To understand the ecology in which organisms are embedded is very important to understand the stability of populations and ecosystems. During my early scientific career I studied the ecology and phylogeny of free-living Polynucleobacter necessaries bacteria. The populations I studied are highly specialised to humic substances rich ponds mainly in the European alps, but in general these bacteria have adapted to various environmental conditions, like a facultative endosymbiotic life style in ciliates, and represent a group of organisms that are obviously evolutionary plastic. However, several experiments suggest that they are unable to adapt to new or changed conditions under natural conditions.
Currently I use beech tree bacteria to get further insight into how bacteria evolve in response to a complex ecological background. Beech tree communities are perfect study organisms as they are diverse in species, represent various locally adapted island communities located often at the same tree, are highly robust to laboratory conditions and well established in evolutionary experiments. In interaction with the background community adaptation of a focal organism might theoretically be constrained or promoted. The direction of evolutionary path might strongly depend on the ecological interaction, which is my main research focus at the moment. This research will be combined with maintenance of biodiversity and phylogenetic comparisons and different patterns of directional or balancing selection.
Sex and Recombination
“Sex is the Queen of Problems in Evolutionary Biology” as Graham Bell stated more than 20 years ago. And it is still today! Sexual reproduction, especially between male and female organisms, is a puzzling question as it involves a lot of theoretical disadvantages and asexual sibling have been shown experimentally to outcompete their sexual relatives. Recombination and segregation have the potential to disrupt genetic associations and to reduce individual fitness. Sex is in general thought to increase genetic variation, which involves evolutionary advantage. But this is only true for negative linkage disequilibria, where genotypes of intermediate fitness are in excess. Forces to create negative genetic associations are mainly drift, negative epistasis or spatial and temporal variation in the environment and should deeply influence short and long term effects of sexual reproduction. For my PhD I was looking on the evolutionary and ecological consequences of sexual and asexual reproduction in rotifers. I compared ecological interactions between sexual and asexual clones and followed adaptive evolution in response to different environmental conditions. How sexual reproduction shapes the underlying genetics that forms adaptive evolution is my major interest here.
For my future research I want to apply more molecular tools to my experimental populations and get insight into methods like genomics and computational biology to understand the architecture of evolving genomes in a better way. Furthermore, I have a big interest in learning more about mathematical modelling, because I think that this is a nice tool that will help us to understand and summarize our experimental data in a better way.