Landscape heterogeneity plays a central role in shaping ecological and evolutionary processes. While species utilization of the landscape is usually viewed as constant within a year, the spatial distribution of individuals is likely to vary in time in relation to particular seasonal needs. Understanding temporal variation in landscape use and genetic connectivity has direct conservation implications. Here, we modelled the daily use of the landscape by caribou in Quebec and Labrador, Canada and tested its...
Data from: Calibration uncertainty in molecular dating analyses: there is no substitute for the prior evaluation of time priorsRachel C. M. Warnock, James F. Parham, Walter G. Joyce, Tyler R. Lyson & Philip C. J. Donoghue
Calibration is the rate-determining step in every molecular clock analysis and, hence, considerable effort has been expended in the development of approaches to distinguish good from bad calibrations. These can be categorized into a priori evaluation of the intrinsic fossil evidence, and a posteriori evaluation of congruence through cross-validation. We contrasted these competing approaches and explored the impact of different interpretations of the fossil evidence upon Bayesian divergence time estimation. The results demonstrate that a...
Island populations provide natural laboratories for studying key contributors to evolutionary change, including natural selection, population size, and the colonization of new environments. The demographic histories of island populations can be reconstructed from patterns of genetic diversity. House mice (Mus musculus) inhabit islands throughout the globe, making them an attractive system for studying island colonization from a genetic perspective. Gough Island, in the central South Atlantic Ocean, is one of the remotest islands in the...
Data from: Postglacial expansion and not human persecution best explains the population structure in the endangered kea (Nestor notabilis)Nick Dussex, D. Wegmann & B. C. Robertson
Inferring past demography is a central question in evolutionary and conservation biology. It is however sometimes challenging to infer the processes that shaped the current patterns of genetic variation in endangered species. Population sub-structuring can occur as a result of survival in several isolated refugia and subsequent recolonization processes or via genetic drift following a population decline. The kea (Nestor notabilis) is an endemic parrot widely distributed in the mountains of the South Island of...
1. Studies on biodiversity and ecosystem functioning (BEF) have elicited debate over the interpretation of the positive relationship between species richness and plant productivity. Manipulating richness cannot be achieved without affecting composition; it is thus essential to consider the latter in statistical models. 2. We firstly review existing approaches that use species richness as an explanatory variable and propose modifications to improve their performance. We use an original dataset to illustrate the analyses. The classical...
Data from: Genomics of the divergence continuum in an African plant biodiversity hotspot, I: drivers of population divergence in Restio capensis (Restionaceae)Christian Lexer, Rafael O. Wüest, Sofia Mangili, Myriam Heuertz, Kai N. Stolting, Peter B. Pearman, Felix Forest, Nicolas Salamin, Niklaus E. Zimmermann & Eligio Bossolini
Understanding the drivers of population divergence, speciation and species persistence is of great interest to molecular ecology, especially for species-rich radiations inhabiting the world’s biodiversity hotspots. The toolbox of population genomics holds great promise for addressing these key issues, especially if genomic data are analyzed within a spatially and ecologically explicit context. We have studied the earliest stages of the divergence continuum in the Restionaceae, a species-rich and ecologically important plant family of the Cape...
1. Various factors have been shown contributing to the ecosystem impact of invasive alien plants, but their relative importance remains unclear. We focused on the effects of neighbouring plant community and soil biota as these biotic factors have been repeatedly put forward to explain invasion success (e.g. as components of the novel weapons and of the biotic release hypothesis). 2. To assess their relative importance in explaining the high impact of Centaurea stoebe during the...
Data from: Unexpected ancestry of Populus seedlings from a hybrid zone implies a large role for postzygotic selection in the maintenance of speciesDorothea Lindtke, Zachariah Gompert, Christian Lexer & C. Alex Buerkle
In the context of potential interspecific gene flow, the integrity of species will be maintained by reproductive barriers that reduce genetic exchange, including traits associated with prezygotic isolation or poor performance of hybrids. Hybrid zones can be used to study the importance of different reproductive barriers, particularly when both parental species and hybrids occur in close spatial proximity. We investigated the importance of barriers to gene flow that act early versus late in the life...
Explaining the strong variation in lifespan among organisms remains a major challenge in evolutionary biology. Whereas previous work has concentrated mainly on differences in selection regimes and selection pressures, we hypothesize that differences in genetic drift may explain some of this variation. We develop a model to formalize this idea and show that the strong positive relationship between lifespan and genetic diversity predicted by this model indeed exists among populations of Daphnia magna, and that...
Data from: Small-scale patterns in snowmelt timing affect gene flow and the distribution of genetic diversity in the alpine dwarf shrub Salix herbaceaAndrés J. Cortés, Stephan Waeber, Christian Lexer, Janosch Sedlacek, Julia A. Wheeler, Mark Van Kleunen, Oliver Bossdorf, Günter Hoch, Christian Rixen, Sonja Wipf & Sophie Karrenberg
Current threats to biodiversity, such as climate change, are thought to alter the within-species genetic diversity among microhabitats in highly heterogeneous alpine environments. Assessing the spatial organization and dynamics of genetic diversity within species can help to predict the responses of organisms to environmental change. In this study, we evaluated whether small-scale heterogeneity in snowmelt timing restricts gene flow between microhabitats in the common long-lived dwarf shrub Salix herbacea L. We surveyed 273 genets across...
University of Fribourg10
Swiss Federal Institute for Forest, Snow and Landscape Research2
Swiss Institute of Bioinformatics1
Fred Hutchinson Cancer Research Center1
Utah State University1
Field Museum of Natural History1
University of Neuchâtel1
Royal Botanic Gardens1
Royal Society for the Protection of Birds1