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.

Answer 1

answer B is correct I just took the test!

Answer 2

`\boxed {\boxed {\sf B. \ A \ population \ of \ wolves \ was \ introduced \ to \ Yellowstone \ National \ Park }}`

Step-by-step explanation:

Let's evaluate each choice. Remember we are looking for an event to decrease the genetic variation and population.

A. Yellowstone expanded its borders

• If the park expanded, it's likely the population would increase. There would be more space and resources for the deer.

B. A population of wolves was introduced

• A wolf is a predator that preys on deer. If they were introduced, they would use the deer as a food source and decrease the population.

B seems like a good answer, but let's check the others.

C. The amount of disease in the deer population decreased.

• This would help the deer population. Less disease means fewer deaths and a greater population.

D. More grass and shrubs were planted in Yellowstone

• Deer are herbivores, so grass and shrubs would provide more food. This would keep the deer nourished and healthy, meaning a greater population.

The best answer choice is B: A population of wolves was introduced into Yellowstone National Park