 Ancestry is a concept that we're familiar with, and so I'm going to risk a pretty huge misconception. Evolution does not happen in a generation between a parent and a child. Evolution happens at the population level of organization, and we're totally going to talk about that in way more detail. I'm going to use, we're going to make evolutionary trees, and the trees are illustrations of ancestry and relatedness. And to get comfortable with the concept of the evolutionary tree, I am going to make a family tree, knowing that you guys are paying close enough attention to not make the huge misconception that our family tree that I'm about to draw you is actually the same thing as an evolutionary tree. I'm making an analogy right now. What? Me? Analogies? I'm making an analogy right now, and you know what else I'm going to do? I'm going to do something epic. I'm going to start my picture on the left side, and I want you to know that I do not want to. It's a little challenging for me. I'm going to start the picture with the most recent people in my world, which are my kids. So we're going to have a little box for Kenan and a little box for Kai. These are my small humans. And I'm putting them in boxes. I'm putting them up at the top of my tree. And what I'm going to show you is that they actually are related to each other. Now, am I drawing a pedigree right now? Heck, no. I'm not drawing a pedigree, so do not be confused. This is an evolutionary tree. But on my tree, Kenan and Kai are my most like the babies out there, and they share a common ancestor. And guess who that is? Oh, you know I got to have me on the tree. I, ancestors of groups, if we're talking about like building a visual, a tree like this, ancestors are represented by dots, by little nodes, and critters or people who are living and in existence are all up at the top. My analogy breaks down because ancestors usually are not alive if you give rise to two different groups of critters, but we can talk about that in the next one. Do I have an ancestor? Like where did I come from? Aw, don't you want to know? No, never mind. I changed my mind. Don't ask that question. But I'm going to tell you this. I came from my mom, and she's right there and her name is Honey Kiss. Honey Kiss gets to be her own node because she's an ancestor, and guess what? Am I the only person that she gave rise to? No, no, no, no. This is my brother, and we call him Wiggy. And so Wiggy has to be on the tree as well. Now, Wiggy has given rise to multiple small humans. He's given rise to Otis. Aw, this makes me want to go hang out with these clowns. He gave rise to Quiny Pie, and he gave rise to the bird dog, Birdie. It makes me want to go visit them. Did Honey Kiss have an ancestor? Oh, you know she had an ancestor. She had an ancestor. This is my grandma. My grandma's name was Honey. Just plain old Honey, not Honey Kiss. And she actually gave rise to my auntie. Are you following this? And my auntie is, we'll call her Auntie. And auntie actually gave rise to two people, Molly and Katie. And Katie actually gave rise just to Stella, and Molly gave rise to Grace and Emma. You now have all the cute humans in my family tree. Aw, just from my mother's side. We just drew a tree. Now, the ancestors, like I said, they usually aren't alive anymore. And in fact, if you looked at this tree, who's the oldest person on the tree? My honey, and my honey isn't alive anymore. So the farther down you go, like if we mapped her mom and her siblings, then we would have even farther back in the tree longer ago ancestors, and they're not around anymore. But my honey kids, I mean my mom and my auntie, they're still here, and all these clowns are still here, and those crazy goofies are definitely still here. And so this is an example of how we can map relatedness. Now, do you agree that Keenan and Kai probably share characteristics with me that make them really related to each other? Or characteristics that maybe they don't have with Uncle Wiggy? And in fact, do you agree that probably Uncle Wiggy has some characteristics that are shared by Otis, Quinn, and Birdie that maybe we do not have? But do you agree that a honey kiss probably hooked us up with some characteristics that all of us have? And my honey probably hooked us up with characteristics that everybody has. Do you see this? So you can look at your most recent common ancestor. I have to write that down. So you can look for a most recent common ancestor that can determine relatedness. And do you agree that Keenan and Kai, their most recent common ancestor is me? But what if we were to say, you know what, we're going to go, we're not messing around with Keenan and Kai, they're cute and everything, but let's? Who is Otis and Kai's most recent common ancestor? Do you agree that it's not me? I'm not even an ancestor of Otis. I'm related to him, but I'm not an ancestor. The most recent common ancestor shared? Not me, honey kiss. And look, Otis, Uncle Wiggy, is not shared by Keenan and me, Kai and Otis. But honey kiss is, both of them go through, have honey kiss as their ancestor. So Kai and Otis share a most recent common ancestor in my mom. Now think about, okay, ready, take a deep breath. Think about Kai. Okay, I'm going to have to go like, you know I got to get pink, I don't even know how I get over there. I'm having issues with my, seriously? Okay, pink is not an option. We'll have to go with orange. We'll deal with orange. What about Stella and Keenan? Let's throw Stella and Keenan into this mix and see who is their most recent common ancestor? Is it me? I'm not Stella's recent common, I'm not Stella's ancestor at all. It's not Katie, it's not my auntie. It's my honey, look. As I record videos late at night and think about my family tree, I get all warm and fuzzy and it makes it better that it's late at night. Okay, you ready for something else on these trees? Because we're not going to build family trees, although it probably would be helpful for you to sit down and like build one and like bring a couple of things to reality. But look, I want to show you, usually in an evolutionary tree, the people in boxes at the top, I don't know why I'm putting stars everywhere because now we have stars everywhere, but the people across the top, so I'll put a box around all the people that have boxes around them, across the top. Usually the top of the tree indicates critters that are alive, like these are critters that you could go out and find. Usually the critters toward the bottom, like ancestors actually aren't alive anymore and only living things like are up at the top. You can also learn about time from an evolutionary tree. Usually we have the vertical axis on an evolutionary tree is actually representing time, like the passage of time. So you can imagine that Honey Kiss giving rise to me and Wiggy is an event that happened longer ago than me giving rise to Keenan and Kai. Do you follow that? Perhaps this analogy is a little too outside of what we're actually going to be talking about because what we're actually going to be talking about is species of critters. So let's do one with some species and really get in those tree thinking concepts.