Question

For the four evolutionary processes below, indicate: how they affect allele and genotype frequencies within a population, whether or not these effects are random, and how they affect differentiation between populations. Number your answers as indicated in the table below to indicate which part of this question you are answering: Process Within-population allele & genotype frequencies Random?Y/N Genetic differences between populations #1 #9 Natural Selection Genetic Drift Mutation #6 #10 . #11 Migration between populations #4 #12

Answer 1

1.Within a population, the allele frequency changes due to natural selection. An allele that offers fitness or a greater chance of survival is selected. Therefore, the allele frequency and the genetic frequency of that allele is greatly increased.

2. Genetic drift is a process which affects the allele frequencies of a population due to chance. It results in random loss or gain of an allele. Therefore, it leads to random changes in allele and genetic frequency. Drift may even lead to fixation or loss of entire genotypes in organisms.

3. A mutation is a random change occurring in the DNA of an organism. It has a weak effect on allele frequencies but it can be a strong force for introducing new alleles.

4). Migration is defined as the movement of individuals from one population to another. Gene flow due to the migration of random individuals into a new population may change the frequency and/or the range of alleles.

5. No, natural selection is not random.

6). Yes, genetic drift is random.

7). Yes, mutations are random.

8) Yes, Migration between two populations is usually random.

9. One of the main evolutionary forces leading to genetic differentiation between populations is natural selection. Since natural selection is based on adaptation to a particular environment, it leads to genetic variations between populations living in different environments.

10). Genetic drift occurs due to chance and may lead to deletion of alleles. This deletion can cause the resulting population to be genetically different from the original population. Genetic drift is also credited with the ability to play a major role in evolution.

11). Mutations are heritable changes in the genome of an organism. The accumulation of these mutations can lead to genetic variation between population and may also be responsible for evolution.

12). Migration causes gene inflow from one population to another. Maintained gene flow between the two populations can result in their combination ( by mating) and might reduce the genetic variation between the two populations.