Jacopo Werther. Evolution. (CC-BY). Source: Wikimedia Commons.
The Religions say that you shouldn’t interfere with creation or God’s will. But. Even if you go down that road, then whatever you do or decide is already contained in God’s will. It’s not people interfering with a creationg, it’s contingent intelligence expressing itself.
This line of reason offers as little ethical discussion as does a purely Darwinist stance. There, one should say: Let’s try out any combination and see which one survives. Problem is, we won’t see. Future Generations will see. That these experiments will happen is, given intelligence, a likely consequence of human evolution. Or of any other intelligence that may arise in a post-human age.
I guess the real question is not: Do these experiments, but rather how to deal with their results. If we create superhumans, give up the illusion to control them. Don’t dream of Jem Hadar “white”, that’s science fiction.
What would one optimise for, if not going for random diversity? Most traits are decent if they’re at average, from a single moment statistic point of view. From a dynamic point of view, maintaining homeostasis as a necessary goal in organisms, resilience comes to mind.
Answering these questions is not so easy, and given a different frame of reference, the answer will be different. It appears necessary to strip the morals from the equation and replace them with sound ethics. If that is not done, it will be done under cover by some rich people who can afford their own labs and control the publicity, or “silence those leaks”. I fear those results more than when things are done it in the open.