Question

now suppose that the tree community in this butterfly population's environment has shifted to include more trees with yellow coloration on their bark, meaning that butterflies with yellow wings (aa) will be better camouflaged. reset the simulation to it default settings. set the selective advantage value for the aa genotype to 0.98 and run the simulation. what happened to the percentage of each allele in the population over 50 generations and why?

Answer 1

An increase in yellow-winged butterflies occurs due to better camouflage against yellow bark, demonstrating directional selection favoring the a allele; the percentage of a allele rises over 50 generations.

Step-by-step explanation:

When the environment of a butterfly population changes to have more trees with yellow bark, and if butterflies with yellow wings (genotype aa) have a selective advantage set to 0.98 in a simulation, we can expect the percentage of the a allele to increase over the course of 50 generations. This is because the yellow-winged butterflies are better camouflaged and thus more likely to survive and reproduce, passing on their alleles to the next generation. In contrast, the frequency of the other allele(s) will decrease since they do not offer the same level of camouflage and therefore those individuals are less likely to survive and reproduce. This phenomenon is an example of directional selection, which occurs when an environmental change favors a particular phenotype, shifting the population's genetic variance toward the advantageous trait.