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Rapid parallel adaptive radiations from a single hybridogenic ancestral population
Alan G Hudson1, Pascal Vonlanthen, Ole Seehausen
1Division of Aquatic Ecology & Macroevolution, Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland. alan.g.hudson@gmail.com
Proceedings. Biological Sciences
|August 6, 2010
Summary
Genomic study of Alpine lake whitefish reveals complex evolutionary history, including hybrid origins and sympatric speciation. Human impacts threaten this unique radiation, highlighting conservation needs for endemic fish populations.
Area of Science:
- Evolutionary biology
- Genomics
- Ecology
Background:
- The Alpine lake whitefish (Coregonus lavaretus) species complex exemplifies recent adaptive radiation post-glacial retreat.
- Endemic flocks exhibit distinct morphologies, diets, and reproductive strategies, suggesting rapid diversification.
Purpose of the Study:
- To investigate the phylogenetic relationships within and among Alpine lake whitefish flocks using genomic data.
- To identify centers of genetic diversity and understand the evolutionary processes driving speciation in this complex.
Main Methods:
- Analysis of over 1000 Amplified Fragment Length Polymorphism (AFLP) loci.
- Sequencing of mitochondrial control region DNA.
- Phylogenetic tree-based and population genetic analyses.
Main Results:
- Significant cytonuclear discordance indicates a hybrid origin from at least two glacial refugial lineages.
- Seven distinct genetic clusters were identified across seven lake systems.
- Evidence for sympatric speciation and parallel evolution of phenotypes was found, alongside human-induced gene flow and diversity loss.
Conclusions:
- The Alpine lake whitefish radiation is characterized by complex origins and ongoing diversification, including sympatric speciation.
- Human activities pose a significant threat to the genetic diversity and long-term survival of these unique fish populations.
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