Potential Publications in Fish Phylogeography Project
Are you
- Interested in evolution?
- Experienced in bioinformatics, computational biology or statistics?
- Free to focus on the phylogeographic analysis of sequence data for 3-4 weeks?
- Keen to get a high-impact publication?
…then read on
We are looking for a collaborator to work with on our interesting, novel, well-funded evolutionary biology project with high publication expectations (at Monash University). Specifically we are seeking someone to assist us with the analysis of genetic sequencing data. This is an excellent opportunity for a recent PhD graduate, or an early career researcher with experience in bioinformatics, computational biology or statistics.
The crater lakes in Nicaragua’s Pacific Basin region are proving to be one of the most fertile areas in the world for novel biological research. In addition to the rugged beauty of the surrounding terrain and the lush tropical forest, underneath the lake’s surfaces evolutionary processes are occurring that many once considered incredibly implausible and that still remain highly controversial today. Specifically, several species of closely related cichlid fish (Amphilophus sp.) are co-existing in sympatry, with speciation events having occurred despite a lack of geographical barriers to prevent gene flow. Despite more than 150 years passing since the publication of The Origin of Species, the relative importance of the mechanisms generating and shaping organismal diversity still continue to be debated vigorously. Understanding these mechanisms that maintain and promote variation in traits under natural selection is therefore a major challenge for evolutionary theory.
Cichlid fishes are a diverse group that are well known for their ability to rapidly evolve and diversify. Closely related species often only vary conspicuously in regard to body colour and trophic characteristics, with differences also occurring within species. We travelled to Nicaragua earlier last year to sample Amphilophus cichlids from Nicaragua’s two great lakes, Lake Nicaragua and Managua. We specifically targeted two species, Amphilophus labiatus and Amphilophus citrinellus. These two species are closely related, however they differ in their diet and key aspects of their trophic morphology. In particular A. labiatus has large fleshy lips, a trait that pops up in several cichlid species across their range (mainly Africa and South/Central America).
Amphilophus labiatus has a patchy distribution, with populations often isolated by tens of kilometres. Elsewhere in Nicaragua, phenotypically similar forms of thick-lipped Amphilophus cichlid (found in different small crater lakes) appear to have occurred due to independent parallel adaptation, within a remarkable short time period. Which leads to the question did the thick-lipped phenotype arise once in the Nicaraguan great lakes or multiple times (in parallel) across the lakes in response to local environmental conditions? Amphilophus citrinellus lives in sympatry with A. labiatus, however it does not possess thick lips, it also has a significantly different diet and a much wider distribution. Importantly, A. citrinellus has two distinct forms that coexist together across much of the lakes. These forms differ in their general body colour, diet and also in the shape and size of the lower pharyngeal jaw, which is thought to be a fundamental cause of phenotypic differentiation and ecological speciation in cichlids via divergent evolution.
We (PhD Candidate Will Sowersby and Assoc. Prof. Bob Wong) have collected samples across the lakes for diet, morphometric and genetic analysis. This work is begin conducted as part of an international collaboration with Dr. Marta Barluenga (Museo Nacional de Ciencias Naturales, Spain), Prof. Walter Salzburger (University of Basel, Switzerland) and Dr. Topi Lehtonen (University of Turku, Finland), who all have multiple publications on Amphilophus cichlids in high impact factor journals. The genetic samples have been prepared for RAD tag sequencing analysis in Europe and the data will be available for analysis shortly.
Specifically we are looking for someone to generate the phylogeography of the two species from multiple locations in both lakes and at the level of gene flow between and within locations.
All samples have been collected and are currently being analysed, we estimate that this will be a short-term commitment. We are looking for a collaborator to work with us for a matter of weeks, starting in March, however we are somewhat flexible with dates at this stage. You should have a PhD in a relevant subject area (e.g. computational biology, bioinformatics, statistics and genomics).
If you are interested please contact Will Sowersby for any further information: [email protected]