Postdoctoral fellow (University of Idaho, USA)
I am an evolutionary geneticist interested in processes leading to adaptation and diversification. My research aims to understand the extent to which populations can adapt and diversify as a result of both genetic and environmental constraints. I use quantitative genetics, experimental evolution and genomics in yeast, fruit flies and stickleback to address these issues:
I am currently a postdoctoral fellow in Dr. Paul Hohenlohe's laboratory in the Department of Biological Sciences at the University of Idaho (Moscow).
The quantitative genetics of gene regulatory networks:
The genetic architecture underlying complex traits is becoming one of the major area of research in evolutionary genetics. Since the response to selection of multiple traits depends on the genetic correlations between them, much of the evolutionary dynamics can be explored by measuring the degree of pleiotropy and epistasis that arises from the underlying gene networks, a promising avenue in evolutionary genetics, medical research and food science. Using yeast (Saccharomyces cerevisiae), I use quantitative genetics within the context of gene networks to understand the genotype-phenotype map. More specifically, in collaboration with Dr. Paul Hohenlohe, I measure G-matrices of stress resistance that involve various gene regulatory networks (see Figure on the right).
Neutral patterns of genomic sequence divergence:
Despite the enormous amount of sequencing data accumulating, very little is known about the genomic patterns of divergence in natural populations. This is due to the lack of a good understanding of how genomic variation is shaped by selection and how this variation in turn influences the response to selection. We face a major problem when trying to detect signals of selection from genome scans because we are still unable to describe precisely the null expectation of sequence divergence in the absence of selection (neutral divergence). In collaboration with Dr. Paul Hohenlohe, I investigate through coalescent simulations, the patterns of genomic variation under neutrality, in the context of population divergence with migration. I measure the levels of autocorrelation as a function of distance between SNPs (see Figure on the right) and explore the range of parameters of population genomics statistics for various demographic models. These models can especially help us delimit region under selection as well as genomic islands of divergence (genomic regions of elevated differentiation i.e high Fst).
Quantitative genetics of good-genes model of sexual selection:
My research in Drosophila focuses on the good-genes model of sexual selection and the evolution of female mate preferences through indirect genetic benefits. I started this work during my PhD with Dr. Howard Rundle at the University of Ottawa (Canada). Using a quantitative genetics approach I measure genetic variances and covariances between female preferences, male sexual displays and offspring fitness. Males produce a suite of pheromones on their cuticule (cuticular hydrocarbons, CHC) that attract females during mating. Their expression depends on the condition of the male and can help predict the strength and direction of sexual selection exerted by females. Male display traits therefore act as honest indicators of their genetic quality and females in turn receive indirect genetic benefits by mating with these males in term of higher fitness offspring.
Through the combination of experimental evolution and quantitative genetics, I investigate how sexual selection and sexual conflict proceed in Drosophila serrata (an Australian fruit fly) across a range of environments and across time. This work aims to better understand the link between genetic variation, selection at or off a fitness optimum.
Evolution of reproductive isolation and mate choice in threespine sticklebacks:
Threespine sticklebacks (Gasterosteus acculeatus) are a classic example of adaptive radiation where multiple species have formed in new ecological niches after the recent glaciers retreat 10 000 years ago. I investigate the role of female mate choice in reproductive isolation between parapatric populations of threespine sticklebacks. This experiment was done in collaboration with Dr. Andrew Hendry and Dr. Katja Räsänen at McGill University (Montreal, Canada) involved laboratory mating trials to determine the extent to which populations that show ecological adaptations are also reproductively isolated. Parapatric stream and lake populations from the Misty system (Vancouver Island, Canada) constitute an excellent model as different pairs of population experience different levels of divergent selection and gene flow. Male threespine stickleback (see photo on the right) display striking nuptial coloration and mating behaviors to attract females. These mating behaviors seem to have both a genetic and an environmental component and seem to influence mating success between populations, which may either reinforce or limit reproductive isolation among populations.
Ecology of hummingbird nesting habitats:
Hummingbirds show an amazing level of diversity (340 species) and are the longest migrating birds given their size. Understanding their ecology is important to monitor populations and develop conservation strategies. I described the vegetation structure in nesting habitats of Black-chinned hummingbirds (Archilochus alexandri) in Cave Creek, a "hotspot" for hummingbird monitoring programs, located in the heart of the "Sky Islands" in the Chiricahua Mountains (Arizona, USA). These so called "islands" are visited by many migrating species as a unique nesting habitats. This project involved field work in collaboration with Dr. Susan Wethington and Dr. Dawn Wilson to characterize the nesting habitat requirements for this species and to define a protocol for conservation programs looking at hummingbird nesting success. This was part of my Masters of Science research project at the SWRS - American Museum of Natural History (Arizona, USA).