Factor In Evolution Research Articles

Phylogenomic analyses of hamsters (Cricetinae) inferred from GBS data and mitochondrial genomes.

Accurate species delimitation and identification is crucial for species conservation, providing a foundation for studies on evolutionary biology, ecology, and essentially all biological disciplines. The subfamily Cricetinae (Cricetidae, Rodentia), known as hamsters, is widely distributed in the Palearctic region. At present, there are nine genera and 18 species of hamsters are recognized worldwide, although the taxonomic status of certain taxa remains unclear. In this study, we collected 146 hamster specimens representing 14 species and generated new mitochondrial genomes and nuclear genome-wide single nucleotide polymorphisms (SNPs) to explore their relationships among these hamsters using multiple species delimitation approaches. Results showed: (1) strong phylogenetic support for the classification of Urocricetus, Nothocricetulus, and Cansumys as separate genera; (2) Urocricetus contained two separate species, U. kamensis and U. lama, with U. alticola and U. tibetanus considered synonyms of U. lama; (3) U. kamensis and U. lama are separated by the Nujiang River, with the matching divergence time suggesting that the formation of the river was the primary evolutionary factor driving the species differentiation, and (4) genetic differentiation occurred within the Tscherskia genus, which included two cryptic species.

Population size rescaling significantly biases outcomes of forward-in-time population genetic simulations.

Simulations are an essential tool in all areas of population genetic research, used in tasks such as the validation of theoretical analysis and the study of complex evolutionary models. Forward-in-time simulations are especially flexible, allowing for various types of natural selection, complex genetic architectures, and non-Wright-Fisher dynamics. However, their intense computational requirements can be prohibitive to simulating large populations and genomes. A popular method to alleviate this burden is to scale down the population size by some scaling factor while scaling up the mutation rate, selection coefficients, and recombination rate by the same factor. However, this rescaling approach may in some cases bias simulation results. To investigate the manner and degree to which rescaling impacts simulation outcomes, we carried out simulations with different demographic histories and distributions of fitness effects using several values of the rescaling factor, Ǫ, and compared the deviation of key outcomes (fixation times, allele frequencies, linkage disequilibrium, and the fraction of mutations that fix during the simulation) between the scaled and unscaled simulations. Our results indicate that scaling introduces substantial biases to each of these measured outcomes, even at small values of Ʈ. Moreover, the nature of these effects depends on the evolutionary model and scaling factor being examined. While increasing the scaling factor tends to increase the observed biases, this relationship is not always straightforward, thus it may be difficult to know the impact of scaling on simulation outcomes a priori. However, it appears that for most models, only a small number of replicates was needed to accurately quantify the bias produced by rescaling for a given Ʈ. In summary, while rescaling forward-in-time simulations may be necessary in many cases, researchers should be aware of the rescaling procedure's impact on simulation outcomes and consider investigating its magnitude in smaller scale simulations of the desired model(s) before selecting an appropriate value of Ʈ.

A global overview of insect-fern interactions and its ecological trends.

Historically, ferns have been described as underutilized by insects. However, studies have shown a diversity of insects interacting with ferns, although the evolutionary and ecological drivers of these interactions are still to be untangled. To fill these gaps, we compiled more than 100 yr of global data on insect-fern interactions from the literature comprising 374 fern and 649 insect species. With this database we assessed how fern trophic specialization, phylogenetic relationships and climate have shaped their interactions with insects. Our findings showed that interactions between ferns and insects can be explained by the phylogenetic relations among them. We observed that insect orders part of the Endopterygota clade tend to interact with similar fern species, which might be a result of the inheritance of Endopterygota ancestors probably due to phylogenetic niche conservationism. Under an ecological context, fern specialization increased with temperature, precipitation, and climatic stability. Our results show that climate might be one of the main factors explaining the spatial variation of insect-fern interactions, postulate also supported by the observed phylogenetic clustering of the studied ferns species. Our study highlights the intricate and multifaceted nature of insect-fern interactions, where evolutionary history and ecological factors converge to shape these relationships.

Dynamics of Barred Coast at Different Temporal Scales (by the Example of Vistula Spit in the Baltic Sea)

According to fundamental concepts, the morphodynamic system of an accumulative sandy coast with underwater bars exhibits cyclic behavior across various time scales. This raises the question: which factor is more significant for the dynamics of a given coast—individual storms or seasonal changes in wave activity? While observations and studies addressing this issue have primarily been conducted on oceanic coasts, there is a lack of comparable data for fetch-limited areas. Monitoring of the bottom topography along the west coast of Vistula Spit (Baltic Sea) revealed a cyclic behavior in morphology, transitioning from a straightened external bar to its connection with the shore. Analysis of field measurement results indicated that seasonal variations in wave intensity do not significantly impact coastal relief. Furthermore, it was found that the complete cycle of underwater bar evolution lasts approximately two years, during which the coast profile maintains a stable shape at the stage of the straightened external bar. The identification of the primary factor influencing coastal evolution can be characterized by the Dean number (Ω), which combines wave parameters (wave height and period) with sediment fall velocity. Utilizing ERA5 wave reanalysis data, we compared the variability of Ω values on both annual and monthly scales. The analysis revealed that for the section of the coast under consideration, there is no clearly dominant evolutionary factor; rather, the coast is influenced approximately equally by individual storm events and seasonal fluctuations in wave energy. Modeling storm-induced bed profile deformations using the CROSS-PB model demonstrated that the position of the external underwater bar remains nearly constant even during intense and prolonged storms. It is concluded that under specific conditions—determined by a combination of sediment size, coastal slope, and wave regime characteristics—the coast can remain stable, exhibiting minimal response to relatively strong storms and seasonal variations in wave energy. Such coasts are characterized by an absence of a dominant evolutionary factor as indicated by fluctuations in the Dean parameter, allowing their morphodynamic cycles to span several seasons. This type of morphodynamics in coastal accumulative relief appears to be typical for conditions found in fetch-limited areas, such as regional and semi-closed seas.

BGC Atlas: a web resource for exploring the global chemical diversity encoded in bacterial genomes.

Secondary metabolites are compounds not essential for an organism's development, but provide significant ecological and physiological benefits. These compounds have applications in medicine, biotechnology and agriculture. Their production is encoded in biosynthetic gene clusters (BGCs), groups of genes collectively directing their biosynthesis. The advent of metagenomics has allowed researchers to study BGCs directly from environmental samples, identifying numerous previously unknown BGCs encoding unprecedented chemistry. Here, we present the BGC Atlas (https://bgc-atlas.cs.uni-tuebingen.de), a web resource that facilitates the exploration and analysis of BGC diversity in metagenomes. The BGC Atlas identifies and clusters BGCs from publicly available datasets, offering a centralized database and a web interface for metadata-aware exploration of BGCs and gene cluster families (GCFs). We analyzed over 35000 datasets from MGnify, identifying nearly 1.8 million BGCs, which were clustered into GCFs. The analysis showed that ribosomally synthesized and post-translationally modified peptidesare the most abundant compound class, with most GCFs exhibiting high environmental specificity. We believe that our tool will enable researchers to easily explore and analyze the BGC diversity in environmental samples, significantly enhancing our understanding of bacterial secondary metabolites,and promote the identification of ecological and evolutionary factors shaping the biosynthetic potential of microbial communities.

The Impact of IQ on Marriage Likelihood: Gender Differences in the UK

This paper explores the relationship between intelligence (IQ) and marriage likelihood, with a focus on gender disparities, particularly in the UK and China. Previous studies have shown that higher intelligence increases the likelihood of marriage for men, while it decreases for women. Through an interdisciplinary analysis of evolutionary, sociological, and biological factors, this paper seeks to explain why such disparities exist. The research highlights that evolutionary pressures traditionally associate intelligence in men with resource acquisition, making them desirable partners, whereas highly intelligent women often face societal resistance due to gender norms that devalue their career achievements in favor of caregiving roles. In the context of China, Confucianism and traditional gender roles further accentuate these disparities, particularly through the persistent practice of hypergamy. The paper concludes with a discussion of how evolving gender roles, media representation, and policy changes can influence future marriage patterns for intelligent women in both the UK and China.

Reptile Diversity Patterns Under Climate and Land Use Change Scenarios in a Subtropical Montane Landscape in Mexico

ABSTRACTAimMountainous regions are rich in reptile biodiversity but face threats from climate and land use changes. Understanding how these factors affect reptile diversity in these regions can highlight key conservation hotspots that require effective conservation actions. Here, we explored reptile taxonomic and functional diversity patterns along the Sierra Madre del Sur region in southeast Mexico, and potential changes in future years caused by different climate and land use change scenarios.LocationSierra Madre del Sur, México.TaxonReptiles.MethodsWe used species distribution models and information on species traits to estimate taxonomic and functional diversity throughout the Sierra Madre del Sur (SMS) region under current and future climate and land use change scenarios.ResultsGreater taxonomic and functional diversity was observed in both temperate and tropical forests. Taxonomic diversity was higher in more drier areas at high elevations while higher functional diversity was observed in wetter areas at intermediate‐to‐high elevations. Lower diversity for both dimensions was associated with anthropic land uses. In future scenarios, both dimensions of diversity are expected to increase in temperate forest in highlands of central Oaxaca and decrease in the southcentral portion of the SMS, particularly for the worst scenarios due to increased deforestation rates.Main ConclusionsHigher taxonomic diversity in more drier areas at high elevations could be due to historical and evolutionary factors, while higher functional diversity in wetter areas at intermediate‐to‐high elevations may be explained by a higher environmental heterogeneity in forests within these conditions. Larger diversity losses in the southcentral portion of the SMS are probably due to larger predicted deforestation rates in those areas. Our results are valuable not just for informing conservation actions, such as the creation of protected natural areas but also to understand the underlying processes behind the patterns of reptile diversity.

Are there conserved biosynthetic genes in lichens? Genome-wide assessment of terpene biosynthetic genes suggests ubiquitous distribution of the squalene synthase cluster

Lichen-forming fungi (LFF) are prolific producers of functionally and structurally diverse secondary metabolites, most of which are taxonomically exclusive and play lineage-specific roles. To date, widely distributed, evolutionarily conserved biosynthetic pathways in LFF are not known. However, this idea stems from polyketide derivatives, since most biochemical research on lichens has concentrated on polyketide synthases (PKSs). Here, we present the first systematic identification and comparison of terpene biosynthetic genes of LFF using all the available Lecanoromycete reference genomes and 22 de novo sequenced ones (111 in total, representing 60 genera and 23 families). We implemented genome mining and gene networking approaches to identify and group the biosynthetic gene clusters (BGCs) into networks of similar BGCs. Our large-scale analysis led to the identification of 724 terpene BGCs with varying degrees of pairwise similarity. Most BGCs in the dataset were unique with no similarity to a previously known fungal or bacterial BGC or among each other. Remarkably, we found two BGCs that were widely distributed in LFF. Interestingly, both conserved BGCs contain the same core gene, i.e., putatively a squalene/phytoene synthase (SQS), involved in sterol biosynthesis. This indicates that early gene duplications, followed by gene losses/gains and gene rearrangement are the major evolutionary factors shaping the composition of these widely distributed SQS BGCs across LFF. We provide an in-depth overview of these BGCs, including the transmembrane, conserved, variable and LFF-specific regions. Our study revealed that lichenized fungi do have a highly conserved BGC, providing the first evidence that a biosynthetic gene may constitute essential genes in lichens.

Positive selection, genetic recombination, and intra-host evolution in novel equine coronavirus genomes and other members of the Embecovirus subgenus.

There are several examples of coronaviruses in the Betacoronavirus subgenus Embecovirus that have jumped from an animal to the human host. Studying how evolutionary factors shape coronaviruses in non-human hosts may provide insight into the coronavirus host-switching potential. Equids, such as horses and donkeys, are susceptible to equine coronaviruses (ECoVs). With increased testing prevalence, several ECoV genome sequences have become available for molecular evolutionary analyses, especially those from the United States of America (USA). To date, no analyses have been performed to characterize evolution within coding regions of the ECoV genome. Here, we obtain and describe four new ECoV genome sequences from infected equines from across the USA presenting clinical symptoms of ECoV, and infer ECoV-specific and Embecovirus-wide patterns of molecular evolution. Within two of the four data sets analyzed, we find evidence of intra-host evolution within the nucleocapsid (N) gene, suggestive of quasispecies development. We also identify 12 putative genetic recombination events within the ECoV genome, 11 of which fall in ORF1ab. Finally, we infer and compare sites subject to positive selection on the ancestral branch of each major Embecovirus member clade. Specifically, for the two currently identified human coronavirus (HCoV) embecoviruses that have spilled from animals to humans (HCoV-OC43 and HCoV-HKU1), we find that there are 42 and 2 such sites, respectively, perhaps reflective of the more complex ancestral evolutionary history of HCoV-OC43, which involves several different animal hosts.IMPORTANCEThe Betacoronavirus subgenus Embecovirus contains coronaviruses that not only pose a health threat to animals and humans, but also have jumped from animal to human host. Equids, such as horses and donkeys are susceptible to equine coronavirus (ECoV) infections. No studies have systematically examined evolutionary patterns within ECoV genomes. Our study addresses this gap and provides insight into intra-host ECoV evolution from infected horses. Further, we identify and report natural selection pattern differences between two embecoviruses that have jumped from animals to humans [human coronavirus OC43 and HKU1 (HCoV-OC43 and HCoV-HKU1, respectively)], and hypothesize that the differences observed may be due to the different animal host(s) that each virus circulated in prior to its jump into humans. Finally, we contribute four novel, high-quality ECoV genomes to the scientific community.

Cross-sectional survey of gender differences in gross motor skills among preschool children in Jinhua City, China

BackgroundWhile gender differences in ball skills are widely recognized, the differences in locomotor skills remain unclear. This study aims to explore these gender differences among preschool children in Jinhua City, China, and to examine the influence of evolutionary factors and local cultural activities on these skills. MethodsA cluster random sampling method was employed to select 777 preschool children aged 5.1–6.7 years from seven kindergartens in Jinhua, Zhejiang Province, Eastern China. The Test of Gross Motor Development-Third Edition (TGMD-3) was used to assess GMS, including locomotor and ball skills. ResultsBoys outperformed girls in ball skills, such as underhand throwing, catching, two-handed striking, and kicking. However, no significant overall gender differences were found in locomotor skills. A deeper analysis revealed that boys excelled in running-related tasks, whereas girls performed better in skipping-related tasks. These findings suggest that TGMD-3 locomotor skills should be divided into running-related and jumping-related categories. The results also show that not all ball skills are dominated by boys, indicating the impact of environmental factors. The findings highlight the role of both evolutionary factors and local cultural activities in shaping these specific gender differences. ConclusionThe study's cross-sectional design provides a snapshot of existing gender differences in motor skills among preschool children. The results suggest the need for gender-sensitive physical education programs to address these disparities early on. Future research should utilize longitudinal methods and objective measures to further understand the development of these skills over time and the underlying factors contributing to these differences.

Unraveling the Complexity of the N e/N c Ratio for Conservation of Large and Widespread Pelagic Fish Species: Current Status and Challenges.

Estimating and understanding the ratio between effective population size (N e) and census population size (N c) are pivotal in the conservation of large marine pelagic fish species, including bony fish such as tunas and cartilaginous fish such as sharks, given the challenges associated with obtaining accurate estimates of their abundance. The difficulties inherent in capturing and monitoring these species in vast and dynamic marine environments often make direct estimation of their population size challenging. By focusing on N e, it is conceivable in certain cases to approximate census size once the N e/N c ratio is known, although this ratio can vary and does not always increase linearly, as it is influenced by various ecological and evolutionary factors. Thus, this ratio presents challenges and complexities in the context of pelagic species conservation. To delve deeper into these challenges, firstly, we recall the diverse types of effective population sizes, including contemporary and historical sizes, and their implications in conservation biology. Secondly, we outline current knowledge about the influence of life history traits on the N e/N c ratio in the light of examples drawn from large and abundant pelagic fish species. Despite efforts to document an increasing number of marine species using recent technologies and statistical methods, establishing general rules to predict N e/N c remains elusive, necessitating further research and investment. Finally, we recall statistical challenges in relating N e and N c emphasizing the necessity of aligning temporal and spatial scales. This last part discusses the roles of generation and reproductive cycle effective population sizes to predict genetic erosion and guiding management strategies. Collectively, these sections underscore the multifaceted nature of effective population size estimation, crucial for preserving genetic diversity and ensuring the long-term viability of populations. By navigating statistical and theoretical complexities, and addressing methodological challenges, scientists should be able to advance our understanding of the N e/N c ratio.

Exploring the dynamics of social roles in hospital evacuation: Factors, roles and behaviors

As a critical city facility of our society, it is important for hospitals to be resilient against emergencies for a health imperative and economic buoyancy. Understanding the evacuation behaviors of hospital roles and the corresponding influencing factors is essential for the accurate execution of emergency response plans and well-being. Therefore, this study aims to explore the dynamics of social roles in hospital evacuation by understanding the mediation effects of role evolution factors (i.e., responsibility, competence, and expectation of evacuation roles). Questionnaires on hospital roles, role evolution factors, and evacuation behaviors were designed and distributed, with a total of 324 responses from various hospital occupants. The common method variance analysis, internal consistency test, item analysis, and exploratory factor analysis consistently indicated good reliability and validity of the questionnaire. Chain mediation models of three prominent evacuation roles, namely leader, emergency responder, and follower were developed, with the three role evolution factors as mediating variables, evacuation behavior as the dependent variable, and hospital role as the independent variable. Findings indicated significant path effects of hospital roles and role evolutionary factors on leadership, emergency responding, and following behaviors. One-way ANOVA on egocentric behavior and hesitant behavior of hospital roles revealed that patients have a higher propensity for negative behaviors compared with hospital staff. In light of the findings, the subtle relationship between hospital roles, role evolution factors, and evacuation behaviors was revealed. Role-specific leadership training, role-based emergency response management, role-related following behavior guidance, and negative behavior reduction measures were proposed for improving hospital safety.

Distinctive and highly variable bird migration system revealed in Eastern Australia.

Our understanding of bird migration is heavily biased toward long-distance movements in the Northern Hemisphere,1,2,3 with only fragmented knowledge from the Southern Hemisphere.4,5 In Australia, while some species migrate,4,6,7,8 the timing and direction of large-scale, multi-species seasonal movements remain critically understudied due to the complexity of movement in this region and a lack of research personnel and infrastructure.7,9 It is still unclear whether there are pronounced and structured mass movements resembling those in the Northern Hemisphere.10,11,12 Here, we analyze data from a latitudinal transect of weather radars spanning the entire coastline of Eastern Australia to determine the magnitude, directions, timing, and variability of bird migration compared to that of Northern Hemisphere migration systems. Bird movements exhibited sequential seasonal peaks along a latitudinal gradient with seasonally contrasting flight directions, confirming that a structured bird migration system exists. Three features were distinct from Northern Hemisphere migrations. First, distinct movements occurred around sunrise with comparable magnitudes to nocturnal migration, likely representing a strong diurnal component to the bird movements. Second, migration intensity averaged 0.06 million birds km-1 in autumn, much lower than Northern Hemisphere migrations.11,12,13 Finally, flight directions were more dispersed, and the timing and amount of migration were highly variable between years compared to Northern Hemisphere migration systems, perhaps in response to variable climate.7 This first quantification of continental-scale movements in Australia revealed a distinctive migration system, and it suggests that much remains to be discovered about the ecological and evolutionary factors shaping animal migrations in the Southern Hemisphere.

An arms race between 5’ppp-RNA virus and its alternative recognition receptor MDA5 in RIG-I-lost teleost fish

The incessant arms race between viruses and hosts has led to numerous evolutionary innovations that shape life’s evolution. During this process, the interactions between viral receptors and viruses have garnered significant interest since viral receptors are cell surface proteins exploited by viruses to initiate infection. Our study sheds light on the arms race between the MDA5 receptor and 5’ppp-RNA virus in a lower vertebrate fish, Miichthys miiuy. Firstly, the frequent and independent loss events of RIG-I in vertebrates prompted us to search for alternative immune substitutes, with homology-dependent genetic compensation response (HDGCR) being the main pathway. Our further analysis suggested that MDA5 of M. miiuy and Gallus gallus, the homolog of RIG-I, can replace RIG-I in recognizing 5’ppp-RNA virus, which may lead to redundancy of RIG-I and loss from the species genome during evolution. Secondly, as an adversarial strategy, 5’ppp-RNA SCRV can utilize the m6A methylation mechanism to degrade MDA5 and weaken its antiviral immune ability, thus promoting its own replication and immune evasion. In summary, our study provides a snapshot into the interaction and coevolution between vertebrate and virus, offering valuable perspectives on the ecological and evolutionary factors that contribute to the diversity of the immune system.

An arms race between 5'ppp-RNA virus and its alternative recognition receptor MDA5 in RIG-I-lost teleost fish.

The incessant arms race between viruses and hosts has led to numerous evolutionary innovations that shape life's evolution. During this process, the interactions between viral receptors and viruses have garnered significant interest since viral receptors are cell surface proteins exploited by viruses to initiate infection. Our study sheds light on the arms race between the MDA5 receptor and 5'ppp-RNA virus in a lower vertebrate fish, Miichthys miiuy. Firstly, the frequent and independent loss events of RIG-I in vertebrates prompted us to search for alternative immune substitutes, with homology-dependent genetic compensation response (HDGCR) being the main pathway. Our further analysis suggested that MDA5 of M. miiuy and Gallus gallus, the homolog of RIG-I, can replace RIG-I in recognizing 5'ppp-RNA virus, which may lead to redundancy of RIG-I and loss from the species genome during evolution. Secondly, as an adversarial strategy, 5'ppp-RNA SCRV can utilize the m6A methylation mechanism to degrade MDA5 and weaken its antiviral immune ability, thus promoting its own replication and immune evasion. In summary, our study provides a snapshot into the interaction and coevolution between vertebrate and virus, offering valuable perspectives on the ecological and evolutionary factors that contribute to the diversity of the immune system.

A multifaceted approach to expanding conservation efforts in the Pan-Himalayan landscape

The Pan-Himalayan biogeographic domain is a significant region for biodiversity conservation and climate resilience. This region has both tropical and extratropical flora and holds ecological, cultural, and socio-economic importance. However, knowledge about the spatial distribution and threats to threatened plant species in the study area is still poorly known. In this study we evaluate the phylogenetic diversity and phylogenetic endemism of threatened flora in the region, and also examine the effect of rapid land cover transformation and landscape fragmentation between 2000 and 2020 on the preservation of distinct evolutionary lineages. Phylogenetic metrics provide a better understanding of ecological, historical, and evolutionary factors that shape plant communities in highly biodiverse regions. Our result show that current protected areas are insufficient for preserving Pan-Himalayan biodiversity, and also reveal a significant gap in conservation efforts within these areas. We highlight conservation priorities areas in the western Himalayan belt encompassing 2.43 million km2 and covering 26.73% of the total area. However, a large conservation gap encompassed 22.67% (2.06 million km2) hotspots of total study area, whereas non-hotspot priorities covered 67.62% (0.77 million km2) of the total protected area, revealing a mismatch between biodiversity hotspots and protected areas. In addition, biodiversity priority areas have been threatened by rapid land cover transformation and landscape fragmentation between 2000 and 2020. There were 6.93% increase in cropland area and 172.64% increase in impervious surface, while an increase in landscape fragmentation and a decrease in landscape cohesion in different hotspots within protected areas. The biodiversity hotspot regions emphasize the need to conserve unique evolutionary lineages and high species occurrence areas with targeted conservation strategies. Mountainous, but cross-border international cooperation is highly recommended for effective preservation strategies. Our study has implications for advancing biodiversity preservation and sustainable ecosystem management not only in the Pan-Himalayan but also in similar regions, as well as for achieving the 2030 protection goal.

The care of non-institutionalized ADL-dependent people in the Orcasitas neighborhood of Madrid (Spain) during the Covid-19 pandemic and its relationship with social inequalities, intergenerational dependency and survival.

Mortality among people with dependency to perform basic activities of daily living (ADL) is higher than that of non-dependent people of the same age. Understanding the evolutionary course and factors involved in non-institutionalized ADL dependency, including the influence of the family structure that supports this population, would contribute to improved health planning. A longitudinal study carried out in the ADL-dependent population of the Orcasitas neighborhood, Madrid (Spain), between June 2020, when the nationwide COVID-19 lockdown ended, and June 2023. A total of 127 patients participated in the study, 78.7% of whom were women and 21.3% were men. Risk analysis was performed via odds ratios (OR) and hazard ratios (HR). Survival analysis was performed using Cox regression. A total of 54.33% of the ADL-dependent persons did not live with their adult children and 45.67% did, being associated living independently with economic capacity and the married marital status but not with the dependency level. In women, being married increased the probability of living independently of their adult children (OR = 12.632; 95% CI = 3.312-48.178). Loss of mobility (OR = 0.398; 95% CI = 0.186-0.853), economic capacity of the dependent (HR = 0.596; 95% CI = 0.459-0.774), and living independently and having better economic capacity (HR = 0.471; 95% CI = 0.234-0.935) were associated with 3-year survival. Those who lived with their adult children had a worse autonomy profile and higher mortality (HR = 1.473; 95% CI = 1.072-2.024). Not being employed, not being married, and not owning a home were significantly associated with being an essential family caregiver. Caregivers were mostly women (OR = 1.794; 95% CI = 1.011-3.182). Among ADL-dependent persons, economic capacity influenced the ability to living independently and affected survival after 3 years. Loss of mobility (wheelchair use) was a predictor of mortality. Social inequalities promote that adult children end up as essential family caregivers. This generates reverse dependency and maintains a vulnerability that is transmitted from generation to generation, perpetuating social and gender inequalities. Dependent parent care in this cohort maintained an archaic pattern in which the eldest daughter cared for her parents. This study made it possible to show that ADL dependence is accompanied by complex interrelationships that must be considered in socio-health planning.

Ontogeny, not prey availability, underlies allopatric venom variability in insular and mainland populations of Vipera ammodytes

Allopatric populations living under distinct ecological conditions are excellent systems to infer factors underlying intraspecific venom variation. The venom composition of two populations of Vipera ammodytes, insular with a diet based on ectotherms and mainland with a diet based on ectotherms and endotherms, was compared considering the sex and age of individuals. Ten toxin families, dominated by PLA2, svMP, svSP, and DI, were identified through a bottom-up approach. The venom profiles of adult females and males were similar. Results from 58 individual SDS-PAGE profiles and venom pool analysis revealed significant differences between juveniles compared to subadults and adults. Two venom phenotypes were identified: a juvenile svMP-dominated and KUN-lacking phenotype and an adult PLA2/svMP-balanced and KUN-containing phenotype. Despite differences in prey availability (and, therefore, diet) between populations, no significant differences in venom composition were found. As the populations are geographically isolated, the lack of venom diversification could be explained by insufficient time for natural selection and/or genetic drift to act on the venom composition of island vipers. However, substantial differences in proteomes were observed when compared to venoms from geographically distant populations inhabiting different conditions. These findings highlight the need to consider ecological and evolutionary processes when studying venom variability. SignificanceThis study provides the first comprehensive analysis of the venom composition of two allopatric populations of Vipera ammodytes, living under similar abiotic (climate) but distinct biotic (prey availability) conditions. The ontogenetic changes in venom composition, coupled with the lack of differences between sex and between populations, shed light on the main determinants of venom evolution in this medically important snake. Seven new proteomes may facilitate future comparative studies of snake venom evolution. This study highlights the importance of considering ecological and evolutionary factors to understand snake venom variation.

Post-fire temporal dynamics of plant-pollinator communities in a tropical savanna.

Fire is a major ecological and evolutionary factor promoting biodiversity and maintaining functioning of naturally fire-prone ecosystems. In tropical savannas, plant communities show a set of fire-adapted traits and both flowering and pollination services have the potential to rapidly regenerate after fire, but fire-suppression policies may disrupt this adaptability following potential woody encroachment. Understanding the effects of fire on plant-pollinator interactions are required to advance conservation of biodiversity and ecosystem functioning. We evaluated the dynamics of plant community assemblage, flower availability, composition of flower functional traits associated with attractiveness to pollinators, and activity and diversity of insect pollinator guilds over ten post-fire stand ages along a 14-year chronosequence in a naturally burned region in the Cerrado, a megadiverse savanna in Brazil. We expect to find a high resilience of plant-pollinator communities and a steady decline in the successional recovery as time-since-fire proceeds. Along the post-fire chronosequence, vegetation was dominated by subshrubs with tubular, white, and nectar flowers arranged in inflorescences, while bees were the predominant pollinators. Plant assemblage and flower number showed an initial significant increase but monotonically declined after 7-9years after fire. Accordingly, pollinator richness and abundance significantly reached highest peaks in interim periods and a steady decline over time. In contrast, the frequency of community-wide plant-life form, flower functional traits, and pollinator diversity remained unaltered over the post-fire chronosequence. We added compelling evidence of a high post-fire resilience of plant-pollinator communities and further understanding of how fire-suppression policies may affect pollination in the Cerrado.

Hydraulic mechanism of limiting growth and maintaining survival of desert shrubs in arid habitats.

The growth and survival of woody plant species is mainly driven by evolutionary and environmental factors. However, little is known about the hydraulic mechanisms that respond to growth limitation and enable desert shrub survival in arid habitats. To shed light on these hydraulic mechanisms, 9-, 31-, and 56-year-old Caragana korshinskii plants that had been grown under different soil water conditions at the southeast edge of the Tengger Desert, Ningxia, China were used in this study. The growth of C. korshinskii was mainly limited by soil water rather than shrub age in non-watered habitats, which indicated the importance of maintaining shrub survival prior to growth under drought. Meanwhile, higher vessel density, narrower vessels and lower xylem hydraulic conductivity indicated that shrubs enhanced hydraulic safety and reduced their hydraulic efficiency in arid conditions. Importantly, xylem hydraulic conductivity mediated by variation in xylem hydraulic architecture regulated photosynthetic carbon assimilation and growth of C. korshinskii. Our study highlights that the synergistic variation in xylem hydraulic safety and hydraulic efficiency is the hydraulic mechanism limiting growth and maintaining survival of C. korshinskii under drought, providing insights into the strategies for growth and survival of desert shrubs in arid habitats.