Find solution
What is the difference between natural selection and genetic drift?

What is an important difference between natural selection and genetic drift?

  • a) natural selection always occurs at a much faster rate than genetic drift b) the requirement for a consistent difference in fitness between genotypes c) the requirement for genetic variation

  • Answer:

    The answer is b. By "consistent", I think they're trying to rule out the case where there may appear to be a short-term fitness difference between two genotypes, but that difference is so inconsistent, that neither has a long-term advantage over the other. E.g. if genotype A is better for some food sources available in summer, and genotype B is better for other food sources available in winter, then over the course of a year, there may be no net advantage. So if A or B increases in frequency in the population, that would be due to genetic drift, not natural selection. In any case, among the three choices, (b) best captures a conceptual difference between the two. Natural selection requires a fitness differences between genotypes. Genetic drift does not.

uc0nnh00... at Yahoo! Answers Visit the source

Was this solution helpful to you?

Other answers

While they are all wrong, it is a question of how wrong. Choice c can be eliminated instantly as both require variation. Choice b is wrong because you can go from no impact on fitness (drift) to a small impact to a great impact based on changing environmental conditions. If you struck the word consistent, it would be correct. By definition, if there is no difference in fitness among genotypes, changes in allele frequency are genetic drift. Choice a can be disproved by simulation. If you run a simulation of a small population with two alleles under conditions of low selective pressure and no selective pressure, drift will outpace selection periodically. The question is probably looking for b, but the best answer is to understand the material well enough to assert why all three answers are wrong.

novangelis

I don't like any of those. THE important difference is that genetic drift changes allele frequencies randomly or through events unrelated to fitness. Natural selection is not random. Rejecting all of them: a) Nope. Genetic drift can be pretty fast. A bottleneck event such as a forest fire can happen in one day. b) What the heck is a CONSISTENT difference? c) Both require genetic variation. You can't change allele frequencies in a population where there are no variants.

emucompboy

Related Q & A:

Just Added Q & A:

Find solution

For every problem there is a solution! Proved by Solucija.

  • Got an issue and looking for advice?

  • Ask Solucija to search every corner of the Web for help.

  • Get workable solutions and helpful tips in a moment.

Just ask Solucija about an issue you face and immediately get a list of ready solutions, answers and tips from other Internet users. We always provide the most suitable and complete answer to your question at the top, along with a few good alternatives below.