It is well established that interpopulation hybrids can experience enhanced fitness in the first generation, followed by depressed fitness in the second generation. Some evidence suggests hybrid fitness problems can be repaired in later generations, and that hybrids may be favored under environmental stress. This study uses the intertidal copepod Tigriopus californicus to assess hybridization over multiple generations in both benign and stressful conditions (high salinity). Experimental hybrid populations will be maintained for up to 17 months and assayed for genetic, morphometric and fitness components every two generations. Tigriopus' short generation time, ease of husbandry and abundance of population-specific molecular markers make it a particularly tractable system for this type of experiment.

Results will test the specific hypothesis that hybridization can create genetic variants that are favored under environmental stress, and will help to elucidate the role of hybridization in the formation of new species. This work is also directly relevant to current concerns about the impacts of invasive species mixing with native populations, or farmed organisms mixing with wild populations. Using the Tigriopus model system allows the effects of benign vs. stressful conditions to be assessed in a rigorous fashion that would be difficult to achieve for most species of concern. Additionally, this project supports opportunities for undergraduate research and training at a university that serves a broad and diverse urban area.

Agency
National Science Foundation (NSF)
Institute
Division of Environmental Biology (DEB)
Type
Standard Grant (Standard)
Application #
0709775
Program Officer
Nancy J. Huntly
Project Start
Project End
Budget Start
2007-07-01
Budget End
2008-06-30
Support Year
Fiscal Year
2007
Total Cost
$12,000
Indirect Cost
Name
University of Southern California
Department
Type
DUNS #
City
Los Angeles
State
CA
Country
United States
Zip Code
90089