What Is Walter Miller Jr's Short Story "Conditionally Human"� About?

This story imagines a future world where over-population has created a need for drastic social measures. The only people allowed to breed are "Class A" – those with an impeccable health and genetic record. To comfort them in their childless state, the rsto f the population are allowed to have specially engineered pets which look more or less human and can utter simple words. Their intelligence is kept at the level of a small child, and their lives are short; if they don't die, they are rounded up and quietly disposed of.

A man whose job is to arrange this disposal finds himself in a dilemma. He finds one of these "pets" being concealed by her adoptive grandfather, who has taught her to pretend to be like the other mutant children. In fact she is a new breed, and has intelligence as great or greater than that of a human child. To kill her would clearly be murder; the man is forced to risk hiding her and taking her to safety. The implication is that others like her will be born, and that the process of evolution will be beyond human control.