Fabrice Eroukhmanoff

Projects

I consider myself as an evolutionary biologist and mainly focus my work on divergence processes in general, with special emphasis on evolutionary genetics and speciation mechanisms.

Sexual selection, reproductive isolation and phenotypic integration in Calopterygid damselflies

Head of project: E. Svensson (Lund University) Collaborators and coworkers: A. Runnemark, K. Karlsson, M. Wellenreuther, S. Kuchta (Lund University), M. Friberg (Stockholm University), D. Outomuro, F. Ocharan (Oviedo University).

In this project, I study different species of the genus Calopteryx with regard to natural and sexual selection, reproductive isolation between populations or species and phenotypic integration. In this genus, males exhibit different patterns of melanization on their wings as sexual indicators. These wing patches are used by females to discriminate among con and heterospecific males, although mate preferences seem to be plastic and conditioned by the presence or absence of sympatric species. I have also started comparing populations of four different species occuring in Sweden and Spain with regard to their wing traits and tried to investigate how these wing traits are correlated with each other among populations and species and how they relate to other non-sexual body traits.

damselfly

Parallel evolution and rapid ecological divergence in an isopod

Head of project: E. Svensson (Lund University) Collaborators and coworkers: K. Karlsson, S. Harris, S. Bensch, M. Wellenreuther, R. Härdling (Lund University), A. Hargeby (Linköping University), O. Hellgren (Oxford University), N. Nowshiravani (University of Santa Cruz),
S. Guéchot (Supagro Montpellier).

isopod

In this project, I study divergence between two ecotypes of Asellus aquaticus, a freshwater isopod present in two lakes of Southern Sweden. In these to lakes, the last oligotrophication event led to the emergence of submerged vegetation such as stonewort, a new habitat that was rapidly colonized by isopods from the neighboring reed belts. In less than two decades, these two ecotypes diverged in several phenotypic traits including size, pigmentation, shape, sexual behavior and physical performance. As in many other studies involving parallel ecological speciation, this very rapid divergence event is thought to result from natural selection linked to predation, since different predators (fish vs. invertebrates) inhabit these two habitats. Thus, this well documented case of parallel evolution also represents a potential case of ecological speciation.

The genetic architecture of secondary sexual traits during hybrid speciation

Collaborators and co-workers: Glenn-Peter Saetre, Thomas Hansen, Jo Skeie Hermansen, Richard Bailey, Tore Elgvin (CEES, Oslo University), Fredrik Haas (Lund University).

Recently, Prof. Saetre and coworkers have obtained the first genetic evidence for homoploid hybrid speciation in birds. They showed that the Italian sparrow (Passer italiae) is a stabilized and uniform hybrid taxon that originated from past events of hybridization between two divergent parental species, the house sparrow (P. domesticus) and the Spanish sparrow (P. hispaniolensis). The two parental species differ in a number of functionally important traits, including melanin-based plumage coloration. This system provides excellent opportunities to study the genetic architecture of secondary sexual traits, as adult males breeding plumage differs between species.

Hybrid speciation is a special case of speciation where hybridization leads to the evolution of a new lineage reproductively isolated from its two parental species and thus involves fusion and stabilization of two differentiated genomes. We are currently producing first generation hybrids and backcrosses in aviaries to recreate the first step of this process and will compare these data with data from Italian sparrows both at the phenotypic level (using line-cross analyses and quantitative genetic models), at the genomic level (using 454 sequencing to uncover large numbers of species-specific SNPs and compare the different transcriptomes) and at the phenotype-genotype map level (e.g. using theoretical models on epistasis).

hybridé

Evolvability of genomic architecture during hybrid speciation

Collaborators and co-workers: Glenn-Peter Saetre, Anna Runemark (University of Oslo), Ole Seehausen (University of Bern), Paul Hohenlohe (University of Idaho), Henrik Jensen (Norwegian University of Science and Technology).

Using the Italian sparrow as a model system, this project funded by the Faculty of Sciences for 2015-2017 will allow us to investigate three major objectives:

Objective 1: Studying the evolvability and dimensionality of genomic
mosaicism within a hybrid species.
Objective 2: Assessing the role of intragenomic conflicts and genetic
incompatibilities in constraining hybrid genome evolution.
Objective 3: Investigating hitchiking of ecologically important genomic
regions and the consequences of hybridization on adaptation.

sparv

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