An ecologist notices that the population of a type of berry in a forest has changed over time. The change in population distribution is shown in the graph. She makes a hypothesis that this was caused by the reintroduction of bears. The bears prefer to eat the sweeter berries. As a result, the bears distribute the seeds of those berry plants.
Explain why her hypothesis is a reasonable explanation for the pattern of selection seen in the graph.
Suppose that an extended drought impacts the area. Plants that produce less-sweet berries are more drought tolerant than plants that produce sweeter berries. Describe how the population distribution would likely change as a result of the drought.
The ecologist's hypothesis that the reintroduction of bears led to the change in population distribution of the berry plants is a reasonable explanation because bears play a significant role in seed dispersal. Bears typically eat the sweeter berries, and as they move around, they deposit the seeds of these plants in different locations through their droppings. This can lead to the distribution of the sweeter berry plants in areas where the bears have been present more frequently.
If an extended drought impacts the area, plants that produce less-sweet berries may have a higher chance of survival compared to plants that produce sweeter berries. This is because plants with less-sweet berries are typically more drought-tolerant as they may require less water to produce fruit. As a result, the population distribution of the berry plants may shift towards more drought-tolerant plants with less-sweet berries, as these plants are better able to survive and reproduce in the drier conditions. This could lead to a decrease in the population of sweeter berry plants and an increase in the population of less-sweet berry plants in the forest.