Dr. Yoshan Moodley
Konrad-Lorenz-Institut für Vergleichende Verhaltensforschung
Department für Integrative Biologie und Evolution
Veterinärmedizinische Universität Wien
T +43 (1) 489 09 15 835
F +43 (1) 489 09 15 801
E-Mail an Yoshan Moodley senden [Link 1]
I began at the KLIVV in January 2009. I was hired to head KLIVV’s Molecular Genetics Laboratory, collaborate with KLIVV scientists, and develop my own research program. My main research interests are in evolutionary genetics and molecular ecology.
- I am using be a continentally distributed diverse antelope species called the imbabala (Tragelaphus sylvaticus) as a model to unravel the evolutionary mechanisms driving intraspecific convergence in phenotype. There is some evidence that the main process involved in the evolution of convergent montane forms is sexual selection.
- I also use the spiral-horned antelopes of Africa to infer which temporal and spatial combinations of speciation processes have led to the astonishing diversity extant among the tragelaphines.
- The black rhinoceros (Diceros bicornis) is possibly the most high-profile animal in modern-day conservation, yet virtually nothing is known about its evolutionary history. Utilising a large pre-existing sample, in collaboration with Michael Bruford of Cardiff University, both mitochondrial and nuclear markers will be used to establish the phylogeographic relationships between extinct and extant black rhino populations as well as historical patterns of dispersal and colonization.
- In addition to this, at the KLIVV I am collaborating with Hans Winkler in establishing a DNA bar-coding database for Austrian bird species, as well as with Richard Wagner in determining the distribution of genetic heterogeneity among groups of spatially distributed wild cichlids in Lake Tanganyika.
I joined the KLIVV in January 2009. My main research interests are evolutionary genetics and molecular ecology. I run my own research program and also collaborate on several projects run by other scientists at the KLIVV. Among the projects within my own research program are:
Convergence in a free ranging mammal
In collaboration with Dr. Andrea Manica, Cambridge University
Theory predicts that evolution is a parsimonious process, where the explanation requiring the fewest assumptions is most likely to be correct. However, under similar environmental conditions, convergent phenotypes may evolve independently, adding homoplasy to a phylogenetic hypothesis based on parsimony. This phenomenon occurs rarely within a species, making studies on the molecular basis of convergent evolution difficult. One species, however, the mbabala (Tragelaphus sylvaticus) is continentally distributed and exhibits very high phenotypic diversity which appears to be environmentally determined. A recent mitochondrial DNA survey showed that convergent ecotypes did not evolve parsimoniously, nor did they evolve in response the same environmental stimuli. Montane ecotypes inhabiting the Ethiopian Highlands (meneliki and powelli), the Imatong Mountains (barkeri), Mt Elgon (heterochrous), the Gregory Rift Highlands (haywoodi) are all phenotypically similar, yet genetically unrelated (Fig. 1).
What molecular mechanisms are involved in convergent evolution? Apart from the intraspecific variation in phenotype, the mbabala’s close evolutionary relationship to the cow means that, unlike many other mammals, these species potentially benefit from a wealth of markers generated by cow genome diversity studies in the past and by tools generated from the bovine genome project. We have therefore adopted the candidate gene approach, to target those genes associated with specific phenotypic characteristics. One obvious suite of phenotypic characters which separate montane, arid zone, forest and savanna ecotypes is their coat colour and pattern. This will include the melanocortin-1 receptor gene (MC1R) and tyrosinase-related protein genes TYRP1 and TYRP2. Other candidate genes include the growth hormone receptor (associated with body size), keratin associated proteins and stratafin (associated with hair and horn growth).
In collaboration with Dr. Ann Apio, Umutara Polytechnic, Prof. Hans Siegismund, University of Copenhagen, Dr. Rasmus Heller, Gulbenkian Institute of Science, Dr. Paul O’Donoghue, University of Chester, Dr. Carolin Kosial, University of Veterinary Medicine, Vienna.
The bovids are among the most adaptable of all mammals. They are a family of ruminants comprising a remarkable 141 species, and they are the dominant herbivores on the African continent. Most diverse among the bovids are the tragelaphines, a genus consisting of ten species that occur throughout sub-Saharan Africa in almost every conceivable habitat from lowland rainforests to montane moorlands and from wetland swamps to semi-deserts. They also vary strikingly in size, shape and behaviour from the diminutive and solitary kéwel (Tragelaphus scriptus) to the massive and highly gregarious eland (T. oryx). This remarkable tragelaphine diversity in morphotype, physiology, behaviour and life history strategies provides an expedient model for studying in situ the complex evolutionary processes at work during the Plio-Pleistocene.
The data to be generated will include whole mitochondrial genomes, between 100–200 kb of autosomal sequence data and functional gene sequences, the latter of which will be obtained by hybridisation to a bovine cDNA chip, and resequencing of closely related tragelaphine homologues. Using these large high-resolution data sets, we will identify the fine molecular signatures left by evolutionary forces over time and ascertain the combinations of forces acting on populations as a result of changing paeleoclimates. Of particular interest will be the case of secondary contact between two species, the imbabala (T. sylvaticus) and the kéwel, and the molecular consequences of gene flow across their hybrid zone in Uganda.
While possessing an unusually high level of diversity, the tragelaphine antelopes also show a high level of convergence with similar phenotypes evolving more than once and possibly as a result of different evolutionary forces. This study will also use functional gene data to determine whether convergent phenotypes arise from the same or different mutational changes. Convergent evolution is often assumed to be adaptive, and hence a product of natural selection. However, both genetic drift and gene flow are also able to account for convergence in certain evolutionary scenarios.
The evolutionary history of the African rhinoceros
In collaboration with Prof. Michael Bruford, Cardiff University, Dr. Paul O’Donoghue, University of Chester, Prof. Chris Walzer, University of Veterinary Medicine, Vienna, Dr. Robert Hermes, IZW Berlin, Prof. Antoinette Kotze, NZG, Pretoria.
Considering the interest in the black rhino, a critically endangered flagship species, it is surprising that its evolutionary history is largely unknown. One possible reason for this may be the difficulty in obtaining samples from populations distributed on a continental scale and that, in many cases, black rhinos are extinct across much of their former range. The few genetic surveys that have been carried out since the 1970's have focussed on obtaining molecular markers from which levels of genetic diversity can be determined. While the assessment of genetic diversity is of critical importance to the conservation of black rhinos, the phylogeographic relatedness between geographic populations is a prerequisite for understanding the evolutionary events that have given rise to present-day subspecies and identifying modern evolutionarily significant units for conservation.
Using large, pre-existing DNA samples from collaborators, the specific objectives of this study are
- To assess the intraspecific phylogeographic relationships of black rhinoceros across their former distributional range
- to identify demographic trajectories from the pattern of mitochondrial (mt) DNA diversity in populations
- to identify historic patterns of dispersal and colonisation across Africa.
- Ph. D. (Conservation Genetics); Department of Chemical Pathology, University of Cape Town, South Africa (2002); Title of Thesis: "Population structuring in southern African zebras"
- M. Sc. (Population Genetics); Department of Zoology, University of the Witwatersrand, South Africa (1998); Title of Dissertation: "Gene flow, dispersal and systematics in sub-populations of the flat lizard, Platysaurus intermedius"
- B. Sc. (Biological Sciences); School of Biological Sciences, University of Auckland, New Zealand (1996)
- Evolutionary Geneticist, Konrad Lorenz Institute for Ethology, Vienna, Austria (2009- )
- Post-doctoral Research Fellow, Max Planck Institute für Infektionsbiologie, Berlin, Germany (2005-2008) Project title: "Tracing human migrations via Helicobacter pylori"
- National Research Foundation (NRF) Post-doctoral Research Fellow School of Biosciences, Cardiff University, Wales, United Kingdom (2003-2005); Project title: "Pan-African phylogeography and adaptation in the ubiquitous Tragelaphus scriptus (bushbuck) complex"
Awards and Scholarships
"A" Bursary, University of Auckland
Senior Prize, Faculty of Science, University of Auckland
Postgraduate Merit Award, University of the Witwatersrand
Scholarship from the Deutscher Akademischer Austausch Dienst
Bursary from the National Research Foundation
Post Doctoral Fellowship from the National Research Foundation
Grant from the International Rhinoceros Foundation (€56.000)
Best Paper Award for 2008 for the paper:
Societies and Organisations
- Member of the IUCN/SSC Equid Specialist Group
- Scientific Advisor to the Cape Mountain Zebra Working Group
- Biodiversity and Ecological Processes Group, Cardiff University
Department of Biochemistry, University of the Witwatersrand, Johannesburg, South Africa
Department of Medical Biochemistry, University of Cape Town, South Africa
Department of Nature Conservation, Government of the Western Cape, South Africa
Department of Genetics, University of Stellenbosch, South Africa
Cape mountain zebra working group meeting, Jonkershoek, South Africa
School of Biosciences, Cardiff University. United Kingdom
Museum für Naturkunde, Humboldt Universität zu Berlin, Germany
Institute of Physicochemical Medicine, Moscow, Russia
Department of Human Genetics, University of Cape Town, South Africa
Darwin Series, Research Institute for Wildlife Ecology, Vienna, Austria
Publikationen [Link 2]