Department of Biology

Sarah bouchemousse

University of Fribourg
Dept of Biology
Unit Ecology & Evolution
Chemin du Musée 10
CH-1700 Fribourg



I am a molecular ecologist and population geneticist interested in ecological and evolutionary processes explaining the establishment and coexistence of species (e.g. local adaptation, competitive interactions, hybridization and introgression). During my training and research work, I developed knowledge and a strong scientific interest simultaneously in ecology and evolution, with a strong focus on non-native species, which are to me very interesting models to address pressing issues in ecology and evolution. To achieve this, I use a diverse set of tools and approaches: population genetics and genomics, molecular barcoding, phylogeography, dynamics of populations and species communities through the organization of fieldwork campaigns.


I mainly focus my research work on non-native species (plant and animals). During my PhD work supervised by F. Viard, I studied a recently introduced sea squirt in Europe (Ciona robusta) and compared its population dynamics and genetic pattern with a native congener (C. intestinalis), with which it lives in sympatry and can hybridize in the laboratory. A main objective was to determine if the two species are successfully hybridizing in the field, and test the hypothesis of adaptive introgression as a main driver of the success of colonization of the non-native species in Europe. During my master thesis and then my first postdoc, I studied the introduction history and fitness traits of a worldwide invasive alga Sargassum muticum by using historical and contemporary specimens to test various hypotheses explaining its establishment and colonization success as selective events and phenotypic plasticity.

During my postdoc in the team of Heinz Müller-Schärer, I will study the leaf beetle Ophraella communa recently and accidentally introduced in Europe. This insect, native to North America, has the potential to reduce the population density of common ragweed (Ambrosia artemisiifolia) known to be a notorious invasive plant at a worldwide scale causing great damage to our society due to its highly allergenic pollen, and as an important and hard-to-control crop weed. The purpose of my postdoc is firstly to illuminate the invasion and spread history of O. communa in different introduced ranges (Asia and Europe) by using a population genomics approach, in order to identify the sources of the introduced populations and the spreading genotypes; and secondly to investigate the potential of adaptation of the leaf beetle to different host plants by means of selection experiments in the field and genomic tools. This postdoc project is tightly linked to the PhD project of Maria Litto and to the framework of SMARTER (“Sustainable management of Ambrosia artemisiifolia in Europe”, www.


Sept. 2016-present
PostDoc, Ecology and Evolution, University of Fribourg, Switzerland
Introduction sources and potential of local adaptation of the lead beetle Ophraella communa in the European introduction range.
Jan. 2016-June 2016
PostDoc, Adaptation and diversity in marine ecosystems, Biological Station of Roscoff, France
Population genetics of the invasive seaweed Sargassum muticum using ancient and contemporary DNA
 PhD, Adaptation and diversity in marine ecosystems, Biological Station of Roscoff, France
Ecological and evolutionary dynamic of two inter-fertile species (within Ciona sp.), one native and one non-native, in their sympatric range
Research Assistant, Adaptation and diversity in marine ecosystems, Biological Station of Roscoff, France
Spatial and temporal diversity of invasive communities established in artificial habitats of the English Channel
2009-2011 MSc in Marine Ecology, University Pierre and Marie Curie, France
2006-2009 BSc in Population Biology, University of Lille, France

Other activities (past and present): teaching assistant at the University Pierre and Marie Curie and at the University of Fribourg


Bouchemousse S, Bishop JDD, Viard F. (2016) Contrasting global genetic patterns in two biologically similar, widespread and invasive Ciona species (Tunicata, Ascidiacea). Scientific Reports 6, 24875, doi: 10.1038/srep24875 

Bouchemousse S, Lévêque L, Dubois G, Viard F (2016) Co-occurrence and reproductive synchrony do not ensure hybridization between an alien tunicate and its interfertile native congener. Evolutionary Ecology, 30: 69-87, doi: 10.1007/s10682-015-9788-1

Bouchemousse S, Haag-Liautard C, Bierne N, Viard F (2015). Past and contemporary introgression between two strongly differentiated Ciona species as revealed by the analysis of post-genomic ancestry SNPs. Submitted to Molecular Ecology. Online on BioRxiv, doi: 10.1101/030346 

Oppliger LV, von Dassow P, Bouchemousse S, Robuchon M, Valero M, Correa J.A., Mauger S, Destombe C (2014) Alteration of sexual reproduction and genetic diversity in the kelp species Laminaria digitata at the southern limit of its range. PLoS ONE 9: e102518, doi: 10.1371/journal.pone.0102518

Ecology & Evolution - ch du musée - 1700 Fribourg - Tel +41 26 / 300 8835 - Fax +41 26 / 300 9741
heinz.mueller[at] - Swiss University