A staggering diversity of complex reproductive strategies has evolved in livebearing animals. The evolution of these innovative reproductive adaptations is one of the most significant phenomena in the rise of multicellular organisms.
We study how these complex adaptations evolve and what their developmental consequences are for maternal-fetal interactions during pregnancy. We focus our studies on livebearing fishes of the family Poeciliidae, because complex reproductive adaptations (e.g. placentation, superfetation, clonality) evolved multiple times independently in this family.