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1.
Proc Natl Acad Sci U S A ; 121(41): e2316827121, 2024 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-39312680

RESUMEN

Movement is a key means by which animals cope with variable environments. As they move, animals construct individual niches composed of the environmental conditions they experience. Niche axes may vary over time and covary with one another as animals make tradeoffs between competing needs. Seasonal migration is expected to produce substantial niche variation as animals move to keep pace with major life history phases and fluctuations in environmental conditions. Here, we apply a time-ordered principal component analysis to examine dynamic niche variance and covariance across the annual cycle for four species of migratory crane: common crane (Grus grus, n = 20), demoiselle crane (Anthropoides virgo, n = 66), black-necked crane (Grus nigricollis, n = 9), and white-naped crane (Grus vipio, n = 9). We consider four key niche components known to be important to aspects of crane natural history: enhanced vegetation index (resources availability), temperature (thermoregulation), crop proportion (preferred foraging habitat), and proximity to water (predator avoidance). All species showed a primary seasonal niche "rhythm" that dominated variance in niche components across the annual cycle. Secondary rhythms were linked to major species-specific life history phases (migration, breeding, and nonbreeding) as well as seasonal environmental patterns. Furthermore, we found that cranes' experiences of the environment emerge from time-dynamic tradeoffs among niche components. We suggest that our approach to estimating the environmental niche as a multidimensional and time-dynamical system of tradeoffs improves mechanistic understanding of organism-environment interactions.


Asunto(s)
Migración Animal , Aves , Ecosistema , Estaciones del Año , Animales , Migración Animal/fisiología , Aves/fisiología
2.
Mol Biol Evol ; 41(9)2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39150953

RESUMEN

The relative importance of genetic drift and local adaptation in facilitating speciation remains unclear. This is particularly true for seabirds, which can disperse over large geographic distances, providing opportunities for intermittent gene flow among distant colonies that span the temperature and salinity gradients of the oceans. Here, we delve into the genomic basis of adaptation and speciation of banded penguins, Galápagos (Spheniscus mendiculus), Humboldt (Spheniscus humboldti), Magellanic (Spheniscus magellanicus), and African penguins (Spheniscus demersus), by analyzing 114 genomes from the main 16 breeding colonies. We aim to identify the molecular mechanism and genomic adaptive traits that have facilitated their diversifications. Through positive selection and gene family expansion analyses, we identified candidate genes that may be related to reproductive isolation processes mediated by ecological thermal niche divergence. We recover signals of positive selection on key loci associated with spermatogenesis, especially during the recent peripatric divergence of the Galápagos penguin from the Humboldt penguin. High temperatures in tropical habitats may have favored selection on loci associated with spermatogenesis to maintain sperm viability, leading to reproductive isolation among young species. Our results suggest that genome-wide selection on loci associated with molecular pathways that underpin thermoregulation, osmoregulation, hypoxia, and social behavior appears to have been crucial in local adaptation of banded penguins. Overall, these results contribute to our understanding of how the complexity of biotic, but especially abiotic, factors, along with the high dispersal capabilities of these marine species, may promote both neutral and adaptive lineage divergence even in the presence of gene flow.


Asunto(s)
Selección Genética , Spheniscidae , Animales , Spheniscidae/genética , Genómica , Especiación Genética , Flujo Génico , Genoma , Aislamiento Reproductivo
3.
Proc Natl Acad Sci U S A ; 119(21): e2113936119, 2022 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-35580185

RESUMEN

The evolutionary history of African hunter-gatherers holds key insights into modern human diversity. Here, we combine ethnographic and genetic data on Central African hunter-gatherers (CAHG) to show that their current distribution and density are explained by ecology rather than by a displacement to marginal habitats due to recent farming expansions, as commonly assumed. We also estimate the range of hunter-gatherer presence across Central Africa over the past 120,000 years using paleoclimatic reconstructions, which were statistically validated by our newly compiled dataset of dated archaeological sites. Finally, we show that genomic estimates of divergence times between CAHG groups match our ecological estimates of periods favoring population splits, and that recoveries of connectivity would have facilitated subsequent gene flow. Our results reveal that CAHG stem from a deep history of partially connected populations. This form of sociality allowed the coexistence of relatively large effective population sizes and local differentiation, with important implications for the evolution of genetic and cultural diversity in Homo sapiens.


Asunto(s)
Antropología Cultural , Arqueología , Variación Genética , Densidad de Población , África , Agricultura , Diversidad Cultural , Humanos
4.
J Infect Dis ; 2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38536055

RESUMEN

The Centers for Disease Control estimates antibiotic-associated pathogens result in 2.8 million infections and 38,000 deaths annually in the United States. This study applies species distribution modeling to elucidate the impact of environmental determinants of human infectious disease in an era of rapid global change. We modeled methicillin-resistant Staphylococcus aureus and Clostridioides difficile using 31 publicly accessible bioclimatic, healthcare, and sociodemographic variables. Ensemble models were created from 8 unique statistical and machine learning algorithms. Using International Classification of Diseases, 10th Edition codes, we identified 305,528 diagnoses of methicillin-resistant S.aureus and 302,001 diagnoses of C.difficile presence. Three environmental factors - average maximum temperature, specific humidity, and agricultural land density - emerged as major predictors of increased methicillin-resistant S.aureus and C.difficile presence; variables representing healthcare availability were less important. Species distribution modeling may be a powerful tool for identifying areas at increased risk for disease presence and have important implications for disease surveillance systems.

5.
Ecol Lett ; 27(1): e14350, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38062899

RESUMEN

Understanding species distributions and predicting future range shifts requires considering all relevant abiotic factors and biotic interactions. Resource competition has received the most attention, but reproductive interference is another widespread biotic interaction that could influence species ranges. Rubyspot damselflies (Hetaerina spp.) exhibit a biogeographic pattern consistent with the hypothesis that reproductive interference has limited range expansion. Here, we use ecological niche models to evaluate whether this pattern could have instead been caused by niche differentiation. We found evidence for climatic niche differentiation, but the species that encounters the least reproductive interference has one of the narrowest and most peripheral niches. These findings strengthen the case that reproductive interference has limited range expansion and also provide a counterexample to the idea that release from negative species interactions triggers niche expansion. We propose that release from reproductive interference enables species to expand in range while specializing on the habitats most suitable for breeding.


Asunto(s)
Modelos Teóricos , Odonata , Animales , Reproducción , Ecosistema
6.
Am Nat ; 203(2): 284-291, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38306277

RESUMEN

AbstractOrganismal divergence can be driven by differential resource use and adaptation to different trophic niches. Variation in diet is a major factor shaping the gut microbiota, which is crucial for many aspects of their hosts' biology. However, it remains largely unknown how host diet diversity affects the gut microbiota, and it could be hypothesized that trophic niche width is positively associated with gut microbiota diversity. To test this idea, we sequenced the 16S ribosomal RNA gene from intestinal tissue of 14 threespine stickleback populations from lakes of varying size on Vancouver Island, Canada, that have been shown to differ in trophic niche width. Using lake size as a proxy for trophic ecology, we found evidence for higher gut microbiota uniqueness among individuals from populations with broader trophic niches. While these results suggest that diet diversity might promote gut microbiota diversity, additional work investigating diet and gut microbiota variation of the same host organisms will be necessary. Yet our results motivate the question of how host population diversity (e.g., ecological, morphological, genetic) might interact with the gut microbiota during the adaptation to ecological niches.


Asunto(s)
Microbioma Gastrointestinal , Smegmamorpha , Animales , Microbioma Gastrointestinal/genética , Smegmamorpha/genética , Lagos , Peces/genética , Dieta , ARN Ribosómico 16S/genética
7.
Proc Biol Sci ; 291(2015): 20232206, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38290546

RESUMEN

Climate-driven species redistributions are facilitated by niche modifications that increase a species's chances of establishment in novel communities. It is well understood how range-extending species adjust individual niche traits when entering novel environments, yet whether modification of ecological niche traits collectively alters the pace of range extensions or contractions remains unknown. We quantified habitat niche, abundance, physiological performance and cellular defence/damage of range-extending coral reef fishes and coexisting local temperate fishes along a 2000 km latitudinal gradient. We also assessed their dietary and behavioural niches, and establishment potential, to understand whether ecological generalism facilitates successful range extension of coral reef fishes. The coral reef fish that increased all ecological niches, showed stronger establishment, increased physiological performance and cellular damage, but decreased cellular defence at their cold-range edge, whereas tropical species that showed unmodified ecological niches showed lower establishment. One temperate species showed decreased abundance, habitat niche width and body condition, but increased cellular defence, cellular damage and energy reserves at their warm-trailing range, while other temperate species showed contrasting responses. Therefore, ecological generalists might be more successful than ecological specialists during the initial stages of climate change, with increasing future warming strengthening this pattern by physiologically benefitting tropical generalists but disadvantaging temperate specialists.


Asunto(s)
Antozoos , Ecosistema , Animales , Arrecifes de Coral , Peces/fisiología , Cambio Climático , Océanos y Mares
8.
Appl Environ Microbiol ; 90(3): e0207523, 2024 03 20.
Artículo en Inglés | MEDLINE | ID: mdl-38319096

RESUMEN

Labyrinthulomycetes play an important role in marine biogeochemical cycles, but their diversity, distribution patterns, and key regulatory factors remain unclear. This study measured the abundance and diversity of Labyrinthulomycetes in the Pearl River Estuary (PRE) to understand its distribution pattern and relationship with environmental and biological factors. The abundance of Labyrinthulomycetes ranged from 24 to 500 cells·mL-1, with an average of 144.37 ± 94.65 cells·mL-1, and its community composition showed obvious ecological partitioning in the PRE. The results of statistical analysis indicated that CDOM, salinity, and chlorophyll a contributed significantly (P < 0.01) to the community composition, explaining 46.59%, 11.34%, and 4.38% of the variance, respectively. The Labyrinthulomycetes distribution pattern combined with the niches of dominant species was revealed; low-salinity species mainly use terrigenous organic matter occupied dominant positions in the upper estuary and showed the highest abundance; moderate-salinity species that can use phytoplankton-derived resources thrived in the middle estuary; and seawater species dominated the lower estuary with the highest diversity but the lowest abundance. In addition, the results of phylogenetic tree analysis indicated that the existence of a novel lineage, and further study on the diversity and ecological functions of Labyrinthulomycetes is needed.IMPORTANCELabyrinthulomycetes play important roles in organic matter remineralization, carbon sinks, and food webs. However, the true diversity of Labyrinthulomycetes is still unclear due to limitations in isolation and culture methods. In addition, previous studies on their relationship with environmental factors are inconsistent and even contradictory, and it is speculated that their community composition may have spatial heterogeneity along the environmental gradient. In this study, the distribution pattern and key regulators of Labyrinthulomycetes in the PRE were revealed. Combining the niche of dominant species, it is suggested that salinity determines the spatial differences in Labyrinthulomycetes diversity, and the resources of substrate (terrestrial input or phytoplankton-derived) determine the dominant species, and its abundance is mainly determined by organic matter concentrations. Our study provided new information on the Labyrinthulomycetes diversity and verified the spatial heterogeneity of Labyrinthulomycetes community composition, providing reliable explanations for the inconsistencies in previous studies.


Asunto(s)
Ríos , Estramenopilos , Clorofila A , Estuarios , Filogenia , Fitoplancton
9.
Mol Ecol ; 33(11): e17363, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38682794

RESUMEN

Hybridisation can be an important driver of evolutionary change, but hybridisation with invasive species can have adverse effects on native biodiversity. While hybridisation has been documented across taxa, there is limited understanding of ecological factors promoting patterns of hybridisation and the spatial distribution of hybrid individuals. We combined the results of ecological niche modelling (ENM) and restriction site-associated DNA sequencing to test theories of niche conservatism and biotic resistance on the success of invasion, admixture, and extent of introgression between native and non-native fishes. We related Maxent predictions of habitat suitability based on the native ranges of invasive Eastern Banded Killifish (Fundulus diaphanus diaphanus Lesueur 1817) and native Western Banded Killifish (Fundulus diaphanus menona Jordan and Copeland 1877) to admixture indices of individual Banded Killifish. We found that Eastern Banded Killifish predominated at sites predicted as suitable from their ENM, consistent with niche conservatism. Admixed individuals were more common as Eastern Banded Killifish habitat suitability declined. We also found that Eastern Banded Killifish were most common at sites closest to the presumed source of this invasion, whereas the proportion of admixed individuals increased with distance from the source of invasion. Lastly, we found little evidence that habitat suitability for Western Banded Killifish provides biotic resistance from either displacement by, or admixture with, invasive Eastern Banded Killifish. Our study demonstrates that ENMs can inform conservation-relevant outcomes between native and invasive taxa while emphasising the importance of protecting isolated Western Banded Killifish populations from invasive conspecifics.


Asunto(s)
Ecosistema , Fundulidae , Especies Introducidas , Animales , Fundulidae/genética , Hibridación Genética , Genética de Población , Introgresión Genética , Análisis de Secuencia de ADN , Biodiversidad
10.
Mol Ecol ; 33(16): e17462, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38993027

RESUMEN

Invasive species are a growing global economic and ecological problem. However, it is not well understood how environmental factors mediate invasive range expansion. In this study, we investigated the recent and rapid range expansion of common tansy across environmental gradients in Minnesota, USA. We densely sampled individuals across the expanding range and performed reduced representation sequencing to generate a dataset of 3071 polymorphic loci for 176 individuals. We used non-spatial and spatially explicit analyses to determine the relative influences of geographic distance and environmental variation on patterns of genomic variation. We found no evidence for isolation by distance but strong evidence for isolation by environment, indicating that environmental factors may have modulated patterns of range expansion. Land use classification and soils were particularly important variables related to population structure although they operated on different spatial scales; land use classification was related to broad-scale patterns and soils were related to fine-scale patterns. All analyses indicated a distinctive genetic cluster in the most recently invaded portion of the range. Individuals from the far northwestern range margin were separated from the remainder of the range by reduced migration, which was associated with environmental resistance. This portion of the range was invaded primarily in the last 15 years. Ecological niche models also indicated that this cluster was associated with the expansion of the niche. While invasion is often assumed to be primarily influenced by dispersal limitation, our results suggest that ongoing invasion and range shifts with climate change may be strongly affected by environmental heterogeneity.


Asunto(s)
Genética de Población , Especies Introducidas , Minnesota , Genómica , Asteraceae/genética , Ambiente , Cambio Climático , Variación Genética , Ecosistema
11.
Mol Phylogenet Evol ; 195: 108056, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38493987

RESUMEN

The yellow spotted stink bug (YSSB), Erthesina fullo (Thunberg, 1783) is an important Asian pest that has recently successfully invaded Europe and an excellent material for research on the initial stage of biological invasion. Here, we reported the native evolutionary history, recent invasion history, and potential invasion threats of YSSB for the first time based on population genetic methods [using double digest restriction-site associated DNA (ddRAD) data and mitochondrial COI and CYTB] and ecological niche modelling. The results showed that four lineages (east, west, southwest, and Hainan Island) were established in the native range with a strong east-west differentiation phylogeographical structure, and the violent climate fluctuation might cause population divergence during the Middle and Upper Pleistocene. In addition, land bridges and monsoon promote dispersal and directional genetic exchanging between island populations and neighboring continental populations. The east lineage (EA) was identified as the source of invasion in Albania. EA had the widest geographical distribution among all other lineages, with a star-like haplotype network with the main haplotype as the core. It also had a rapid population expansion history, indicating that the source lineage might have stronger diffusion ability and adaptability. Our findings provided a significant biological basis for fine tracking of invasive source at the lineage or population level and promote early invasion warning of potential invasive species on a much subtler lineage level.


Asunto(s)
Heterópteros , Animales , Filogeografía , Filogenia , Heterópteros/genética , Evolución Biológica , Mitocondrias/genética , ADN Mitocondrial/genética , Variación Genética
12.
Mol Phylogenet Evol ; 190: 107959, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37918682

RESUMEN

Despite their limited vagility and pronounced habitat heterogeneity in the tropics, many anuran species have unexpectedly extensive geographic ranges. One prominent example of this phenomenon is Pithecopus hypochondrialis, which is found in the Cerrado, Guianan savanna, and Llanos domains, as well as isolated tracts of savanna and open habitat within the Amazon Forest. The present study employs an integrative species delimitation approach to test the hypothesis that P. hypochondrialis is in fact a species complex. We also reconstruct the relationships among the lineages delimited here and other Pithecopus species. In this study, we employ Ecological Niche Modelling (ENM) and spatiotemporal phylogeographic reconstruction approaches to evaluate a multitude of scenarios of connectivity across the Neotropical savannas. We identified three divergent lineages, two of which have been described previously. The lineages were allocated to a lowland Pithecopus clade, although the relationships among these lineages are weakly supported. Both the ENM and the phylogeographic reconstruction highlight the occurrence of periods of connectivity among the Neotropical savannas over the course of the Pliocene and Pleistocene epochs. These processes extended from eastern Amazonia to the northern coast of Brazil. The findings of the present study highlight the presence of hidden diversity within P. hypochondrialis, and reinforce the need for a comprehensive taxonomic review. These findings also indicate intricate and highly dynamic patterns of connectivity across the Neotropical savannas that date back to the Pliocene.


Asunto(s)
Ecosistema , Pradera , Animales , Filogeografía , Filogenia , Anuros/genética
13.
Virol J ; 21(1): 180, 2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-39113041

RESUMEN

The spread of the African swine fever virus (ASF virus) genotype ii in the Eurasian region has been very successful and often inexplicable. The virus spreads rapidly and persists in areas with wild boar populations, but areas without feral pig populations are also affected. The virus has shown the ability to survive for a long time in the environment without a population of susceptible hosts, both pigs and Ornithodoros soft ticks. Published data indicated that ASF viruses persist significantly longer in an environment with some freshwater snails (especially Pomacea bridgesii, Tarebia granifera, Asolene spixii, Melanoides tuberculate, and Physa fontinalis), compared to freshwater without snails. Data obtained in this study suggest that gastropods theoretically can be the hosts of the ASF virus. Also, we have proven the possibility of long-term existence of an infectious virus when infected in vitro.


Asunto(s)
Virus de la Fiebre Porcina Africana , Fiebre Porcina Africana , Animales , Virus de la Fiebre Porcina Africana/genética , Virus de la Fiebre Porcina Africana/fisiología , Virus de la Fiebre Porcina Africana/aislamiento & purificación , Porcinos , Fiebre Porcina Africana/virología , Gastrópodos/virología , Ornithodoros/virología
14.
J Anim Ecol ; 93(6): 705-714, 2024 06.
Artículo en Inglés | MEDLINE | ID: mdl-38644583

RESUMEN

Ecological similarity plays an important role in biotic interactions. Increased body size similarity of competing species, for example, increases the strength of their biotic interactions. Body sizes of many exothermic species are forecast to be altered under global warming, mediating shifts in existing trophic interactions among species, in particular for species with different thermal niches. Temperate rocky reefs along the southeast coast of Australia are located in a climate warming hotspot and now house a mixture of temperate native fish species and poleward range-extending tropical fishes (vagrants), creating novel species assemblages. Here, we studied the relationship between body size similarity and trophic overlap between individual temperate native and tropical vagrant fishes. Dietary niche overlap between vagrant and native fish species increased as their body sizes converged, based on both stomach content composition (short-term diet), stable isotope analyses (integrated long-term diet) and similarity in consumed prey sizes. We conclude that the warming-induced faster growth rates of tropical range-extending fish species at their cool water ranges will continue to converge their body size towards and strengthen their degree of trophic interactions and dietary overlap with co-occurring native temperate species under increasing ocean warming. The strengthening of these novel competitive interactions is likely to drive changes to temperate food web structures and reshuffle existing species community structures.


Asunto(s)
Tamaño Corporal , Cambio Climático , Peces , Cadena Alimentaria , Animales , Peces/fisiología , Dieta/veterinaria , Contenido Digestivo , Australia
15.
Am J Bot ; 111(5): e16322, 2024 05.
Artículo en Inglés | MEDLINE | ID: mdl-38641895

RESUMEN

PREMISE: Functional traits reflect species' responses to environmental variation and the breadth of their ecological niches. Fagus grandifolia and Oreomunnea mexicana have restricted distribution in upper montane cloud forests (1700-2000 m a.s.l.) in Mexico. These species were introduced into plantings at lower elevations (1200-1600 m a.s.l.) that have climates predicted for montane forests in 2050 and 2070. The aim was to relate morphological leaf traits to the ecological niche structure of each species. METHODS: Leaf functional traits (leaf area, specific leaf area [SLA], thickness, and toughness) were analyzed in forests and plantings. Atmospheric circulation models and representative concentration pathways (RCPs: 2.6, 4.5, 8.5) were used to assess future climate conditions. Trait-niche relationships were analyzed by measuring the Mahalanobis distance (MD) from the forests and the plantings to the ecological niche centroid (ENC). RESULTS: For both species, leaf area and SLA were higher and toughness lower in plantings at lower elevation relative to those in higher-elevation forests, and thickness was similar. Leaf traits varied with distance from sites to the ENC. Forests and plantings have different environmental locations regarding the ENC, but forests are closer (MD 0.34-0.58) than plantings (MD 0.50-0.70) for both species. CONCLUSIONS: Elevation as a proxy for expected future climate conditions influenced the functional traits of both species, and trait patterns related to the structure of their ecological niches were consistent. The use of distances to the ENC is a promising approach to explore variability in species' functional traits and phenotypic responses in optimal versus marginal environmental conditions.


Asunto(s)
Cambio Climático , Fagus , Bosques , Hojas de la Planta , Hojas de la Planta/fisiología , Hojas de la Planta/anatomía & histología , Fagus/fisiología , Fagus/anatomía & histología , México , Ecosistema
16.
Biol Lett ; 20(6): 20240120, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38863390

RESUMEN

What makes an odour pleasant or unpleasant? The inherent properties of the constituent chemical compounds, or the nose of the beholder, driven by idiosyncratic differences and culture-specific learning? Here, 582 individuals, including Tanzanian Hadza hunter-gatherers, Amazonian Tsimane' horticulturalists, Yali from the Papuan highlands and two industrialized populations (Poles, Malaysians), rated the pleasantness of 15 odour samples. We find considerable similarities in odour assessments across cultures, but our data do not fully support a claim regarding the universality of smell preferences. Despite cross-cultural similarities in olfactory assessments, probably driven by odour properties, we suggest that odour availability in ecological and cultural niches bears an undeniable effect on human odour preferences.


Asunto(s)
Comparación Transcultural , Odorantes , Humanos , Adulto , Masculino , Femenino , Adulto Joven , Olfato/fisiología , Polonia , Persona de Mediana Edad , Malasia , Adolescente , Percepción Olfatoria , África Oriental
17.
Oecologia ; 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39227465

RESUMEN

The niche of aphids is largely defined by their consumption of plant phloem sap and its composition, including nutrients and specialized metabolites. Niche construction is the change of the environment by organisms, which may influence the fitness of these organisms and their offspring. To better understand interactions between plants and aphids, it is necessary to investigate whether aphids modify the chemical composition of the phloem sap of their host plants and whether conspecifics are affected by previous infestation. In the current study, ears of wheat (Triticum aestivum) plants were infested with clonal lineages of the English grain aphid (Sitobion avenae) or were left uninfested. The metabolic composition of ear phloem sap exudates was analyzed through amino acid profiling and metabolic fingerprinting. Aphids of the clonal lineages were either put on previously aphid-infested or on uninfested ears and their colony sizes followed over time. Furthermore, it was investigated whether aphids choose one treatment group over another. Sitobion avenae infestation affected the relative concentrations of some metabolites in the phloem exudates of the ears. Compared to uninfested plants, the relative concentration of asparagine was higher after aphid infestation. Colonies grew significantly larger on previously aphid-infested ears, which the aphids also clearly chose in the choice experiment. The pronounced positive effect of previous infestation on aphid colonies indicates niche construction, while the choice of these constructed niches reveals niche choice by S. avenae on wheat. The interplay between these different niche realization processes highlights the complexity of interactions between aphids and their hosts.

18.
J Phycol ; 60(3): 604-620, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38551849

RESUMEN

Crocosphaera watsonii is a unicellular N2-fixing (diazotrophic) cyanobacterium observed in tropical and subtropical oligotrophic oceans. As a diazotroph, it can be a source of bioavailable nitrogen (N) to the microbial community in N-limited environments, and this may fuel primary production in the regions where it occurs. Crocosphaera watsonii has been the subject of intense study, both in culture and in field populations. Here, we summarize the current understanding of the phylogenetic and physiological diversity of C. watsonii, its distribution, and its ecological niche. Analysis of the relationships among the individual Crocosphaera species and related free-living and symbiotic lineages of diazotrophs based on the nifH gene have shown that the C. watsonii group holds a basal position and that its sequence is more similar to Rippkaea and Zehria than to other Crocosphaera species. This finding warrants further scrutiny to determine if the placement is related to a horizontal gene transfer event. Here, the nifH UCYN-B gene copy number from a recent synthesis effort was used as a proxy for relative C. watsonii abundance to examine patterns of C. watsonii distribution as a function of environmental factors, like iron and phosphorus concentration, and complimented with a synthesis of C. watsonii physiology. Furthermore, we have summarized the current knowledge of C. watsonii with regards to N2 fixation, photosynthesis, and quantitative modeling of physiology. Because N availability can limit primary production, C. watsonii is widely recognized for its importance to carbon and N cycling in ocean ecosystems, and we conclude this review by highlighting important topics for further research on this important species.


Asunto(s)
Cianobacterias , Fijación del Nitrógeno , Filogenia , Cianobacterias/genética , Cianobacterias/metabolismo , Cianobacterias/fisiología
19.
Environ Res ; 252(Pt 4): 119129, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38734292

RESUMEN

Climate change has had a significant impact on many marine organisms. To investigate the effects of environmental changes on deep-water benthic fishes, we selected the genus Oplegnathus and applied species distribution modeling and ecological niche modeling. From the last glacial maximum to the present, the three Oplegnathus species (O. conwayi, O. robinsoni, and O. peaolopesi) distributed in the Cape of Good Hope region of southern Africa experienced fitness zone fluctuations of 39.9%, 13%, and 5.7%, respectively. In contrast, O. fasciatus and O. punctatus, which were primarily distributed in the western Pacific Ocean, had fitness zone fluctuations of -6.5% and 11.7%, respectively. Neither the O. insignis nor the O. woodward varied by more than 5% over the period. Under future environmental conditions, the range of variation in fitness zones for the three southern African Oplegnathus species was expected to be between -30.8% and -26.5%, while the range of variation in fitness zones for the two western Pacific stonefish species was expected to remain below 13%. In addition, the range of variation in the fitness zones of the O. insignis was projected to be between -2.3% and 7.1%, and the range of variation in the fitness zones of the O. woodward is projected to be between -5.7% and -2%. The results indicated that O. fasciatus and O. punctatus had a wide distribution and high expansion potential, while Oplegnathus species might have originated in western Pacific waters. Our results showed that benthic fishes were highly adaptable to extreme environments, such as the last glacial maximum. The high ecological niche overlap between Oplegnathus species in the same region suggested that they competed with each other. Future research could explore the impacts of environmental change on marine organisms and make conservation and management recommendations.


Asunto(s)
Cambio Climático , Ecosistema , Animales , Peces/clasificación , Peces/fisiología , Perciformes/fisiología
20.
Environ Res ; 263(Pt 2): 120115, 2024 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-39369778

RESUMEN

Marine habitats and ecosystems are increasingly being impacted by global climate change and the global spread of captive breeding. In this study, we focused on five typical Trachinotus species (Trachinotus anak, Trachinotus blochii, Trachinotus mookalee, Trachinotus goreenisi, Trachinotus ovatus) as research subjects. We utilized species distribution models and ecological niche models to predict the present and future potential distribution of these species, as well as to assess ecological niche overlap and evaluate the early warning of invasion by Trachinotus species. T. ovatus stands out with its broad distribution range and high adaptability to different environments. It occupies 1.114% of medium-high suitable areas, spanning 100,147 km2. Our predictions also suggest that T. ovatus would undergo a significant expansion (approximately 55% of the total area) under both past and future environmental scenarios, demonstrating a higher tolerance and adaptability to changes in ambient temperatures. It can be discerned that T. ovatus exhibits strong environmental adaptability, which may potentially lead to biological invasion along the southeastern coast of China. The T. anak, on the other hand, showed a higher expansion trend under high carbon dioxide concentrations (RCP8.5), indicating a certain convergence with carbon dioxide concentration. Our models showed that under future climatic conditions, T. ovatus would become the dominant species, with increased competition with T. mookalee and decreased competition with T. goreenisi, T. mookalee, and T. anak. Based on our findings and the net-pen culture mode of T. ovatus, we identified the hotspot habitat of T. ovatus to be located in the Indo-Pacific convergence zone. However, there is a possibility of an expansion trend towards the southeast coast of China in the future. Therefore, it is crucial to provide an early warning for the potential biological invasion of T. ovatus.

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