Chown S.L.,Stellenbosch University |
Hoffmann A.A.,University of Melbourne |
Kristensen T.N.,University of Aarhus |
Angilletta Jr. M.J.,Arizona State University |
And 3 more authors.
Climate Research | Year: 2010
Much attention has been given to forecasting the likely effects of ongoing climate change on biodiversity. A large and often contentious literature has developed about how changes in species' ranges should be modelled and how additional biological mechanisms might be incorporated to improve their utility. Nonetheless, 2 areas stand out as relatively underappreciated: the importance of understanding a species' physiological capacities when forecasting its response to climate change, and the likely influence that capacities for genetic change across generations and changes in plastic responses, or the lack thereof, will have on a species' response. Although perhaps not as well developed as correlative approaches to understanding species responses to change, mechanistic approaches are advancing rapidly. In this review, we explore several of the key messages emerging from the mechanistic approach, embodied in evolutionary physiology, to understanding and forecasting species responses to climate change. © Inter-Research 2010.
Kauserud H.,University of Oslo |
Kumar S.,University of Oslo |
Brysting A.K.,Center for Ecological and Evolutionary Synthesis |
Norden J.,University of Oslo |
Carlsen T.,University of Oslo
Mycorrhiza | Year: 2012
In this methodological study, we compare 454 sequencing and a conventional cloning and Sanger sequencing approach in their ability to characterize fungal communities PCR amplified from four root systems of the ectomycorrhizal plant Bistorta vivipara. To examine variation introduced by stochastic processes during the laboratory work, we replicated all analyses using two independently obtained DNA extractions from the same root systems. The ITS1 region was used as DNA barcode and the sequences were clustered into OTUs as proxies for species using single linkage clustering (BLASTClust) and 97% sequence similarity cut-off. A relatively low overlap in fungal OTUs was observed between the 454 and the clone library datasets - even among the most abundant OTUs. In a non-metric multidimensional scaling analysis, the samples grouped more according to methodology compared to plant. Some OTUs frequently detected by 454, most notably those OTUs with taxonomic affinity to Glomales, were not detected in the Sanger dataset. Likewise, a few OTUs, including Cenococcum sp., only appeared in the clone libraries. Surprisingly, we observed a significant relationship between GC/AT content of the OTUs and their proportional abundances in the 454 versus the clone library datasets. Reassuringly, a very good consistency in OTU recovery was observed between replicate runs of both sequencing methods. This indicates that stochastic processes had little impact when applying the same sequencing technique on replicate samples. © 2011 Springer-Verlag.
Kubisch A.,University of Hohenheim |
Kubisch A.,Montpellier University |
Winter A.-M.,Center for Ecological and Evolutionary Synthesis |
Fronhofer E.A.,Eawag - Swiss Federal Institute of Aquatic Science and Technology
Ecography | Year: 2016
In times of severe environmental changes and resulting shifts in the geographical distribution of animal and plant species it is crucial to unravel the mechanisms responsible for the dynamics of species' ranges. Without such a mechanistic understanding, reliable projections of future species distributions are difficult to derive. Species' ranges may be highly dynamic. One particularly interesting phenomenon is range contraction following a period of expansion, referred to as 'elastic' behaviour. It has been proposed that this phenomenon occurs in habitat gradients, which are characterized by a negative cline in selection for dispersal from the range core towards the margin, as one may find, for example, with increasing patch isolation. Using individual-based simulations and numerical analyses we show that Allee effects are an important determinant of range border elasticity. If only intra-specific processes are considered, Allee effects are even a necessary condition for ranges to exhibit elastic behavior. The eco-evolutionary interplay between dispersal evolution, Allee effects and habitat isolation leads to lower colonization probability and higher local extinction risk after range expansions, which result in an increasing amount of marginal sink patches and consequently, range contraction. We also demonstrate that the nature of the gradient is crucial for range elasticity. Gradients which do not select for lower dispersal at the margin than in the core (especially gradients in patch size, demographic stochasticity and extinction rate) do not lead to elastic range behavior. Thus, we predict that range contractions are likely to occur after periods of expansion for species living in gradients of increasing patch isolation, which suffer from Allee effects. Ecography © 2015 Nordic Society Oikos.
Kjesbu O.S.,Norwegian Institute of Marine Research |
Kjesbu O.S.,Center for Ecological and Evolutionary Synthesis |
Opdal A.F.,University of Bergen |
Korsbrekke K.,Norwegian Institute of Marine Research |
And 2 more authors.
ICES Journal of Marine Science | Year: 2014
Hidden within the seminal 1914 publication by Johan Hjort, we find what is probably one of the first comprehensive teleost time-series ever published. The series is liver size and fat content of northeast Arctic (NEA) cod measured during the traditional winter fishery in Lofoten, Northern Norway, in 1880-1912 and 1883-1913, respectively. The data were collected well before the advent of the great industrialized fisheries in the 1930s. The raw data used by Hjort originate from annual reports of the Lofoten fishery, initiated by Member of Parliament and pioneer fishery inspector of Northern Norway, Ketil Motzfeldt, in 1859. Based on these reports and following various calibration exercises, we present robust estimates of the hepatosomatic index (HSI) from 1859 to 2012 (except 1863), i.e. over 153 years-extending Hjort's analysis both backwards (1859-1879) and forwards (1913-present). This series of bulk HSI contained five major periods: 1859-1880, 1881-1919, 1920-1974, 1975-2003, and 2004-2012; the highest HSI was recorded 1920-1974, whereas the lowest was from the most recent period. Despite variability, total length was a significant predictor of HSI, 1932-2012. A weak but significant relationship existed with both total-stock biomass and ocean temperature, as well as with the North Atlantic Oscillation winter index under a 1-year lag. The present exceptionally long HSI series will give an excellent opportunity for further research on the "quality of the cod" in a historic perspective. © 2014 International Council for the Exploration of the Sea. All rights reserved.
Alcaide M.,CSIC - Doñana Biological Station |
Alcaide M.,Harvard University |
Cadahia L.,CSIC - Doñana Biological Station |
Cadahia L.,Center for Ecological and Evolutionary Synthesis |
And 2 more authors.
Condor | Year: 2010
Estimating indices of abundance of threatened species is crucial to preserving biodiversity. Over the last few decades, noninvasive genetic sampling has proven to be a more straightforward and less expensive approach than capture-mark-recapture analyses. In particular, molted feathers have become extremely popular for the monitoring of bird populations. Diagnostic molecular markers such as microsatellites, however, are still not available for many avian species of conservation concern. Highly polymorphic genes of the major histocompatibility complex (MHC), on the other hand, have become reasonably accessible during the last few years. We tested the suitability of MHC profiles as DNA fingerprints to assist the identification of individuals of a scavenger difficult to monitor through traditional approaches, the Andean Condor (Vultur gryphus). To achieve this aim, we isolated polymorphic and putatively functional genes of MHC class I (exon 3, 6 alleles) and MHC class IIB (exon 2, 11 alleles). Single-strand conformational polymorphism and direct sequencing of MHC genes, combined with molecular sexing and inference of age class from feather color, allowed us to identify 80 different individuals from 110 molted feathers collected at roost sites. Inferred sex and age ratios were concordant with previous studies relying on direct observations. Among adults, the number of males was double that of females; among juveniles, this ratio was inverted. Besides providing valuable data regarding genetic variation at functionally important genes related to resistance to pathogens, we demonstrate additional potential of polymorphic MHC loci beyond their well-known role in evolutionary ecology. © The Cooper Ornithological Society 2010.