Immortality Is Unnatural

PZ Meyers provides an evolutionary reason for why immortality is “both impossible and undesirable”:

We already have a potent defense against death put in place by evolution: it’s called more death. That sounds contradictory, I know, but that’s the way it works. Every cell replication has a probability of corruption and error, and our defense against that is to constrain every subpopulation of cells and tissues with a limited lifespan …

The undesirability of immortality derives from the proponents’ emphasis on what is good for the individual over what is good for the population. There’s a kind of selfish appeal to perpetuating oneself forever, but from the perspective of a population, such individuals have an analog: they are cancers. That’s exactly what a cancer is: a unit of the organism, a liver cell or skin cell, that has successfully shed the governors on its mortality and achieved immortality…and grows selfishly, at the expense of the organism.