Question

Be sure to provide sufficient detail in your responses so that we can have useful and meaningful discussion and review on our web talk.

What is meant by “allele frequencies” and how do allele frequencies play a role in evolution?

Describe in your own words what the Hardy-Weinberg principle means and how it can be used to understand whether evolution is occuring.

What are the prerequisites for natural selection occurring and what does natural selection mean? Provide one example of natural selection that we discussed and describe in your own words.

Describe in your own words what is meant by biological fitness and adaptations.

How does speciation occur and what is one way that you know two groups of organisms are different species?

Compare and contrast analogous and homologous traits.

In the below phylogeny, what is the sister group to mammals? What is the closest relative to birds?

Answer 1

Allele frequency refers to how commonly an allele occurs in the population. It is the proportion of one allele to all other alleles in a population. It can be represented as-

Allele frequency= Number of copies of the specific allele in a population/ total number of all the alleles

Allele frequency shows the richness of a gene pool. Thus, any change in the allele frequencies of a population causes a change in the gene pool, which leads to evolution. To conclude, Evoultion is nothing but a change in allele frequencies.

Hardy weinberg principle was given by Godfrey Hardy and Wilhelm Weinberg states that the frequency of alleles & genotype remains constant in a population in every successive generation if the population is stable . Hardy Weinberg equilibrium of a gene means that there is no evolution occurring.There are five basic assumptions which, if not met, may cause evolution i.e. allele frequencies will change from generation to generation.