Question

Which of the following is an example of the bottleneck effect?

A
Bald eagles are hunted until near extinction, then the population recovers.

B
A small group of iguanas float to an island, and a new population is started.

C
Red fox pups are more likely to survive in a snowy environment if they are born white.

D
A farmer chooses seeds from the largest apples to plant next year, which results in larger apples from year to year.

Answer 1

The correct answer is A.

The bottleneck effect refers to a reduction in population size, often caused by a random event such as a natural disaster or human activity, that leads to a loss of genetic diversity in the population. In this case, the population of bald eagles is reduced to near extinction, which would likely result in a significant loss of genetic diversity. If the population recovers, it may do so with reduced genetic variation, which can have negative consequences for the species in the long term.

B is an example of the founder effect, which occurs when a small group of individuals colonizes a new area and starts a new population. The genetic diversity of the new population may be influenced by the characteristics of the founding group.

C is an example of natural selection, where traits that confer an advantage in a particular environment are more likely to be passed on to future generations.

D is an example of artificial selection, where humans intentionally select certain traits to be passed on to future generations. This can result in changes in the genetic makeup of a population over time, but it is not an example of the bottleneck effect.