Question

a scientist has been tracking and studying a population of deer in yellowstone national park. he surveys the population every six months. usually, the population is thriving and has a gene pool with a wide variety of traits. but during one six - month period, an event occurred that affected the population, and when the scientist returned, the amount of genetic variation had decreased significantly. which of the following is most likely the event that occurred to change the population? yellowstone national park expanded its borders. a population of wolves was introduced into yellowstone national park. the amount of disease in the deer population decreased. more grass and shrubs were planted in yellowstone national park.

Explanation:

• Expanding park borders (Option 1) would likely increase genetic variation as more deer could enter.
• Decreasing disease (Option 3) would allow more deer to survive, potentially increasing genetic variation.
• Planting more grass and shrubs (Option 4) provides more food, which could support a larger population and potentially more genetic variation.
• Introducing wolves (Option 2) would act as a selective pressure. Wolves would prey on deer, and if certain traits make deer more vulnerable (or less), this could reduce the genetic variation as only deer with certain traits (e.g., faster runners if speed helps escape wolves) survive and reproduce.

Answer:

B. A population of wolves was introduced into Yellowstone National Park.