Field studies and conceptual work on hybridization-mediated extinction risk in climate relicts are extremely rare. Nuphar pumila (Nymphaeaceae) is one of the most emblematic climate relicts in Europe with few isolated populations in the Alpine arc. The extent of introgression with related lowland and generalist species Nuphar lutea has never been studied using molecular methods. All biogeographical regions where N. pumila naturally occurs in the neighbourhood of the Alpine arc were sampled and studied using...
Data from: Selection against recombinant hybrids maintains reproductive isolation in hybridizing Populus species despite F1 fertility and recurrent gene flowCamille Christie, Kai N. Stölting, Luisa Bresadola, Barbara Fussi, Berthold Heinze, Daniel Wegmann, Christian Lexer & Camille Christe
Natural hybrid zones have proven to be precious tools for understanding the origin and maintenance of reproductive isolation (RI) and therefore species. Most available genomic studies of hybrid zones using whole- or partial-genome resequencing approaches have focused on comparisons of the parental source populations involved in genome admixture, rather than exploring fine-scale patterns of chromosomal ancestry across the full admixture gradient present between hybridizing species. We have studied three well-known European ‘replicate’ hybrid zones of...
Data from: Genomic and functional approaches reveal a case of adaptive introgression from Populus balsamifera (balsam poplar) in P. trichocarpa (black cottonwood)Adriana Suarez-Gonzalez, Charles Hefer, Camille Christie, Oliver Corea, Christian Lexer, Quentin C. B. Cronk, Carl J. Douglas, Charles A. Hefer & Camille Christe
Natural hybrid zones in forest trees provide systems to study the transfer of adaptive genetic variation by introgression. Previous landscape genomic studies in Populus trichocarpa, a keystone tree species, indicated genomic footprints of admixture with its sister species P. balsamifera and identified candidate genes for local adaptation. Here, we explored patterns of introgression and signals of local adaptation in P. trichocarpa and P. balsamifera, employing genome resequencing data from three chromosomes in pure species and...
Data from: The relative contribution of species richness and species composition to ecosystem functioningNadine Sandau, Yvonne Fabian, Odile T. Bruggisse, Rudolf P. Rohr, Russell E. Naisbit, Patrik Kehrli, Alexandre Aebi, Louis-Félix Bersier & Odile T. Bruggisser
The influence of species diversity on ecosystem functioning has been the subject of many experiments and remains a key question for ecology and conservation biology. However, the fact that diversity cannot be manipulated without affecting species composition makes this quest methodologically challenging. We used partial Mantel tests to evaluate the relative importance of diversity and of composition on biomass production. Here, we applied partial Mantel tests (controlling for the other variable) on two datasets, the...
Asexual reproduction is a common and fundamental mode of reproduction in plants. Although persistence in adverse conditions underlies most known cases of clonal dominance, proximal genetic drivers remain unclear, in particular for populations dominated by a few large clones. In this study, we studied a clonal population of the riparian tree Populus alba in the Douro river basin (northwestern Iberian Peninsula) where it hybridizes with Populus tremula, a species that grows in highly contrasted ecological...
Networks play a prominent role in the study of complex systems of interacting entities in biology, sociology, and economics. Despite this diversity, we demonstrate here that a statistical model decomposing networks into matching and centrality components provides a comprehensive and unifying quantification of their architecture. The matching term quantifies the assortative structure in which node makes links with which other node, while the centrality term quantifies the number of links that nodes make. We show,...
Data from: Adaptive evolution and segregating load contribute to the genomic landscape of divergence in two tree species connected by episodic gene flowCamille Christe, Kai N. Stölting, Margot Paris, Christelle Fraїsse, Nicolas Bierne & Christian Lexer
Speciation often involves repeated episodes of genetic contact between divergent populations before reproductive isolation (RI) is complete. Whole-genome sequencing (WGS) holds great promise for unravelling the genomic bases of speciation. We have studied two ecologically divergent, hybridizing species of the ‘model tree’ genus Populus (poplars, aspens, cottonwoods), Populus alba and P. tremula, using >8.6 million single nucleotide polymorphisms (SNPs) from WGS of population pools. We used the genomic data to (i) scan these species’ genomes...
University of Fribourg7
University of Vienna4
University of Neuchâtel1
West Virginia University1
University of Lausanne1
Institute of Biosciences and Bioresources1
University of British Columbia1
Swiss Federal Institute for Forest, Snow and Landscape Research1
University of Victoria1