Evolutionary and Systematic Botany
The principal aim of our scientific work is to celebrate the science of plant evolution and systematics in all of its diversity, juxtaposing the different forms, patterns, and processes observable in the living world (biodiversity) with the multitude of methodological tools being used in our scientific endeavour to study the multi-facetted and interwoven layers of diversity from the DNA level over the species level to the global scale of organismal patterns.
Plant systematics is a fascinating scientific discipline because it combines in a synthesising manner the extremely diverse and highly specialised fields dealing with the diversity of plant life on earth: (a) taxonomy as the cornerstone that enables us to grasp and cherish organismic diversity, collect information about it, and communicate this information to others, (b) phylogenetics that tries to reconstruct the spatial and temporal details of the history of these taxonomic entities, and (c) evolutionary biology that tries to explain the processes that lead to the ongoing differentiation populations and the emergence of new entities of biodiversity or to their loss.
Dealing with biodiversity in this systematic manner that is sometimes called ´abstact biodiversity research´ (i.e., describing biodiversity within a certain taxonomic group, reconstructing its history, and evaluating the processes that shape it), the field of systematics constitutes the counterbalance and logic complement of the ecological disciplines that are dealing with biodiversity on temporarily and spatially more restricted axes, but without the taxonomical restriction inherent to the systematic discipline (´concrete biodiversity reasearch´ addressing eco-systems and their structural and functional diversity along with questions of stability of organismal communities).
Fields of presently on-going research projects in the plant evolution and systematics group
1. Evolution of polyploidy complexes
Aspects of the evolutionary biology of plants, especially the importance of the processes of polyploidisation and hybridisation, form the major field of our current research: In the field of polyploidy, we are focussing on the two genera Leucanthemum (41 species; ploidy levels from 2x to 22x) and Leucanthemopsis (ploidy levels from 2x to 6x) of the Compositae-Anthemideae as a model groups to reconstruct the reticulate species trees caused by polyploid speciation (including novel next-generation-sequencing methods and novel species-tree reconstruction methods) and the consequences of polyploidy through crossing experiments and expression studies.
2. The role of hybridisation in plant evolution
We have studied hybridisation in plant groups as diverse as Salix, Viola, and Senecio. In the latter case, we are presently using transplantation experiments, food-choice experiments with slugs and snails, and phytochemical analyses in the Senecio nemorensis syngameon to infer the connection between the patterns of genetic variation observed in hybrid swarms, the variation of the spectra of secondary metabolites (here: alkaloids), and the consequences on herbivory-mediated fitness of parental and intermediate genotypes.
3. Biogeography, phylogeography, and phyloecology
Based on molecular phylogenetic reconstructions above and on population genetic analysis at and below the species level we are addressing questions concerning the temporal and spatial diversification of plant species and species groups (historical biogeography, phylogeography), especially in the Mediterranean region. Combining phylogenetic and phylogeographical reconstructions with GIS-based eco-climatological modelling of ecological niches we are aiming at a better understanding of causes and consequences of plant differentiation processes.
4. Phylogeny and taxonomy of Compositae-Anthemideae
The reconstruction of the tree of life is one of the fundamental problems of evolutionary research. In the camomile tribe (Anthemideae) of the sunflower family (Compositae, Asteraceae) with its 112 genera and its over 1700 species we are trying to incorporate results of molecular phylogenetic reconstructions into the taxonomy of the tribe.