Journal article
Adaptive radiation in extremophilic Dorvilleidae (Annelida): diversification of a single colonizer or multiple independent lineages?
Ecology and evolution, Vol.2(8), pp.1958-1970
08/2012
Handle:
https://hdl.handle.net/2376/109792
PMCID: PMC3433998
PMID: 22957196
Abstract
Metazoan inhabitants of extreme environments typically evolved from forms found in less extreme habitats. Understanding the prevalence with which animals move into and ultimately thrive in extreme environments is critical to elucidating how complex life adapts to extreme conditions. Methane seep sediments along the Oregon and California margins have low oxygen and very high hydrogen sulfide levels, rendering them inhospitable to many life forms. Nonetheless, several closely related lineages of dorvilleid annelids, including members of
Ophryotrocha, Parougia, and
Exallopus, thrive at these sites in association with bacterial mats and vesicomyid clam beds. These organisms are ideal for examining adaptive radiations in extreme environments. Did dorvilleid annelids invade these extreme environments once and then diversify? Alternatively, did multiple independent lineages adapt to seep conditions? To address these questions, we examined the evolutionary history of methane‐seep dorvilleids using 16S and Cyt b genes in an ecological context. Our results indicate that dorvilleids invaded these extreme habitats at least four times, implying preadaptation to life at seeps. Additionally, we recovered considerably more dorvilleid diversity than is currently recognized. A total of 3 major clades (designated “
Ophryotrocha,” “Mixed Genera” and “
Parougia”) and 12 terminal lineages or species were encountered. Two of these lineages represented a known species,
Parougia oregonensis, whereas the remaining 10 lineages were newly discovered species. Certain lineages exhibited affinity to geography, habitat, sediment depth, and/or diet, suggesting that dorvilleids at methane seeps radiated via specialization and resource partitioning.
At methane seeps along the Cascadian margin, sulfide‐tolerant dorvilleid annelids dominate the benthos. A combination of preadaptation to high‐sulfide and low‐oxygen conditions, release from predation and competition, and resource specialization probably enabled multiple lineages of these worms to invade cold seeps and radiate into a diverse species assemblage.
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Details
- Title
- Adaptive radiation in extremophilic Dorvilleidae (Annelida): diversification of a single colonizer or multiple independent lineages?
- Creators
- Daniel J Thornhill - Auburn UniversityTorsten H Struck - Zoological Research Museum Alexander KoenigBrigitte Ebbe - Alfred‐Wegener‐Institute for Polar and Marine ResearchRaymond W Lee - Washington State UniversityGuillermo F Mendoza - Scripps Institution of OceanographyLisa A Levin - Scripps Institution of OceanographyKenneth M Halanych - Auburn University
- Publication Details
- Ecology and evolution, Vol.2(8), pp.1958-1970
- Number of pages
- 13
- Grant note
- NSF NURP/NOAA (OCE‐04‐25060; OCE‐04‐25317; UAF‐05‐0143)
- Identifiers
- 99900547371801842
- Language
- English
- Resource Type
- Journal article