If a river originates 200 meters above sea level and travels 400 kilometers to the ocean, what is the average gradient in meters per kilometer? 0.2 m/km 2 m/km 5 m/km 0.5 m/km

Which of the following is a true statement? a. individuals evolve to have adaptations. b. individuals have adaptations that can change over time. c. individuals have traits that may or may not make them successful at reproduction. d. populations cant evolve, only individual organisms.