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Journal articleFuchs S, Garrood WT, Beber A, et al., 2021,
Resistance to a CRISPR-based gene drive at an evolutionarily conserved site is revealed by mimicking genotype fixation
, PLoS Genetics, Vol: 17, Pages: 1-19, ISSN: 1553-7390CRISPR-based homing gene drives can be designed to disrupt essential genes whilst biasing their own inheritance, leading to suppression of mosquito populations in the laboratory. This class of gene drives relies on CRISPR-Cas9 cleavage of a target sequence and copying (‘homing’) therein of the gene drive element from the homologous chromosome. However, target site mutations that are resistant to cleavage yet maintain the function of the essential gene are expected to be strongly selected for. Targeting functionally constrained regions where mutations are not easily tolerated should lower the probability of resistance. Evolutionary conservation at the sequence level is often a reliable indicator of functional constraint, though the actual level of underlying constraint between one conserved sequence and another can vary widely. Here we generated a novel adult lethal gene drive (ALGD) in the malaria vector Anopheles gambiae, targeting an ultra-conserved target site in a haplosufficient essential gene (AGAP029113) required during mosquito development, which fulfils many of the criteria for the target of a population suppression gene drive. We then designed a selection regime to experimentally assess the likelihood of generation and subsequent selection of gene drive resistant mutations at its target site. We simulated, in a caged population, a scenario where the gene drive was approaching fixation, where selection for resistance is expected to be strongest. Continuous sampling of the target locus revealed that a single, restorative, in-frame nucleotide substitution was selected. Our findings show that ultra-conservation alone need not be predictive of a site that is refractory to target site resistance. Our strategy to evaluate resistance in vivo could help to validate candidate gene drive targets for their resilience to resistance and help to improve predictions of the invasion dynamics of gene drives in field populations.
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Journal articleRother L, Kraft N, Smith DB, et al., 2021,
A micro-CT-based standard brain atlas of the bumblebee
, Cell and Tissue Research, Vol: 386, Pages: 29-45, ISSN: 0302-766X<jats:title>Abstract</jats:title><jats:p>In recent years, bumblebees have become a prominent insect model organism for a variety of biological disciplines, particularly to investigate learning behaviors as well as visual performance. Understanding these behaviors and their underlying neurobiological principles requires a clear understanding of brain anatomy. Furthermore, to be able to compare neuronal branching patterns across individuals, a common framework is required, which has led to the development of 3D standard brain atlases in most of the neurobiological insect model species. Yet, no bumblebee 3D standard brain atlas has been generated. Here we present a brain atlas for the buff-tailed bumblebee <jats:italic>Bombus terrestris</jats:italic> using micro-computed tomography (micro-CT) scans as a source for the raw data sets, rather than traditional confocal microscopy, to produce the first ever micro-CT-based insect brain atlas. We illustrate the advantages of the micro-CT technique, namely, identical native resolution in the three cardinal planes and 3D structure being better preserved. Our <jats:italic>Bombus terrestris</jats:italic> brain atlas consists of 30 neuropils reconstructed from ten individual worker bees, with micro-CT allowing us to segment neuropils completely intact, including the lamina, which is a tissue structure often damaged when dissecting for immunolabeling. Our brain atlas can serve as a platform to facilitate future neuroscience studies in bumblebees and illustrates the advantages of micro-CT for specific applications in insect neuroanatomy.</jats:p>
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Journal articleSmith TP, Clegg T, Bell T, et al., 2021,
Systematic variation in the temperature dependence of bacterial carbon use efficiency
, ECOLOGY LETTERS, Vol: 24, Pages: 2123-2133, ISSN: 1461-023X- Author Web Link
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- Citations: 9
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Journal articleHui T-YJ, Brenas JH, Burt A, 2021,
Contemporary Ne estimation using temporally spaced data with linked loci
, Molecular Ecology Resources, Vol: 21, Pages: 2221-2230, ISSN: 1471-8278The contemporary effective population size Ne is important in many disciplines including population genetics, conservation science and pest management. One of the mostpopular methods of estimating this quantity uses temporal changes in allele frequencydue to genetic drift. A significant assumption of the existing methods is the independence among loci while constructing confidence intervals (CI), which restricts the typesof species or genetic data applicable to the methods. Although genetic linkage doesnot bias point Ne estimates, applying these methods to linked loci can yield unreliableCI that are far too narrow. We extend the current methods to enable the use of manylinked loci to produce precise contemporary Ne estimates, while preserving the targeted CI width and coverage. This is achieved by deriving the covariance of changes inallele frequency at linked loci in the face of recombination and sampling errors, suchthat the extra sampling variance due to between-locus correlation is properly handled. Extensive simulations are used to verify the new method. We apply the methodto two temporally spaced genomic data sets of Anopheles mosquitoes collected froma cluster of villages in Burkina Faso between 2012 and 2014. With over 33,000 linkedloci considered, the Ne estimate for Anopheles coluzzii is 9,242 (95% CI 5,702–24,282),and for Anopheles gambiae it is 4,826 (95% CI 3,602–7,353).
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Journal articleDaniel F, Prentice IC, Gallagher R, et al., 2021,
AusTraits, a curated plant trait database for the Australian flora.
, Scientific Data, Vol: 8, Pages: 1-20, ISSN: 2052-4463We introduce the AusTraits database - a compilation of values of plant traits for taxa in theAustralian flora (hereafter AusTraits). AusTraits synthesises data on 448 traits across28640 taxa from field campaigns, published literature, taxonomic monographs, andindividual taxon descriptions. Traits vary in scope from physiological measures ofperformance (e.g. photosynthetic gas exchange, water-use efficiency) to morphologicalattributes (e.g. leaf area, seed mass, plant height) which link to aspects of ecologicalvariation. AusTraits contains curated and harmonised individual- and species-levelmeasurements coupled to, where available, contextual information on site properties andexperimental conditions. This article provides information on version 3.0.2 of AusTraitswhich contains data for 997808 trait-by-taxon combinations. We envision AusTraits as anongoing collaborative initiative for easily archiving and sharing trait data and also providesa template for other national or regional initiatives globally to fill persistent gaps in traitknowledge.
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Journal articleKordas R, Pawar S, Woodward G, et al., 2021,
Metabolic plasticity can amplify ecosystem responses to global warming
<jats:title>Abstract</jats:title> <jats:p>Organisms have the capacity to alter their physiological response to warming through acclimation or adaptation, but empirical evidence for this metabolic plasticity across species within food webs is lacking, and a generalisable framework does not exist for modelling its ecosystem-level consequences. Here we show that the ability of organisms to raise their metabolic rate following chronic exposure to warming decreases with increasing body size. Chronic exposure to higher temperatures also increases the sensitivity of organisms to short-term warming, irrespective of their body size. A mathematical model parameterised with these findings shows that metabolic plasticity could account for an additional 60% of ecosystem energy flux with just +2 °C of warming. This could explain why ecosystem respiration continues to rise in long-term warming experiments and highlights the need to embed metabolic plasticity in predictive models of global warming impacts on ecosystems.</jats:p>
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Journal articleHarrison S, Cramer W, Franklin O, et al., 2021,
Eco-evolutionary optimality as a means to improve vegetation and land-surface models
, New Phytologist, Vol: 231, Pages: 2125-2141, ISSN: 0028-646XGlobal vegetation and land-surface models embody interdisciplinary scientific understanding of the behaviour of plants and ecosystems, and are indispensable to project the impacts of environmental change on vegetation and the interactions between vegetation and climate. However, systematic errors and persistently large differences among carbon and water cycle projections by different models highlight the limitations of current process formulations. In this review, focusing on core plant functions in the terrestrial carbon and water cycles, we show how unifying hypotheses derived from eco-evolutionary optimality (EEO) principles can provide novel, parameter-sparse representations of plant and vegetation processes. We present case studies that demonstrate how EEO generate parsimonious representations of core, leaf-level processes that are individually testable and supported by evidence. EEO approaches to photosynthesis and primary production, dark respiration, and stomatal behaviour are ripe for implementation in global models. EEO approaches to other important traits, including the leaf economics spectrum and applications of EEO at the community level are active research areas. Independently tested modules emerging from EEO studies could profitably be integrated into modelling frameworks that account for the multiple time scales on which plants and plant communities adjust to environmental change.
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Journal articleTudge SJ, Purvis A, De Palma A, 2021,
The impacts of biofuel crops on local biodiversity: a global synthesis
, BIODIVERSITY AND CONSERVATION, Vol: 30, Pages: 2863-2883, ISSN: 0960-3115- Author Web Link
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- Citations: 14
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Journal articleHordley LA, Gillings S, Petchey OL, et al., 2021,
Diversity of response and effect traits provides complementary information about avian community dynamics linked to ecological function
, Functional Ecology, Vol: 35, Pages: 1938-1950, ISSN: 0269-8463Functional diversity metrics based on species traits are widely used to investigate ecosystem functioning. In theory, such metrics have different implications depending on whether they are calculated from traits mediating responses to environmental change (response traits) or those regulating function (effect traits), yet trait choice in diversity metrics is rarely scrutinized.Here, we compile effect and response traits for British bird species supplying two key ecological services—seed dispersal and insect predation—to assess the relationship between functional diversity and both mean and stability of community abundance over time.As predicted, functional diversity correlates with stability in community abundance of seed dispersers when calculated using response traits. However, we found a negative relationship between functional diversity and mean community abundance of seed dispersers when calculated using effect traits. Subsequently, when combining all traits together, we found inconsistent results with functional diversity correlating with reduced stability in insectivores, but greater stability in seed dispersers.Our findings suggest that trait choice should be considered more carefully when applying such metrics in ecosystem management.
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Journal articleCulina A, Adriaensen F, Bailey LD, et al., 2021,
Connecting the data landscape of long-term ecological studies: The SPI-Birds data hub.
, Journal of Animal Ecology, Vol: 90, Pages: 2147-2160, ISSN: 0021-8790The integration and synthesis of the data in different areas of science is drastically slowed and hindered by a lack of standards and networking programmes. Long-term studies of individually marked animals are not an exception. These studies are especially important as instrumental for understanding evolutionary and ecological processes in the wild. Furthermore, their number and global distribution provides a unique opportunity to assess the generality of patterns and to address broad-scale global issues (e.g. climate change). To solve data integration issues and enable a new scale of ecological and evolutionary research based on long-term studies of birds, we have created the SPI-Birds Network and Database (www.spibirds.org)-a large-scale initiative that connects data from, and researchers working on, studies of wild populations of individually recognizable (usually ringed) birds. Within year and a half since the establishment, SPI-Birds has recruited over 120 members, and currently hosts data on almost 1.5 million individual birds collected in 80 populations over 2,000 cumulative years, and counting. SPI-Birds acts as a data hub and a catalogue of studied populations. It prevents data loss, secures easy data finding, use and integration and thus facilitates collaboration and synthesis. We provide community-derived data and meta-data standards and improve data integrity guided by the principles of Findable, Accessible, Interoperable and Reusable (FAIR), and aligned with the existing metadata languages (e.g. ecological meta-data language). The encouraging community involvement stems from SPI-Bird's decentralized approach: research groups retain full control over data use and their way of data management, while SPI-Birds creates tailored pipelines to convert each unique data format into a standard format. We outline the lessons learned, so that other communities (e.g. those working on other taxa) can adapt our successful model. Creating community-specific hubs (such
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Journal articleDrury JP, Clavel J, Tobias JA, et al., 2021,
Tempo and mode of morphological evolution are decoupled from latitude in birds
, PLoS Biology, Vol: 19, ISSN: 1544-9173The latitudinal diversity gradient is one of the most striking patterns in nature, yet its implications for morphological evolution are poorly understood. In particular, it has been proposed that an increased intensity of species interactions in tropical biota may either promote or constrain trait evolution, but which of these outcomes predominates remains uncertain. Here, we develop tools for fitting phylogenetic models of phenotypic evolution in which the impact of species interactions-namely, competition-can vary across lineages. Deploying these models on a global avian trait dataset to explore differences in trait divergence between tropical and temperate lineages, we find that the effect of latitude on the mode and tempo of morphological evolution is weak and clade- or trait dependent. Our results indicate that species interactions do not disproportionately impact morphological evolution in tropical bird families and question the validity of previously reported patterns of slower trait evolution in the tropics.
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Journal articleLuo X, Keenan T, Chen JM, et al., 2021,
Global variation in the fraction of leaf nitrogen allocated to photosynthesis
, Nature Communications, Vol: 12, ISSN: 2041-1723Plants invest a considerable amount of leaf nitrogen in the photosynthetic enzyme ribulose-1,5- bisphosphate carboxylase-oxygenase (RuBisCO), forming a strong coupling of nitrogen and photosynthetic capacity. Variability in the nitrogen-photosynthesis relationship indicates different nitrogen use strategies of plants (i.e., the fraction nitrogen allocated to RuBisCO; fLNR), however, the reason for this remains unclear as widely different nitrogen use strategies are adopted in photosynthesis models. Here, we use a comprehensive database of in-situ observations, a remote sensing product of leaf chlorophyll and ancillary climate and soil data, to examine the global distribution in fLNR using a random forest model. We find global fLNR is 18.2 ± 6.2%, with its variation largely driven by negative dependence on leaf mass per area and positive dependence on leaf phosphorus. Some climate and soil factors (i.e., light, atmospheric dryness, soil pH, and sand) have considerable positive influences on fLNR regionally. This study provides insight into the nitrogen-photosynthesis relationship of plants globally and an improved understanding of the global distribution of photosynthetic potential.
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Journal articleClive J, Wisden W, Savolainen V, 2021,
The de-scent of sexuality: should we smell a rat?
, Archives of Sexual Behavior: an interdisciplinary research journal, Vol: 50, Pages: 2283-2288, ISSN: 0004-0002In their Target Article, Pfau, Jordan, and Breedlove (2019) proposed a connection between the transient receptor potential cation channel 2 gene (TRPC2) and same-sex sexual behavior (SSSB) in primates. This novel theory is an attractive prospect for researchers investigating sexuality in the natural world. The proposal relies on evidence from proximate mechanism studies of TRPC2 knockout (KO) experiments in mice, in which non-functional TPRC2 alters the development of an olfactory sensory structure called the vomeronasal organ (VNO), resulting in an increase of SSSB in both males and females (Axel et al., 2002; Kimchi, Xu, & Dulac, 2007). In combination with an examination of TRPC2 sequence data and evolutionary relationships across primates, Pfau et al. proposed some hypotheses for the fitness consequences of SSSB in primates. Pfau et al. speculated that primates with multi-male/multi-female societies may have evolved via improved social cohesion facilitated by an increase in SSSB, mediated by non-functional TRPC2, and/or pleiotropy between increased SSSB and reduced same-sex aggression. Here, although we support some of these ideas by providing a more complete examination of TRPC2 in primates, we also advocate greater caution when interpreting available data on SSSB.
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Journal articleSato H, Kelly D, Mayor S, et al., 2021,
Dry corridors opened by fire and low CO2 in Amazonian rainforest during last glacial maximum
, Nature Geoscience, Vol: 14, Pages: 578-585, ISSN: 1752-0894The dynamics of Amazonian rainforest over long timescales connects closely to its rich biodiversity. While palaeoecological studies have suggested its stability through the Pleistocene, palaeontological evidence indicates the past existence of major expansions of savanna and grassland. Here we present integrated modeling evidence for a grassier Neotropics during the Last Glacial Maximum (LGM), congruent with palaeoecological and biological studies. Vegetation re-constructions were generated using the Land Processes and eXchanges (LPX) model, driven by model reconstructions of LGM climate, and compared against palynological data. A factorial experiment was performed to quantify the impacts of fire and low CO2 on vegetation and model-data agreement. Fire and low CO2 both individually and interactively induced widespread expansion of savanna and grassland biomes while improving model-data agreement. The interactive effects of fire and low CO2 induced the greatest ‘savannafication’ of the Neotropics, providing integrated evidence for a number of biogeographically relevant open vegetation formations including two dry corridors; paths of savanna and grassland through and around Amazonia that facilitated major dispersal and evolutionary diversification events. Our results show a bimodality in tree cover that was driven by fire and further enhanced by ‘CO2 deprivation’, which suggests biome instability in this region of climate space.
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Journal articleMilodowski DT, Coomes DA, Swinfield T, et al., 2021,
The impact of logging on vertical canopy structure across a gradient of tropical forest degradation intensity in Borneo
, JOURNAL OF APPLIED ECOLOGY, Vol: 58, Pages: 1764-1775, ISSN: 0021-8901- Author Web Link
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- Citations: 18
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Journal articleTao R, Sack L, Rosindell J, 2021,
Biogeographic drivers of evolutionary radiations
, Frontiers in Ecology and Evolution, Vol: 9, Pages: 1-14, ISSN: 2296-701XSome lineages radiate spectacularly when colonising a region, but others do not. Large radiations are often attributed to species’adaptation into niches, but sometimes instead to other drivers, such as biogeography. Here we aim to disentangle the factorsdetermining radiation size, by modelling simplified scenarios without the complexity of explicit niches. We build a spatiallystructured neutral model free from niches and incorporating a form of protracted speciation that accounts for gene flow betweenpopulations. We characterise the behaviour of the model for a range of different networks of connectivity between patches. Wefind that a wide range of radiation sizes are possible depending on the combination of geographic isolation and species' dispersalability. For example, when considering isolated archipelagos, low rates of dispersal from the mainland result in decreasedcompetition and thus increased radiation size. Dispersal between habitat patches also has an important effect. At extremely lowdispersal rates, each habitat patch has its own endemic species, intermediate dispersal rates foster larger radiations. Asdispersal rates increase further, a critical point is reached at which identical lineages can vary greatly in radiation size due torare and stochastic dispersal events. At the critical point, some lineages remain a single species for a long time, whilst otherswith identical characteristics produce the largest radiations of all. The mechanism for this is a ‘radiation cascade’ in whichspeciation leads to reduced numbers of individuals per species, and thus reduced gene flow between conspecifics in isolatedpatches, leading to yet more speciation. Once a radiation cascade begins, it continues rapidly until it is arrested by a newequilibrium between speciation and extinction. We speculate that such cascades may occur more generally and are not onlypresent in neutral models. This may help to explain rapid radiation, and the extreme radiation si
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Journal articleMiller BA, Pearse WD, Flint CG, 2021,
Saving the Forest from the Trees: Expert Views on Funding Restoration of Northern Arizona Ponderosa Pine Forests through Registered Carbon Offsets
, FORESTS, Vol: 12- Author Web Link
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- Citations: 1
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Journal articleBlundo C, Carilla J, Grau R, et al., 2021,
Taking the pulse of Earth's tropical forests using networks of highly distributed plots
, BIOLOGICAL CONSERVATION, Vol: 260, ISSN: 0006-3207- Author Web Link
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- Citations: 54
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Journal articleHill SL, Pinkerton MH, Ballerini T, et al., 2021,
Robust model-based indicators of regional differences in food-web structure in the Southern Ocean
, JOURNAL OF MARINE SYSTEMS, Vol: 220, ISSN: 0924-7963- Author Web Link
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- Citations: 5
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Journal articleEberhart-Hertel LJ, Rodrigues LF, Krietsch J, et al., 2021,
Egg size variation in a long-lived polyandrous shorebird in the context of senescence and breeding phenology
<jats:p>We have withdrawn this manuscript due to a duplicate posting of manuscript number 240150. Therefore, we do not wish this work to be cited as reference for the project. If you have any questions, please contact Luke J. Eberhart-Hertel at<jats:email>luke.eberhart@orn.mpg.de</jats:email></jats:p>
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Journal articleChristensen A, Piggott M, Sebille EV, et al., 2021,
Investigating microscale patchiness of motile microbes driven by the interaction of turbulence and gyrotaxis in a 3D simulated convective mixed layer.
<jats:title>Abstract</jats:title> <jats:p>Microbes play a primary role in aquatic ecosystems and biogeochemical cycles. Spatial patchiness is a critical factor underlying these activities, influencing biological productivity, nutrient cycling and dynamics across trophic levels. Incorporating spatial dynamics into microbial models is a long-standing challenge, particularly where small-scale turbulence is involved. Here, we combine a fully 3D direct numerical simulation of convective mixed layer turbulence, with an individual-based microbial model to test the key hypothesis that the coupling of gyrotactic motility and turbulence drives intense microscale patchiness. The fluid model simulates turbulent convection caused by heat loss through the fluid surface, for example during the night, during autumnal or winter cooling or during a cold-air outbreak. We find that under such conditions, turbulence-driven patchiness is depth-structured and requires high motility: Near the fluid surface, intense convective turbulence overpowers motility, homogenising motile and non-motile microbes approximately equally. At greater depth, in conditions analogous to a thermocline, highly motile microbes can be over twice as patch-concentrated as non-motile microbes, and can substantially amplify their swimming velocity by efficiently exploiting fast-moving packets of fluid. Our results substantiate the predictions of earlier studies, and demonstrate that turbulence-driven patchiness is not a ubiquitous consequence of motility but rather a delicate balance of motility and turbulent intensity.</jats:p>
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Journal articleLeague G, Pitch S, Geyer J, et al., 2021,
Sexual selection theory meets disease vector control: Testing harmonic convergence as a “good genes” signal in Aedes aegypti mosquitoes
, PLoS Neglected Tropical Diseases, ISSN: 1935-2727Background:The mosquito Aedes aegypti is a medically important, globally distributed vector of the viruses that cause dengue, yellow fever, chikungunya, and Zika. Although reproduction and mate choice are key components of vector population dynamics and control, our understanding of the mechanisms of sexual selection in mosquitoes remains poor. In “good genes” models of sexual selection, females use male cues as an indicator of both mate and offspring genetic quality. Recent studies in Ae. aegypti provide evidence that male wingbeats may signal aspects of offspring quality and performance during mate selection in a process known as harmonic convergence. However, the extent to which harmonic convergence may signal overall inherent quality of mates and their offspring remains unknown.Methodology/Principal findings:To examine this, we measured the relationship between acoustic signaling and a broad panel of parent and offspring fitness traits in two generations of field-derived Ae. aegypti originating from dengue-endemic field sites in Thailand. Our data show that in this population of mosquitoes, harmonic convergence does not signal male fertility, female fecundity, or male flight performance traits, which despite displaying robust variability in both parents and their offspring were only weakly heritable.Conclusions/Significance:Together, our findings suggest that vector reproductive control programs should treat harmonic convergence as an indicator of some, but not all aspects of inherent quality, and that sexual selection likely affects Ae. aegypti in a trait-, population-, and environment-dependent manner.
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Journal articleZhou L, Liu F, Liu Q, et al., 2021,
Aluminum increases net carbon fixation by marine diatoms and decreases their decomposition: Evidence for the iron-aluminum hypothesis
, LIMNOLOGY AND OCEANOGRAPHY, Vol: 66, Pages: 2712-2727, ISSN: 0024-3590 -
Journal articleShah T, Schneider JV, Zizka G, et al., 2021,
Joining forces in Ochnaceae phylogenomics: a tale of two targeted sequencing probe kits
, AMERICAN JOURNAL OF BOTANY, Vol: 108, Pages: 1201-1216, ISSN: 0002-9122- Author Web Link
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- Citations: 20
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Journal articleLeroi AM, Lambert B, Rosindell J, et al., 2021,
Neutral Theory is a tool that should be wielded with care
, NATURE HUMAN BEHAVIOUR, Vol: 5, Pages: 809-809, ISSN: 2397-3374- Author Web Link
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- Citations: 1
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Journal articleKuhn-Régnier A, Voulgarakis A, Nowack P, et al., 2021,
Quantifying the Importance of antecedent fuel-related vegetationproperties for burnt area using random forests
, Biogeosciences, Vol: 8, ISSN: 1726-4170The seasonal and longer-term dynamics of fuel accumulation affect fire seasonality and the occurrence of extreme wildfires. Failure to account for their influence mayhelp to explain why state-of-the-art fire models do not simulate the length and timing of the fire season or interannual variability in burnt area well. We investigated the impact of accounting for different timescales of fuel production and accumulation on burnt area using a suite of random forest regression models that included the immediateimpact of climate, vegetation, and human influences in agiven month and tested the impact of various combinationsof antecedent conditions in four productivity-related vegetation indices and in antecedent moisture conditions. Analyses were conducted for the period from 2010 to 2015 inclusive. Inclusion of antecedent vegetation conditions representing fuel build-up led to an improvement of the global,climatological out-of-sample R2from 0.579 to 0.701, but theinclusion of antecedent vegetation conditions on timescales≥ 1 year had no impact on simulated burnt area. Currentmoisture levels were the dominant influence on fuel drying. Additionally, antecedent moisture levels were importantfor fuel build-up. The models also enabled the visualisationof interactions between variables, such as the importanceof antecedent productivity coupled with instantaneous drying. The length of the period which needs to be consideredvaries across biomes; fuel-limited regions are sensitive to antecedent conditions that determine fuel build-up over longertime periods (∼ 4 months), while moisture-limited regionsare more sensitive to current conditions that regulate fuel drying.
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Journal articleKuhn- Regnier A, Voulgarakis A, Nowack P, et al., 2021,
The importance of antecedent vegetation and drought conditions as global drivers of burnt areas
, Biogeosciences, Vol: 18, Pages: 3861-3879, ISSN: 1726-4170The seasonal and longer-term dynamics of fuel accumulation affect fire seasonality and the occurrence of extreme wildfires. Failure to account for their influence may help to explain why state-of-the-art fire models do not simulate the length and timing of the fire season or interannual variability in burnt area well. We investigated the impact of accounting for different timescales of fuel production and accumulation on burnt area using a suite of random forest regression models that included the immediate impact of climate, vegetation, and human influences in a given month and tested the impact of various combinations of antecedent conditions in four productivity-related vegetation indices and in antecedent moisture conditions. Analyses were conducted for the period from 2010 to 2015 inclusive. Inclusion of antecedent vegetation conditions representing fuel build-up led to an improvement of the global, climatological out-of-sample R2 from 0.579 to 0.701, but the inclusion of antecedent vegetation conditions on timescales ≥ 1 year had no impact on simulated burnt area. Current moisture levels were the dominant influence on fuel drying. Additionally, antecedent moisture levels were important for fuel build-up. The models also enabled the visualisation of interactions between variables, such as the importance of antecedent productivity coupled with instantaneous drying. The length of the period which needs to be considered varies across biomes; fuel-limited regions are sensitive to antecedent conditions that determine fuel build-up over longer time periods (∼ 4 months), while moisture-limited regions are more sensitive to current conditions that regulate fuel drying.
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Journal articleRurangwa ML, Aguirre-Gutierrez J, Matthews TJ, et al., 2021,
Effects of land-use change on avian taxonomic, functional and phylogenetic diversity in a tropical montane rainforest
, Diversity and Distributions: a journal of conservation biogeography, Vol: 27, Pages: 1732-1746, ISSN: 1366-9516AimAlthough land use change is a leading cause of biodiversity loss worldwide, there is scant information on the extent to which it has affected the structure and composition of bird communities in the Afrotropical region. This study aimed to quantify the effects of habitat transformation on taxonomic, functional and phylogenetic diversity in Afrotropical bird communities.LocationNyungwe landscape, a montane rainforest with adjoining farmland in south-west Rwanda.MethodsData on bird occurrence, abundance and functional traits were collected in 2017/18 using point counts. We also collected data on habitat and morphological traits for all bird species recorded. We quantified bird diversity using a range of metrics, including the inverse Simpson index, functional dispersion and the standardized effect size of mean nearest taxon distance.ResultsIn comparison with primary forest areas, even low levels of land use change altered species composition and reduced species diversity. Although overall functional diversity and phylogenetic diversity were similar across land use types, we found a significant contraction of trophic and locomotory trait structures of bird communities in restored areas and cultivated areas, respectively. Soil moisture, elevation and lower vegetation height were major factors influencing taxonomic, functional and phylogenetic dimensions of bird communities, although their effects varied across these dimensions.Main conclusionsThe sensitivity of forest species to minor habitat disturbance emphasizes the value of conserving primary vegetation. Long-term conservation of bird communities in Afromontane ecosystems requires halting wide-scale destruction of primary forest, promoting vegetation heterogeneity in the ecological restoration of degraded habitats and adopting wildlife-friendly agricultural practices. Our results suggest that monitoring and conservation in these landscapes can be refined using taxonomic, functional and phylogenetic diversity metr
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Journal articleSmith TP, Flaxman S, Gallinat AS, et al., 2021,
Temperature and population density influence SARS-CoV-2 transmission in the absence of nonpharmaceutical interventions
, Proceedings of the National Academy of Sciences of USA, Vol: 118, Pages: 1-8, ISSN: 0027-8424As COVID-19 continues to spread across the world, it is increasingly important to understand the factors that influence its transmission. Seasonal variation driven by responses to changing environment has been shown to affect the transmission intensity of several coronaviruses. However, the impact of the environment on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains largely unknown, and thus seasonal variation remains a source of uncertainty in forecasts of SARS-CoV-2 transmission. Here we address this issue by assessing the association of temperature, humidity, ultraviolet radiation, and population density with estimates of transmission rate (R). Using data from the United States, we explore correlates of transmission across US states using comparative regression and integrative epidemiological modeling. We find that policy intervention (“lockdown”) and reductions in individuals’ mobility are the major predictors of SARS-CoV-2 transmission rates, but, in their absence, lower temperatures and higher population densities are correlated with increased SARS-CoV-2 transmission. Our results show that summer weather cannot be considered a substitute for mitigation policies, but that lower autumn and winter temperatures may lead to an increase in transmission intensity in the absence of policy interventions or behavioral changes. We outline how this information may improve the forecasting of COVID-19, reveal its future seasonal dynamics, and inform intervention policies.
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Journal articleO'Loughlin SM, Forster AJ, Fuchs S, et al., 2021,
Ultra-conserved sequences in the genomes of highly diverse <i>Anopheles</i> mosquitoes, with implications for malaria vector control
, G3-GENES GENOMES GENETICS, Vol: 11, ISSN: 2160-1836- Author Web Link
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- Citations: 2
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