Worldwide Genotyping in the Planktonic Foraminifer Globoconella inflata: Implications for Life History and Paleoceanography
| Type | Article | ||||||||
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| Date | 2011-10 | ||||||||
| Language | English | ||||||||
| Author(s) | Morard Raphael1, 2, Quillevere Frederic1, Douady Christophe J.3, 4, de Vargas Colomban2, de Garidel-Thoron Thibault5, 6, Escarguel Gilles1 | ||||||||
| Affiliation(s) | 1 : Univ Lyon 1, CNRS, UMR 5276, Lab Geol Lyon Terre Planetes Environm, F-69622 Villeurbanne, France. 2 : UPMC, CNRS, UMR Evolut Plancton & PaleoOceans 7144, Stn Biol Roscoff, Roscoff, France. 3 : Univ Lyon 1, CNRS, UMR Ecol Hydrosyst Fluviaux 5023, F-69622 Villeurbanne, France. 4 : Inst Univ France, Paris, France. 5 : Aix Marseille Univ, CEREGE UMR6635, Aix En Provence, France. 6 : CNRS, CEREGE UMR6635, Aix En Provence, France. |
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| Source | Plos One (1932-6203) (Public Library Science), 2011-10 , Vol. 6 , N. 10 , P. - | ||||||||
| DOI | 10.1371/journal.pone.0026665 | ||||||||
| WOS© Times Cited | 38 | ||||||||
| Abstract | The planktonic foraminiferal morpho-species Globoconella inflata is widely used as a stratigraphic and paleoceanographic index. While G. inflata was until now regarded as a single species, we show that it rather constitutes a complex of two pseudo-cryptic species. Our study is based on SSU and ITS rDNA sequence analyses and genotyping of 497 individuals collected at 49 oceanic stations covering the worldwide range of the morpho-species. Phylogenetic analyses unveil the presence of two divergent genotypes. Type I inhabits transitional and subtropical waters of both hemispheres, while Type II is restricted to the Antarctic subpolar waters. The two genetic species exhibit a strictly allopatric distribution on each side of the Antarctic Subpolar Front. On the other hand, sediment data show that G. inflata was restricted to transitional and subtropical environments since the early Pliocene, and expanded its geographic range to southern subpolar waters similar to 700 kyrs ago, during marine isotopic stage 17. This datum may correspond to a peripatric speciation event that led to the partition of an ancestral genotype into two distinct evolutionary units. Biometric measurements performed on individual G. inflata from plankton tows north and south of the Antarctic Subpolar Front indicate that Types I and II display slight but significant differences in shell morphology. These morphological differences may allow recognition of the G. inflata pseudo-cryptic species back into the fossil record, which in turn may contribute to monitor past movements of the Antarctic Subpolar Front during the middle and late Pleistocene. | ||||||||
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