Understanding the processes generating biodiversity and the factors responsible for changes in biodiversity in space and time are of fundamental importance for evolutionary biologists, ecologists and biogeographers. These are also questions of main interest for the Systematic Zoology and Biodiversity group. The group uses a set of model groups, mainly invertebrate taxa such as mollusks, leeches and corals, but also vertebrate groups such as fish and birds to study evolutionary changes in various places on earth.

Based on a research strategy that explicitly addresses spatial and temporal aspects of evolution on various scales, the group studies evolutionary events ranging from Miocene to Holocene times and from continent-wide to local scales.

Ongoing research projects address questions such as:

• What are the factors driving adaptive and non-adaptive radiations? This question is studied in European spring snail taxa and North American slug species within the context of selection vs. genetic drift.
• Why do species differentiate and how do environmental events affect rates of speciation? These questions are concerned with the role of geological and environmental changes on rates of speciation in ancient lakes.
• How did Pleistocene refugia contributed to the genesis of biodiversity? Based on the study of refugia in Tibet, Patagonia, The Pacific Northwest, Europe, and Australia, the contribution of these refugia on speciation processes and qualitative differences among refugia are being studied.
• What are the factors causing an unequal distribution of taxonomic and genetic biodiversity? This question addresses the effects of abiotic and biotic factors on the distribution of endemic diversity in ancient lake systems.
• How does human impact affect the distribution of disease-causing vectors? This question centers around the influence of man-made changes (such as the construction of the Three Gorges Dam in China) on the co-evolution of the schistosomiasis host-parasite system.
• What makes species invasive? This question focuses on the role of environmental changes enabling invasive species to conquer ancient lakes and the competitive advantage of invasive Quagga mussels in Europe.

Besides these species-driven questions, the Systematic Zoology and Biodiversity group also studies theoretical aspects of evolution related to molecular clock approaches and modeling of distribution of biodiversity on various levels.