Rapid evolutionary radiation of marine zooplankton in peripheral environments
- †Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia; ‡Coral Reef Research Foundation, P.O. Box 1765, Koror, PW 96940, Palau; and ¶Department of Ecology and Evolutionary Biology, P.O. Box 951606, University of California, Los Angeles, CA 90095
-
Communicated by Robert T. Paine, University of Washington, Seattle, WA, May 2, 2005 (received for review January 28, 2005)
Abstract
Populations of jellyfish, Mastigias sp., landlocked in tropical marine lakes during the Holocene, show extreme genetic isolation (0.74 ≤ φST ≤ 1.00), founder effects (genetic diversity: 0.000 ≤ π ≤ 0.001), rapid morphological evolution, and behavioral adaptation. These results demonstrate incipient speciation in what we propose may be modern analogues of Plio-Pleistocene populations isolated in ocean basins by glacially lowered sea level and counterparts to modern marine populations isolated on archipelagos and other distant shores. Geographic isolation in novel environments, even if geologically brief, may contribute much to marine biodiversity because evolutionary rates in marine plankton can rival the most rapid speciation seen for limnetic species, such as cichlids and sticklebacks. Marine lakes present situations rare in their clarity for studying evolution in marine taxa.
Footnotes
-
↵ § To whom correspondence should be addressed. E-mail: mndawson{at}ucdavis.edu.
-
Author contributions: M.N.D. and W.M.H. designed research; M.N.D. performed research; and M.N.D. and W.M.H. wrote the paper.
-
Abbreviations: COI, cytochrome c oxidase subunit I; GLK, Goby Lake; NLK, Uet era Ngermeuangel; OLO, Ongael Lake; OTM, Ongeim'l Tketau; TLM, Tketau Lake.
-
Data deposition: The DNA sequence data reported in this paper has been deposited in the GenBank database (accession nos. AY902925-AY903047).
- Copyright © 2005, The National Academy of Sciences
