Why are mutation and recombination important in the process of natural selection and the evolution of organisms?

Question

Accepted Answer

Hi and welcome back everybody. Our next question says, what is the primary source of new alleles within a population? A mutation? B natural selection, GC genetic drift or D recombination. So the key here is that we're asking for new alleles. So completely new genes we didn't have before, not changes in the frequency of the genes we have or the combination of genes we have. So the only source in this list that provides completely new genes is choice a mutation because that's an actual change to the DNA sequence. And these changes can occur as a result of errors in DNA replication, very different, various different types of them. And of course exposure to mutagens and they do introduce these novel genes into the population. Let's look at our other answer. Choices. Choice B natural selection, uh by which individuals with genes that contribute benefits to survival are more likely to survive and reproduce and pass those genes on. Of course, this over time in the process of evolution causes changes in the species, but it doesn't produce new genes. It just acts to cause certain genes to be more likely to be passed on to offspring So that's why choice B is not our correct answer. Try see genetic drift is a random process that can change the frequency of alleles in a population due to chance events. So the classic example of this is the bottleneck effect where you end up with something like a group, a population becomes isolated or a population moves to a new area and a certain allele has a higher prevalence in that small off group. So one person in a group of 100 has red hair where in the population they come from. One person in 10,000 has red hair. So suddenly your new population has a much higher frequency of that alley. But again, notice this is acting on alleles existing in the population. It is not a source of new alleles. So choice c incorrect and finally choice, the recombination. This occurs when you have crossing over during meiosis and you can end up with new combinations of genes that are different from the parents. But again, there's no new genes being introduced, the genes are just being combined in new ways. So that's why choice d isn't our answer. So once again, the primary source of new alleles within a population is choice a mutation. It's the only chance. It's the only answer. Choice here that involves completely new alleles. See you in the next video.

Why are mutation and recombination important in the process of natural selection and the evolution of organisms?

Verified Solution

Key Concepts

Mutation

Recombination

Natural Selection