Below is a short outline of some of the areas in which groups in the Zoological Institute offer master projects. Further topics can be discussed with the group leaders. The projects are deliberately vague, as the details shall be worked out with the candidates. The development of the details of a project is an important part of doing a master thesis.
Interested candidates should contact the group leaders directly.
The adaptive radiations of cichlid fishes in the East African Great Lakes represent the most species-rich and diverse animal adaptive radiations. More than 1500 cichlid species have evolved in lakes Tanganyika, Malawi and Victoria in a period of no more than a few million years only. The evolutionary success of the cichlids can be attributed to several ecologically relevant and, hence, naturally selected traits such as mouth morphology, but also to sexually selected traits such as coloration (see Salzburger 2009; Molecular Ecology). This project aims to test whether ecological speciation is the causal factor of diversification in cichlids from Lake Tanganyika. To this end, closely related species pairs will be compared in terms of their ecological adaptations.
see www.evolution.unibas.ch/salzburger/ for further information.
Lake Tanganyika is the oldest of the three East African Great Lakes and harbors the morphologically, ecologically and genetically most diverse assemblage of cichlid fishes. Unlike in lakes Victoria and Malawi, where only one group of cichlids (the haplochromines) have radiated, the Tanganyikan cichlid assemblage consists of several parallel adaptive radiations. One of these are the Tropheini, a group of about 30 mostly rock-dwelling species. The aim of this project is to study the adaptive radiation of the Tropheini by integrating phylogenetic and population genetic analyses with eco-morphological assessments of all species belonging to this group.
see www.evolution.unibas.ch/salzburger/ "for further information.
Parasites and pathogens are the largest functional group of species on earth. In natural ecosystems, the vast majority of organisms suffer from some forms of infection. This goes hand in hand with reduced fecundity and survival, lower chances of mating and even with the extinction of local populations. Surprisingly, we still know only very little about the impact of infectious diseases on the ecology and evolution of their hosts. In a long term field project in Southern Finland, we study the impact of infectious diseases on host species of the genus Daphnia. Populations of Daphnia occur in small rock pools on the Skerry islands in the Baltic Sea. In our project we combine experimental work in the field with observations from natural populations. Within our Finland-project several options for master projects are open. The details of project will be worked out with potential master students, to fit the individual interests of the candidates.
see www.evolution.unibas.ch/ebert/ f
or further information.
Field station in Finland: http://luoto.tvarminne.helsinki.fi/english/
Evolution does not take place in isolation, but rather within a framework of interacting species. Darwin called this "the tangled bank of nature". While coevolution of complex communities is difficult to understand, science made good progress in understanding how pairs of antagonists coevolve. However, we still lack good examples of well documented cases of specific antagonistic coevolution. Host - parasite interactions are often cited as prime examples for this form of coevolution, but evidence is rather thin. Using field and laboratory research we try to understand the coevolution between Daphnia magna and two of its main parasites, the bacterium Pasteuria ramosa and the microsporidium Octosporea bayeri. Within this larger project a number of questions are well suited for master project. The details of project will be worked out with potential master students, to fit the individual interests of the candidates.
see www.evolution.unibas.ch/ebert/ for further information
Simultaneous hermaphrodites are male and female at the same time. Individuals therefore need to decide how to distribute limited reproductive resources to their male and female function (e.g. to the production of sperm or eggs). This decision is called sex allocation, and it is an important life history decision in all sexually reproducing organisms. In our earlier work we have shown that the free-living flatworm Macrostomum lignano is a highly suitable model organism to study this question. In this project we will study how different mechanisms of sexual selection, such as sperm competition and cryptic female choice, are important determinants of the evolution of sex allocation, and how these interact with the mating behaviour. The details of project will be worked out with potential master students, to fit the individual interests of the candidates.
see evolution.unibas.ch/scharer for further information or download a small flyer describing the Schärer Group.
In simultaneous hermaphrodites we can expect that individuals often have identical, and therefore incompatible, mating interests (e.g. both individuals may want to give, but not receive sperm). This can lead to a serious conflict of interest over how matings should occur and what should happen to the sperm an individual has received from a partner. These sexual conflicts lead to rapid evolution of sperm and genital morphology. In this project we will study these questions in members the free-living flatworm genus Macrostomum, combining a comparative approach, and experimental work in selected species. The details of project will be worked out with potential master students, to fit the individual interests of the candidates.
see evolution.unibas.ch/scharer for further information or download a small flyer describing the Schärer Group.
Animal families represent a particular social community. They are characterized by cooperation and conflicts, and also by the transient nature of the community which usually ends when offspring become independent of parental resources. Parents provide resources and offspring compete, sometimes subtly by communication and sometimes fiercely by aggression and siblicide. Possible Master project will focus on the role of behavioural control (parents or offspring, siblings) in the evolution of family interactions. Predictions from parent-offspring conflict and co-adaptation theory will be tested in our experimental system, the common earwig (Forficula auricularia). Earwig females show maternal care and their offspring are only partially dependent on maternal resources, allowing us to approximate in this system conditions that may have prevailed during the early evolution of animal families. The details of the project will be developed together with the Master student.
see evolution.unibas.ch/koelliker for further information.
Communication is one possibility for resolving social conflicts, but the conflicts make communication systems prone to cheating, which raises questions about the evolution of honest signalling. Insects are famous to use chemical communication (pheromones) in an astonishing variety of functional contexts ranging from species recognition to social parasitism. In a recent study (Mas et al. 2009. Proc. R. Soc. Lond. B.; doi:10.1098/rspb.2009.0498), our group could show a role for chemical communication in earwig parent-offspring interactions by condition-dependent hydrocarbons (waxy components) secreted on the cuticle of the offspring. In this project, the Master student will experimentally test in more detail the functional role of CHCs as (honest?) chemical signals in earwig family interactions. The details of the project will be developed together with the Master student.
see evolution.unibas.ch/koelliker for further information.
For many species, multiple mating with different partners is a common occurrence and has important consequences for both the structure and dynamics of family life and the traits of the offspring. While multiple mating can increase genetic variability and therefore enhance parental fitness, variation in paternity can also generate competition between offspring. This offspring conflict can result in higher mortality rates and require a greater level of maternal care to compensate such costs. While empirical evidence is currently lacking, recent studies in the European earwig Forficula auricularia, have indicated that the competitive ability of offspring and therefore the reproductive success of the mother, is strongly influenced by their mating partners. Therefore it is important for the females to either chose their mating partners carefully or develop post-mating strategies that control for paternity effects.
The master project will focus on the effect of multiple paternity in the European earwig. To this end, the master student will (1) assess paternity within offspring using molecular markers that he/she will previously establish, and (2) conduct behavioural experiments to identify factors influencing multiple mating, multiple paternity and the potential for paternity skew within clutches.
The song of male birds serves to attract females and to repel males. In studies on nightingales and on winter wrens, we aim to identify strategies that males pursue to accomplish these goals. For example, birds often sing in communication networks in which third individuals can obtain information on the quality and motivation of two males by listening to their singing interactions. We use song playbacks to simulate such interactions between males, to investigate the effect on the interacting birds themselves, or on other birds that listen to the interactions such as male neighbours or mate-searching females. To study how males choose their territories and how females choose their mates, we also use radio-telemetry.
see www.camargue.unibas.ch for further information.
Every year, about 2 billion songbirds migrate from Europe to sub- Saharan Africa. Long-distance migrants such as the nightingale have to cope with highly variable environmental conditions in different ecosystems across large geographical scales. To understand the ecology of a species and to take effective conservation measures, we need to know the migration routes of the birds. However, virtually nothing is known about the location of wintering grounds and about habitat use in sub-Saharan Africa in any European songbird. In collaboration with the Swiss Ornithological Institute (Schweizerische Vogelwarte Sempach), we study year-round movements, migration, and winter ecology of nightingales from breeding sites in England, France, Italy and Bulgaria.
see www.camargue.unibas.ch and www.vogelwarte.ch (link "Mitarbeit") for further information.
My research interest is genome evolution and factors dictating genomic stability. I use comparative genomics to study both similarities and differences in genomic regions of interest. I complement in-silico approaches that explore the genomic data available from public databases with laboratory experiments to verify the bioinformatic findings.
Telomeres are specialized structures that define the ends of linear chromosomes and protect them from loss of sequence and ectopic repair. Studies in different organisms reveal that these structures are not well conserved among eukaryotes, however most involve a specialized nucleoprotein complex - a telomere cap. The cap engages in an intricate relationship with the DNA damage-sensing and the double-strand repair machinery a set of protein that are very well conserved among eukaryotes. This project focuses on a cross-species comparison of recently discovered telomeric cap proteins in Drosophila. Comparative genetics among fruit flies reveals signatures of selection that can uncover functional information about these proteins. It also provides insights into the evolutionary processes that act on proteins associated with the telomere and into the pressures that lead to their divergence. Hypotheses built on this comparative approach will be tested experimentally in vivo, through mutagenesis and homolog swapping.
Development, survival, and reproduction of an organism depend on the faithful passage of genetic information from one generations to the next. The transmission of information, however, is not perfectly accurate and new mutations do occur in each generation, providing the genetic variation on which selection can act. There is ample evidence that mutation rate varies across the genome and some regions or sites are more mutable than others. The analysis of differences in nucleotide substitution frequency across genomes can shed light on the relative contribution of factors that affect mutation rate. In order to study these factors, I would like to take advantage of the facts that (i) most genomes are littered with "fossilized" interspersed repeated sequences (e.g. transposable elements) which are not under selection and that (ii) related species will share the same insertion in the same context in their genomes. By direct comparison of identical insertions between two species we can determine the nucleotide substitution level at the genomic coordinate where the insertion resides and deduce the local mutation rate over time that separates the two species. This approach can be sequentially applied to thousands of insertions throughout the genome and should help to investigate fluctuations in local mutation rate. Our studies in primates revealed a possible link between mutation rate and potentially error-prone mismatch repair. We are working on a system that would allow us to study the possible influence of DNA repair on mutation rate.
These are only two examples of the kind of questions my group is interested in. Others include the effects of mutations on the process of aging, evolution of replication and repair machinery, or effects of transposition on the mutation rate. I have established collaborations with a laboratory at the National institutes of Health (NIH) and the University of Iceland. The details of a masters project will be worked out together with the candidate. Specific master projects can also be found here.