> Being a male, I'm troubled by the fitness of the Y-chromosome over the generations. It seems to me that it can only accumulate errors and mutations. One poss

> Being a male, I'm troubled by the fitness of the Y-chromosome over the generations. It seems to me that it can only accumulate errors and mutations. One possible safety hatch that comes to mind is that it's possible for XX males to exist. There's only one gene on the Y chromosome which has anything to do with male development, the SRY gene, which causes the proto-gonads to develop into testes (all male development following that is the result of the testes producing androgens). During meiosis, it's possible for the SRY gene to break off of the Y chromosome on one sperm and make its way into the X chromosome on the other sperm. When this happens, it's called de la Chapelle syndrome [0]. So if the Y chromosome eventually becomes unusable, we might end up in a future where males are created by inducing de la Chapelle syndrome in vitro by splicing an SRY gene into the zygote. The only problem is that males with de la Chapelle syndrome are sterile, but I'm sure that if we get to the level of technology where this kind of gene splicing is commonplace, we can come up with some kind of hack to get around it. It's been speculated for a while that eventually we'll develop the technology to make one egg fertilize another in vitro, resulting in a healthy XX zygote, so that's one way (though the eggs wouldn't come from people with de la Chapelle's... which means we wouldn't need to induce it in the first place... so female-only world it is). [0] https://en.wikipedia.org/wiki/XX_male_syndrome https://en.wikipedia.org/wiki/XX_male_syndrome