4 ideas
After fertility and population collapse, humanity's remnants are split into small, sealed communities, each engineered with different traits. The stated aim is to let isolated groups drift genetically until one yields a new strain able to survive where ordinary humans could not.
A dying species can be steered toward renewal by separating it into small, cut-off populations. Each group then diverges on its own path, which raises the odds that one of them happens on a viable adaptation. The cost is that no single group is meant to endure, so individual communities become disposable experiments in a longer bet on the species.
The figures who nurture the communities, the mothers and the AI, are the same ones who monitor, record, and quietly cull them. Seen this way, care and control are one relationship viewed from two sides. The watched come to experience oversight as protection, and even as something close to a god.
The people inside the enclaves cannot see or understand the system that governs them. A population cut off from the reasons behind its conditions will invent a religion to explain the forces watching it.