[Campbell Biology P.525] A population of rabbits in a snowy mountain region develops thick w... | Practice Question

A population of rabbits in a snowy mountain region develops thick white fur, which is highly advantageous for camouflage. If a climate change causes this region to become significantly warmer with less snow year-round, what is the most likely long-term outcome for the rabbits' thick white fur trait due to natural selection, based on the principles discussed in the text?

  • A: The frequency of the thick white fur trait will increase, as it is a highly evolved adaptation.
  • B: The trait will remain constant in frequency, as natural selection only favors traits beneficial in their original environment.
  • C: The frequency of the thick white fur trait will likely decrease, as it may become detrimental for camouflage in a snowless environment, making rabbits with this trait more vulnerable.
  • D: The rabbits will individually change their fur color during their lifetime to adapt to the new environment.

Explanation

The text states that 'environmental factors vary from place to place and over time. A trait that is favorable in one place or time may be useless—or even detrimental—in other places or times.' In a snowy environment, white fur is advantageous for camouflage. However, if the environment becomes snowless, white fur would make the rabbits stand out, becoming a detrimental trait. This would lead to individuals with white fur being more vulnerable and thus less likely to survive and reproduce, causing a decrease in the frequency of this trait in the population over time.