Prof. Dr. Thomas Bartolomaeus
Comparative ultrastructure and evolution of the Invertebrates
Research focus
Evolution
Taxonomy
The identification of nemertine species is hardly possible on the basis of external features, therefore the histological organization is used for determination. Because this information is hardly available and its acquisition is often only possible by comparison with collection-based material in museums, we build up a database on the most important Northern European nemertines in a long-term project. This database contains biological, ecological and molecular marker sequences (COI, 18S, 28S, 16S) as well as complete, high-resolution digital section series, which allow a very fast comparison of information. The data are collected in the context of Bachelor theses and facilitate the identification of species using molecular and morphological markers. The development and maintenance of the database under Morph·D·Base is done in collaboration with Jörn von Döhren and Peter Grobe (ZFMK Bonn).
Ultrastructure and phylogeny of polychaetes (Annelida)
Despite their high taxon specificity, chaetae show a high structural diversity among polychaetes, so that they play an important role in taxonomy. Chaetae shape and orientation are determined by a single cell, the chaetoblast, the microvilli of which pattern changes during chaetogenesis. Changes in the superficial microvilli patttern "frozen in time" determine the specific state of a chaeta. Due to the taxon specificity of chaetae, it can be assumed that chaetogenesis is subject to strict regulation to ensure that chaetae develop identically in individuals, populations and species. Therefore, the regulation of chaetogenesis should be conserved in such a way that it could be passed on within parentage communities. An identical structure and formation of chaetae should therefore represent a strong phylogenetic signal indicating larger communities of descent. Studies on chaetogenesis are currently performed in collaboration with Ekin Tilic.
Larval protonephridia are generally called "head kidneys" and are the first renal organs that are differentiated in the course of ontogenesis in polychaetes. The head kidneyes indeed are restricted to the larval stage. They consist of a limited number of cells but show a high variability between groups. So far, it has been shown that a corresponding ultrastructure of these organs indicates monophyletic units among annelids. In addition, head kidneys are very well suited for RDF coding. This work is done in collaboration with Björn Quast, Peter Grobe and Lars Vogt.
Teaching
Lectures
Animal morphology and evolution, Adaptive radiation of the Metazoa, Ecology, Organismic Biology:
Evolution, Biodiversity, Physiology.
Practical courses
Comparative morphology and evolution of animals, Adaptive radiation of the Metazoa, Causes and mechanisms of evolution, Marine Biology, Ecology of the Wadden Sea (in List/Sylt) and of tidelands and rocky shores of the Atlantic coast (in Concarneau, France).
Seminars & Colloquia on Evolutionary Biology.