title: Rapid evolutionary radiation of marine zooplankton in peripheral environments.
abstract: Populations of jellyfish, Mastigias sp., landlocked in tropical marine lakes during the Holocene, show extreme genetic isolation (0.74 < or = phiST < or = 1.00), founder effects (genetic diversity: 0.000 < or = pi < or = 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.
authors.affiliation: Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia.
authors.forename: Michael N
authors.initials: MN
authors.lastname: Dawson
authors.forename: William M
authors.initials: WM
authors.lastname: Hamner
mesh_terms: D000818:Animals; D044822:Biodiversity; D005075:Biological Evolution; D003576:Electron Transport Complex IV / Q000235:genetics; D004777:Environment; D019143:Evolution, Molecular; D018703:Founder Effect; D014644:Genetic Variation; D005828:Genetics, Population; D005843:Geography; D008928:Mitochondria / Q000378:metabolism; D008958:Models, Molecular; D015233:Models, Statistical; D008969:Molecular Sequence Data; D009792:Oceans and Seas; D019029:Palau; D010802:Phylogeny; D015048:Zooplankton / Q000235:genetics* / Q000502:physiology*
chemical_list: D003576:Electron Transport Complex IV