Question

1. After a rare fur color mutation occurred, a mouse population evolved to have this new fur color (i.e. over many generations more individuals in the population had this new color variant). Explain how natural selection could lead to this increase in frequency of individuals in the population with this new color variant over many generations. Also explain what conditions are necessary for natural selection to occur in this scenario.

Answer 1

In this context, the most likely scenario is that this new fur color variant allows them to avoid the attack of a determined predator. This fur variant may provide a type of camouflage or they may be imitating a danger signal for the predator. So, the predator will eat only the normal fur color individuals while the mutated individuals will survive.

In order to natural selection occurs in this scenario, it is necessary that the trait were hereditable. This will promotes more mutated individuals in the population. Other conditions is that this trait provides an increase of fitness in the individuals. When we talk about fitness, we refer to the capacity of an individual to survive under certain conditions. Thanks to this mutation, the mice population will increase their fitness.