Suppose a biologist observes many individuals in a species of flowering plant. She notices that some of the individuals open their flowers in the middle of the day and close at dusk, while others do not open until much later in the afternoon and close after dark. Flowers need to be open for pollinators to visit and transfer pollen for the plant to reproduce. Which of the following is likely to occur over time? A.
artificial selection

B.
competition

C.
extinction

D. speciation