Author Archives: Ben Wielstra

In a paper published in Annales Zoologici Fennici we tested the influence of shared ancestry and climate on the variation in life history traits in Triturus newts. Some variation can be explained by climate, some by shared ancestry and some … Continue reading →

My application for a Newton International Fellowship has been succesful! I will conduct this two-year postdoctoral fellowship, using the Ion Torrent protocol I designed during my postdoc at Naturalis to study hybridzones in Triturus, in the lab of Professor Terry Burke … Continue reading →

The crested newt traditionally referred to as ‘Triturus karelinii’ comprises three distinct mitochondrial DNA clades. These clades are found in the east, the centre and the west of the range. The difference between mitochondrial DNA clades is comparable to the … Continue reading →

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 →