The banning of microscopes is indeed one curious aspect, allthough this would also work to stop close examination of microcircuits (like the one in the relatively primitive hand camera that Juliette inherited from George, and gave to Walker to examine).Evidence of DNA tampering ?
Another point is the secret selective breeding program going on.
And there is also the intro of the series, which shows the stairs while highlighting them in a way that suggests DNA strands.
Finally, if medical experiments are going on that could be the whole point of the Silo thing, with the supposed doomsday being an excuse that may not even have happened (or if it did, not have been that bad that the surface is still completely unliveable after more than 300 years). What the Silo denizens are told becomes less believable with every new piece of info that comes out.
I have not read the books, no idea if there is anything more to do this or it is coincidence/misdirection.
Whether or not Juliette and co are "superhuman", in any case the show has a tendency to let its character survive neck-breaking stuff without nary a scratch. Knox and Shirley dropping down without brakes on the cables they were using, is a prime example, besides all the stunts Juliette has survived. Then again, action heroes have been surviving unlikely stunts for decades.