 Okay, so I pulled four critters from the last slide show. And we already know, like every critter that we looked at in that slide show was an animal. So we already know if we had to like sort these animals into groups, we know that all of them, oh, if we had to compare and contrast these critters, our compare would be, dude, they're all animals. And we, even if we don't know how we know that or why that's true, we still have a really intuitive sense that, yeah, they are, like, look at them, yeah, they're all animals. Some of those ocean critters, we might question, like, is that really an animal? How do we know? We'll learn how we know that those things actually were animals. But I want you to think about what is it? Let's try to define what it is that actually lets us know when something is related to something else. First, let me ask you this question. Who's more closely related to whom in this drawing? Pictures, whoever, whatever that is. You've got four critters, and if you had to sort them into two groups of who's most closely related to each other in the group, did you know what I'm even saying? Nobody does. But I'm going to tell you what the answer is. Hopefully you look at this and you're like, Riggs, seriously, this next test is going to be very easy if these are the kinds of questions you're asking, because there are two birds, and the birds are more closely related to each other than they are to the gorilla and the panda. Who are more closely related to each other than they are to the birds? Does that work for you? So, but how did you know that? And let's list it out. You know that things are closely related when they actually have morphological similarities. What does that mean? Morphological, let's have a new color and say what morphological means. The morphology of something is like its form, like its structure. So morphological similarities are actually anatomical, or think about what we just did. Anatomical, like structural, like things you can see. What word would you apply to that? I'll tell you. I hope you yelled that loud. It's the phenotypic similarities. Does that work for you? So morphological similarities or anatomical similarities between critters means that they actually have phenotypic similarities. They actually share characteristics in their phenotypes, what they look like in common, which should lead you to the next one. Because if there are phenotypic similarities, then what causes those phenotypic similarities? Come on, please answer that question and let me know that the entire last, like 12 lectures, wasn't in vain. If they have phenotypic similarities, what creates the phenotype? Genotypes, genetic, that says genetic. They have genetic similarities. Which means, how are you going to define that? Let's go with the flow here, doggies. That means that they have genotype similarities. And do you agree with that? Like, think about how do you look like your mama and do you got a bunch of her DNA? And so if you have the DNA that made her phenotype, then you are going to look like her. You're going to have morphological similarities to things you're more closely related to. This, to me, the way that you look like people you're related to is super intuitive. Making the leap that that must mean that you also have genetic similarities, that's not a hard leap. That's not a big leap. That's not like leaping over an ocean or trying to jump over a creek or anything like that. It's kind of, yeah, that makes sense. Remember it. We're going to talk about what it, like, ancestry. Like, why your ancestors look like you. And we're going to think about it in kind of a visual sense. So we're going to build a little family tree and talk about relatedness and ancestors so that we can map this kind of stuff moving forward. Okay, I'll be right back for that.