ORCID Profile
0000-0002-4797-9143
Current Organisation
University of Sheffield
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Publisher: Springer Science and Business Media LLC
Date: 05-10-2014
Publisher: Wiley
Date: 05-2023
DOI: 10.1002/ECE3.9961
Abstract: We call for journals to commit to requiring open data be archived in a format that will be simple and clear for readers to understand and use. If applied consistently, these requirements will allow contributors to be acknowledged for their work through citation of open data, and facilitate scientific progress.
Publisher: Wiley
Date: 25-07-2014
DOI: 10.1002/ECE3.1173
Publisher: Wiley
Date: 27-05-2010
DOI: 10.1111/J.1365-2656.2010.01703.X
Abstract: 1. Two major theories underpin our understanding of how predation risk shapes life history. The first is centred around predator induced changes in activity that subsequently reduce food intake and thus growth. The second is centred around size selective, predator induced changes in development. 2. Here, we challenge these theories using experiments and probabilistic models of maturation reaction norms to investigate predator induced life history in the water flea Daphnia pulex facing two different predators. 3. We combine this reaction norm investigation with an assessment of growth rate, development rate, moult number and moult duration to uncover the mechanisms controlling predator induced life history plasticity when D. pulex face either large or small size selective predators. 4. The probabilistic reaction norms reveal predator specific norms of reaction in size and age along a food gradient. Fish cues reduce age and size, with a bias in age, and do so by reducing moult number and duration. Midge cues increase age and size, with a bias in size, and do so by fine scale modulation of early growth rates. 5. These data contribute towards developing a unified view of how predation risk from multiple predators shapes life history evolution.
Publisher: Cold Spring Harbor Laboratory
Date: 12-08-2022
DOI: 10.1101/2022.08.12.503188
Abstract: 1 Widely documented, megaevolutionary jumps in phenotypic ersity continue to perplex researchers because it remains unclear whether these dramatic changes can emerge from microevolutionary processes. Here we tackle this question using new approaches for modeling multivariate traits to evaluate the magnitude and distribution of elaboration and innovation in the evolution of bird beaks. We find that elaboration, evolution along the major axis of phenotypic change, is common at both macro- and megaevo-lutionary scales whereas innovation, evolution away from the major axis of phenotypic change, is more prominent at megaevolutionary scales. Indeed, the major axis of phenotypic change among species beak shapes at megaevolutionary scales is an emergent property of innovation across clades. Our analyses suggest that the reorientation of phenotypes via innovation is a ubiquitous route for ergence that can arise through gradual change alone, opening up new avenues for evolution to explore.
Publisher: Springer Science and Business Media LLC
Date: 27-11-2017
DOI: 10.1038/S41559-017-0373-6
Abstract: Phenotypic plasticity is the ability of an in idual genotype to alter aspects of its phenotype depending on the current environment. It is central to the persistence, resistance and resilience of populations facing variation in physical or biological factors. Genetic variation in plasticity is pervasive, which suggests its local adaptation is plausible. Existing studies on the adaptation of plasticity typically focus on single traits and a few populations, while theory about interactions among genes (for ex le, pleiotropy) suggests that a multi-trait, landscape scale (for ex le, multiple populations) perspective is required. We present data from a landscape scale, replicated, multi-trait experiment using a classic predator-prey system centred on the water flea Daphnia pulex. We find predator regime-driven differences in genetic variation of multivariate plasticity. These differences are associated with strong ergent selection linked to a predation regime. Our findings are evidence for local adaptation of plasticity, suggesting that responses of populations to environmental variation depend on the conditions in which they evolved in the past.
Publisher: Wiley
Date: 14-07-2021
DOI: 10.1111/MPP.13101
Abstract: Septoria tritici blotch (STB), caused by the fungus Zymoseptoria tritici , is one of the most economically important diseases of wheat. Recently, both factors of a gene‐for‐gene interaction between Z . tritici and wheat, the wheat receptor‐like kinase Stb6 and the Z . tritici secreted effector protein AvrStb6, have been identified. Previous analyses revealed a high ersity of AvrStb6 haplotypes present in earlier Z . tritici isolate collections, with up to c.18% of analysed isolates possessing the avirulence isoform of AvrStb6 identical to that originally identified in the reference isolate IPO323. With Stb6 present in many commercial wheat cultivars globally, we aimed to assess potential changes in AvrStb6 genetic ersity and the incidence of haplotypes allowing evasion of Stb6 ‐mediated resistance in more recent Z . tritici populations. Here we show, using targeted resequencing of AvrStb6 , that this gene is universally present in field isolates s led from major wheat‐growing regions of the world in 2013–2017. However, in contrast to the data from previous AvrStb6 population studies, we report a complete absence of the originally described avirulence isoform of AvrStb6 amongst modern Z . tritici isolates. Moreover, a remarkably small number of haplotypes, each encoding AvrStb6 protein isoforms conditioning virulence on Stb6‐ containing wheat, were found to predominate among modern Z . tritici isolates. A single virulence isoform of AvrStb6 was found to be particularly abundant throughout the global population. These findings indicate that, despite the ability of Z . tritici to sexually reproduce on resistant hosts, AvrStb6 avirulence haplotypes tend to be eliminated in subsequent populations.
Publisher: American Association for the Advancement of Science (AAAS)
Date: 27-10-2023
Publisher: Wiley
Date: 06-04-2021
Abstract: Approximately 25% of mammals are currently threatened with extinction, a risk that is lified under climate change. Species persistence under climate change is determined by the combined effects of climatic factors on multiple demographic rates (survival, development and reproduction), and hence, population dynamics. Thus, to quantify which species and regions on Earth are most vulnerable to climate‐driven extinction, a global understanding of how different demographic rates respond to climate is urgently needed. Here, we perform a systematic review of literature on demographic responses to climate, focusing on terrestrial mammals, for which extensive demographic data are available. To assess the full spectrum of responses, we synthesize information from studies that quantitatively link climate to multiple demographic rates. We find only 106 such studies, corresponding to 87 mammal species. These 87 species constitute % of all terrestrial mammals. Our synthesis reveals a strong mismatch between the locations of demographic studies and the regions and taxa currently recognized as most vulnerable to climate change. Surprisingly, for most mammals and regions sensitive to climate change, holistic demographic responses to climate remain unknown. At the same time, we reveal that filling this knowledge gap is critical as the effects of climate change will operate via complex demographic mechanisms: a vast majority of mammal populations display projected increases in some demographic rates but declines in others, often depending on the specific environmental context, complicating simple projections of population fates. Assessments of population viability under climate change are in critical need to gather data that account for multiple demographic responses, and coordinated actions to assess demography holistically should be prioritized for mammals and other taxa.
Publisher: Wiley
Date: 10-01-2013
DOI: 10.1111/ELE.12047
Abstract: Acquisition and allocation of resources are central to life-history theory. However, empirical work typically focuses only on allocation despite the fact that relationships between fitness components may be governed by differences in the ability of in iduals to acquire resources across environments. Here, we outline a statistical framework to partition the genetic basis of multivariate plasticity into independent axes of genetic variation, and quantify for the first time, the extent to which specific traits drive multitrait genotype-environment interactions. Our framework generalises to analyses of plasticity, growth and ageing. We apply this approach to a unique, large-scale, multivariate study of acquisition, allocation and plasticity in the life history of the cricket, Gryllus firmus. We demonstrate that resource acquisition and allocation are genetically correlated, and that plasticity in trade-offs between allocation to components of fitness is 90% dependent on genetic variance for total resource acquisition. These results suggest that genotype-environment effects for resource acquisition can maintain variation in life-history components that are typically observed in the wild.
Publisher: Cold Spring Harbor Laboratory
Date: 18-09-2020
DOI: 10.1101/2020.09.18.303370
Abstract: Septoria tritici blotch (STB), caused by the fungus Zymoseptoria tritici , is one of the most economically important diseases of wheat. Recently, both factors of a gene-for-gene interaction between Z. tritici and wheat, the wheat receptor-like kinase Stb6 and the Z. tritici secreted effector protein AvrStb6, have been identified. Previous analyses revealed a high ersity of AvrStb6 alleles present in historic Z. tritici isolate collections, with up to ~ 18% of analysed isolates possessing the avirulence isoform of AvrStb6 identical to that originally identified in the reference isolate IPO323. With Stb6 present in many commercial wheat cultivars globally, we aimed to assess potential changes in AvrStb6 genetic ersity and the incidence of alleles allowing evasion of Stb6 -mediated resistance in more recent Z. tritici populations. Here we show, using targeted re-sequencing of AvrStb6, that this gene is universally present in field isolates s led from major wheat-growing regions of the world between 2013–2017. However, in contrast to the data from studies of historic isolates, our study revealed a complete absence of the originally described avirulence isoform of AvrStb6 amongst modern Z. tritici isolates. Moreover, a remarkably small number of alleles, each encoding AvrStb6 protein isoforms conditioning virulence on Stb6- containing wheat, were found to predominate among modern Z. tritici isolates. A single virulence isoform of AvrStb6 was found to be particularly abundant throughout the global population. These findings indicate that, despite the ability of Z. tritici to sexually reproduce on resistant hosts, AvrStb6 avirulence alleles tend to be eliminated in subsequent populations.
Publisher: The Royal Society
Date: 17-11-2010
Abstract: A long-standing question in ecology is whether phenotypic plasticity, rather than selection per se , is responsible for phenotypic variation among populations. Plasticity can increase or decrease variation, but most previous studies have been limited to single populations, single traits and a small number of environments assessed using univariate reaction norms. Here, examining two genetically distinct populations of Daphnia pulex with different predation histories, we quantified predator-induced plasticity among 11 traits along a fine-scale gradient of predation risk by a predator ( Chaoborus ) common to both populations. We test the hypothesis that plasticity can be responsible for convergence in phenotypes among different populations by experimentally characterizing multivariate reaction norms with phenotypic trajectory analysis (PTA). Univariate analyses showed that all genotypes increased age and size at maturity, and invested in defensive spikes (neckteeth), but failed to quantitatively describe whole-organism response. In contrast, PTA quantified and qualified the phenotypic strategy the organism mobilized against the selection pressure. We demonstrate, at the whole-organism level, that the two populations occupy different areas of phenotypic space in the absence of predation but converge in phenotypic space as predation threat increases.
Publisher: Wiley
Date: 20-11-2013
DOI: 10.1002/ECE3.766
Publisher: Wiley
Date: 12-05-2016
Abstract: Despite the capacity of invasive alien species to alter ecosystems, the mechanisms underlying their impact remain only partly understood. Invasive alien predators, for ex le, can significantly disrupt recipient communities by consuming prey species or acting as an intraguild predator (IGP). Behavioural interactions are key components of interspecific competition between predators, yet these are often overlooked invasion processes. Here, we show how behavioural, non-lethal IGP interactions might facilitate the establishment success of an invading alien species. We experimentally assessed changes in feeding behaviour (prey preference and consumption rate) of native UK coccinellid species (Adalia bipunctata and Coccinella septempunctata), whose populations are, respectively, declining and stable, when exposed to the invasive intraguild predator, Harmonia axyridis. Using a population dynamics model parameterized with these experimental data, we predicted how intraguild predation, accommodating interspecific behavioural interactions, might impact the abundance of the native and invasive alien species over time. When competing for the same aphid resource, the feeding rate of A. bipunctata significantly increased compared to the feeding in isolation, while the feeding rate of H. axyridis significantly decreased. This suggests that despite significant declines in the UK, A. bipunctata is a superior competitor to the intraguild predator H. axyridis. In contrast, the behaviour of non-declining C. septempunctata was unaltered by the presence of H. axyridis. Our experimental data show the differential behavioural plasticity of competing native and invasive alien predators, but do not explain A. bipunctata declines observed in the UK. Using behavioural plasticity as a parameter in a population dynamic model for A. bipunctata and H. axyridis, coexistence is predicted between the native and invasive alien following an initial period of decline in the native species. We demonstrate how empirical and theoretical techniques can be combined to understand better the processes and consequences of alien species invasions for native bio ersity.
Publisher: Cold Spring Harbor Laboratory
Date: 03-11-2022
DOI: 10.1101/2022.11.02.514877
Abstract: In the face of rapid global change and an uncertain fate for bio ersity, it is vital to quantify trends in wild populations. These trends are typically estimated from abundance time series for suites of species across large geographic and temporal scales. Such data implicitly contain phylogenetic, spatial, and temporal structure which, if not properly accounted for, may obscure the true magnitude and direction of bio ersity change. Here, using a novel statistical framework to simultaneously account for all three of these structures, we show that the majority of current abundance trends estimates among 10 high-profile datasets, representing millions of abundance observations, are likely unreliable or incorrect. Our new approach suggests that previous models are too simplistic, incorrectly estimating global abundance trends and often dramatically underestimating uncertainty, an aspect that is critical when translating global assessments into policy outcomes. Further, our approach also results in substantial improvements in abundance forecasting accuracy. Whilst our results do not improve the outlook for bio ersity, our framework does allow us to make more robust estimates of global wildlife abundance trends, which is critical for developing policy to protect our biosphere.
Publisher: Wiley
Date: 19-03-2008
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Start Date: 2020
End Date: 2024
Funder: Natural Environment Research Council
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