Cool. Maybe the next step could be to grow structures that didn't previously exist.
I have a problem, maybe a blessing/curse sort of thing. I think about the details, and the ramifications of those details, and so on and so forth. I can usually manage a reasonable suspension of disbelief when I'm reading someone else's work, though. Even if I have questions and might suspect plot-holes, I still manage to put it aside. When it's my own work, though, I get hung up on things.
Like, cool science fiction scenario: people can grow wings, extra arms, etc. But then I start thinking about it. In the case of wings, for instance, even if we had ginormous angel type ones, I can't really see us getting off the ground. What is the heaviest animal that can fly, after all? I'm talking both extant and extinct. I'm pretty sure that of extinct animals, there were ones that were probably heavier than extant flying creatures (hugeass birds might top off at like 40 something pounds), but of course their whole anatomy was designed to take advantage of weight distribution, aerodynamics, etc. They weren't just some mammal with wings slapped on.
And of course the musculature. How do the wings attach, how do they work? How do the muscles supply enough power without totally altering the rest of human anatomy, interfering with arm movement, etc? You can't just slap wings on a quadruped and have it work. Alas.
It would be cool if spiders developed flight.
I should look up the evolution of insect wings.
But anyway, I get all concerned w/ how the musculature would attach and how else it would affect anatomy/behavior, etc., and I'm *glad* that I think this way, but sometimes it gets in the way of just having fun silly science fiction premises.