ANNMARIE S. HWANG

(Former Name:  AnnMarie S. Chinen)

Research Interests:  Population Genetics, Molecular Evolution, and Conservation Genetics

 My research focuses on the use of the intertidal copepod, Tigrioups californicus, as a model system to study the outcomes of long-term hybridization.  As wildlife managers are faced with difficult decisions concerning both inbreeding and outbreeding depression, the success of conservation efforts will be largely dependant upon how well we are able to predict the outcomes of hybridizing populations.  T. californicus is a highly tractable system for examining hybridization over multiple generations. Because of its short generation time (~23 days), we can observe the evolutionary trajectories of experimental populations and determine their genetic composition in transitory states of evolution.

In our lab, previous studies under benign conditions have shown significant hybrid breakdown in early generations, but there is also evidence that hybrid fitness problems may be repaired in later generations.  Additionally, some studies suggest that hybrids may be favored under environmental stress. 

My research examines the outcomes of experimental replicate swarms under both benign and stressful conditions.  Specifically, I am assessing the fitness, morphological and genetic consequences of hybridization under constant salinity stress. This 18-month study examines experimental hybrid populations reared under constant salinity stress and surveyed at regular intervals for morphometric, molecular and fitness components.  In particular I am interested in determining (1) if environmental stress alters the magnitude or duration of outbreeding depression and (2) whether or not hybridization can generate new genetic variants that are favored under environmental stress.  This current project is among the most rigorous studies conducted on the genetic and phenotypic outcomes of animal hybridization under stress and it provides an example of the consequences of long-term hybridization in a manner that would be difficult to achieve in most threatened populations.