REITZEL, A.R.*; HEYLAND, A.; Boston University; University of Florida: The Evolution of Female Gamete Size: Comparisons of Plants and Marine Invertebrates

Maternal provisioning strategy is a key trait in the evolution of a species life history. Maternal investment in diverse taxa correlates with a number of life history characteristics including fecundity, development time, dispersal strategy, and juvenile success upon settlement. The diverse maternal allocation strategies we observe in today�s species are considered successful adaptations for maximizing fitness. Two groups, terrestrial plants and marine invertebrates, exhibit a tremendous range of maternal investment strategies between species. Plants exhibit a seed size range of 10 orders of magnitude with seeds in a single vegetative area spanning 5-6 orders of magnitude in size. Marine invertebrates also exhibit a similar, though smaller, range in egg size, approximately 4 orders of magnitude. Reproductive strategies in terrestrial plants and marine invertebrates can be divided into three stages: seed/embryo, dispersal stage (larva or seed), and juvenile. Each of these stages has been individually emphasized in studies to address potential selection pressures and their role in life history evolution. The function of each stage for plants and invertebrates is identical: maternal investment at maternal site, movement away from maternal site, and settlement/establishment in a unique site. What the likely selection pressures are and their relative magnitude for shaping maternal provisioning strategy have elicited a multitude of hypotheses. In our analysis, we compare and contrast these hypotheses for terrestrial plants and marine invertebrates to synthesize competing and complementary understandings for the evolution of maternal investment strategies.