A coming ‘Age of Interdependent Forms’ seems destined to mark the success of what could be called ‘despecialized/interspecific fitness’ among neotenic strains (perpetuating juvenile traits) of species such as humans and domestic animals. Humans as well as the first domesticants underwent a neotenic evolution in the wild during the repeated interglacial periods which, acting on a number of mammalian forms, selected against adult species-specific ancestral adaptations to a stable environment. Neotenic species continue to look and behave more like ancestral youths than adults—even after sexual maturity and throughout their life-history. As they retain lifelong youthful dependency motivations, they can easily, under suitable conditions, become interdependent forms. By the time of melting of the last Pleistocene glacier, all the domestic partners had already become more dependency-prone than formerly, and were behaviorally despecialized enough to form the alliance that is now changing the order of nature.