Meeting Abstract

95.4  Thursday, Jan. 7  Measuring the heritability of plasticity in a colonial model hydroid, Hydractinia symbiolongicarpus RYAN, C.A*; DUDGEON, S.R.; California State University, Northridge; California State University, Northridge carly.ryan.16@csun.edu

The influence of environmental variation on the phenotypes of individuals has long been of interest to researchers. In species which demonstrate a high level of phenotypic plasticity, individuals have a mechanism to cope with living in a predictably unpredictable environment. The phenotypic changes wrought by this mechanism however have the potential to alter the fate of individual organisms, thus affecting allele frequencies, which can affect the downstream evolution of the species. However, it is largely unknown if the extent of plasticity itself is a heritable trait which is subject to selection. That selection can act on the shape of a reaction norm is an idea that has been postulated, but has rarely been tested by explicit experimentation. We have explicitly addressed this hypothesis in the colonial model system Hydractinia symbiolongicarpus using the concepts of clonal repeatability and quantitative genetics to ask the question: is the morphological plasticity exhibited by these encrusting hydroids in response to hypoxia in fact a quantifiable, heritable trait?