Trade-offs among complexity, regeneration and defector risk across fraternal cooperative organizations

Fraternal cooperative organizations (FCOs), which encompass metazoan multicellularity and eusociality, rely on a division of labour among specialized members. I present a comprehensive framework to concretely classify FCO members by specialization, state transition and potency, which are associated with complexity, regeneration and defector susceptibility of the group. Across FCOs, specialization hinders plasticity, potency and regenerative capacity due to sophisticated fate-determination systems. In addition, such a sophisticated system is vulnerable to spontaneous malfunctions, generating dysfunctional or cheating group members (cancers or excessively produced queens) characterized by unregulated proliferation/reproduction. The framework explains why complex FCOs exhibit limited regeneration and why highly regenerative FCOs cannot become complex. As an exception, plants can be complex and regenerative owing to their structural robustness against cancer.