Three-spine sticklebacks are small fish that originated in the oc...

Question

Three-spine sticklebacks are small fish that originated in the ocean and continue to exist there, but then some took up residence in hundreds of streams and freshwater lakes in the Northern Hemisphere. Predict whether you would expect to find different species in lakes today.

Accepted Answer

Hi everyone, here's our next problem. It says a single ancestral species can diverge into two species in the same geographical region. This type of evolution is referred to as So we have single species in the same geographical regions, so no geographical barriers blocking them from each other preventing genetic exchange. But they end up diverging into two different species. Perhaps they develop adaptations to take advantage of different food sources and originally they were part of one species, but they end up becoming different enough that they no longer interbreed. So speciation the same geographical area with geographical barriers. Playing no part is called sim Patrick speciation. We see that's Choice B here, so that's our correct term, but we'll just look at the other choices. Choice A is alot Patrick speciation that is when you have geographical barriers causing speciation. So you now have an ancestral species that got separated by being on two different islands or having a large mountain range between them and the barriers prevent them from exchanging genetic material and eventually they diverge into different species. So that's not our answer here. Since we're looking at the same geographical area, choice E. Is para patrick speciation. This is when a species is spread out over a large geographical area but only reproducing within the local area. So maybe you have a certain kind of grass spread out over a very large geographical area, but it's only reproducing with grasses immediately around it and maybe due to differences in conditions um in the in this large area, the original same species begins to diverge due to different habitats even though it was originally all able to interchange material. But this large spread and reproduction only within the local area, ends up driving speciation. So that's not our answer again. Because they're in what we were looking at is same geographical region and choice D convergent evolution. That's when you have similar structures evolving without dissent from a common ancestor. So due to similar environmental pressures, similar selection pressures, you've got similar structures that evolve um even though that structure isn't due to descent from a common ancestor species. Um but not what we're looking at here. So not our answer. So the type of evolution where you have a single ancestral species that can diverge into two species and the same geographical region is Type B. Sim. Patrick speciation. Thanks for watching See you in the next video.

Three-spine sticklebacks are small fish that originated in the ocean and continue to exist there, but then some took up residence in hundreds of streams and freshwater lakes in the Northern Hemisphere. Predict whether you would expect to find different species in lakes today.

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