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Ben Wielstra

Dr. Ben Wielstra, Research associate - Taxonomy and Systematics


Email: ben.wielstra@naturalis.nl
Phone: +31(0)610242379
Room number: Sylvius buiding 6.4.16b
“Closely related species provide a unique insight into evolution”

I am interested in the evolutionary history of closely related species – how such species originated and obtained their current distribution and how they interact during the course of their evolution, as ecological divergence drives them apart and gene flow pulls them together. My research combines phylogeographical and spatial ecological methods to retrace the distribution of species and spatial contact between them through time. As a model system I mainly use salamanders. Given these animals generally combine low dispersal capabilities with a strong physiological link to environmental conditions, their ranges are strongly affected by geological and climatic change.


Since 2013 I am a research associate at Naturalis.

In 2016-2018 I am a Marie Skłodowska-Curie Fellow at the University of California, Los Angeles and the University of Sheffield.

In 2014-2016 I was a Newton International Fellow at the University of Sheffield.

In 2012-2013 I conducted postdoctoral research at Naturalis Biodiversity Center.

In 2007-2012 I conducted PhD research in a collaboration between the University of Twente and Naturalis Biodiversity Center.

In 2000-2007 I studied Biology at Leiden University, conducting several research projects at Naturalis Biodiversity Center.


Research interest

My main interest is the interaction among closely species, both ecologically and genetically, during the course of their evolution. This requires studying a model system with quite specific characteristics, which can be studied in a natural setting. At Naturalis Biodiversity Center we found the prefect model: crested newts (Triturus cristatus superspecies). Crested newts have long been employed in evolutionary biology. The group is distributed in the Mediterranean region, an area characterized by a turbulent geological and climatological history. The crested newt superspecies is composed of several forms which are distinct enough to be deemed species, but similar enough to exclude one another ecologically. The ranges of crested newt species are largely parapatric and border each other along narrow contact zones. Here, genetic interaction between species occurs. The contact zones are dynamic, meaning they shift position over time. Taken together, crested newts are the perfect model system to address my research questions about subjects such as speciation, niche evolution, competition and gene flow.

Triturus cristatus superspecies: your new favourite model organism. Upper panel: left a larva just hatched; right a larva close to metamorphosis. Lower panel: left a female; right a male in breeding costume. These sleepy newts were temporarily sedated and after non-invasisve tissue sampling they were released again. Pictures by me.


amphibia, evolutionary biology, species displacement, biogeography, hybrid zones, systematics

Current research topics

I mainly focus on introgressive hybridization and range dynamics in Triturus newts. Please check my personal website for my recent research output.


At Naturalis Biodiversity Center I work closely with Pim Arntzen. At the University of Sheffield my host durin my Newton International Felloship was Terry Burke. My hosts during my Marie Skłodowska-Curie Fellow are Brad Shaffer at the University of California, Los Angeles and Roger Butlin at the University of Sheffield.

Supervision PhDs


Isolde van Riemsdijk



2014: Lecture Master program ‘Herpetology’, University of Antwerp, Belgium.
2012: ‘In the spotlight’ lecture, Institute of Biology Leiden, Netherlands.

2013: Patricia Lagler (University of Natural Resources and Life Sciences, Vienna, Austria).
2013: Willem Meilink (Free University of Brussels, Belgium).

Available student projects


Naturalis Repository

For an up to date overview of my publications, please check my Google Scholar profile.