Author Archives: Ben Wielstra

A male pygmy marbled newt (left) and a male marbled newt. Pictures by Michael Fahrbach. Although my work is heavily focused on crested newts, there are two marbled newt species in the genus Triturus as well. In a new paper … Continue reading →

In an article aimed at high school students for the journal Frontiers for Young Minds my former student Nienke Prins and I explain hybrid zone movement. Obviously we also mention the best example of hybrid zone movement there is: crested … Continue reading →

In the Dune area of Meijendel, close to Leiden, a population of crested newts occurs. The history of this population is dodgy. While genetic data could not confirm that this population is introduced, the isolated position and apparent rapid expansion … Continue reading →

Three banded newt species are currently recognized. However, this was not always the case. Previously, my lab has shown that these morphologically similar species are genetically super distinct. That is why we suggested their treatment as distinct species – despite … Continue reading →

Befitting its intimidating scientific name, Ichthyosaura, the alpine newt is an interesting beast. The alpine newt is characterized by hugely divergent mtDNA lineages that may well reflect cryptic species (genetically distinct but morphologically similar species). The distribution of these cryptic … Continue reading →

Reference: Wielstra, B., Boer, I. den, France, J., de Visser, M., Struijk, R. (2023). MtDNA barcoding van exotische amfibieën in de duinen. RAVON 89(2): 26-29. Reference: de Visser, M., Prins, N., France, J., Struijk, R., Wielstra, B. (2023). Exotische amfibieën … Continue reading →

The job of immune genes is to fight off pathogens. However, pathogens don’t take this beating lying down. Pathogens adapt to evade the immune genes, forcing the immune genes to counter-adapt in return. To improve your chances against infection in … Continue reading →

The first crested newt I ever saw was in Meijendel, a dune area close to Leiden (where I studied biology at the time). This crested newt population is odd because it is completely isolated from the main distribution range. Could … Continue reading →

Adult marbled and crested newts have two versions – a long and a short one – of their largest chromosome: chromosome 1. They randomly transmit either the long or the short version to each of their sex cells, resulting in … Continue reading →

Phylogeography – the study of the geographical genetic structure within species or groups of closely related species – was until recently typically based on one or a few genes. Nowadays, many genes can be consulted. This allows us to better … Continue reading →