As evolution is the process of adapting living organisms to their environments, what changes could be realistically expected as the result of a prison environment? Shouldn't the purpose of prison be to change criminals into suitable members of society? If so, then prison is doing the exact opposite.

While in prison, a person develops evolutionary changes enabling them to survive in the bizarre prison society. Think of it as the Galapagos. When they are returned to normal society, of what use are the changes that occurred? If prison, or the rough equivalent, were redesigned based on evolution, it would more closely resemble a non-prison environment. It would provide the subject with the tools necessary to function in a non-prison environment. In fact, it would as much as possible mimic the normal environment, but with the proper mechanisms in place to ensure that appropriate evolution does occur.

If criminals can reasonably be considered people who failed to adapt to their environments, then certainly, the current prison environment does not correct their failed adaptations. If anything, it exacerbates the failures, and adds new adaptations that will inevitably fail upon release of the prisoner. If a person truly is incapable of adapting to the normal environment, then it would be a fascinating scientific fact that in some individuals, evolution is effectively disabled.