Thomas Blankers

Marie Curie post-doctoral research fellow at the University of Amsterdam

General description

I am broadly interested in understanding the speciation process and the evolutionary forces governing diversity in the animal kingdom. The diversity of life on earth is not only fascinating, it is also central to our existence. A substantial portion of diversity is directly or indirectly dependent on sexual communication: directly because the visual, chemical, and auditory phenotypes involved in sexual signaling are among the most beautiful and diverse traits known to man and indirectly because sexual communication is fundamental to individual and population reproductive success and therefore plays a major role in the speciation process. I study insect models to understand the genetic basis of variation in sexual communication traits as well as the genetic evolution during the speciation process more generally. I am active in diverse fields, including animal behavior and communication, evolutionary biology, population genetics, quantitative genetics, and in my current position I will also venture out into the functional genetic domain. Below is a chronological list of my specific research projects. 

The genetic basis of pheromone communication in noctuid moths (post-doc, University of Amsterdam – supervision Astrid T. Groot.) 

The genetic architecture of behavior is a major topic in biology but remains poorly understood. The behaviors with the most dramatic effect on animal fitness are those involved in mate attraction and courtship, which are directly related to reproductive success. Males and females share a genome but have idiosyncratic roles in courtship rituals; mating traits thus experience sex-specific selection regimes. Variation at the gene expression level can facilitate sex-specific trait evolution to some degree. However, sex-specific traits inevitably covary, leading to correlated evolutionary responses (pleiotropy). In this project funded by a Marie Curie individual fellowship at the University of Amsterdam, I aim to reveal how genes controlling traits involved in mating behavior can have widespread phenotypic effects across sexes. I will use quantitative genetic measurements of pheromone communication variation in wild-type and allelic knock-out and knock-in lines of noctuid moths (genus Heliothis). First, I will examine the correlated evolution of pheromone signals in male and female moths and identify candidate genes using differential expression analyses. Then, I will examine the phenotypic effects using the cutting-edge CRISPR/Cas9 system and a quantitative genetic framework to explore behavioral effects. This study advances our understanding of the genetics of a major sexual communication channel, pheromone-based mate finding and selection, which has important ramifications on the fitness, diversity, and species richness of one of the world’s most notorious and costly crop pest lineages. 

The evolutionary and population genetics of a rapid island radiation of flightless crickets (post-doc, Cornell University, NY – supervision: Kerry L. Shaw, co-authors: Kevin P. Oh, Aureliano Bombarely, W. Hayden Waller)

I worked at Cornell University from Aug 2016 – Aug 2018 in Kerry Shaw’s lab on the evolutionary genetics of Laupala cricket diversity. Laupala is a species rich (38 described species) genus of flightless swordtail crickets endemic to the Hawaiian archipelago. The group has among the highest speciation rates in animals (the youngest island, Hawaii, is less than half a million years old and home to seven endemic species!) and is therefore of premier interest to speciation genetics. This project involves two major parts: (i) the genetic architecture of divergence in male song rhythm (pulse rate) across several species of Hawaiian swordtail crickets (Laupala) and (ii) population genomics in a genetically and geographically highly variable species, Laupala cerasina. The first part consists of a series of linkage mapping and QTL studies which have largely been published (publications 12 and 13 in my list of publications, one additional study in preparation). The second part is still work in progress and will consist of a study on population structure, evolutionary history, and genome-wide analysis of genetic divergence as well as an analysis of variation in the cricket-associated gut microbiome.

Acoustic communication, sexual selection, and speciation in field crickets (PhD thesis, Humboldt University / Naturkundemuseum Berlin – supervision: R. Matthias Hennig, Frieder Mayer, co-authors: David A. Gray, Emma Berdan)

My PhD project in Berlin was focused on acoustic mate choice behavior in North American field crickets and the patterns of genetic variation during speciation with gene flow. My thesis integrates insights from neuro-ethological, behavioural, quantitative genetics, and genomic approaches in field crickets to provide novel insights in the role of sexual selection in speciation. We provided detailed descriptions of female preference functions, their effect on male signal evolution, and patterns of diversification among females of different species (pubs 3 & 5). We also explored the integration of signal and preference traits by analyzing species differences in a multivariate framework (pubs 4 & 9) and also by means of a QTL study that looks at the genetic architecture of male signal traits, female preference, and the architecture of gene expression related to those traits (in preparation). Lastly, we performed a detailed analysis of the genetic evolution in two closely related species, Gryllus rubens and G. texensis, to elucidate the role of neutral genetic divergence and sexual selection during speciation with gene flow (10).

Adaptive radiation and ecomorphology of lizards and salamanders (MSc research, Stony Brook University, NY – supervision: John J. Wiens, Steph B. Menken)

During my MSc at the University of Amsterdam, I visited the Wiens’ lab at Stony Brook University for a research project on the ecomorphology of salamanders and lizards. Using comparative phylogenetic methods, we explored two large clades, the plethodontid salamanders and the iguanian lizards, for relationships between morphology and microhabitat use as well as for general phylogenetic patterns of diversification (pubs 1 & 2).