The Experts below are selected from a list of 204 Experts worldwide ranked by ideXlab platform
Alvaro Sanchez - One of the best experts on this subject based on the ideXlab platform.
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cooperators trade off ecological resilience and evolutionary stability in public goods games
Journal of the Royal Society Interface, 2017Co-Authors: Joseph Rauch, Jane Kondev, Alvaro SanchezAbstract:Microbial Populations often rely on the cooperative production of extracellular ‘public goods’ molecules. The cooperative nature of public good production may lead to Minimum Viable Population sizes, below which Populations collapse. In addition, ‘cooperator’ public goods producing individuals face evolutionary competition from non-producing mutants, or ‘freeloaders’. Thus, public goods cooperators should be resilient not only to the invasion of freeloaders, but also to ecological perturbations that may push their Populations below a sustainable threshold. Through a mathematical analysis of the Ecological Public Goods Game, we show that game parameters that improve the cooperating Population9s stability to freeloader invasion also lead to a low ecological resilience. Complex regulatory strategies mimicking those used by microbes in nature may allow cooperators to beat this trade-off and become evolutionarily stable to invading freeloaders while at the same time maximizing their ecological resilience. Our results thus identify the coupling between resilience to evolutionary and ecological challenges as a key factor for the long-term viability of public goods cooperators.
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cooperators trade off ecological resilience and evolutionary stability in public goods games
Journal of the Royal Society Interface, 2017Co-Authors: Joseph Rauch, Jane Kondev, Alvaro SanchezAbstract:Microbial Populations often rely on the cooperative production of extracellular ‘public goods’ molecules. The cooperative nature of public good production may lead to Minimum Viable Population size...
Daniel Brito - One of the best experts on this subject based on the ideXlab platform.
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Estimating Minimum Area of Suitable Habitat and Viable Population Size for the Northern Muriqui ( Brachyteles hypoxanthus )
Biodiversity and Conservation, 2006Co-Authors: Daniel Brito, Carlos Eduardo Viveiros GrelleAbstract:A Population viability analysis (PVA) using the computer package VORTEX was conducted to assess the Minimum Viable Population (MVP) of the Atlantic Forest endemic primate Brachyteles hypoxanthus. The objectives were: (1) to estimate demographic and genetic MVPs that could be used as quasi-extinction thresholds for future modeling, and (2) to estimate the Minimum area of suitable habitat (MASH). The model predicted that Populations of 40 and 700 individuals were necessary to achieve demographic and genetic stability, respectively. The model was more sensitive to changes in inbreeding depression, sex ratio and reproduction (percentage of breeding females). MASH estimated to contain genetically Viable Populations reached 11,570 ha. Muriquis have managed to persist despite severe habitat disturbance, but the results suggest that although most of the extant Populations are not threatened by extinction, they are too small to be genetically Viable in the long-run, and will loose most of their heterozygosity.
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Evaluation of Minimum Viable Population Size and Conservation Status of the Long-furred Woolly Mouse Opossum Micoureus paraguayanus: An Endemic Marsupial of the Atlantic Forest
Biodiversity & Conservation, 2006Co-Authors: Daniel Brito, Gustavo A. B. FonsecaAbstract:A Population viability analysis (PVA) using the computer package VORTEX was conducted to assess the Minimum Viable Population (MVP) of the Atlantic Forest endemic marsupial Micoureus paraguayanus . The objectives were: to estimate demographic and genetic MVPs that could be used as quasi-extinction thresholds for future modeling, to estimate the Minimum area of suitable habitat (MASH), and to use these results to apply IUCN red list criteria so as to suggest its proper status classification. The model predicted that Populations of 100 and 2000 individuals were necessary to achieve demographic and genetic stability, respectively, within a time frame of 100 years. The model was sensitive to changes in inbreeding depression, mortality and reproduction. MASH estimated to contain genetically Viable Populations reached 1300 ha. Fortunately, there still are quite a number of forest remnants equal to or larger than this. Isolation is suggested as the principal threat facing M. paraguayanus . Therefore, promoting conditions for dispersal together with efforts dealing with translocation, should prove to be the most appropriate management strategies for M. paraguayanus at this stage. A landscape pattern composed of large patches holding MVPs and sets of smaller patches harboring Viable metaPopulations that maximize probability of dispersal can provide a Viable scenario for the conservation of M. paraguayanus .
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Minimum Viable Population and conservation status of the atlantic forest spiny rat trinomys eliasi
Biological Conservation, 2003Co-Authors: Daniel Brito, Marcos S L FigueiredoAbstract:Abstract A Population viability analysis (PVA) was conducted to assess the Minimum Viable Population (MVP) of the Atlantic Forest spiny rat Trinomys eliasi, a species threatened by habitat loss and restricted geographical distribution. Objectives were to suggest quasi-extinction thresholds, estimate Minimum areas of suitable habitat (MASH) and MVPs, and compare results with the species’ current status. The computer package VORTEX was used. The model predicted sizes of 200 animals to achieve demographic stability, but buffering declines in genetic variability required Populations of 2000 animals. Estimated MASHs were approximately 250 and 2500 ha for demographic and genetic stability, respectively. Mortality rate and mean litter size were the most sensitive parameters to changes in model assumptions. The protection of known Populations and the search for extant Populations are the first steps in conservation. T. eliasi's issue could help protecting the coastal shrubland ecosystem of Rio de Janeiro state. Observing IUCN's criteria for listing threatened species, it is suggested that T. eliasi should be ranked as vulnerable in red lists.
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short communication Minimum Viable Population and conservation status of the atlantic forest spiny rat trinomys eliasi
2003Co-Authors: Daniel Brito, Marcos De Souza, Lima FigueiredoAbstract:A Population viability analysis (PVA) was conducted to assess the Minimum Viable Population (MVP) of the Atlantic Forest spiny rat Trinomys eliasi, a species threatened by habitat loss and restricted geographical distribution. Objectives were to suggest quasi-extinction thresholds, estimate Minimum areas of suitable habitat (MASH) and MVPs, and compare results with the species’ current status. The computer package VORTEX was used. The model predicted sizes of 200 animals to achieve demographic stability, but buffering declines in genetic variability required Populations of 2000 animals. Estimated MASHs were approximately 250 and 2500 ha for demographic and genetic stability, respectively. Mortality rate and mean litter size were the most sensitive parameters to changes in model assumptions. The protection of known Populations and the search for extant Populations are the first steps in conservation. T. eliasi’s issue could help protecting the coastal shrubland ecosystem of Rio de Janeiro state. Observing IUCN’s criteria for listing threatened species, it is suggested that T. eliasi should be ranked as vulnerable in red lists. # 2002 Elsevier Science Ltd. All rights reserved.
Joseph Rauch - One of the best experts on this subject based on the ideXlab platform.
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cooperators trade off ecological resilience and evolutionary stability in public goods games
Journal of the Royal Society Interface, 2017Co-Authors: Joseph Rauch, Jane Kondev, Alvaro SanchezAbstract:Microbial Populations often rely on the cooperative production of extracellular ‘public goods’ molecules. The cooperative nature of public good production may lead to Minimum Viable Population sizes, below which Populations collapse. In addition, ‘cooperator’ public goods producing individuals face evolutionary competition from non-producing mutants, or ‘freeloaders’. Thus, public goods cooperators should be resilient not only to the invasion of freeloaders, but also to ecological perturbations that may push their Populations below a sustainable threshold. Through a mathematical analysis of the Ecological Public Goods Game, we show that game parameters that improve the cooperating Population9s stability to freeloader invasion also lead to a low ecological resilience. Complex regulatory strategies mimicking those used by microbes in nature may allow cooperators to beat this trade-off and become evolutionarily stable to invading freeloaders while at the same time maximizing their ecological resilience. Our results thus identify the coupling between resilience to evolutionary and ecological challenges as a key factor for the long-term viability of public goods cooperators.
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cooperators trade off ecological resilience and evolutionary stability in public goods games
Journal of the Royal Society Interface, 2017Co-Authors: Joseph Rauch, Jane Kondev, Alvaro SanchezAbstract:Microbial Populations often rely on the cooperative production of extracellular ‘public goods’ molecules. The cooperative nature of public good production may lead to Minimum Viable Population size...
Barry W Brook - One of the best experts on this subject based on the ideXlab platform.
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genetics in conservation management revised recommendations for the 50 500 rules red list criteria and Population viability analyses
Biological Conservation, 2014Co-Authors: Richard Frankham, Corey J A Bradshaw, Barry W BrookAbstract:Conservation managers typically need to make prompt decisions based on limited information and resources. Consequently, generalisations have essential roles in guiding interventions. Here, we (i) critique information on some widely accepted generalisations and variables affecting them, (ii) assess how adequately genetic factors are currently incorporated into Population viability analysis (PVA) models used to estimate Minimum Viable Population sizes, and (iii) relate the above to Population size thresholds of the IUCN Red List criteria for threatened species that were derived from genetic considerations. Evidence accumulated since 1980 shows that genetically effective Population size (Ne) = 50 is inadequate for preventing inbreeding depression over five generations in the wild, with Ne ⩾ 100 being required to limit loss in total fitness to ⩽10%. Further, even Ne = 500 is too low for retaining evolutionary potential for fitness in perpetuity; a better approximation is Ne ⩾ 1000. Extrapolation from census Population size (N) to Ne depends on knowing the ratio of Ne/N, yet this information is unavailable for most wild Populations. Ratio averages (∼0.1–0.2) from meta-analyses are sufficient, provided adjustments are made for dissimilar life histories. Most PVA-based risk assessments ignore or inadequately model genetic factors. PVA should routinely include realistic inbreeding depression, and genetic impacts on evolutionary potential should be incorporated where appropriate. Genetic generalisations used in conservation, the treatment of genetics in PVAs, and sections of the IUCN Red List criteria derived from genetic considerations, all require revision to be more effective conservation tools.
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Minimum Viable Population size not magic but necessary
Trends in Ecology and Evolution, 2011Co-Authors: Barry W Brook, Corey J A Bradshaw, Lochran W Traill, Richard FrankhamAbstract:We agree with Flather and colleagues that there is no ‘magic number’ or universal threshold around which one can plan for threatened species management to cover all contingencies; neither have we ever claimed so. As Flather and colleagues reiterate, a Minimum Viable Population size [MVP; the abundance above which the probability of extinction (over conservation-relevant timescales) is unacceptably low for any species] is illusory. There is substantial variation in MVP among species and probably across subPopulations for widespread or spatially disjunct species, and there is no obvious ‘decision threshold’, as reviewed by Traill et al. and elsewhere. Yet even with this uncertainty, ignoring MVP because of concerns over its imperfections or risk of misuse, as Flather et al. seem to prefer, would be imprudent.
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Minimum Viable Population size a meta analysis of 30 years of published estimates
Biological Conservation, 2007Co-Authors: Lochran W Traill, Corey J A Bradshaw, Barry W BrookAbstract:Abstract We present the first meta-analysis of a key measure in conservation biology: Minimum Viable Population (MVP) size. Our analysis is based on studies published since the early 1970s, and covers 141 sources and 212 species (after filtering 529 sources and 2202 species). By implementing a unique standardization procedure to make reported MVPs comparable, we were able to derive a cross-species frequency distribution of MVP with a median of 4169 individuals (95% CI = 3577–5129). This standardized database provides a reference set of MVPs from which conservation practitioners can generalize the range expected for particular species (or surrogate taxa) of concern when demographic information is lacking. We provide a synthesis of MVP-related research over the past 30 years, and test for ‘rules of thumb’ relating MVP to extinction vulnerability using well-known threat correlates such as body mass and range decline. We find little support for any plausible ecological and life history predictors of MVP, even though correlates explain >50% of the variation in IUCN threat status. We conclude that a species’ or Population’s MVP is context-specific, and there are no simple short-cuts to its derivation. However, our findings are consistent with biological theory and MVPs derived from abundance time series in that the MVP for most species will exceed a few thousand individuals.
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Minimum Viable Population sizes and global extinction risk are unrelated
Ecology Letters, 2006Co-Authors: Barry W Brook, Lochran W Traill, Corey J A BradshawAbstract:Theoretical and empirical work has shown that once reduced in size and geographical range, species face a considerably elevated risk of extinction. We predict Minimum Viable Population sizes (MVP) for 1198 species based on long-term time-series data and model-averaged Population dynamics simulations. The median MVP estimate was 1377 individuals (90% probability of persistence over 100 years) but the overall distribution was wide and strongly positively skewed. Factors commonly cited as correlating with extinction risk failed to predict MVP but were able to predict successfully the probability of World Conservation Union Listing. MVPs were most strongly related to local environmental variation rather than a species' intrinsic ecological and life history attributes. Further, the large variation in MVP across species is unrelated to (or at least dwarfed by) the anthropogenic threats that drive the global biodiversity crisis by causing once-abundant species to decline.
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estimates of Minimum Viable Population sizes for vertebrates and factors influencing those estimates
Biological Conservation, 2003Co-Authors: David H Reed, Barry W Brook, Julian J Ogrady, Jonathan D Ballou, Richard FrankhamAbstract:Population size is a major determinant of extinction risk. However, controversy remains as to how large Populations need to be to ensure persistence. It is generally believed that Minimum Viable Population sizes (MVPs) would be highly specific, depending on the environmental and life history characteristics of the species. We used Population viability analysis to estimate MVPs for 102 species. We define a Minimum Viable Population size as one with a 99% probability of persistence for 40 generations. The models are comprehensive and include age-structure, catastrophes, demographic stochasticity, environmental stochasticity, and inbreeding depression. The mean and median estimates of MVP were 7316 and 5816 adults, respectively. This is slightly larger than, but in general agreement with, previous estimates of MVP. MVPs did not differ significantly among major taxa, or with latitude or trophic level, but were negatively correlated with Population growth rate and positively correlated with the length of the study used to parameterize the model. A doubling of study duration increased the estimated MVP by approximately 67%. The increase in extinction risk is associated with greater temporal variation in Population size for models built from longer data sets. Short-term studies consistently underestimate the true variances for demographic parameters in Populations. Thus, the lack of long-term studies for endangered species leads to widespread underestimation of extinction risk. The results of our simulations suggest that conservation programs, for wild Populations, need to be designed to conserve habitat capable of supporting approximately 7000 adult vertebrates in order to ensure long-term persistence. # 2003 Elsevier Science Ltd. All rights reserved.
Marcos S L Figueiredo - One of the best experts on this subject based on the ideXlab platform.
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Minimum Viable Population and conservation status of the atlantic forest spiny rat trinomys eliasi
Biological Conservation, 2003Co-Authors: Daniel Brito, Marcos S L FigueiredoAbstract:Abstract A Population viability analysis (PVA) was conducted to assess the Minimum Viable Population (MVP) of the Atlantic Forest spiny rat Trinomys eliasi, a species threatened by habitat loss and restricted geographical distribution. Objectives were to suggest quasi-extinction thresholds, estimate Minimum areas of suitable habitat (MASH) and MVPs, and compare results with the species’ current status. The computer package VORTEX was used. The model predicted sizes of 200 animals to achieve demographic stability, but buffering declines in genetic variability required Populations of 2000 animals. Estimated MASHs were approximately 250 and 2500 ha for demographic and genetic stability, respectively. Mortality rate and mean litter size were the most sensitive parameters to changes in model assumptions. The protection of known Populations and the search for extant Populations are the first steps in conservation. T. eliasi's issue could help protecting the coastal shrubland ecosystem of Rio de Janeiro state. Observing IUCN's criteria for listing threatened species, it is suggested that T. eliasi should be ranked as vulnerable in red lists.