Evolutionary Experimentation Program

The Evolutionary Experimentation Program (EEP) was an experiment run in Vault 87 on the orders of the United States government to create improved soldiers for the American military. Unknown to their fellow Vault dwellers, some inhabitants of the Vault were subjected to the experiments. Although reportedly having died an "unknown death", they were in fact exposed to a genetically modified version of the FEV virus.

After their infection, 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 in the Capital Wasteland. The mutants found in Vault 87 mention that they capture humans and dunk them in the vats filled with the green nutrient solution that feeds the FEV to make more Super Mutants, continuing the program.