This was a short story I read sometime before 2000, most likely sometime between 1981 and 1995. It was collected in a paperback with other stories, which I believe (but am not sure) were by separate authors. I also believe (but am not sure) that the cover of the paperback was pink. I may have checked out the book from the public library, which means the book itself could have been arbitrarily old.
On a planet with a hostile atmosphere, there are humans living within a dome or some other artificial environment. Each generation genetically engineers the next generation to be closer to being able to live outside the dome. At the end of the story (and perhaps also the beginning of the story—I'm not sure how much time elapses during the narrative) the final generation is almost ready to be released into the wild, but they are strong (with a low, dense, non-humanoid body shape) and out of control, and they risk damaging (or actually do damage) the dome and therefore the lives of the older generations. The young ones will survive and thrive on the planet, the older ones think to themselves with pride, even if the rest of us must parish.
The subtext of the story is that while the youngsters may technically be human (in the sense of DNA), they are no longer human from any meaningful point of view. The reader is left questioning the wisdom of their plan.
Maybe the first generation engineers all the subsequent generations, instead of each engineering the next. That's not how I remember it, but if each generation engineered the next, then the penultimate generation would be not human enough to convey the subtext. Also, the final generation is wild, presumably lacking any kind of education or technical know-how, so presumably the penultimate generation would be close enough to wild that they wouldn't be able to genetically engineer anything. This IMHO would make it hard for the author to pull off each-generation-engineers-the-next, but maybe she or he was able to.