FN Archimer Export Format PT J TI Sister-species of eastern Pacific hydrothermal vent worms (Ampharetidae, Alvinellidae, Vestimentifera) provide new mitochondrial COI clock calibration BT AF CHEVALDONNE, Pierre JOLLIVET, Didier DESBRUYERES, Daniel LUTZ, Richard VRIJENHOEK, Robert AS 1:;2:;3:;4:;5:; FF 1:;2:;3:PDG-DRO-EP;4:;5:; C1 Ctr Oceanol Marseille, CNRS, DIMAR, F-13007 Marseille, France. UPMC CNRS INSU, Stn Biol Roscoff, UMR 7127, F-29682 Roscoff, France. IFREMER, Ctr Brest, F-29280 Plouzane, France. MBARI, Moss Landing, CA 95039 USA. Rutgers State Univ, IMCS, New Brunswick, NJ 08901 USA. C2 CNRS, FRANCE UNIV PARIS 06, FRANCE IFREMER, FRANCE MBARI, USA UNIV RUTGERS STATE, USA SI BREST SE PDG-DRO-EP IN WOS Ifremer jusqu'en 2018 copubli-france copubli-int-hors-europe IF 0.726 TC 70 UR https://archimer.ifremer.fr/doc/2002/publication-895.pdf LA English DT Article DE ;Allopatric speciation;Polychaetes;Polychaetes;Hydrothermal vent AB Introduction : The evolutionary age of some of the hydrothermal vent taxa have recently become a highly debated issue. Vestimentiferan worms (= siboglinid polychaetes) in particular, have been claimed to be as old as 430 million years based on the occurrence of fossilized tubes resembling those of currently known Vestimentifera (Little et al., 1997), while other authors, based on molecular data, have claimed they must be younger than 100 million years old (Black et al, 1997; Halanych et al., 1998). One explanation for this apparent discrepancy might be that tubes, such as those found in the Silurian fossil vent communities, did not belong to vestimentiferans, but rather to other tube-dwelling polychaetes. However, it is also possible that the choice of the molecular clock used to estimate the age of the vestimentiferan radiation from the molecular data, was simply not appropriate. Opportunities to accurately calibrate molecular clocks are relatively rare and cannot be generalized to all genes nor to all taxa. Such an opportunity appeared during a phylogeographic study of the hydrothermal-vent ampharetid polychaete Amphisamytha galapagensis Zottoli, 1983, which is widely distributed in the Eastern Pacific (Chevaldonne et al., in prep.). Originally described from the Galapagos Rift, this worm was later found at most vent sites of the East Pacific Rise (EPR), but also on the northeastern Pacific ridge systems (Desbruyeres, 1997). However, our ongoing molecular studies suggest that specimens from the northeastern ridges (Gorda, Juan de Fuca and Explorer ridges) should be assigned to a new cryptic sister-species that is distinct from A. galapagensis but very closely related (Chevaldonne et al., in prep.). These related worms occupy distinct ridge systems that formerly were part of the Farallon-Pacific Ridge, which was disrupted by subduction under the North-American Plate about 28.5 MYA (Atwater, 1989; Severinghaus & Atwater, 1990). Thus, they provide a unique opportunity to investigate the processes that lead to allopatric speciation events between vent assemblages of both ridge systems (Tunnicliffe, 1988), and to calibrate the rate of molecular evolution in deep-sea annelids. PY 2002 SO CBM - Cahiers de Biologie Marine SN 0007-9723 PU Station Biologique de Roscoff VL 43 IS 3-4 UT 000179938200034 BP 367 EP 370 ID 895 ER EF