Mothers can influence the phenotype of their offspring in ways beyond the genes that are transferred. Such maternal effects are widespread, and continuing research demonstrates just how subtle and profound they can be. There is tremendous interdisciplinary interest in maternal effects because of their evolutionary implications, but several key, inter-related questions remain unanswered. Since the exciting discovery that egg yolks contain maternally derived steroid hormones researchers have been investigating the many ways by which yolk steroids can provide a mechanism for maternal effects on offspring phenotype. At this stage it seems likely that the consequences of yolk steroids for offspring are complex, may be positive or negative depending on the traits examined, and that they differ both within and among taxa. To date, however, there have been limited interactions between researchers studying this phenomenon in different taxa and it is not yet clear if large-scale patterns regarding the function of yolk steroids in offspring development occur. As part of the broader impacts of this symposium, speakers from the full spectrum of career stages (doctoral student to full professor) will be brought together to encourage collaborative opportunities that are essential to maintaining a vigorous discipline. Such interactions will encourage a more synthetic approach to the study of yolk steroids by bringing together, for the first time, researchers working on related questions in birds, reptiles, fishes, and amphibians.
