Evolutionary Experimentation Program

The Evolutionary Experimentation Program (EEP) is an experiment run in Vault 87 to create improved soldiers. Unknown to their fellow vault dwellers, some inhabitants of the vault were subjugated to the experiments. Although reportedly having died an "unknown death", they were exposed to a modified FEV virus.

After exposure, the subjects underwent physical and mental changes. Their form became asexual and muscular, however their mental abilities diminished and they became overly aggressive. They became the Super Mutants found on the East Coast. The mutants found in Vault 87 mention that they capture humans and dunk them in the green stuff to make more Super Mutants, continuing the program.