Decreased Evolutionary Plasticity as a Result of Phylogenetic Immobilization and Its Ecological Significance

Abstract

This review addresses the phylogenetic immobilization phenomenon first described by I.I. Schmalhausen: decreased evolutionary plasticity as a result of stabilizing selection and deleterious mutations with habitat-specific fitness effects. Examples of immobilization are examined and their classification proposed. The role of environmental stability and morphological conservatism in the immobilization development is assessed. The applicability of the immobilization concept for the solution of evolutionary theory issues and the possibility of using immobilization for breeding purposes and the conservation of taxa with low evolutionary plasticity is discussed.