Postzygotic Isolation Evolves before Prezygotic Isolation between Fresh and Saltwater Populations of the Rainwater Killifish, Lucania parva. (30th January 2012)

• Record Type: Journal Article
• Authors: Kozak Kozak, Genevieve M. Genevieve M.; Rudolph Rudolph, Arthur B. Arthur B.; Colon Colon, Beatrice L. Beatrice L.; Fuller Fuller, Rebecca C. Rebecca C.
• Other Names: Sawamura Sawamura Kyoichi Kyoichi Academic Editor.
• Is Part Of: International journal of evolutionary biology. Volume 2012(2012)
• Publication Date: 2012-01-30
• Subjects: Evolution (Biology) -- Periodicals; Biological Evolution; Biological Phenomena; Evolution (Biology); Electronic journals; Periodical; Fulltext; Internet Resources; Periodicals; Periodicals; 576.805
• DOI: 10.1155/2012/523967
• Languages: English
• ISSNs: 2090-8032

Abstract

Abstract : Divergent natural selection has the potential to drive the evolution of reproductive isolation. The euryhaline killifish Lucania parva has stable populations in both fresh water and salt water. Lucania parva and its sister species, the freshwater L. goodei, are isolated by both prezygotic and postzygotic barriers. To further test whether adaptation to salinity has led to the evolution of these isolating barriers, we tested for incipient reproductive isolation within L. parva by crossing freshwater and saltwater populations. We found no evidence for prezygotic isolation, but reduced hybrid survival indicated that postzygotic isolation existed between L. parva populations. Therefore, postzygotic isolation evolved before prezygotic isolation in these ecologically divergent populations. Previous work on these species raised eggs with methylene blue, which acts as a fungicide. We found this fungicide distorts the pattern of postzygotic isolation by increasing fresh water survival in L. parva, masking species/population differences, and underestimating hybrid inviability.