A finch population with heritable variation in beak size arrives on an island where only large seeds are available as a food source. Describe the process of natural selection that would follow.
A) Finches with smaller beaks would grow larger beaks so that they could eat the large seeds. All birds will reproduce and the frequency of large beaks within the population will increase.
B) Finches with larger beaks will more easily eat the large seeds and are thus more likely to survive and produce offspring with similarly large beaks. The frequency of large beaks within the population will increase.
C) All of the finches with small and medium beaks will soon die; all of the finches with large beaks will survive. The frequency of large beaks within the population will increase.
D) Finches with smaller beaks would grow larger beaks so that they could eat the large seeds. Only these birds that grew larger beaks will reproduce and the frequency of large beaks within the population will increase.
E) Finches with larger beaks will more easily eat the large seeds and not need to reproduce.

Question

Quizplus · Accepted Answer

Finches with larger beaks are better adapted to the available food source (large seeds) and are more likely to survive and reproduce, passing on the trait for larger beaks to their offspring. This leads to an increase in the frequency of the trait for larger beaks in the population over time, illustrating natural selection.

A Finch Population with Heritable Variation in Beak Size Arrives