The images show two different types of galapagos tortoises that scientists believe descended from the same species. the first type (left) lives on islands that have high vegetation and few grasses. the second type (right) lives on an island that has large amounts of grasses and low-lying shrubs. what explains the differences in the second turtle's characteristics? a. the environment triggered a gene mutation in neck length to the second turtle survive. b. mutations are random, so the high number of individuals with longer necks is simply by chance. c. turtles with genes for long necks had a better chance of surviving to reach reproductive age. d. turtles with short necks completely lacked adaptations for survival, so they died off.