 I have an example for you. This is an actual, this is what an actual tree will look like in your world, like an actual evolutionary tree. This is what they look like. Actually, I say that and then now I'm going, well actually there's a whole bunch of different ways that they can look and you can interpret all of them because you're just going to look for the nodes to determine who's most closely related to whom. But let's take a look at this thing and sort of analyze what it's actually telling us. I think that it's super easy to be, it's like a puzzle. And so your job is to parse through the information that you're given and try and figure out relationships and ancestry given just what you're given here. Remember that this was the whole time thing, I don't know how you want to say this, is does time go up? Like more time at the top? You'll notice that we have, let's see, five critters on this tree. Totally could have gone out and gotten you some pictures of these critters so you could actually see them. You could ask you nine million questions about this cladogram. For example, I could say, okay, who is most closely related to the moss? Who's most closely related to that moss? Push pause and go in and say, see if you can figure out who's most closely related to that guy. And then now that you push pause and you figured it out, I'm going to tell you you're right because you're going to trace back the moss and you're going to see, oh, D is a common ancestor that gave rise to the moss and oh, D is a common ancestor that also gave rise to the pine. So the most recent common ancestor of the moss and the pine is ancestor D. That's super easy. Can I give you a harder one? You know I can, you know you like the challenge. What about red algae and green algae? Who is the most recent common ancestor of the red algae and the green algae? Well, we got to do exactly the same thing. We're going to have to roll through, we're going to take red algae and find out where its ancestor is. We have an ancestor at B. That doesn't really mean anything. It just means that we have an ancestor at B. I'm missing a whole part of my palette which is really finding it quite irritating. But let's go ahead and trace back green algae. Green algae has an ancestor at C. Is that a shared ancestor with red algae? Not, not, not. The most recent common ancestor between green algae and red algae is B. Do you totally agree with that? Okay, are you ready for this one? Who is more closely related? Moss and pine or red algae and green algae? Now, if you just listen to that question, mosses and pines, are you kidding me? They're not even like, how could, they're both plants, awesome, but they can't be related to each other. Red algae, green algae, they're both algaes. Those are totally more closely related. Look, who of these ancestors is most recent? B is an ancestor, but look how far along ago it happened. That was way heckin' long ago. D is the most recent common, the most recent, recent common ancestor which means moss and pines shared a more recent common ancestor than red algae and green algae even though they share the same name. Similar to birds and dinosaurs, really? Like, birds and dinosaurs, actually birds are dinosaurs. Let's say birds and reptiles. Birds actually are reptiles and share recent common ancestors with snakes and lizards and alligators and all those reptiles, a more recent common ancestor there than they would share to like mammals. Isn't that weird? I love that so much. Okay, I feel like there were more questions that I needed to ask you. I could give you, here would be another extension on this problem, I could give you a trait. I could give you several traits. Okay, look, I'm gonna give you trait number one, trait number two, I'm gonna give you trait number three, guess what, I'm gonna give you trait number four and then because I really love you, I'm gonna give you trait number five and then I can ask you things like, okay, what traits do green algae have? Okay, look, I want to know green algae, what traits do they have? Numbers. Do they have trait number one, green algae? No, they don't have that trait. That trait happened over here. Do they have trait number two? Now, yeah, do they have trait number three? They totally have trait number three. Do they have trait number four? They totally have trait number four. Do they have trait number five? They totally have trait number five. Green algae have five, four and three. Those are the traits that they have. Mosses have trait one, two, three, four and five. Pines have traits two, three, four and five. Do you see how, like the traits that we throw on there show us how related things are? Everybody has trait number five, everybody on our cladogram has trait number five, whatever it is, we will do cladograms for specific critter kinds because we want to, we want to learn about the algae and we want to learn about the moss and the pine and so we actually are going to use these cladograms to help us learn about the critter and the diversity of the critter. But just given a cladogram, you can actually know a lot about those critters when they're looking at this thing. All right, you know we're going to do a ton of these in class. So if you're feeling a little bit like, uh, we'll have lots of practice. Now, was the whole topic of this lecture evolution and how, I mean, we haven't even mentioned evolution hardly at all. So let's go ahead and define the concept of evolution and then we're going to do a quick little summary and talk about our lab.