Underwater
A spices of genetically mutated humans that have retreated underwater and made a living, all live in a small underwater country called Yaluah.
In this world, at the age of 12 you are split up into categories by a panel of leaders, that review your whole life and determine what category you fit into:
~Able to fight
~Able to reproduce
~Able to discover
~Useless
Fighters protect the town, and make sure no Earth dwellers come in, and no sea dwellers in low ranking come out.
Reproducers become parents and live normal lives, they get standard occupations, and are genetically altered to give birth to “perfect” looking children.
The people who discover train to be and later become scientists, researchers, historians, geneticists, etc and and are the people who give genetic alterations.
People who are useless are ruled by the panel “unable to fit in” which results in banishment from the town’s main lands, being stripped of all genetic alterations, and forced into cramped reservations. They are not allowed to have children, and doing so will result in death of the parents and child.