I just don't see the value in staying within some arbitrarily defined bound of "human". If anything, humanity is exemplified by our ability to manipulate nature

I just don't see the value in staying within some arbitrarily defined bound of "human". If anything, humanity is exemplified by our ability to manipulate nature to our benefit. Genetic engineering doesn't seem substantively different to me. I also don't see how this relates to the instinct to procreate. We don't procreate because we think its the "human" thing to do, we do it because we're human and we have an instinct to procreate. If procreation conflicted with some other drive or interest of ours, we might decide to forgo it (and many do). But this doesn't seem out of bounds of what is typically human either.