Dispersion is the distribution of individuals in a population throughout an area. We're going to look at 3 types of dispersion here. The first is random. And in random dispersion, the position of one individual is independent from another in the population. Usually, this is due to random factors like wind dispersals. So if you can imagine a dandelion blowing its seeds off into the wind, you might end up with a dispersion of those seeds like you see here, totally random. Now, clumped is going to be when the organisms group together, and usually, this is due to social factors. And you can see here we have these groups of organisms clumping together in the population. The last type we're going to look at is uniform. And in uniform dispersion, the individuals are more or less evenly spaced throughout the area. It's not going to be, you know, as perfect as this image here, but they're more or less evenly spaced, and it's usually due to competition for resources. In fact, you can especially see this if the animals rather express territoriality. So they have a territory, this bounded space that they're going to defend. So if each of these organisms is defending its territory then, you know, they're going to have a distribution that spaces them out because they're going to have to, you know, make sure their territories don't overlap, for example. Now one way that population ecologists estimate population size, because as you can imagine it's impractical and kind of impossible to just go and try to count every single organism. So one of the methods they use is the mark-recapture method. And basically, what you do is you capture some organisms, and you mark them, like you can see with this snail here, and then these marked organisms will be released into the wild again. Ecologists will later capture another group from the population, and they'll look at the recaptured group for marked organisms. And usually they'll iterate this a few times, so you can see here's, like, the initial batch of organisms they catch, and here's the or I should write recapture here. Right? Because they've recaptured a few. And, you know, they'll usually iterate this a few times and then use statistical models to estimate population size. You guys don't need to worry about the math, just the general idea of capturing a group of organisms, marking them, and then capturing new groups, and seeing how many in the new group are marked. With that, let's go ahead and flip the page.