(05.02 MC)A scientist hаs kept recоrds оf the cоlor vаriаtions in a field of phlox for several generations. Phlox is an annual plant that produces flowers in a variety of shades ranging from white to red. Initially the field contained equal proportions of white, pink, and red flowers. By the end of the study the proportions of flowers in the field were 80% red, 15% pink, and 5% white. Which of the following inferences best explains the change in flower color proportions?