Sympatric Speciation and Hybrid Zones

by Jason Amores Sumpter
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Unlike Allah Patrick speciation in Sim Patrick speciation. The population that divides into multiple species actually lives in the same geographic area. Sim Patrick means same country in Greek, and this can occur due to disruptive selection, which favors those extreme FINA types like we saw before. And once we have disruptive selection with those extreme FINA types favored, those FINA types can continue to diverge, get more and more different from each other and eventually become two different species. Now you can also have Sim Patrick speciation due to something called Polly Ploy T, which is when a biotic or my ta tick error leads to the doubling of chromosome number. Now this tends to be fatal for organisms like you and I, but for plants, it's actually not that harmful. And this has led to some major evolutionary leaps in plants. You can have what's called auto polyp Lloyd E, which is that when that mutation resulting the doubling of chromosomes comes from the same species, so you have two sets of chromosomes from one species. You can also have a low poly ploy T, which is when parents from two different species mate and produce an offspring with two sets of chromosomes from both species, So this is generally seen in plants. And we can say that here, in our example here, in our example, perhaps what's happening is a form of disruptive selection or polyp loyalty. Either way, this population of trees is in the same location. However, speciation still occurs now. Generally, when speciation happens, you tend to see something called reinforcement, which is natural selection for traits that isolate a population or essentially reinforce those barriers between species. However, sometimes you will see the formation of what's called a hybrid zone, which is a geographic region. Were interspecies. Breeding occurs and hybrids are common, and we have these all over the world for various different species. What's interesting is from hybridization. New species will sometimes arise because in hybrid zones you'll tend to see three things happen. You'll either see reinforcement like we talked about and in reinforcement, the hybrids. These guys right here, this that's what be kind of bluish purple color is supposed to represent. These hybrids are less significantly less fit than the pure bred species and the pure bred species. The pure bred species continues to diverge, so we see one offshoot going this way. One going that way. So they're going to continue to diverge, which is going to reinforce those barriers. Those differences between them. Occasionally, though, you will have a fusion, which is where those two separate species actually merge into a single one. And that's when those hybrids these guys right here. Those hybrids tend to be very fit. Lastly, you can have a sort of stability situation. So here we just have a stabilizing Oops. Stabilization. And here what's gonna happen is the hybrids will continue to be present. The two species will continue to be present, but they won't continue to diverge from each other. Everyone is going to just kind of chug along businesses usual. No reinforcement, no fusion, just a stable situation. So that's all I have for this video. Guys. I'll see you next time