The mutation that causes the arctic fox to have white fur instead of brown fur can be classified as a beneficial mutation. This is because the arctic foxes live in a snowy environment, and having white fur helps them blend in with the snow. This camouflage makes it easier for them to hunt for food, like rodents and small mammals, and it also helps them avoid being seen by their predators, such as eagles, wolves, and polar bears.
With white fur, the fox is more likely to survive in its habitat because it can hunt more effectively and stay safe from being eaten by predators. If a fox has brown fur in a snowy area, it would be easier for predators to spot it, making it less likely to survive. So, in this case, the white fur mutation is helpful for the fox's survival in the Arctic environment!