Which of the following could be an ultimate explanation for the behavior of migration in birds?
A) Decreasing day length in the fall influences a bird's circadian rhythm, which triggers flight behavior.
B) Birds use a sun compass to orient as they fly south in the fall.
C) Birds fly south in the fall because food resources are more plentiful there in the winter.
D) none of the above

Question

Quizplus · Accepted Answer

Ultimate explanations in biology refer to the evolutionary reasons behind a behavior. The behavior of migration in birds is primarily driven by the search for resources, such as food, which are more plentiful in different regions depending on the season. Choices A and B describe proximate mechanisms, or how the behavior occurs, rather than why it evolved.

Which of the Following Could Be an Ultimate Explanation for the Behavior