Meeting Abstract
Phenotypic evolution in animals is constrained by the mechanics of early development. Large-scale evolutionary changes are initially shaped by developmental program, where simple trade-offs can ultimately result in a vast spectrum of physiological, morphological, and ecological differences. Because early development is strongly influenced by maternal effects, we focus on finding the genetic contribution of maternal background to developmental phenotypes. The polychaete Streblospio benedicti provides a unique opportunity to address this issue because it has two types of mothers who produce distinct offspring that differ in egg size, early development, and larval morphology. It is an ideal genetic model for understanding how transitions in developmental program evolve. Using crosses between these types, we reveal the distribution of genetic factors affecting a suite of developmental phenotypes. Our cross design further isolates the role of maternal genetic effects on development. By identifying the loci responsible for early developmental phenotypes, we begin to uncover how major transitions in development evolve.
