““As with all other causes of age-related death, the evolved level of protection against potentially cancer-causing mutations is limited by the cost of creating and maintaining the machinery to achieve that protection. On the one hand, there’s no sense in putting all of an organism’s eggs into the basket of being so resistant to aging processes that it can stay young and healthy for two hundred years, if there are strong odds that it will freeze, starve, sicken, or become something’s lunch in its third decade; those resources would be better spent on warmer fur, sharper claws, or simply a shorter gestational period. But on the other hand, the animal does need to remain internally intact for as long as it can reasonably be expected to survive those threats from the external environment, because every year of youth is another opportunity to spread one’s genes around.””
