Evolutionary Biology, Numerical Phylogenetics, Diptera Systematics, Evolution of Sepsidae, DNA-based Taxonomy
The Evolutionary Biology laboratory has three main research themes:
The international Tree-of-Life project has the goal to reveal the evolutionary relationships among the 1.7 million described species on our planet. In our lab, we use morphological and DNA sequence data for this purpose and our trees are not only used for elucidating relationships but also for reconstructing the evolution of a diverse array of traits that are important in contemporary evolutionary biology (e.g. sexual dimorphisms in Sepsidae, brain size changes in primates). The main focus taxon of our phylogenetic research is Diptera (mosquitoes, flies) and we are part of the NSF-funded FlyTree project that aims to reconstruct the relationships among the 150,000 described species. However, the laboratory has also facilitated phylogenetic research on corals, fish, crustacean, and birds. Within Diptera, the main emphasis is currently the Sciomyzoidea with approximately 2,500 species and the Calyptratae with approximately 18,000 species.
(2) DNA-based Taxonomy
Reliable species identifications and delimitations are important to society in general and the life sciences in particular. Without species identifications scientific results cannot be published and the published information on a species cannot be retrieved from the literature. With the decline of traditional taxonomy and the advent of affordable DNA sequencing, the field is currently discussing to what extent DNA sequences can replace traditional techniques for species delimitation and identification ('DNA barcoding', 'DNA taxonomy'). We are testing these proposals based on broad surveys of COI sequence variability in Metazoa. Special focus is on Sepsidae (Diptera) that is particularly suited for this purpose because it has many widespread species that live on several continents. We test whether these widespread species have large intraspecific, genetic variability and/or contain cryptic species-level diversity. Fortunately, Sepsidae can be maintained in the lab and we can also test for reproductive isolation. This allows us to assess whether morphological or DNA sequence information are better correlated with species limits. In other projects, we use DNA sequences for estimating the species richness of insect samples, matching the immature and adult stages of dragonflies, and barcoding fish species that are of commercial interest.
(3) Evolution of Sepsidae
The Sepsidae ('black scavenger flies') is with little more than 300 described species a relatively small and cosmopolitan taxon of flies that have attracted interest from biologists working in different fields ranging from the evolution of sexual dimorphisms over behaviour to developmental biology, and genomics. The main reasons for this interest are that many species possess intriguing morphological and behavioural characters, can be easily bred under laboratory conditions, and have short development times. In our lab, we extensively study the evolution of sexual dimorphisms and mating behavior. The data allow us to address how sexual dimorphisms evolve in response to changes of behaviour and to test competing theories for the evolution of sexual dimorphisms via sexual selection (e.g., sexual conflict vs. cryptic female choice). Our approach is comparative in that we use a phylogenetic tree for 77 sepsid species and study the behavior and morphology of a large number of species that we keep in culture (ca. 25 species).
The NUS Evolutionary Biology Laboratory in 2004 and has a long-standing interest in supporting undergraduate and postgraduate research. Students in our lab have published numerous papers in ISI journals and many of our undergraduate graduates continue with their postgraduate studies at NUS and/or foreign universities (Harvard University, University of California at Riverside, University of Zurich, Sheffield University, Cornell University, Centre National de la Recherche Scientifique France). Please contact A/P Rudolf Meier if you are interested in carrying out a research project.
Editorial Boards, Awards, etc:
For full list of publications, see link to Evolution Lab web