Extinction Processes Research Articles

Grassland Afforestation Drives Biotic Homogenisation of Soil Microbial Communities at a Regional Scale.

Grassland afforestation poses a threat to biodiversity beyond land-use conversion. Diversity patterns are shaped by temporal dynamics, particularly, time since afforestation can decline beta diversity and lead to biotic homogenisation. Our study examines the effect of grassland afforestation on soil prokaryotic and fungal beta diversity. We evaluate the contributions of colonisation and extinction processes to beta diversity, as well as the replacement of endemic species by ubiquitous ones. Along a 200 km climatic gradient in Argentina's Pampas region, we analysed grasslands and mature eucalypt plantations at different times since afforestation. Soil samples were collected at each site and analysed using 16S (V3-V4) and ITS2 amplicon sequencing to identify prokaryotic and fungal communities, respectively. The analyses revealed biotic homogenisation at the transition from grassland to newly planted stands, evidenced by a decrease in intratreatment beta diversity. Increasing time since afforestation did not exacerbate this decline. However, our findings indicate that there are different responses between prokaryotes and fungi. The homogenisation of prokaryotes in young stands is due to the low heterogeneity in colonising communities. On the other hand, the decline in fungal beta diversity is likely caused by other mechanisms beyond extinction or replacement. The study highlights the impacts of the afforestation process on the beta diversity of soil microbial communities of grasslands, affecting taxonomic groups in different ways. Although microbial diversity may be partially restored in time in eucalypt plantations, it is important to investigate its underlying mechanisms and the ecological implications for microbial diversity and its spatial distribution.

Correlating concurrent-flow flame spread rates in different pressure and oxygen conditions: Ground experiments and comparisons with previous micro-, partial, and normal gravities experiments

Ambient pressure and gravity are important parameters in buoyant flow that governs upward flame spread process. Based on the concept of pressure modelling, this experimental study investigates extinction and upward flame spread process of a thermally-thin solid fuel in different pressure and oxygen conditions. Experiments are performed in a combustion chamber in air at different pressures (ranging from 10 kPa to 100 kPa) and different oxygen molar fraction environment (9–21 %). As pressure increases, different burning behaviors are observed: no ignition, partial flame spread, steady flame spread, and accelerating flame spread. Similar trend is observed as the ambient oxygen molar fraction increases. In partial pressure conditions (e.g., 25–50 kPa), flames exhibit characteristics that are typically observed in micro- and partial gravity environments: blue and dim. Flame spread rate and sample burnt length are deduced and compared between different pressure and oxygen levels. Overall, the burning intensity and the flame spread rate decrease with the decrease in ambient pressure and oxygen. The decrease in flame spread rate at reduced pressure is attributed to increase in flame standoff distance and decrease in convective heat transfer to the solid, whereas the decrease in flame spread rate in reduced oxygen molar fraction environment is attributed to decrease in flame temperature. Lastly, current and previous studies performed at different ambient environments are correlated using the concept of flame standoff distance (δf), which is estimated using the theoretical viscous boundary layer thickness (δv). It was found that approximating δf∼δvfor forced flow and δf∼1/3δv for natural flow can predict the flame spread rate reasonably well for data obtained in micro-, partial, and normal gravities, for a wide range of environmental conditions away from extinction limits.

Testing relationships between multiple regional features and biogeographic processes of speciation, extinction, and dispersal.

The spatial and environmental features of regions where clades are evolving are expected to impact biogeographic processes such as speciation, extinction, and dispersal. Any number of regional features (such as elevation, distance, area, etc.) may be directly or indirectly related to these processes. For example, it may be that distances or differences in elevation or both may limit dispersal rates. However, it is difficult to disentangle which features are most strongly related to rates of different processes. Here, we present an extensible Multi-feature Feature-Informed GeoSSE (MultiFIG) model that allows for the simultaneous investigation of any number of regional features. MultiFIG provides a conceptual framework for incorporating large numbers of features of different types, including categorical, quantitative, within-region, and between-region features, along with a mathematical framework for translating those features into biogeographic rates for statistical hypothesis testing. Using traditional Bayesian parameter estimation and reversible-jump Markov chain Monte Carlo, MultiFIG allows for the exploration of models with different numbers and combinations of feature-effect parameters, and generates estimates for the strengths of relationships between each regional feature and core process. We validate this model with a simulation study covering a range of scenarios with different numbers of regions, tree sizes, and feature values. We also demonstrate the application of MultiFIG with an empirical case study of the South American lizard genus Liolaemus, investigating sixteen regional features related to area, distance, and elevation. Our results show two important feature-process relationships: a negative distance/dispersal relationship, and a negative area/extinction relationship. Interestingly, although speciation rates were found to be higher in Andean versus non-Andean regions, the model did not assign significance to Andean- or elevation-related parameters. These results highlight the need to consider multiple regional features in biogeographic hypothesis testing.

Sedimentary facies controlled biogeochemical process of biotic extinction and turnover across the Cambrian SPICE event

The Steptoean positive carbon isotope excursion (SPICE) event, one of the largest carbon cycle perturbations in the Cambrian, coincides with shallow-shelf-fauna extinction and plankton revolution (critical transition of plankton). The event is globally documented, but biogeochemical responses of these biotic evolutions in varying facies environments are not well understood. Here high-resolution paired δ18Ocarb, δ13Ccarb and δ13Corg datasets from varied paleodepth environments in the Tarim Basin, NW China reveal facies-dependent signatures of the event, with globally synchronous patterns but notable intra-basinal variability. Shallow marine facies record the end-Marjuman extinction with a distinct negative δ13Corg excursion prior to the event, while the transitional facies region marks twice positive δ13C excursions corresponding to an asynchronous plankton revolution from shallow and deep areas during the event. The varying isotope responses are interpreted in the context of primary productivity and redox conditions, with deeper basins recording more 13C enriched signals (i.e., higher δ13C) due to greater organic matter preservation under anoxic conditions, compared to the platform area. The biotic extinction, the planktonic revolution and the interaction of organisms along the shallow to deep marine depth gradient were reflected by the significant isotopic shifts recorded during the event, suggesting depth-dependent biogeochemical processes that shaped marine ecosystems.

AVOTREX: A Global Dataset of Extinct Birds and Their Traits

ABSTRACTMotivationHuman activities have been reshaping the natural world for tens of thousands of years, leading to the extinction of hundreds of bird species. Past research has provided evidence of extinction selectivity towards certain groups of species, but trait information is lacking for the majority of clades, especially for prehistoric extinctions identified only through subfossil remains. This incomplete knowledge potentially obscures the structure of natural communities, undermining our ability to infer changes in biodiversity across space and time, including trends in functional and phylogenetic diversity. Biases in currently available trait data also limit our ability to identify drivers and processes of extinction. Here we present AVOTREX, an open‐access database of species traits for all birds known to have gone extinct in the last 130,000 years. This database provides detailed morphological information for 610 extinct species, along with a pipeline to build phylogenetic trees that include these extinct species.Main Types of Variables ContainedFor each extinct bird species, we provide information on the taxonomy, geographic location, and period of extinction. We also present data on island endemicity, flight ability, and body mass, as well as standard measurements of external (matching the AVONET database of extant birds) and skeletal morphology from museum specimens where available. To ensure comprehensive morphological data coverage, we estimate all missing morphological measurements using a data imputation technique based on machine learning. Finally, we provide an R package to graft all extinct species onto a global phylogeny of extant species (BirdTree).Spatial Location and GrainGlobal.Time Period and GrainAll known globally extinct bird species from 130,000 years ago up until 2024.Major Taxa and Level of MeasurementBirds (Class Aves), species level.Software FormatSpreadsheets (.csv) stored in Dryad.

Conservation gaps for Brazilian bats, limited protection across conservation units and the importance of the indigenous lands.

In Brazil, there is 13% of the world's bat diversity, is the second most diverse group of mammals, playing a crucial role in providing ecosystem services that benefit humans. However, anthropogenic disturbances exacerbate processes of species extinction, shifts in geographic distributions, and phenological changes, despite efforts to safeguard biodiversity through the creation of Conservation Units and Indigenous Lands. Moreover, gaps in taxonomic knowledge and challenges related to species distribution hinder the effective implementation of conservation strategies in protected areas. This study assesses the contribution of Brazilian Conservation Units (both Full Protection and Sustainable Use) and Indigenous Lands to the conservation of bat species and their ecosystem services. It also presents maps illustrating species richness by trophic guilds and threat classification according to IUCN, including species listed as Data Deficient. The findings reveal low percentages of potential bat distribution areas within these protected regions, especially for insectivorous, nectarivorous, and frugivorous bats in the Cerrado biome, which are classified as Near Threatened. Additionally, the highest bat species richness was observed in the Amazon and Atlantic Forest biomes.

Numerical simulation of detonation propagation and extinction in two-phase gas-droplet ammonia fuel

Numerical simulations of detonation propagation and extinction in ammonia droplet-laden premixed ammonia–oxygen gas are performed in a 2-D planar channel. The sustained propagation and ultimate quenching of detonation with perturbations from ammonia droplets are observed under lower and larger values of initial droplet number density (Nd,0) and diameter (d0), respectively. The detonation always quenches under d0=15μm. The detonation propagation/extinction behaviour and cell structure are dependent on both d0 and Nd,0. The positive correlations between droplet volume fraction, inter-phase mass, momentum, and energy transfers and d0 are more nonlinear than their counterparts of Nd,0. The post-Mach stem region experiences higher-intensity detonative combustion and thus droplet evaporative, accelerative, and heating effects than the post-incident wave region. During the detonation extinction process, the detonation wave degenerates into detonative spots which then decouple into shock and reaction fronts; gaseous pressure, heat release rate, and nitric oxide volume fraction peaks decline.

Conservation with hard borders: Ethiopian wolves are threatened by fragmentation and isolation

Unlike most canids, versatile and capable of navigating vast landscapes, endangered Ethiopian wolves (Canis simensis) are endemic to an archipelago of Afroalpine islands. As a habitat specialist, the Ethiopian wolf is ill‐equipped to move across a highly transformed and densely populated agriculture matrix. Hard borders imposed by expanding subsistence agriculture lock Ethiopian wolves into further isolation, with few opportunities for dispersal and recolonisation. We report and evaluate empirical information from long‐term monitoring across the species' range to understand processes of habitat loss, recolonisation and extinction in recent and historical times, and to assess what conservation measures and strategies would ensure their persistence. Ethiopian wolves occurred in six isolated populations, totalling 454 wolves (population sizes ranged between 281 and 24) occupying 2700 km2 of Afroalpine habitat. We describe three population extinctions and three local extinctions within fragmented populations, and present evidence of factors accelerating the extinction process, such as disease (rabies and canine distemper virus), persecution, road kills and poisoning. Of all the suitable habitat available to wolves, 86% was included within nine protected areas, including three new Community Conservation Areas and two national park extensions in the past 10 years. As all Ethiopian wolf populations are small and vulnerable to stochastic events and environmental perturbation, conservation efforts to ensure the long‐term survival of the species need to integrate: 1) support for protected areas to halt agriculture encroachment and to regulate sustainable uses of natural resources; 2) efforts to minimise all causes of mortality, including but not limited to disease; and 3) conservation translocations to overcome fundamental barriers to dispersal in the highlands of Ethiopia.

Къэбэрдей-шэрджэсыбзэр ужьыхынымкIэ, кIуэдыжыпэнымкIэ шынагъуэ зыпылъ Iуэхугъуэ щхьэхуэхэр

This paper highlights the most important issues of the state and functioning of the modern Kabar-dino-Circassian language in impending globalization and the existing realities in the field of state language policy. The study examines the fundamental risk factors that, without appropriate drastic measures, will inevitably accelerate the process of extinction and subsequent disappearance of the Adyghe language. Material for the presented research was normative legal acts in the field of functioning, preservation and development of the languages of the peoples of the Russian Federa-tion, journalistic materials of the republican newspaper “Adyge Psal”, Kabardian broadcasts of radio and television of the Republic. The work uses descriptive, comparative research methods, synthesis, and analysis. Conducted research allows us to conclude that the most important condi-tion for the preservation and development of minority languages, which include Kabardino-Circassian, is the implementation of a unified “protective” state language policy in the country, which would not only declare the legal and social status of the language but also provide a real opportunity for its use in official spheres with a guarantee translation, since an indispensable con-dition for the functioning of any language is its relevance to society; the suppression of the cur-rently violent interference in the natural course of language development by introducing fictional terms into its vocabulary instead of established lexical units that native speakers actively use.

Untangling the colonization history of the Australo-Pacific reed warblers, one of the world's great island radiations.

Island radiations, such as those of the Australo-Pacific, offer unique insight into diversification, extinction, and early speciation processes. Yet, their speciation and colonization histories are often obscured by conflicting genomic signals from incomplete lineage sorting or hybridization. Here, we integrated mitogenomes and genome-wide SNPs to unravel the evolutionary history of one of the world's most geographically widespread island radiations. The Australo-Pacific reed warblers (Acrocephalus luscinius complex) are a speciose lineage including five species that have become extinct since the 19th century and ten additional species of conservation concern. The radiation spans over 10,000 km across Australo-Papua, Micronesia and Polynesia, including the Mariana, Hawaii and Pitcairn Island archipelagos. Earlier mtDNA studies suggested a stepping-stone colonization process, resulting in archipelago-level secondary sympatry of divergent mtDNA lineages in the Mariana Islands and Marquesas. These studies hypothesised that morphologically similar species on neighbouring islands arose from ecological convergence. Using hDNA from historical museum specimens and modern genetic samples, we show that incomplete lineage sorting and/or gene flow have shaped the radiation of Australo-Pacific reed warblers rather than secondary sympatry. The nuclear genome reconstructs a simpler biogeographic history than mtDNA, showing close relationships between species in the Mariana Islands and Marquesas despite their paraphyletic mtDNA lineages. Gene flow likely involved early and late colonizing waves of the radiation before the loss of ancestral dispersive ability. Our results highlight how collection genomics can elucidate evolutionary history and inform conservation efforts for threatened species.

Conflict Dynamics of Post-Retrieval Extinction: A Comparative Analysis of Unconditional and Conditional Reminders Using Skin Conductance Responses and EEG.

The post-retrieval extinction paradigm, rooted in reconsolidation theory, holds promise for enhancing extinction learning and addressing anxiety and trauma-related disorders. This study investigates the impact of two reminder types, mild US-reminder (US-R) and CS-reminder (CS-R), along with a no-reminder extinction, on fear recovery prevention in a categorical fear conditioning paradigm. Scalp EEG recordings during reminder and extinction processes were conducted in a three-day design. Results show that the US-R group exhibits a distinctive extinction learning pattern, characterized by a slowed-down yet successful process and pronounced theta-alpha desynchronization (source-located in the prefrontal cortex) during CS processing, followed by enhanced synchronization (source-located in the anterior cingulate) after shock cancellation in extinction trials. These neural dynamics correlate with the subtle advantage of US-R in the Day 3 recovery test, presenting faster spontaneous recovery fading and generally lower fear reinstatement responses. Conversely, the CS reminder elicits CS-specific effects in later episodic tests. The unique neural features of the US-R group suggest a larger prediction error and subsequent effortful conflict learning processes, warranting further exploration.

Predicting extinction limits of concurrent smoldering spread by a reduced analytical model

Smoldering is a flameless combustion mode occurring on the surface of charring fuels, such as wood and cigarettes. Although the smoldering process is slow and has a low temperature compared to flaming, it is easy to be initiated by a weak heat source and persists under poor oxygen conditions. Extensive work has been done for flame extinction to develop scaling models to predict the limiting oxygen concentration (LOC), but limited work is available for the smoldering extinction. This study develops a reduced analytical model to predict the extinction limits of smoldering. The model simultaneously solves smoldering propagation rate, surface temperature, and surface oxygen mass fraction as part of the solutions. The extinction limit is determined as the critical condition where solutions satisfying all governing equations cease to exist. The model provides a qualitative description and captures the essential characteristics of a previous experiment. The smoldering rate decreases with increasing fuel diameter, and a larger-diameter fuel is easier to extinguish. The mechanisms of the extinction process are investigated, showing the dominant role of radiative heat loss in the smothering limit at low airflow velocities and convective heat loss near the blowoff limit at high airflow velocities. Further analysis of the effect of oxygen concentration shows an increasing trend of LOC with fuel diameter, and the smothering branch cannot be predicted without considering the heat loss through radiation from the solid surface. Novelty and Significance StatementThe novelty of this research is the prediction of smoldering propagation rates and extinction limits across various fuel diameters using a reduced analytical model. The model is modified to accommodate a thin fuel configuration and high airflow velocity condition, where convective heat and mass transfer play a more important role. The model's significance is that it not only provides essential insights into the mechanisms but also has the capability to simultaneously determine key parameters such as spread rate, reaction temperatures, and surface oxygen concentration as part of the solutions. Additionally, this study demonstrates the model's ability to reproduce the limit conditions, including smothering/blowoff limits and limiting oxygen concentration (LOC).

Nature's value and biodiversity ethics in a changing world: Insights from a special issue and questions for the future

Motivated by philosophical quandaries arising from environmental ethics and the moral philosophy of biodiversity, we convened a special issue of Biological Conservation entitled “Ethics and practice of biodiversity science: how hidden moral assumptions impact conservation research and policy,” inviting a range of expert voices to examine these questions from a variety of perspectives, backgrounds, and traditions. We sought to discover how many of the founding value statements of conservation biology were still current, and if new any ones had supplemented or replaced them. Broad initial momentum from a wide range of contributors soon met with the headwinds of the COVID-19 pandemic, but we eventually emerged with 34 global contributors representing a diverse array of viewpoints. The contributed pieces range from philosophical investigations of value in Nature, applied conservation ethics for endangered species, the rights and roles of Indigenous peoples, macroevolutionary processes of mass extinction, human well-being and social justice, the history of colonialism in conservation, and subtle cultural differences between global powers with respect to Nature. All speak to often unstated values in conservation science. Finally, we offer some questions of our own stemming from these contributions that might provide new or expanded avenues for investigation.

Histamine H3 receptor activation in the insular cortex during taste memory conditioning decreases appetitive response but accelerates aversive memory extinction under an ad libitum liquid regimen

Conditioned taste aversion (CTA) is a robust associative learning; liquid deprivation during this conditioning allows researchers to obtain readable measures of associative learning. Recent research suggests that thirst could be a crucial motivator that modulates conditioning and memory extinction processes, highlighting the importance of the body’s internal state during learning. Furthermore, the histaminergic system is one of the major modulatory systems controlling several behavioral and neurobiological functions, such as feeding, water intake, and nociception. Therefore, this research aimed to assess the effect of H3 histaminergic receptor activation in the insular cortex (IC) during CTA. For this, we conditioned adult male Wistar rats under two regimens: water deprivation and water ad libitum. A classical CTA protocol was used for water deprivation. Before CTA acquisition, 10 μM R-α-methylhistamine (RAMH), an H3 receptor agonist, was injected into the IC. Results showed that RAMH injections decreased CTA in water-deprived rats without affecting the significant aversion conditioning in rats that were given water ad libitum. Moreover, RAMH accelerated the process of aversive memory extinction under ad libitum water conditions. According to our findings, the degree of liquid satiety differentially affected taste-aversive memory formation, and H3 histamine receptors were more involved under water deprivation conditions during acquisition. However, these receptors modulated the strength of aversive conditioning by altering the rate of aversive memory extinction in the absence of deprivation. In conclusion, histaminergic activity in the IC may influence taste memory dynamics through different mechanisms depending on the degree of liquid satiety or deprivation during conditioning.

A typical coastal plain taxon in central Brazil: Relationships and description of a new species of non-annual killifish (Cyprinodontiformes; Rivulidae) from the Paraná River basin

We describe a new species of the genus Atlantirivulus from a small first-order stream on the right margin of the Paraná River basin in the Mato Grosso do Sul, Brazil. The region of occurrence of the new species is known to be a hotspot for Melanorivulus species. This area, however, is approximately 700 km away from the record of occurrence of its closest congeners, which are distributed along the Brazilian coast in different hydrographic basins. Atlantirivulus enigmaticus, new species, is distinguished from all congeners by it s unique coloration, which consists of the flank being purplish grey with light green iridescence with brownish red dots scattered along of the body, by the neuromasts of the infraorbital series being aligned around eye, and by the presence of the short ventral process of the posttemporal. The phylogenetic position of the new species within the Atlantirivulus genus was based on molecular phylogenetic analysis using sequences of the mitochondrial gene cytochrome oxidase subunit 1. The results show that the new species is closely related to Atlantirivulus luelingi from the coastal drainages of the Brazilian state Santa Catarina. The phylogenetic position of the new species among congeners endemic to coastal river basins may be related to ancestral connections between coastal drainages and the Paraná River basin. The new species constitutes the westernmost record for the genus, and the first record of Atlantirivulus in the Paraná River basin. Insufficient collection efforts in areas of potential occurrence for the group and extinction processes in the broad region between the locality of the new species and the distribution areas of the remaining species may be a possible explanation for this disjunct distribution.

The extinction inventories of convents in 1834

In 1834, by Decree of 30 May and as part of the general ecclesiastical reform undertaken by Joaquim António de Aguiar, Minister and Secretary of State, and carried out by the Commission for the General Reform of the Clergy (1833-1837), all convents, monasteries, colleges, hospices and religious houses of all religious orders were extinguished, with the female houses remaining subject to their respective bishops until the death of the last nun, the date of their definitive closure. The process of extinction of religious houses involved the drawing up of hundreds of inventories currently in the Torre do Tombo National Archive. This wealth of information makes it possible to carry out countless archival, history, and art history studies associated with economic and sociological studies. In this study, we intend to focus on the inventories of the Santo André de Rendufe monastery and the Convent of Christ in Tomar. The fact that both institutions have a Benedictine character (in the first case, black monks and in the second, friars of the Order of Christ) but are located in different places in the kingdom will allow us to make comparisons, propose hypotheses and draw conclusions that may help us to understand better how the above-mentioned processes of extinction of religious houses and the collection of their archives and documentary collections were conducted.

The Tropical Andes Biodiversity Hotspot: A Comprehensive Dataset for the Mira-Mataje Binational Basins

We present a flora and fauna dataset for the Mira-Mataje binational basins. This is an area shared between southwestern Colombia and northwestern Ecuador, where both the Chocó and Tropical Andes biodiversity hotspots converge. We systematized data from 120 sources in the Darwin Core Archive (DwC-A) standard and geospatial vector data format for geographic information systems (GIS) (shapefiles). Sources included natural history museums, published literature, and citizen science repositories across 13 countries. The resulting database has 33,460 records from 6,821 species, of which 540 have been recorded as endemic, and 612 as threatened. The diversity represented in the dataset is equivalent to 10% of the total plant species and 26% of the total terrestrial vertebrate species in both hotspots. The dataset can be used to estimate and compare biodiversity patterns with environmental parameters and provide value to ecosystems, ecoregions, and protected areas. The dataset is a baseline for future assessments of biodiversity in the face of environmental degradation, climate change, and accelerated extinction processes.

Measuring local genetic variation in permethrin-resistant head lice (Phthiraptera: Pediculidae) from Buenos Aires, Argentina.

The cosmopolitan ectoparasite human head louse, Pediculus humanus capitis (De Geer)(Phthiraptera:Pediculidae), affects mostly school-aged children, with infestations reported every year mainly due to louse resistance to pyrethroids. One of the main resistance mechanisms of pyrethroids is the target site insensitivity (kdr), which is caused by single-nucleotide point mutations (SNPs) located in the voltage-sensitive sodium channel gene. In this study, we analyzed individual head lice toxicologically via the description of their susceptibility profile to permethrin and genetically through the genotypification of their kdr alleles as well as nuclear microsatellite loci. Lice were collected from 4 schools in the city of Buenos Aires, Argentina. The resistance ratios varied from 33.3% to 71.4%, with a frequency of the T917I kdr mutation of 87.31% and with 83.6% of the head lice being homozygous resistant to pyrethroids. Microsatellite data indicated that all the louse school populations had genotype proportions that deviated from Hardy-Weinberg expectations, with FIS > 0 reflecting a deficit of heterozygotes. Bottleneck analysis suggested that all louse school populations underwent a recent reduction in population sizes, while 3 of the 4 schools had gene flow values around 1, indicating ongoing gene flow among those schools. Our study suggests that school louse populations in the city of Buenos Aires may form a metapopulation, where each school represents a small population that undergoes extinction and recolonization processes under strong permethrin selection. This is the first multilevel analysis integrating toxicological, kdr-genotyping, and microsatellite data in human louse populations.

Cenozoic seeds of Vitaceae reveal a deep history of extinction and dispersal in the Neotropics.

The remarkably diverse plant communities of the Neotropics are the result of diversification driven by multiple biotic (for example, speciation, extinction and dispersal) and abiotic (for example, climatic and tectonic) processes. However, in the absence of a well-preserved, thoroughly sampled and critically assessed fossil record, the associated processes of dispersal and extinction are poorly understood. We report an exceptional case study documenting patterns of extinction in the grape family (Vitaceae Juss.) on the basis of fossil seeds discovered in four Neotropical palaeofloras dated between 60 and 19 Ma. These include a new species that provides the earliest evidence of Vitaceae in the Western Hemisphere. Eight additional species reveal the former presence of major clades of the family that are currently absent from the Neotropics and elucidate previously unknown dispersal events. Our results indicate that regional extinction and dispersal have substantially impacted the evolutionary history of Vitaceae in the Neotropics. They also suggest that while the Neotropics have been dynamic centres of diversification through the Cenozoic, extant Neotropical botanical diversity has also been shaped by extensive extinction over the past 66 million years.

ФАКТОРЫ РИСКА ПРЕЖДЕВРЕМЕННОГО СТАРЕНИЯ ЛИЦА У ЖЕНЩИН

Of course, aging is a normal physiological process of the body's extinction, while there are no unambiguously effective methods that completely stop it. However, premature aging in some ways goes beyond the norm, because with an increase in the quality and duration of life, people have a younger appearance than their ancestors at their same age. Most of all, the external signs of premature aging are expressed on the face, which is becoming a widespread problem, and a comprehensive study of this aspect is one of the burning issues of modern medical science. Goal. The study of recent studies highlighting the problem of premature aging, as well as exogenous and endogenous risk factors. The mechanisms of the development of premature aging have a multifactorial basis. The prerequisites for the development of premature aging of the face were studied, the most significant exogenous and endogenous factors that increase the risk of this pathology were considered; risk groups were identified. An analysis of past and current studies has shown that in order to predict and prevent premature aging, a variety of both conjugate and independent indicators should be taken into account. As a result of consideration of factors of various nature, unambiguous mechanisms of premature aging have not yet been established. In the future, it is necessary to study in depth the problem of early aging, as well as the relationship of all risk factors among themselves.