Thank you for finding me! I am a biologist intrigued by the process of EVOLUTION, and fascinated by its outcomes. I am currently working as a Postdoc at the University of Bern in Switzerland.
Why are living organisms so incredibly diverse? – This is the overarching question that is driving my research. Defined broadly, my approach is to apply population genomics within a clear ecological framework to shed light on the processes influencing adaptive (population) diversification. However, my research is not contingent upon a specific type of approach, but rather follows my instinct for interesting questions, whereby I’m open to take whatever route is needed to address a question appropriately. Many ideas emerge as I observe the living world around me, and as I stumble across inexplicable patterns during biological data analysis. My main empirical study system is the threespine stickleback fish that has adapted rapidly to distinct environments. However, I have also been working with other organisms (cichlid fish, Daphnia, icefish, and lampreys). You can find my published work here.
Current projects involve the study of stickleback populations inhabiting distinct environments, such as lakes differing mainly in abiotic factors (e.g., Haenel et al. 2019), or lakes differing in a single biotic factor – that is, the presence vs. absence of a competing fish species. I am describing how the genome (e.g., Miller, Roesti, Schluter 2019), as well as traits (forthcoming), diverge due to this species interaction. It happens to be that most of my current empirical work uses allopatric populations, which stands in contrast to the majority of my previous work, where the emphasis was on population divergence in the presence of gene flow (e.g., Roesti et al. 2012, Roesti et al. 2014, Roesti et al. 2015). I plan to again focus on the latter in the near future.
More recently, I’ve really started valuing – and enjoy conducting – large field experiments to test specific predictions prompted by observations in wild populations. Threespine stickleback make it possible to conduct such experiments, which is one of many reasons why I like working with this organism. One of the questions I am currently answering experimentally is whether a simple biotic change to the environment of an organism has resulted in substantial reproductive isolation (speciation) as a by-product.
Results from my empirical research stimulate and inform my theoretical work. I’m using simulations to better understand the genomic footprints of selection (e.g., Roesti et al. 2014). I have longstanding interest in gaining an evolutionary understanding of intra-genomic variation in the rate of crossover (recombination), and how this variation influences the genome during adaptive diversification (e.g., Roesti et al. 2012, Roesti et al. 2013, Haenel et al. 2018, Roesti 2018). Simulations further help me explore how crossover rate variation in context of polygenic adaptation influences evolutionary genomic methodologies and inferences, such as the search for targets of selection through genome scans (Roesti et al. 2012, Berner & Roesti 2017, Roesti 2018). I have also done theory work exploring the genetic signature of selection during parallel adaptation involving pre-existing genetic variation, including standing and introgressed genetic variation (Roesti et al. 2014).
If you like to get further information on my past or ongoing work, do not hesitate to contact me!
SNIPPETS OF MY RESEARCH (non-chronological)