Some mutations have a positive effect on the organism in which they occur. They are called beneficial mutations . They lead to new versions of proteins that help organisms adapt to changes in their environment. Beneficial mutations are essential for evolution to occur. They increase an organism’s changes of surviving or reproducing, so they are likely to become more common over time. There are several well-known examples of beneficial mutations. Here are just two:
A sudden climate change hits Alaska and it starts to become warmer. As a result many species of mammals have started to adapt to the warmer climate and now grow less fur.

Given the mammals growing less fur is a beneficial mutation, will less fur become more common or less common?