In northern Canada, a population of rabbits was predominantly white in color. The allele for white color is recessive, while the allele for gray color is dominant. Over the last several decades, the average annual temperature of this area has increased, and the long-term deposits of ice and snow have become scarce. We see the result of this change in the graph above.
How can we explain this change in terms of allelic frequency?
A Gray alleles are dominant over white.
B Changes in the environment caused genetic mutations that were passed to offspring.
C In order to survive, rabbits changed from white to gray and they passed the gray allele to offspring.
D Gray rabbits were more likely to survive in the changed habitat. The gray alleles were passed to offspring.
E The allele for gray color became the recessive allele in the gene pool.
D Gray rabbits were more likely to survive in the changed habitat. The gray alleles were passed to offspring.
This change in allelic frequency can be explained by natural selection. In the changed habitat with less ice and snow, the white rabbits would be more easily seen by predators, while the gray rabbits would blend in better with their surroundings and have a higher chance of survival. As a result, the gray rabbits would be more likely to pass on their gray alleles to the next generation, leading to an increase in the frequency of the gray allele in the population.