be a sin. Apa, morphy and a side sim ply Zo Morphy both very difficult to say. Okay, so a sin apa morphy is going to be a trait shared by taxi and their most common ancestor. This is commonly called a derived treat or a shared drived trait, and this is going to be found in an ancestor and all of its descendants, but not the previous ancestor. So this is going to be basically a trait that evolved within a group. So, for example, let's say if we're looking at, we're looking at the dinosaurs right here. And let's say that the ancestor of the dinosaurs had bird hipped or it had bird hips, which sounds funny, but they reference it right here. So let's say it has bird like hips. The original ancestor of all of the dinosaurs had bird like hips, but then you can see as we go up, lizard like hips evolved. So lizard, I'm sorry I'm in the way. I should probably get out of the picture so you can see so lizard hips evolved over time in the groups of dinosaurs and it evolved in this particular ancestor and all of these species ended up getting lizard hips. So all of these species have lizard like hips and so did their common ancestor, but not the previous ancestor. The previous ancestor did not have that characteristic. So that's going to be a sin. Apa morphy A trait shared by taxi and their most common ancestor, which we can see right here. So we have this common ancestor has lizard hips and all of these ants. All of these descendants have those lizard hips, But this is not shared by the previous ancestor, which is down here. Okay, that is a sin. Apa Morphey Now the simples a more fees are a little bit different. Sim plies a more fees are going to be ancestral traits that are going to be shared by the ancestor and at least two or more of the descendant Taxila. So I'm going to write by two tax or more. Okay, so at least two descendant Taxila now simply Isa Morphy. I want you to know that it's also simply called applies. Oh, Morphey. They both mean the same thing. It just depends on which your professor prefers, applies a more fee or simply is a morphy. They are the same thing. And that is an ancestral trait shared by two or more. Descendant tax. Um So what would that be So like? We said, if the ancestor of the dinosaurs way down here had bird hips and these descendants did not have bird hips, they do not have a simples a morphy. But notice that along this line all of these descendants have bird like hips, which you can see right here they have bird hips. So there are at least two different tax A here that share a traits with their ancestor. Not all of them. Dio This group does not share that particular trait. They do not have bird like hips, but some more than two off. The descendants of the original dinosaur have birdlike hips and work saying that the original dinosaur did have birdlike hips. So this is a simples, a morphine or simply applies a morphy where the ancestral trait from the original ancestor, which is down here, is shared by two or more of its descendant tax A. But not all off its descendant, Taxila. I know that could be kind of confusing. Hopefully, that wasn't too bad. Now I just realized that I did not give you an example of an out group. So let me show you an example of an out group. Okay, so let's say that we were studying are dinosaurs. So are dinosaurs air going to include all of these guys right here? So we have all of these organisms under dinosaurs and say we were studying dinosaurs. What would be our out group for our in group, which is the dinosaur group? Well, a good out group for our dinosaurs would be pterosaurs. Why? Because it's monofilament IQ. Remember? It's one ancestor and all of its descendants. So somewhere up here, we're gonna have an ancestor, and it's going to be the pterosaurs are gonna be a great out group. And scientists might use pterosaurs for comparison for different evolutionary traits with dinosaurs. So that would be a great out group. Now, what if we wanted to study all of the what? I'm not sure how you say this. Ornithology. Dorian's? What if we wanted to study all the ornithology Koreans? Well, that's going to include the dinosaurs and the pterosaurs right. So that means that are out group would be crocks and their relatives. So we would use crocks and their relatives as a out group for the study of the ornithology. Dorian's. I believe that is the correct way to say that. So I hope that was helpful. Just remember that the really important things from this particular lesson are going to be what ACL aid is, What a modify, let it group and what a para fi letting group are inside of a file a genie and how to recognize those different areas or those different groups of organisms inside of a file a genie and be able to identify what a sin APA morphy is. I think knowing what a sin Apple Morpheus is more important than knowing what a Simplicio Morpheus. But again, it depends on what your professor wants. Okay, everyone, let's go on to our next topic