Universiteit Leiden

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Ben Wielstra

Assistant professor

Dr. B.M. Wielstra
+31 71 527 5135

Genomes can undergo major changes in composition due to 1) hybridization, combining the genetic material of two distinct species, and 2) structural re-arrangements, splitting up a single stretch of DNA into two independently evolving units. I study how genomes evolve in response to the associated positive and negative fitness consequences. The study system I work on is the genus Triturus, the crested and marbled newts.

More information about Ben Wielstra


My work heavily relies on genomic data and the main study system I work on is the genus Triturus, the crested and marbled newts. I am particularly 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 early work mainly involved phylogeography (inferring glacial refugia), systematics (resolving rapid radiations) and taxonomy (diagnosing cryptic species). Recently, I have been studying hybridization, both under natural conditions (in particular hybrid zone movement) and anthropogenically induced (the complicated conservation issues of ‘genetic pollution’). Presently, I am conducting a research program, funded with an ERC Starting Grant, aiming to understand the evolution of balanced lethal systems. Balanced lethal systems are extremely maladaptive as they cut reproductive potential in half. Yet, they have evolved time and again along the branches of the tree of life. I hope to solve this evolutionary mystery.

Brief biography

I studied biology at IBL, after which I pursued my PhD at Naturalis Biodiversity Center. Subsequently, I conducted five years of postdoctoral research abroad, at the University of Sheffield and UCLA, before returning to IBL (and Naturalis) as Assistant Professor.

I am an honorary researcher at Naturalis Biodiversity Center.

My Google Scholar profile can be found here

Check out my personal website Newt Research.


Grants and fellowships as PI:

  • ERC Starting Grant
  • Marie Skłodowska-Curie Individual Global Fellowship
  • Newton International Fellowship

Grants and fellowships as host:

  • NWO Open Competitie ENW M-1
  • NWO Promotiebeurs voor leraren
  • Martin & Temminck Fellowship
  • NWO-ALW Open Programme

Key publications

Wielstra, B. (2020). Balanced lethal systems. Current Biology 30(13): R742-R743.

Wielstra, B. (2019). Historical hybrid zone movement: more pervasive than appreciated? Journal of Biogeography 46(7): 1300-1305.

Wielstra, B., McCartney-Melstad, E., Arntzen, J.W., Butlin, R.K., Shaffer, H.B. (2019). Phylogenomics of the adaptive radiation of Triturus newts supports gradual ecological niche expansion towards an incrementally aquatic lifestyle. Molecular Phylogenetics and Evolution 133: 120-127.

Assistant professor

  • Science
  • Instituut Biologie Leiden
  • IBL Animal Sciences

Work address

Sylviusweg 72
2333 BE Leiden
Room number 3.5.18



No relevant ancillary activities

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