試題詳解

49. Which of the following is a direct cause of microevolution within a population?

(A) The formation of a new species over millions of years.

(B) A change in the frequency of an allele due to random chance (genetic drift).

(C) The large-scale extinction of a taxonomic group.

(D) The diversification of life forms into new phyla.

(E) The development of complex multicellular organisms from single-celled ancestors.