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.
journal_name
Proc Natl Acad Sci U S Aauthors
Dawson MN,Hamner WMdoi
10.1073/pnas.0503635102keywords:
subject
Has Abstractpub_date
2005-06-28 00:00:00pages
9235-40issue
26eissn
0027-8424issn
1091-6490pii
0503635102journal_volume
102pub_type
杂志文章abstract::Evidence is presented for two natural transcription initiators positioned internally in the histidine operon of Salmonella typhimurium. They were detected using highly polar S. typhimurium his mutants as recipients for F' Escherichia coli his episomes. These intergeneric complementation tests provide a sensitive metho...
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