Lessons from the study of plant mating systems for exploring the causes and consequences of inbreeding in marine invertebrates

Abstract

AbstractMany benthic marine invertebrates resemble plants in being modular and either sessile or sedentary, and by relying on an external vector to disperse their gametes. These shared features, along with recent evidence of inbreeding in these taxa, suggest that theory and practice bearing on the evolutionary costs and benefits of inbreeding for plants could advance our understanding of the ecology and evolution of invertebrate animals. We describe how the theory for the evolution of inbreeding and outbreeding could apply to benthic invertebrates, identify and compare techniques used to quantify inbreeding in plants and animals, translate relevant botanical concepts and empirical patterns to their zoological equivalents, and articulate predictions for how inbreeding might be associated with major axes of variation in sessile and sedentary marine invertebrates. The theory of inbreeding and outbreeding provides critical insight into major patterns of life-history variation in plants and holds similar promise as a complementary perspective on the evolution of reproductive traits, lifespan, ecological strategies, and dispersal in marine invertebrates. Extending what we have learned from plants to marine invertebrates promises to broaden the general study of mating systems.