 Hello there, all you bio rock stars. So we're here today to start the first lecture on our last entire unit in this course. We're going to spend the next six lectures talking about biodiversity, really, but also about the process that leads to biodiversity. Before we go there, it's really important to remind ourselves of where we've been, because honestly, we have spent a great deal of time, like 18 lectures. We've spent in a really small place. We've been looking at molecules. We've been looking at cells. We've been looking at different kinds of cells and the organelles that they have inside of them. We've looked at how cells make energy, how cells make babies, how cells are used to make baby critters, how you can look at the genetic information in a cell and figure out what those little baby critters are going to look like, and ultimately why we'd even bother making baby critters in the first place. All of it leads up to our conversation about the incredible biodiversity around us and where it came from, how do we get here? It's pretty fantastic and it's a really lovely way to tie up the pieces in the class. Our overview topic is evolution. Evolution is a process. We will spend today sort of trying to define it, but in the next couple lectures, we're going to spend more time looking at the mechanisms of evolution, what is it and how does it actually work. But before we do that, I want to just tempt you a little bit with thinking about biodiversity. Biodiversity is seriously like the coolest part of biology because critters, I mean, you guys know me by now. You know me well enough to know that I pretty much get excited about a whole lot of stuff, but I get so excited when I think about or look at all the different kinds of critters out there. And I have a really fast, fast, really fast, I promise, slideshow of animal diversity and it's actually like barely even, I mean, can it even really count as an animal slideshow? Because the fact is that my pictures that I'm going to show you are just a tiny little sliver. And I'm going to show you pictures of animal diversity, but don't forget that in the entire span of all the critters on the planet, animals are just one little branch and really they're like a really, really little branch. Check it out. You know this already. We know that we know about eukaryotes and we've looked at lots of different kinds of eukaryotes. We know about the two kinds of prokaryotes. We have archaeans and bacteria and these two groups of prokaryotes have incredible diversity of critters in them. They're just not quite as warm and fuzzy as the eukaryotes. We know eukaryotes have nuclei. We're going to do a slideshow of animal diversity. Look at this, tiny little circle, one tiny little branch of this gigantic tree of eukaryotes that is animals. And we're going to get to talk about animals in detail. We're also going to talk about plants in detail. We're also going to talk about fungi and protists and bacteria and archaea in some detail after we discuss the concept of evolution. But this tree shows you kind of how they're all related to each other. And you can see right about here there's a root to this tree, which means somewhere back along the line all these different groups arose from one root. So, okay, seriously. Some of these you might look at them and be like, mm-mm, that's not an animal. And if you didn't slice this thing open and look at it cells, you might believe that. Here's a sponge. It is the most primitive animal in our slideshow here. Here's another type of sponge. It's an ocean critter, jellyfish, total animals. Look at the diversity of this. Here's another jellyish thing. Here's a flatworm. Dude, these things are awesome. A whole bunch of flatworms are actually parasites. Oh, so you know I love them. What is that thing? I have no idea, but it's a critter. It's an animal. Four ocean critters. Some sort of clam-like, look at that thing. I mean, these are beautiful ocean. Don't you want to cuddle this little cuddlefish? And it's related to this little segmented worm from the ocean. Yeah, don't mess with that thing. Here's some more little segmented worms from the ocean. This thing, are you kidding me? Like, if anyone ever finds that in a tide pooling adventure, you got to let me know because I'd love to be checking that thing out. My little favorite animal buddies. These are the moss piglets or the water bears. They're microscopic critters. These are the ones that I told you about at the beginning of the semester that you can actually freeze them or try to freeze them down to absolute zero and then thaw them out and they come back. Aren't they cute? You got some crabs. You got some millipedes. Like, look at the different kinds of critters and all of these things are animals. So we're going to learn about all the things, like the characteristics that all of these guys have in common that make them actually qualified as animals. We're probably a little more familiar with the vertebrates. All those things before this were invertebrates, but here are vertebrates. And in spite of the incredible diversity, seriously, like these things are fantastic, in spite of that diversity, they have a lot in common. All of them have a vertebral column. All of them have a spinal cord running down the middle. All of them have characteristics also in common with all like the sponges, which is why they are all classified as animals. Dude, this, oh, I could tell you a story about every single critter here, but I have to tell you about this one. This guy, little turtle man, has seen that little white thing in his mouth. Yeah, that's not like he forgot to brush his teeth. He has a little like tongue lure in his mouth, and he sits in the water and he opens up his mouth and he sticks out his tongue lure. What? And then a fish is like, I feel like eating that little worm thing that's sitting down there. I'm going to go and guess what happens. This is the master fisherman. This guy yum-shellizes the fish that came down to eat the little worm thing. Incredibly effective strategy. So if you see that little worm thing, don't go sticking your fingers in that hole. Snakes, of course, birds, reptiles and birds. Let's start talking about that fun stuff. That's actually super interesting, the relationship between them. Birds are like, I had to put 8,000 pictures of birds in here because look at these things. I mean, they're shocking. What's that? It's not a bird anymore. It's a pangolin. It's a mammal. And that thing and a kidnap? Are you kidding me? That thing's incredible. I don't know if I want to cuddle that thing, but send it out to the ant hill and it can do some damage. And this is my favorite guy of all, the platypus. Dude, when the platypus was first discovered by Europeans, they killed it, of course, because that's what we do with things that we are interested in studying. So they killed the platypus and they stuffed it so that they could study it at a later date and they sent a stuffed platypus home to all their home dogs in England. And the home dogs in England opened up the box and they're like, who played the joke on us? There's no such thing as a duck beaver thing. And the people who found it are like, no, seriously, it's real till we killed it, which makes perfect sense. Gotta have an elephant in the slideshow, some little cutie patooties, and that's kind of still cutie patootie. Don't get too close or it'll spit on you. That thing, I'm not sure how cutie patootie that is, but it's still a mammal. And this one's a little tiny little antelope. And that is a little bit scary, but I think that's a jackal. The fox having a little song and a red panda go to the Eureka Zoo and you can visit one of those. Yeah, and animals gotta eat each other too. You gotta, you know, we all gotta eat. That thing that looks like you probably shouldn't piss it off. That one, you can totally cuddle with it and cuddle with that and cuddle with that. I'm ready to cuddle with all these guys. We'll stop right there. Think about everything that we looked at. And one of the main components of our next set of lectures is the fact that we can actually, I can put a label on that slideshow and say we're gonna look at a bunch of animals. And you, with the exception of maybe some of those sea critters, you actually could point them out. You know what an animal is. And we're gonna start talking about how do we know? What makes something an animal? And why do all animals have traits in common that, say, plants don't have? Like, why is that? It has to do with relatedness. And so that's what we're gonna talk about in the next little section. Okay, I'll be right back.