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Published on: October 5, 2017
Glacial-driven vicariance in the amphipod Gammarus duebeni
1University of Rostock, Institute of Biology, Albert-Einstein-Strasse 3, D-18051 Rostock, Germany. lukas.krebes@uni-rostock.de
Molecular Phylogenetics and Evolution
|August 6, 2009
Summary
The amphipod Gammarus duebeni comprises five distinct lineages, with freshwater populations originating from multiple marine invasions. These genetic patterns reveal glacial history and competition shaping their distribution.
Area of Science:
- Evolutionary Biology
- Genetics
- Marine Biology
Background:
- The amphipod Gammarus duebeni exhibits an amphi-Atlantic distribution.
- Understanding its genetic diversity is crucial for evolutionary and ecological studies.
Purpose of the Study:
- To investigate the genetic diversity and population structure of Gammarus duebeni across marine and freshwater habitats.
- To elucidate the evolutionary history and speciation processes within the Gammarus duebeni complex.
Main Methods:
- Mitochondrial DNA sequencing (COI and ND2 genes) was performed on 306 specimens.
- Analysis included marine populations from the Atlantic, Baltic, and North Seas, and freshwater populations from Ireland, Cornwall, and Brittany.
Main Results:
- Five distinct allopatric lineages of Gammarus duebeni were identified.
- Freshwater populations originated from multiple marine invasions, with distinct lineages.
- Pleistocene glaciations and sea-level changes likely drove vicariant events, leading to 'glacial relict' freshwater lineages.
- Inter-specific competition, particularly with Gammarus pulex, appears to influence freshwater distribution, alongside salinity.
Conclusions:
- Gammarus duebeni is a complex of allopatric lineages shaped by historical climate events and ecological interactions.
- Freshwater populations represent multiple colonization events from marine ancestors.
- The complex serves as a model for studying allopatric speciation, habitat shifts, and adaptation to freshwater environments.
- Current subspecies classifications require re-evaluation pending nuclear genetic analyses.
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