Blute Blog

At a conference, I was recently asked why in my paper on a theory of sexual selection, I proposed that conventional sex between males and females is trade in which males include females as well as males among their offspring and females include males as well as females among their offspring. Of course the reason given was the proposal that there are some naturally-selected differences between them, and that under uncertainty, such trade reduces the risk of extinction like investing in an index fund rather than trying to pick stocks or dollar cost averaging rather than trying to time markets. However, the point of the query was why specify the function as trading the sex of some offspring rather than just creating (explicitly or implicitly genetic) variation which is the most common explanation.

The reason was that there are so many genetic (and environmental) mechanisms of sex determination, many more than the familiar XY and ZW systems, many of which remain unknown, even mysterious. My way for simplicity’s sake was to take what is known as “the phenotypic gambit”. If one is willing to assume that the often many genes involved in influencing a trait have an additive effect on fitness, then that effect will be heritable and hence available for natural selection to work on. Under those conditions then, one can speak of the evolution of observable characteristics such as those of males and females and not just of genes.