The Particular Maternal Effect of Propagule Size, Especially Egg Size: Patterns, Models, Quality of Evidence and Interpretations

SYNOPSIS. Propagule size is perhaps the most widely recognized and studied maternal effect in ecology, yet its evolution is not well-under-stood. The large body of extant optimality theory treats parental invest-ment solely as an ecological problem, largely from the perspective of progeny. This approach has had limited success explaining the ubiquitous variation in propagule size within and among natural populations at most temporal and spatial scales. This problem aside, an unassailable gap in propagule size theory is that it pays little heed to the fact that offspring size is a joint phenotype of two individuals- the offspring and its mother. Hence, the ecology of mothers is decidedly as important in shaping the evolution of propagule size phenotypes. There are two reasons to suspect that this gap may account for the lack of success of optimality theory to explain variation in nature. The first is that optimality models of propa-gule size make no allowance for, nor can they explain, widespread, mul-tivariate correlations between maternal characters and clutch parameters,