Ecology and evolution: neither separate nor merged

Hierarchy theory—conveniently acknowledged, generalized, expanded in time and taxonomical scope, and modified—is a standing candidate framework for the multiscale integration of ecology and evolution. In hierarchy theory, ecology continues to be a science of physical and chemical flows and cycles, a science of energy and matter transfers, a science of codetermination between biotic and abiotic (weather, soil, nutrients, geology) factors. In the dual hierarchy framework, ecology is, more generally, the science of interactions. A key methodological innovation in conceiving these interactions is network theory. The hierarchy perspective integrates ecology and evolution by studying and modeling how interactions determine a change in information content (the evolutionary hierarchy)