Matt Ridley's The Red Queen also talks about the effects of parasites, which also maps in to why there are genders (more accurately sexual reproduction). The problem is the mismatch between lengths of generations. A parasite that has one generation every week gets 52 shots a year at an unchanging host. As time passes the probability of success for the parasite increases. The human with ~20 years per generation has to withstand that long before making a new one that is different and (partially) resets the clock.
Gender comes in because asexual reproduction would produce offspring virtually identical to their parent which means a successful parasite would have a large number of hosts to exploit. By combining DNA from two different individuals (note how much we avoid individuals from the same family with substantially similar DNA) things are mixed up enough to give a head start against the parasites.
Gender comes in because asexual reproduction would produce offspring virtually identical to their parent which means a successful parasite would have a large number of hosts to exploit. By combining DNA from two different individuals (note how much we avoid individuals from the same family with substantially similar DNA) things are mixed up enough to give a head start against the parasites.
https://en.wikipedia.org/wiki/The_Red_Queen:_Sex_and_the_Evo...