Manon de Visser

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I am fascinated by the evolutionary mechanisms that shape the natural world. Most specifically by what happens when species become threatened, or populations become isolated. When species adapt to their changing environments, it sometimes happens that nature - oddly enough - "fools" itself as a result of basic, evolutionary principles. As a post-doctoral researcher I currently work on explaining how a weird, evolutionary flaw in crested and marbled newts of the genus Triturus evolved naturally. My project is a collaboration between Naturalis and the Institute of Biology Leiden (IBL). Next to this project, I am also involved with nature conservation, (genetically) monitoring exotic amphibians, and telling the stories of our researches through 'scicomm' activities. My PhD defense is expected to occur end 2024.


Balanced Lethal System, Evolution, Conservation, Genetics, Genomics, Inbreeding, Evo-Devo, Embryology, Newts, Salamanders, Amphibians, Gene Expression, Invasive species, Exotics, Science Communication, Scicomm

Manon de Visser

Post-doctoral / Guest Researcher
& Volunteer Taxidermy Team
Understanding Evolution
+31 (0)6 48 396 715

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Lethal Systems

Photo of a crested newtI am a member of the Wielstra lab (ERC Starting Grant-funded research), where we study the genomics underlying the best-known case of a balanced lethal system: chromosome 1 syndrome in Triturus newts. Balanced lethal systems are considered an evolutionary failure, because natural selection is unable to get rid of the associated recessive, lethal alleles. I investigate the lethality and evolutionary origin of this system in collaboration with IBL. Are you curious to find out more? Just click here to read about balanced lethal systems!


What is it like to work as a PhD in the field of genomics, for both Naturalis and the University of Leiden? And what do I actually learn from the salamanders - and other animals - that I study? I find it important to share my knowledge and experiences with the world!

Manon's evolution lesson at 'Natuurlab' (only in Dutch)
>> Hoe werkt evolutie Les 2: een dodelijk raadsel

DNA talks on YouTube (a selection of episodes)
>> Manon's DNA talk 1: an odd salamander syndrome
>> Manon's DNA talk 5: DNA barcoding of amphibians
>> Manon's DNA talk 8: Banded newts are like oil and water

On the collaboration between museums, zoos and universities 
>> Biologist Manon de Visser about mangabeys

Spotlight interview (only in Dutch)
>> Dieren DNA: salamander raadsels

>> Working with supercomputers
>> Personal blog (wide range of topics!)

Manon with an enlarged, 3D-printed skull of a crested newt (genus: Triturus)


Awards & Prizes:

  • Selected as 'Face of Science 2023' by the Royal Netherlands Academy of Arts and Sciences (KNAW), The Youth Academy (De Jonge Akademie) and NEMO Kennislink, after being nominated by Associate Professor and marine biologist Dr Lisa Becking.
  • "1st prize for one-minute pitch" at the Netherlands Society of Evolutionary Biology PhD & Postdoc meeting 2021 (NLSEB2021), for the pitch: "The balanced lethal system in Triturus: an evolutionary trap!"
  • "3rd best oral presentation" at the Programming For Evolutionary Biology Conference 2021 (miniPEB2021), Freie Universität Berlin, for the talk: "Studying the lethality and evolutionary origin of the balanced lethal system in Triturus newts".
  • "1st prize for oral presentation" within subtheme: Global Health - Humans and Animals" at the University of Copenhagen EuroLeague of Life Sciences (ELLS) Student Conference 2017, for the MSc project "The Importance of Genomics for the Conservation Management of the Critically Endangered Pygmy Hog (Porcula salvania)".
  • "Best oral presentation" at the Benelux International Society of Applied Ethology (ISAE) meeting 2016, for the MSc project "The effect of exposure to visitors on stress in the critically endangered blue-eyed black lemur (Eulemur flavifrons) and other primate species at Apenheul Primate Park, the Netherlands."

Scientific Publications:

  • Kazilas, C., Dufresnes, C., France, J., Kalaentzis, K., Martínez-Solano, I., De Visser, M.C., Anrtzen, J.W., Wielstra, B. (2024) Spatial genetic structure in European marbled newts revealed with target enrichment by sequence capture, Molecular Phylogenetics and Evolution 194: 108043.
  • Kalaentzis K., Arntzen J.W., Aziz A., Van den Berg V., Beukema W., France J.M., Olgun K., Van Riemsdijk I., Üzüm N., De Visser M.C. & Wielstra B.M. (2023) Hybrid zone analysis confirms cryptic species of banded newt and does not support competitive displacement since secondary contact, Ecology and Evolution 13(9): e10442.
  • Robbemont J., Van Veldhuijzen S., ..., De Visser M.C. & Wielstra B.M. (2023) An extended mtDNA phylogeography for the alpine newt illuminates the provenance of introduced populations, Amphibia-Reptilia 44(3): 347-361.
  • Kuijt, M., Oskam, L., Den Boer, I., Dufresnes, C., France, J., Gilbert, M. J., De Visser, M.C., Struijk, R.P.J.H, Wielstra, B. (2023) The introduction of three cryptic tree frog species in the Dutch coastal dunes challenges conservation paradigms. Amphibia-Reptilia 44(1), 1-10.
  • Koster, S., Prins, N., Dufresnes, C., France, J., De Visser, M.C., Struijk, R.P.J.H., Wielstra, B. (2023) The conservation paradox of an introduced population of a threatened species: spadefoot toads in the coastal dunes of the Netherlands. Amphibia-Reptilia 44(1), 11-18.
  • De Brouwer, J., Helder, B., France, J., De Visser, M.C., Struijk, R.P.J.H., Wielstra, B. (2023) An isolated crested newt population in Dutch coastal dunes: distribution relict or introduction? Amphibia-Reptilia 44(1), 19-26.
  • Vliegenthart, C., Van de Vrede, M., Den Boer, I., Gilbert, M., Lemmers, P., France, J., De Visser, M.C., Struijk, R.P.J.H., Wielstra, B. (2023) The limits of mtDNA barcoding for determining the provenance of invasive species: a midwife toad example. Amphibia-Reptilia 44(1), 27-33.
  • Wielstra, B.M., Den Boer, I., France, J.M., De Visser, M.C., Struijk, R. (2023) MtDNA barcoding van exotische amfibieën in de duinen. RAVON 89(2): 26-29.Van der Goot, A., De Visser, M., Hiemstra, A.F. (2022) Smooth newts Lissotriton vulgaris observed hibernating in a waterfowl nest. Herpetological Bulletin: 162: 41-42.
  • De Visser M., Prins E., Bosse M., Crooijmans R., Ter Meulen T. (2022). Maximum longevity and juvenile mortality in zoo-housed mangabeys. Zoo biology: 1-11.
  • Fahrbach M., De Visser M.C., Wielstra B.M. The hybrid zone between the Italian and Northern crested newts (Triturus carnifex and T. cristatus) reaches Germany, Salamandra 57(3): 428-434.
  • De Visser M.C., Liu, L., Bosse, M. (2021). Pygmy hogs, Current Biology 31(8):R366-R368.
  • Liu, L., Bosse, M., Megens, H.J., De Visser, M.C., Groenen, M.A.M., Madsen, O. (2020) "Genetic consequences of long‐term small effective population size in the critically endangered pygmy hog." Evolutionary Applications 14:710-720.
  • Van Tuijl, C., Van Bochove, K., De Visser, M.C. (2019). Genetic Structure of Badger Populations in a Fragmented Landscape: How Do Barriers Affect Populations on a Genetic Level? Lutra 62: 65-76.

Popular Science Articles:

  • Struijk, R.P.J.H., Prins, N., Koster, S., Putters, N., Jansen, N., Esselaar, J., De Visser, M.C., France, J.M., Wielstra, B.M. (2024) Knoflookpad in Callantsoog: verspreiding, voortplanting en geografische herkomst, RAVON 26(1): 2-5.
  • De Visser, M.C., Prins, N., France, J.M., Struijk, R., Wielstra, B. (2023) Exotische amfibieën in de duinen ontmaskerd met mtDNA barcoding. Holland's Duinen 82(1): 25-29.
  • Struijk, R.P.J.H., Backx, B., Demirkapu, B., De Visser, M., Wielstra, B. (2022). 'Rise and fall' van een populatie westelijke smaragdhagedissen in Scheveningen. RAVON 24(4): 24-27.
  • Helder B., De Brouwer J., Ouwehand J., De Visser M. & Wielstra B. (2021). Koi-kamsalamander, Schubben & Slijm (48): 8.
  • Meilink W.R.M., France J., De Visser M. C. & Wielstra B. (2021). Balanced Lethal Systems: An Evolutionary Mystery. Frontiers For Young Minds. 9:632945.
  • De Visser M.C., France J.M., Meilink W.R.M. & Wielstra B.M. (2021). Een evolutionair raadsel: het dodelijke chromosoom 1 syndroom in Triturus-salamanders, RAVON 23(1): 9-12.
  • Struijk R.P.J.H, Demirkapu B., De Visser M.C. & Wielstra B.M. (2021). Exotische smaragdhagedissen in de duinen bij Scheveningen, Kijk op Exoten (34): 12-13.