Write a short essay describing the roles of mutation, migration, and selection in bringing about speciation.

Question

Accepted Answer

Hi, everyone. Let's look at our next problem. It says the primary way in which mutation contributes to speciation is by. So let's look at our answer choices, considering this wording the primary way. So some of these may be ways in which mutation can contribute to speciation. But we want to focus in on the one that is the most important. So choice A says increasing genetic diversity within a population. Well, mutation increases genetic diversity since it introduces new variations, new alleles by changing DNA. Um but just having genetic diversity um does not necessarily contribute to speciation. You can keep on having multiple alleles that can coexist without forming a new species. So this wouldn't be a primary way of mutation contribute to speciation. So choice B says causing reproductive isolation between populations. Well, this is kind of again, this is a little bit of a nebulous question since we're looking at primary way. So I'm going to mark this as a really promising answer for the primary way, but I won't select it just yet just so we can look at our other answer choices and evaluate them. But mutation can cause reproductive isolation between populations if the populations become separated from each other, they've had mutations that continue to cause more and more change to the two populations that can end up resulting in a situation where they are incapable of mating with each other and producing fertile offspring, which is the definition of separate species. So this would definitely the mutations developed the point that the two populations can no longer exchange genes that will definitely be a main method of speciation. So now let's look at choice. C choice C says preventing gene flow between populations. Well, again, mutation is not going to be the cause of preventing the gene flow. Uh Mutations can arise and still be exchanged. Uh mutations that result in multiple alley als that can exist in a population, but they don't by themselves prevent gene flow. So gene flow would be prevented maybe by physical distance between two populations. And eventually, if the two populations diverge enough that they can no longer mate, well, then gene flow is prevented. But that's not the primary way that mutations contribute to speciation. Usually the gene flow prevention occurs from some other cause. So we're gonna cross that one out. And then choice D says increasing the fitness of individuals with the population within a population. Well, this is definitely a result of mutation can be a result of mutation. The mutation contributes an advantage um allowing the individual to more likely to survive and reproduce. It can increase the fitness of individuals. But that doesn't necessarily cause speciation. It can cause one a little to out compete another where you'd lose an ally will um that causes an individual be less fit in your population. But again, it doesn't necessarily cause speciation, the development of two different separate species. So that's not our best answer there. So we'll circle back to this choice, be causing reproductive isolation between populations. So once our populations are reproductively isolated, even if they no longer have a physical barrier between them, um they will eventually develop me more and more mutations over time, they will change further and further. Um And they will be essentially different species. See you in the next video.

Write a short essay describing the roles of mutation, migration, and selection in bringing about speciation.

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Key Concepts

Mutation

Migration (Gene Flow)

Natural Selection