In this episode we explore a sub-process of Natural Selection called Sexual Selection:
Sexual selection is composed of two processes
Intersexual selection: When one sex preferentially mates with another based on certain characteristics
Intrasexual competition: When members of the same sex compete with each other for access to their counterpart.
Next we dive into why Intersexual selection is often synonymous with “female choice” — why do females preferentially select the males based on traits they find attractive, while the males compete with each other to showcase the preferred trait?
This is explained by Triver’s Theory of Parental Investment, the sex which invests greater towards reproduction will be more choosy about who they mate with. This is for two reasons
They must solve the adaptive problem of maximizing their limited reproductive window.
Reproduction is a resource-sink, they must ensure that the investment will pay off.
Finally we end with Richard Prum’s hypothesis on the evolution of beauty. While the peacock’s tail might be an “honest signal”, the specific version of beauty that the female selects for is purely aesthetic. The coloring of blue and green throughout the tail serves no adaptive purpose. Instead, the color pattern is a by-product of her neural wiring and exists merely because she finds its pleasing. This is a massive paradigm shift in evolutionary thinking, because it means that traits not only evolve because they must, but also because an organism wants them. Aesthetics are a genuine evolutionary force.
