INCIDENCE AND CONSEQUENCES OF INHERITED ENVIRONMENTAL EFFECTS

Inherited environmental effects are those components of the phenotype that are derived from either parent, apart from nuclear genes. Inherited environmental effects arise as the product of parental genes and the parental environment, or their interation, and can include contributions that reflect the abiotic, nutritional, and other ecological features of a parental environment. Separating the impact of inherited environmental effects from inherited genetic effects on offspring phenotype variation has been and continues to be a challenge. This complexity is represented in the presentation of a qualitative model that distinguishes the possible paths of nongenetic cross-generational transmission. This model serves as the framework for considering the nature, in published works, of what was actually measured. Empirical evidence of inherited environmental effects arising from these pathways is documented for a diversity of plant and animal taxa. From these results one can conclude that the impact of inherited environmental effects on offspring can be positive or negative depending on the nature of the contribution and the ecological context in which the offspring exists. Finally, there is a description of theoretical and experimental efforts to understand the consequences of parental effects relative to their impact on population dynamics, the expression of adaptive phenotype plasticity, and character evolution.