What are considered significant factors in maintaining the surprisingly high levels of genetic variation in natural populations?

Video transcript

Hi, everybody. Let's look at our next problem. All of the following are factors that contribute to maintaining high levels of genetic variation in natural populations. Except so let's recall that we're going to look for the answer that does not contribute to maintaining those high levels of genetic variation in natural populations. When we look over our answer choices, we see they are a mutation. B gene flow, see genetic drift and D gene therapy. Well, here's where we want to zoom in on that phrase, natural populations because we can pick out right away that our answer choice would be choice. D gene therapy as that's not going to be part of genetic variation in a natural population. This is obviously something human mediated in which humans alter the genome of an attempt to prevent disease or mitigate the effects of a disease. So, gene therapy right away is going to be our answer. But let's just go through other answer. Choices to be thorough choice. A mutation obviously changes to D N A whether arising spontaneously or through some sort of external force like UV radiation. And this is probably this is the means by which we have genetic variation because the DNA changes and those changes get affected by the natural environment, they might be selected for or against in a population as they might give greater or lesser fitness to the organisms that carry those mutations. So it definitely is a factor that contributes to maintaining genetic variation. So not our answer choice and gene flow is the movement of genes from one population to another. This can happen through migration from one place to another or hybridization, interbreeding of two different species or two different varieties. And this obviously does contribute to genetic variation. It can introduce new alleles into a population. So not our answer choice. And then finally, genetic drift, which is the random fluctuation of allele frequencies due to chance, not natural selection, but something like a group population that moves from one area to another just happens to have a higher representation of certain that's rather rare in the larger population or we have um higher numbers of a certain survive or are killed in some sort of plague or natural disaster. So, fluctuations and a low frequencies due to chance and this does maintain high levels of genetic variations in large populations. We often think of it in small populations where it can cause a loss of genetic variation. So if you have a smaller group that breaks off and it has a smaller representation of certain alley that you can lose genetic variation, but in large populations, it can contribute to genetic diversity since it might result in the prevalence of multiple alleles that might otherwise get selected against by natural selection. Perhaps just by chance, certain alleles continue to coexist in the population. So since that can contribute to levels of genetic variation, that's also another answer. So again, all of the following are factors that contribute to maintaining high levels of genetic variation and natural populations except choice D gene therapy. In the next video.