"Evolutionary implications of sex reducing heritable variation: Disaggregated individuals, haploid leks, and the Red Queen on asexual Red Bull"

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Previously we showed that, contrary to conventional thought, sex decreases heritable variation. Here we will investigate the implications of sex not being for genetic mixing, but rather the function of sex is to filter out new variation. First, we will use sex to demarcate new individuals and generations, while lack of sex defines an individual. Much of evolution and ecology depends on being able to identify individuals. A modified definition of individuals may have profound effects on our view of the world, such as instantly showing that obligately asexual organisms cannot be adaptive because their evolutionary trajectories are dominated by drift and mutation, not selection. Second, if individuals are demarcated by sex, then haploid organisms (e.g. animal eggs and sperm) can each be considered separate individuals. This implies that sexual conflict and sexual selection can be occurring inside of a fertilised egg cell, such as a female haploid nucleus deciding which male haploid nucleus to fuse with. We will look for such effects and model them mathematically. Third, probably the best place to see whether sex decreases heritable variation is in organisms that only have sex with themselves. Self-sex, including self-fertilisation, is a viable means of reproduction for many organisms, but details about their genetic diversity are seldom studied. Fourth, the Red Queen is a premier mathematical model of a co-evolutionary arms-race between two species, where the Red Queen (from Alice in Wonderland) runs as fast as she can to stay in place. In these models, increased heritable variation is the engine that keeps the queen running, with sex being the fuel for her engine. But, if sex reduces variation, then maybe the Red Queen should skip - skip sex - in order to run faster to keep up with her co-evolutionary adversaries. We will modify the mathematical models accordingly, so that the Red Queen does not crumble like a house of cards. This should have huge implications for theories of evolution of disease and evolution of sex.