A reader alerted me to a posting by Greta Christina on The Blowfish Blog.1 She discusses Why Did Gayness Evolve?.
This is not your ordinary posting on the topic. For one thing, she acknowledges that you can only discuss the evolution of homosexuality if there's a significant genetic component. She makes the assumption that there is a genetic component but it is not proven.
From that point on, her analysis of the possible reasons for evolving homosexuality is as good as it gets. Greta Christina avoids the obvious clichés and concentrates on real biology. The words "spandrels" is used a lot.
This is someone who understands evolution. Speaking of understanding evolution, in order to discuss whether homosexuality evolved you need to have a workable definition of evolution. My definition restricts evolution to heritable changes in a population and that's why the discussion of a possible genetic component is relevant.
Some people prefer a different definition of evolution—something like "descent with modification." I wonder how you can discuss the possible evolution of homosexuality using such a definition of evolution? Would it mean that the increased prevalence (and acceptance) of homosexual behavior in ancient societies was an example of evolution?
1. Thank-you Fred.