Category Archives: Uncategorized

Hybridizing species sometimes exchange genes in nature (a phenomenon called introgression). Introgression has particularly been documented for mitochondrial DNA. This might mean mitochondrial DNA is more susceptible to introgression, but it is also the case that researchers have simply studied … Continue reading →

The Triturus karelinii-group of crested newts comprises three mitochondrial DNA lineages, but no morphological differences are known. In a paper published in Zoologischer Anzeiger we analyse skull shape to see if there are differences between lineages. While we do not … Continue reading →

The Quaternary Ice Age heavily influenced the distribution of species. During the colder glacial periods, species went extinct in part of their range, while during warmer interglacial periods, they could recolonize these regions again. This contraction-expansion pattern left its mark … Continue reading →

On 3 October 2012 I defended my PhD thesis, which can be found here.

A regular observation around the zones where closely related species meet, mate and produce offspring (hybrid zones) is that mitochondrial DNA of one of the species extents into part of the range of the other species (asymmetric mitochondrial DNA introgression). … Continue reading →

Geographical groups characterised by distinct mitochondrial DNA may still belong to a single species. However, if they are also ecologically distinct, this supports their species status. In a paper published in PLoS ONE we explore ecological differences among the three … Continue reading →

Crested newts comprise four ‘morphotypes’: 1) the Triturus karelinii-group, 2) T. carnifex + T. macedonicus, 3) T. cristatus, and 4) T. dobrogicus. These four morphotypes range from sturdy to slender bodies. Body build is reflected by the number of rib-bearing … Continue reading →

In a paper in the Journal of Zoological Systematics and Evolutionary Research we explore the evolution of body form in crested newts. In general crested newts started out with large bodies with a short trunk and a wide head. Over … Continue reading →

Within the crested newt assemblage, known as the Triturus cristatus superspecies, T. karelinii has been severely understudied. Limited data suggests there might me more than one species involved and the systematic position within the crested newt superspecies is unclear. Furthermore, … Continue reading →

Male crested newt of the T. karelinii-group (now called T. ivanbureschi). Picture by Michael Fahrbach. The Triturus karelinii-group of crested newts has sometimes been considered to comprise two species, ‘T. karelinii proper’ in the east and ‘T. arntzeni’ in the … Continue reading →