Biology/ Genetics

Question

Choose any wild, existing species of Eukaryote that interests you. Please don’t choose humans and don’t choose a domesticated species. In studying a population of your organism, you focus on a particular gene (this does not have to be an actual gene, just a realistic one). At first it seems that your study sample is uniform at this locus but then you discover a unique, novel mutation. In other words, every single copy of the gene in your sample is identical except for the unique copy of a new variant allele that you have discovered.

 

In your own words, describe the normal function of the gene at this locus and how the function of the new allele differs, if at all. For the sake of this exercise, we will assume that the new allele is not strongly deleterious and that it will ultimately become fixed (replace the original allele) in the population. In your own words, tell the story of how and why the new variant becomes fixed. To keep your reader informed, be sure to state its frequency at three or more points in time, measured in generations.

Answer 1

This mutated allele is dominant and causes testicular cancer in ground squirrels. The onset of the cancer occurs just before the ground squirrel is of reproductive age, but only becomes problematic after the ground squirrel is past reproductive age. At this point, his cancer-causing mutation has been passed down. The testicular cancer allele also makes the testicles grow slightly bigger when the squirrel is of reproductive age, which is attractive to female ground squirrels. The mating success of cancerous squirrels is thus higher than the mating success of squirrels without the mutated allele and so the mutation has a higher likelihood of being passed down than its counterpart and becomes fixed in the population over many generations.