A population of green beetles (GG; Gg) lives in a specific habitat. The allele for color is represented by the colors on their backs. Over time, through random chance, the gene pool of the beetle population changes and more brown (gg) beetles are present in the population. How would you describe the sequence of events that lead to a change in allelic frequency?
A) Mutations within the population occurred. The brown allele (g) spread throughout the population of beetles.
B) Beetles with the brown allele immigrated into the population; the beetles mated and reproduced, incorporating the recessive allele into the gene pool.
C) Brown beetles had a survival advantage over the green beetles. Over time, the brown allele increased within the beetle population and the genotype became gg.
D) The beetles' habitat changed over time. The green beetles were the victims of predators and the brown beetles were not. Over time the allelic frequency changed and the gene pool became gg.

Answer: The correct answer is- B) Beetles with the brown allele immigrated into the population; the beetles mated and reproduced, incorporating the recessive allele into the gene pool.

As per the information given in the question, a specific habitat was initially inhabited by green beetles population ( Gg and GG), which shows a dominant trait ( as represented by capital letter allele).

Over a period, due to some random chance event, population of brown beetles ( bb) would have immigrated, which increased the frequency of recessive allele ( that is g) in the gene pool. When brown beetle population further interbreed, they would produce more brown beetles, eventually leading to the change in the allelic frequency ( frequency of a gene variant) of the population.

Thus, option B) is the right answer.