[quote=@POOHEAD189] I'm talking about the future of the species if society deems it ok, and any kind of coupling that bring offspring, not just marriage. It would still be icky in society, and we as a species would naturally be disinclined to it because of our evolutionary history and instincts. However, if the genetics were modified for their children, there was no religion against it, nor cultural taboos, then if I had to guess there would be a small population of genetically odd individuals that don't have the same genetic coding as most do, so they find their sister fuckable! [/quote] So is the purpose of marriage to enforce some arbitrary genetic control? Should marriage rights be determined by that genetic scheme? If that is the case then you should have no objection to incestuous marriages that produce no children right? Also you should be concerned with people who are passing along genetic diseases. Why stop there, why not pick genetic traits that you personally like and select for them?