Question

bird beak variation
bird beak size is often related to the type of food the bird eats and the size of the food source. some birds eat seeds as food. birds with large beaks are better able to eat larger seeds, while birds with small beaks typically eat smaller seeds.
an environmental change occurred that resulted in a reduction in one type of food, namely small seeds. the change caused a shift in the distribution of beak sizes observed. the graph shows the distribution of birds of various beak sizes before and after the change.
how can an environmental change cause a shift in the traits of a population?
a. an environmental change can cause organisms to choose traits that are more favorable
b. an environmental change can make some organisms better suited for survival than others
c. an environmental change can cause some organisms to change their behaviors and quit reproducing
d. an environmental change can make organisms that are less suited for survival reproduce more rapidly

Explanation:

When small seeds (food for small-beaked birds) became scarce, birds with larger/medium beaks (better able to eat remaining larger seeds) had higher survival and reproductive success. Over time, this shifted the population's beak size distribution. Organisms cannot "choose" traits (eliminating A), the change does not force organisms to stop reproducing (eliminating C), and less suited organisms do not reproduce more rapidly (eliminating D). This matches the principle of natural selection, where environmental changes favor traits that improve survival.

Answer:

B. An environmental change can make some organisms better suited for survival than others.