Question

7. Researchers have found an exception to the observation that populations of rock pocket mice that live on dark rocks generally have dark fur. On one lava flow of dark rock, all the mice have light fur. This lava flow of dark rock is relatively young (< 800 years old) and is far from any population of rock pocket mice that have dark fur.

What is a likely reason why dark fur has not evolved in the population of mice that live on this lava flow?

Answer 1

Ans 1- This may have happen because, there may have been insufficient time for melanic mice to evolve in this population.

the researchers suggest that the light-colored fur of the mice on this lava flow “likely reflects the fact that lava flow is an extension of the relatively young Sunset Crater (<800 years old); consequently there may have been insufficient time for melanic mice to evolve in this population. In addition, there are no populations of melanic mice nearby from which melanic migrants may invade.”This illustrates that natural selection can only operate when one or more alleles for an adaptive trait are present in the population. This is one reason why evolution is a slow process, and the slow pace of evolution is one reason why not all characteristics observed in living organisms are adaptive.