Which example illustrates darwin's main contribution to the theory of evolution? a. an agricultural pest has been exposed to a pesticide that wipes out the entire species. b. in a laboratory, a scientist chooses the most intelligent mice and breeds them to advance the species. c. when exposed to antibiotics, most bacteria in a population die but some survive and live to reproduce. d. in the african savannah, a scientist observes that a wildebeest calf has inherited its coat pattern from its father.