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

The answer would be B) A wolf pack has been introduced into the population. This is because of the following:

-If a population increases, the gene pool increases; if it decreases, gene pool decreases
-If Yellowstone expanded their borders, that would give the deer more room, but not necessarily increase, or decrease the population.
-If the amount of disease were to decrease, then the population would grow.
-If more grassland and shrubs are planted, the deer would have an abundance of food, and the population would increase.

The only logical answer is the wolves, because the wolves would consume the deer as a food source, causing the population to drop, and subsequently,

Answer 2

Answer: A population of wolves was introduced into Yellowstone National Park.

Explanation: The following should be the answer because all of the other options would be beneficial to the deer population and therefore the gene pool would not be affected. However, these new wolves that were introduced would most likely prey on the deer and hence decrease the existing gene pool which in turn affected the genetic variation of the deer population.