Evolution, survival, and suicide

We humans are aware of certain things that other animals don't seem to be aware of. We know we will die. When we focus intently on that fact, we find it very unpleasant. Existential angst may not be adaptive, but thinking creatively about ways to postpone death has a clear adaptive purpose -- living for another day is another chance to reproduce or help your offspring to thrive. And while humans do sometimes commit suicide, it is rare. Existential angst is sufficiently controlled that most of us live as long as we can, even when suffering pain and despair. Why? There's no objective, logical reason, but it surely looks like an adaptive aspect of our minds molded by evolution. Genes that predisposed a significant portion of people to kill themselves would be selected against by evolution.

This is as good a time as any to counter objections along the lines of, "If we are molded by evolution, why do some people commit suicide? Why is there homosexuality? Why do some people kill their children?" Fundamental to evolution is the idea of variability -- different genes result in different consequences. This variability is a necessary condition for evolution to take place. If all members of a species were perfectly adapted to some environment and their genes were identical, then when the environment changes there would be no basis for adapting to the new one. The animal lineages that have survived have some variability, much of it not helpful for the current environment. As a result, at any given time there are traits that are not adaptive -- but they are present only in a very small part of the population. All the human genetic diseases fall in this category of variability. What they all have in common is that they are rare. Natural selection keeps trimming them back and keeping the frequency of the causal genes low. But if the environment changes, one of these genes that is now not adaptive may suddenly become adaptive, may dramatically increase in the gene pool, and help humanity adapt to this new environment. Suicide, homosexuality, and killing of children are all very rare, and as such are not arguments against evolution.

So we mostly work very hard to postpone death as long as possible. And yet there are exceptions to this -- ones that prove the rule. Women and men will both sometimes risk death in defense of their children. We all die and our genes survive only through our children, so sometimes it is more adaptive to die ourselves if we can save the lives of our children.

Men also have a willingness to band together into military units to fight other bands of men, with a significant risk of death. But in our environment of evolutionary adaptation (EEA), defeating a neighboring band was often accompanied by stealing or raping their women, providing more opportunities to leave descendants, and this may have offset the risk of death. Even today, with men organized into armies instead of bands, the rape of conquered women is all too common.

One classic dystopian future involves the computers achieving sentience and then taking over the world and exterminating humanity. To me this seems incredibly unlikely, because there is no inherent reason why an artificial mind should want to preserve itself or replicate itself. From the very beginning, evolution has selected above all for survival and reproduction in organisms. As consciousness developed, those same pressures made the overriding goal of that consciousness to survive and leave descendants. Thinking that a sentient intelligence would naturally have those same goals seems to me like projection. Our minds care deeply about those things based on evolution, but no evolutionary process has operated on computer programs. We would have to program it to want to survive and replicate itself. We have to program it to "want" anything.