Keep Out

A colonization program uses a biochemical agent called daptine to produce children whose physiology can be gradually conditioned to survive Martian air, temperature and food; they are raised inside a dome under carefully altered environments until maturity. A teacher recounts the decades-long experiment that enlarged lungs, promoted insulating body hair and made the settlers comfortable with alien conditions. As the youngsters approach adulthood and legal freedom, simmering contempt for their Earth-born overseers culminates in a secret plan to kill the adults and claim the planet for their descendants. The narrative probes engineered adaptation and the ethical, social and generational consequences of deliberately altered evolution.