Rational Philosophy

Why sex makes sense.

Yesterday I posted a piece on new or renewed questions about why organisms reproduce sexually (as opposed to asexually). In short, no current theory can explain why organisms have evolved to reproduce sexually. Theories have been proposed — such as the desirabilty of high gene mutation rates to aid adaptation and resistance to parasites — but these theories haven’t been borne out through scientific analysis.

VS.

As I tried to clear my mind for meditation this morning on my subway ride to work, it occurred to me that perhaps we are asking the wrong question. Instead of asking why evolution led to such a broad and successful range of sexual reproducers, would it make sense instead to ask “why not”?

I’ll try to explain what I mean.

Darwin’s theory of natural selection is often misparaphrased as “survival of the fittest.” (I almost did it myself, before I researched the origin of that phrase; Herbert Spencer coined it after he adopted, adapted and misused Darwin’s theory for his own purposes). If we look around us we see that the world is far from filled with absolutes. Instead, the various paths that life and evolution have taken have led to an enormous and bewildering array of living things. The number of types and subtypes of plants, animals, insects, etc., is dizzying.

Bdelloid Rotifers do very nicely without sex, but that doesn’t mean that we all need to. We’re not competing with Bdelloid Rotifers, we’re all just doing what we do until something comes along to stop us.

To couch this in more scientific terms, theories of gene mutation don’t need to explain why sexual reproduction is better than asexual reproduction as an evolutionary fork in the road. They just need to explain how it is that sexual reproduction is a viable evolutionary fork.

Mathematically, a new species will only fail to survive if the threats to its survival outweigh its ability to adapt and thrive. When the number of threats is low, the species doesn’t need to be a super-survivor, it just needs to be good enough.

The same is true within human society. We can’t all be superstars, supremely attractive, incredibly smart, strong, mature, creative, resourceful. But that doesn’t mean we can’t survive and lead a fruitful life, reproduce, create a genetic legacy. Just one clear look at the world around us demonstrates the futility in seeking to understand why, from an evolutionary perspective, a particular trait has survived. Why not? What was the force that would have stopped it from being perpetuated?

And given the amount of time most people spend thinking about sex and participating in it or wanting to participate, there would have to a fairly major turn of events to stop us continuing down this particular alley.

For a rational, science-based explanation of life’s meaning and purpose, please refer to my book: LIFE! Why We Exist… And What We Must Do To Survive.