Dimorphic development in Streblospio benedicti: genetic analysis of morphological differences between larval types

摘要: The marine polychaete Streblospio benedicti exhibits two distinct larval types, making it a model for the study of developmental evolution. Females produce either large eggs or small ones, which develop into lecithotrophic planktotrophic larvae with concomitant morphological and life-history differences. Here, we investigate inheritance key traits that distinguish types. We use genetic crosses to establish influence maternal zygotic differences on phenotypes. find effect size number chaetae, while length these chaetae are also strongly influenced by genotype. Interestingly, distribution phenotypes produced suggests intermediate parental types should not be uncommon. Yet, despite gene flow between in natural populations, such intermediates rarely found nature, suggesting selection may maintaining modes.