hi in this lesson will be talking about community ecology and the interactions in communities. Now a community is all the populations of different organisms that live in the same area, and these different species in a community are going to interact with one another. We call this inter specific interactions, and these interactions can be beneficial or harmful to the survival and reproduction of the organisms involved. Now, this idea of being beneficial for survival and reproduction gets at the idea of fitness, which is the ability of an organism to survive and reproduce compared to the average member of their population. Because these interactions affect fitness and because fitness is a strong driver of evolution, we're going to see co evolution where species influence each others and evolution due to the either harmful or beneficial interactions they have. So a common example is something like this bird which can feed on these flowers because it's Bill has evolved to be, you know, just the right shape to get in there. And you know the bird is gonna get food. The flower is going to get to use. The bird is a pollinator, pretty common example. But the point I want to make to you guys is that this goes beyond, you know, making two parts that fit together. Look at this interaction. Rabbits air fast, right? Rabbits aren't fast just because it's fun to be fast or their fans of the flash there fast because there are predators hunting them. They need to be fast to get away. So I want you to think about the evolution that takes place. Due to these interactions, almost is like an evolutionary arms race between these organisms in the battle for survival. Let's actually take a look at the different types of interactions. First one I wanna look at is called Commence Soliz, Um, and this is an interaction where one organism benefits and the other is just unaffected. So here you can see an example of that. These fish hang around the shark, basically waiting for some scraps to come their way. It's a good way to get a free meal, and you know, the shark is basically unaffected. They're just kind of freeloaders, but he's going to get his meal anyways. Now it's worth noting that, as with everything in biology, you know, these aren't super well defined boundaries so to speak. I mean, we call this relationship between the shark and these fish. Commence Soliz. Um but it's not uncommon to see a shark eat one of the fish that's trailing it happens regularly. So, you know, commence Soliz. Um yes, but just know that there's always exceptions. So the next type of interaction I wanna look at his competition. This is negative for both of the organisms involved. This is when individuals compete for the same resource is and it's not gonna work out well for either of them. And here you can see an example of that where two males are competing for mates and you know, this could result in a fatal injury, for example, or something like that. At worst, it's going to mean one of them doesn't get to mate. I'm sorry at best. It's gonna mean one of them doesn't get to make. At worst, one of them could tie, um, the next interaction. I wanna talk about our type of interaction on Talk About is positive for one organism and negative for the other. And this is like what we saw going on with the hair and links right? That was an example of predation. But you can also have herbivorous, which you see here, which is good for the cow. Not so good for the plant. It's eating and parasitism, which will talk more about later. Now. Lastly, you have mutual is, um which is positive for both organisms. And you can see an example of that here between these clownfish and see an enemy. Hi, Nemo. All right, let's flip the page.