Question

In order to support his theory of evolutionary change, Charles Darwin concentrated his studies on the many species of finches in the Galapagos Islands. Darwin noted that many of the birds had different shapes and styles of beak.

What is a possible explanation for what Darwin observed?
Responses
A The birds had beaks that were adapted for feeding differently.The birds had beaks that were adapted for feeding differently.
B Some birds had been injured by predators and were poor competitors.Some birds had been injured by predators and were poor competitors.
C People had bred the bird to have beaks with varied shapes and sizes.People had bred the bird to have beaks with varied shapes and sizes.
D The birds always had different beaks.

Answer 1

A — The birds had beaks that were adapted for feeding differently.

This variation is explained by natural selection: different beak shapes gave advantages for different food sources, so birds with useful beaks survived and reproduced more often. Options B, C, and D do not account for adaptive change by selection.