Extinction Processes Research Articles

Selectivity of mass extinctions: Patterns, processes, and future directions

AbstractA central question in the study of mass extinction is whether these events simply intensify background extinction processes and patterns versus change the driving mechanisms and associated patterns of selectivity. Over the past two decades, aided by the development of new fossil occurrence databases, selectivity patterns associated with mass extinction have become increasingly well quantified and their differences from background patterns established. In general, differences in geographic range matter less during mass extinction than during background intervals, while differences in respiratory and circulatory anatomy that may correlate with tolerance to rapid change in oxygen availability, temperature, and pH show greater evidence of selectivity during mass extinction. The recent expansion of physiological experiments on living representatives of diverse clades and the development of simple, quantitative theories linking temperature and oxygen availability to the extent of viable habitat in the oceans have enabled the use of Earth system models to link geochemical proxy constraints on environmental change with quantitative predictions of the amount and biogeography of habitat loss. Early indications are that the interaction between physiological traits and environmental change can explain substantial proportions of observed extinction selectivity for at least some mass extinction events. A remaining challenge is quantifying the effects of primary extinction resulting from the limits of physiological tolerance versus secondary extinction resulting from the loss of taxa on which a given species depended ecologically. The calibration of physiology-based models to past extinction events will enhance their value in prediction and mitigation efforts related to the current biodiversity crisis.

Extinction: A synthesis of disciplines for theoretical and practical advances

Abstract Extinction is a new open-access journal focused on the patterns and processes underlying the loss of biodiversity. It aims to inform conservation efforts, with a broad spatial and temporal scope. Extinction biology – the scientific study of species loss – has a long history and has recently become a more interdisciplinary and integrated field. This journal offers a unique, synthetic forum in which to present cutting-edge research and discuss its implications. This includes ecological, molecular, paleontological, and social perspectives, based on empirical data, theory, and modelling, to understand extinction processes. By tackling the big challenges, the research published in Extinction will be valuable for researchers and practitioners concerned with extinction and its role in shaping the history and future of life on Earth.

Dynamical behaviours of discrete amensalism system with fear effects on first species.

Amensalism, a rare yet impactful symbiotic relationship in ecological systems, is the focus of this study. We examine a discrete-time amensalism system by incorporating the fear effect on the first species. We identify the plausible equilibrium points and analyze their local stability conditions. The global attractivity of the positive equilibrium, $ E^* $, and the boundary equilibrium, $ E_1 $, are analyzed by exploring threshold conditions linked to the level of fear. Additionally, we analyze transcritical bifurcations and flip bifurcations exhibited by the boundary equilibrium points analytically. Considering some biologically feasible parameter values, we conduct extensive numerical simulations. From numerical simulations, it is observed that the level of fear has a stabilizing effect on the system dynamics when it increases. It eventually accelerates the extinction process for the first species as the level of fear continues to increase. These findings highlight the complex interplay between external factors and intrinsic system dynamics, enriching potential mechanisms for driving species changes and extinction events.

한국춤의 심미구조에 내재된 역학적 사유규범

The purpose of the current study is to specify the nature of Korean dance by clarifying the dynamic contemplative norm inherent in the aesthetic structure of Korean dance. The traditional styles of Korean dance conveyed a universal aesthetic view and the cognitive systems developed through dynamics have solidified the aesthetic structure of Korean dance to define the awareness of aesthetic truth. The aesthetic structure of Korean dance can be discussed in terms of the spiritual, emotional, and active structural systems. The spiritual structure is identified as the ‘spirit of dance’ where the concept of Oneness of Heaven and Men in the Book of Changes underlies as the nature of Korean dance. The emotional structure is the orientation of body and mind. The mind reflects the abstract spirit and its emotion is expressed through the body to convey the contents of dance. The active structure embodies the natural meaning of mind through the circulating process of generation and extinction of breaths. The dynamic contemplative norm inherent in the aesthetic structure is threefold: first, the contemplative norm of ‘the law of heaven, earth, and men’ explains the law of universe and nature and specifies the natural principle of Korean dance as a ‘metaphysical law’ to conceptualize the property of space through the generation and change of universe and humankind. Second, the contemplative norm of ‘law of change’ is specified in terms of time and space in the phrase, ‘the law of one ying and one yang,’ and interprets the law of Yixue in terms of time and space. Third, the contemplative norm of ‘law of sun and moon’ is specified in terms of time in the phrase, ‘endlessly created universe’ and clarifies the property of time through yin and yang, the law of universe.

The image of mangurt in the story ‘Grey Fierce’ (Kokserek) by M. Auezov

The article reveals the theme of mankurtising through the story of Mukhtar Auezov's “Kökserek”. Mankurtization is the loss of self-values of the individual and ontologically falling into the existential void of the individual. This decline is seen in the form of alienation of the individual from himself and the values of the society in which he lives. Mankurtization is a process of extinction in which the individual enters unconsciously Mancurtization is a process of extinction, into which an individual enters unconsciously. Under the totalitarian system, they tried to erase the ideological space of the Turkic peoples. In Soviet times, the transformation(policy of mancurtization) of a wolf (Turks) into a dog (slave) was carried out. Mukhtar Auezov uses a wolf as a symbol of this event. The study used methods of comparative analysis, discursive analysis, content analysis. As a result, the authors conclude that the image of ‘wolf’ symbolizes freedom, national values and spiritual strength of the Turkic people.

Brassica seed meal fumigation restores beneficial bacterial communities by enriching taxa with high resistance and resilience

PurposeBrassica seed meals (BSMs) are widely used as biofumigants to control various soil-borne plant diseases. However, the mechanism of bacterial community reconstruction following fumigation with BSMs remains poorly understood.MethodsIn the present study, to decipher the mechanism of bacterial community reconstruction in fumigated soil and to understand the effect of bacterial communities in fumigated soil on rhizosphere recruitment and subsequent disease control, we investigated the bulk soil and rhizosphere bacterial communities using field experiments in soils treated with various fumigants (Brassica campestris seed meal, Brassica juncea seed meal, and the chemical fumigant dazomet) in two greenhouses subsequently used to grow tomato and cantaloupe, respectively.ResultsThis study revealed that bulk soil bacterial community composition changed significantly after fumigation extinction and recovery. Firmicutes and Proteobacteria, showing high resistance and resilience in the extinction and recovery processes, respectively, represented the key microorganisms for community reconstruction and rhizosphere recruitment. Moreover, nutrients supplied by BSMs, especially available phosphorus (AP), in fumigated soils determined the post-restoration changes in bacterial community composition. Additionally, BSMs showed greater potential than chemical fumigant dazomet in rebuilding beneficial bacterial communities and controlling potential soil pathogens by enriching gram-positive phyla Firmicutes and Actinobacteria and their respective affiliated genera Bacillus and Streptomyces.ConclusionThese results provide a fundamental ecological understanding of the response of soil-inhabiting microbes to fumigation and the reconstruction of soil beneficial bacterial communities after BSM fumigation. Thus, this study improves the understanding of the effects of biofumigants on soil-borne plant disease control in agriculture.

Current overlapping distribution of megaherbivores and top predators: An approach to the last terrestrial areas with ecological integrity

The Earth's wildlife is facing a new, fast and huge extinction process due to the impact of humans. This scenario not only affects the biodiversity itself but also the capacity of the ecosystems to retain their structure and functions. The roles of megaherbivores and top predators are crucial for ecosystem ecological integrity and key in many eco-evolutionary processes. We provide a global overview of the current ecological integrity of terrestrial surfaces, built through an inventory of the areas that still preserve their integral community of megaherbivores and top predators. The targeted species were the taxa present during the upper Holocene, which represents the ecological scenario before the current biodiversity crisis caused by humans. We established the ecosystem's ecological integrity by mapping the areas where all targeted taxa are currently present. We used the maps provided by the Red List of the International Union for Conservation of Nature and the information obtained through a bibliography review for the former distribution ranges to build the cartography. We identified 81 areas with a full community of megaherbivores and top predators, most of which are very small in size (<10.000 km2). Only eco-regions that have the lowest species diversity have large patches of ecological integrity, mostly overlapping with large areas of Intact Forest Landscapes. Overall, 15.8 % of the Earth's terrestrial surfaces currently retain their target taxa. Our results are an important complement for the available maps of ecosystem ecological integrity, since we offer a detailed global inventory of key areas for conservation of functional wildlife.

Ilyocyprisleptolinea Wang & Zhai, sp. nov., an ostracod (Ostracoda, Crustacea) from the late Quaternary of Inner Mongolia, northern China.

Ilyocyprisleptolinea Wang & Zhai, sp. nov. is described from late Quaternary sediments in central-eastern Inner Mongolia, northern China. The new species, which has a carapace shape and pitted surface typical of the genus, is characterised by double rows of fine, densely arranged marginal ripplets, separated by an inner list, along both anterior and posterior calcified inner lamellae in the left valve. Outline analysis and Principal Component Analysis indicate that its morpho-space overlaps with I.bradyi Sars, 1890, I.japonica Okubo, 1990, and I.mongolica Martens, 1991, which have living or fossil representatives in Inner Mongolia, but it is clearly discriminated from I.innermongolica Zhai & Xiao, 2013. Judging from the relatively coarse lithology dominated by silt and sand, and the lack of accompanying brackish-water ostracods, I.leptolinea Wang & Zhai, sp. nov. may have lived in a relatively shallow freshwater lake. It perhaps can be added to the list of species that went extinct during the Quaternary, but the timing and process of extinction await further investigation.

Nearby large islands diminish biodiversity of the focal island by a negative target effect.

The Equilibrium Theory of Island Biogeography postulates that larger and closer islands support higher biodiversity through the dynamic balance of colonization and extinction processes. The negative diversity-isolation (i.e. the distance to the mainland) relationship is derived based on the assumption that the mainland is the only source pool for island biotas. However, nearby islands could also act as species sources for focal islands via a source effect. In this study, we move a further step and hypothesize that nearby islands may reduce bird colonizers of the focal island and diminish its biodiversity, resulting in a negative target effect. To test our hypothesis, we assessed the effects of island area and isolation (metrics considering both the mainland and nearby islands) on taxonomic (i.e. species richness), functional and phylogenetic diversity of terrestrial breeding birds on 42 islands in the largest archipelago of China, the Zhoushan Archipelago. Furthermore, we compared the predictive power of the distance to the large island under a set of relative area thresholds and the relative area of nearby islands on species richness under a set of distance thresholds to explore the role of nearby islands as a source and/or target island. We found that island area had a positive effect on species richness, phylogenetic diversity and functional diversity, while the distance to the mainland had a negative effect only on species richness. Species richness on the focal island increased with increasing distance to the nearest larger island, indicating the negative target effect. Furthermore, the negative target effect depended on the area of nearby islands relative to the area of the focal island. Our finding of the negative target effect suggests islands located between the mainland and the focal island can be not only sources or stepping stones, but also colonization targets. This result demonstrates the importance of considering multiple geographical attributes of islands in island biogeographic studies, especially the characteristics related to source and/or target effects.

The Nazi Concentrationary Machine. The Human Body between Tearing and Annihilation in La Part du fils by Jean-Luc Coatelem

This article aims to explore the representation of the human body and its metamorphoses during the Second World War. The material on which the present analysis relies is provided by Jean-Luc Coatalem’s novel La part du fils (2019), a narrative approaching and insisting on the idea of the human being as a convict trapped between destruction, body decomposition, and alienation. Committed to his sense of moral and familial duty, the narrator starts his investigation to reconstruct his grandfather’s identity, annihilated in a German concentration camp. His fruitful research delivers material rich in details about the practices of the Nazi system and particularly about the concentration machine. Unjustified arrests, the detention of those considered dangerous to the system, deportation, forced labour, violence, starvation, and sleep deprivation become agents of metamorphosis in the carceral space where most of the captives have been annihilated. Accordingly, our analysis aims, on the one hand, to expose war in its most detailed form and the whole process referring to arrest, imprisonment, and forced labour. On the other hand, the analysis focuses on the functional Nazi mechanism to reveal the human being in the complete process of extinction, specifically through physical destruction, alienation or, more frequently, a fusion of both.

Half-millennium evidence suggests that extinction debts of global vertebrates started in the Second Industrial Revolution

Extinction debt describes the time-lagged process of species extinction, which usually requires dozens to hundreds of years to be paid off. However, due to the lack of long-term habitat data, it is indeterminate how strong the signal of extinction debts is at the global scale and when the debts started. Here, by compiling the geographical distributions of 6120 reptiles, 6047 amphibians, and 4278 mammals and correlating them with annual forest cover data from 1500 to 1992, we show that the beginning of the Second Industrial Revolution (the mid-19th century) was the earliest signal of cumulative extinction debts for global forest-dwelling vertebrate groups. More importantly, the impact of global protected areas on mitigating accumulated vertebrate extinction debt is not as immediate as that of mitigating reduced forest cover but rather suffers from pronounced time-lag effects. As the disequilibrium of vertebrate richness and forested habitat is currently taking place, preventive actions should be taken to promote a well-balanced status among forest restoration, protected areas, and biodiversity conservation to slow the accumulating debts for global forest-dwelling vertebrates.

Are you looking or looking away? Visual exploration and avoidance of disgust- and fear-stimuli: An eye-tracking study.

The present eye-tracking study investigates whether individuals with different levels of contamination fear are more likely to focus their attention on disgusting stimuli to explore them or to pull their attention away to avoid them. Ninety-two nonclinical participants with varying degrees of contamination fear performed a dot probe task. Eye-tracking methodology was employed to record gaze patterns during the task. In each trial participants looked at two pictures (disgust-neutral, fear-neutral, or neutral-neutral). Participants were further asked about the contents of the picture and the confidence of their answer. The results show that reaction times were slower and fixations were longer and more frequent for disgust targets compared with fear and neutral targets, which was further amplified in individuals with high contamination fear. However, image details of disgusting pictures were remembered less correctly than details of fearful pictures. These findings confirm the idea that attention on disgusting stimuli is maintained. Further, the findings indicate that disgust is processed more superficially and might also be related to disgust-associated uncertainty and ambiguity. The results may help to understand the difficult-to-change nature of disgust, which could be relevant to habituation and extinction processes in exposure therapy. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Current Trends and Approaches to the Search for Genetic Determinants of Aging and Longevity.

The online version contains supplementary material available at 10.1134/S1022795422120067.

Three-dimensional hybrid simulation of vacuum arc extinction considering dynamic behavior of cathode spots

Vacuum arc extinction directly determines the plasma distribution at the current zero point, which affects the post-arc insulation recovery. In that regard, studying the extinction process to improve the post-arc insulation recovery ability is of great significance. In the extinction process, as the current decreases, cathode spots are extinguished and their distribution exhibits apparent discreteness and asymmetry, while the plasma density decays drastically. On the one hand, the discreteness of cathode spots makes the simulation setup regarding the whole cathode surface as a continuous emission source no longer applicable. On the other hand, the drastic decay of plasma density requires a simulation tool that can balance the computational efficiency and accuracy of the extinction process. To deal with these problems, the dynamic behavior of cathode spots is considered in this paper, and a three-dimensional hybrid plasma model is established. In order to simulate a more realistic situation, two applied axial magnetic field configurations for practical applications—bell-shaped and saddle-shaped configurations—are introduced. Both configurations are used to compare the position distribution and extinguishing sequence of cathode spots, as well as the evolution of plasma. More importantly, the method applied in this study can be employed to evaluate the effect of different magnetic field conditions on vacuum interruption, which would enable one to simulate the extinction process in a realistic manner.

P105 Women with greater post-traumatic stress symptom severity and less disrupted sleep have improved fear extinction recall compared to men

Abstract Sleep has been found to play a key role in fear conditioning, extinction learning and extinction recall, the paradigm modelling the development, maintenance and treatment of anxiety disorders including post-traumatic stress disorder (PTSD), which are disorders commonly associated with sleep disturbances. Previous studies examining associations between sleep and fear or extinction processes predominately focused on objectively measured sleep architecture using polysomnography, and the majority of the research has been done in healthy populations. To date, little research has focused on subjective sleep measures and particularly in clinical populations including PTSD, which often experience subjectively poor sleep. Here we investigated whether subjective sleep disturbance, sleep onset latency, wake after sleep onset or sleep efficiency were related to fear conditioning, extinction learning or extinction recall in a large sample of individuals with a range of PTSD symptom severity and healthy controls. Overall, we did not find that sleep was associated with fear conditioning extinction learning or extinction recall. However, emerging evidence highlighting the critical role of sex in PTSD risk, fear conditioning processes, as well as in the sleep-fear conditioning relationship. Exploratory analyses examining sex-specific effects found that shorter sleep onset latency and greater sleep efficiency during the previous night were associated with improved extinction recall in women with higher PTSD symptom severity. This suggests that less time falling asleep and longer time asleep while in bed may be protective against the commonly observed impaired extinction recall in PTSD in highly symptomatic women, but is not relevant in men.

Sex differences in the effect of subjective sleep on fear conditioning, extinction learning, and extinction recall in individuals with a range of PTSD symptom severity

Sleep has been found to play a key role in fear conditioning, extinction learning and extinction recall, and sleep disturbances are linked to many mental disorders including post-traumatic stress disorder (PTSD). Previous studies examining associations between sleep and fear or extinction processes primarily focused on objectively measured sleep architecture. Little research has so far focused on subjective sleep measures and particularly in clinical populations, which often experience subjectively poor sleep, including PTSD. Here we investigated whether subjective sleep disturbance, sleep onset latency, wake after sleep onset or sleep efficiency were related to fear conditioning, extinction learning or extinction recall in a large sample of individuals with a range of PTSD symptom severity (n = 248). Overall, we did not find that subjective sleep was associated with fear conditioning or extinction processes. However, exploratory analyses examining the moderating effect of sex found that shorter sleep onset latency and greater sleep efficiency were associated with improved extinction recall in women with higher PTSD symptom severity. This suggests that less time falling asleep and longer time asleep while in bed may be protective in highly symptomatic women against the commonly observed impaired extinction recall in PTSD. More studies are needed to explore sex-specific effects further.

Locus coeruleus input-modulated reactivation of dentate gyrus opioid-withdrawal engrams promotes extinction.

Extinction training during the reconsolidation window following memory recall is an effective behavioral pattern for promoting the extinction of pathological memory. However, promoted extinction by recall-extinction procedure has not been universally replicated in different studies. One potential reason for this may relate to whether initially acquired memory is successfully activated. Thus, the methods for inducing the memory into an active or plastic condition may contribute to promoting its extinction. The aim of this study is to find and demonstrate a manipulatable neural circuit that engages in the memory recall process and where its activation improves the extinction process through recall-extinction procedure. Here, naloxone-precipitated conditioned place aversion (CPA) in morphine-dependent mice was mainly used as a pathological memory model. We found that the locus coeruleus (LC)-dentate gyrus (DG) circuit was necessary for CPA memory recall and that artificial activation of LC inputs to the DG just prior to initiating a recall-extinction procedure significantly promoted extinction learning. We also found that activating this circuit caused an increase in the ensemble size of DG engram cells activated during the extinction, which was confirmed by a cFos targeted strategy to label cells combined with immunohistochemical and in vivo calcium imaging techniques. Collectively, our data uncover that the recall experience is important for updating the memory during the reconsolidation window; they also suggest a promising neural circuit or target based on the recall-extinction procedure for weakening pathological aversion memory, such as opioid withdrawal memory and fear memory.

A Systematic Review of Fear Learning, Extinction Learning, and Reversal Learning in Obsessive-Compulsive Disorder: Implications for Treatment.

Objective: Given the implications in the etiology and treatment of obsessive-compulsive disorder (OCD), this systematic review examined fear acquisition, extinction learning, and reversal learning processes in individuals with OCD.Data Sources: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, PubMed (1946-October 26, 2021), PsycInfo, and Embase were searched for empirical studies utilizing classical or reversal learning paradigms to compare learning and extinction processes in individuals with and without OCD.Study Selection: A total of 15,603 articles (7,761 from PubMed, 1,128 from PsycInfo, 6,711 from Embase, 3 from citation review) were identified. Articles were screened for duplicates and inclusion/exclusion criteria. Eleven studies met all inclusion/exclusion criteria.Results: Across studies, minimal evidence of abnormal fear learning was found. However, developmental differences emerged for extinction learning. Youth with OCD displayed impaired extinction learning and safety signal discrimination. Meanwhile, adults largely showed deficits in extinction recall. Conflicting findings emerged regarding impairments in reversal learning. Across learning processes, neuroimaging data implicated the importance of the ventromedial prefrontal cortex (vmPFC).Conclusions: The physiological and neuroimaging data suggest that extinction learning impairment varies across development. Notably, key associative learning processes remain largely unexamined. Findings underlying abnormalities in extinction learning suggest the potential of novel therapeutic approaches, such as neuromodulation and psychotherapy augmentation strategies (ie, attention bias modification training), to precisely target and resolve identified deficits.

Manifesto: Fertilizing mourning – Global South’s offering to a world in flames

This manifesto takes the coincidence of Peru’s and Greece’s bicentennials of independence, and their overlap with the COVID-19 pandemic, as a departure point, in order to propose a different understanding of mourning from the Global South. The article is an open invitation to reinforce mourning’s capacity to be a reproductive life force, responding to contemporary experiences of loss in the face of the COVID-19 pandemic and the accelerated processes of extinction, especially in resource extraction zones, like the Amazon. Taking inspiration from ancient Indigenous techniques for soil regeneration, fertilizing mourning is a call to merge traditional knowledge, collective practices and non-anthropocentric world-views that resist individualism and capitalism both in the Global South and in places that defend communal life in the north of the planet. This manifesto proposes that to transform prevalent colonial, modern structures, it is necessary to develop a different relationship with nature, by reconsidering the entanglements between life, death and regeneration.

Mapping species diversification metrics in macroecology: Prospects and challenges

The intersection of macroecology and macroevolution is one of today’s most active research in biology. In the last decade, we have witnessed a steady increment of macroecological studies that use metrics attempting to capture macroevolutionary processes to explain present-day biodiversity patterns. Evolutionary explanations of current species richness gradients are fundamental for understanding how diversity accumulates in a region. Although multiple hypotheses have been proposed to explain the patterns we observe in nature, it is well-known that the present-day diversity patterns result from speciation, extinction, colonization from nearby areas, or a combination of these macroevolutionary processes. Whether these metrics capture macroevolutionary processes across space is unknown. Some tip-rate metrics calculated directly from a phylogenetic tree (e.g., mean root distance -MRD-; mean diversification rate -mDR-) seem to return very similar geographical patterns regardless of how they are estimated (e.g., using branch lengths explicitly or not). Model-based tip-rate metrics —those estimated using macroevolutionary mixtures, e.g., the BAMM approach— seem to provide better net diversification estimates than only speciation rates. We argue that the lack of appropriate estimates of extinction and dispersal rates in phylogenetic trees may strongly limit our inferences about how species richness gradients have emerged at spatial and temporal scales. Here, we present a literature review about this topic and empirical comparisons between select taxa with several of these metrics. We implemented a simple null model approach to evaluate whether mapping of these metrics deviates from a random sampling process. We show that phylogenetic metrics by themselves are relatively poor at capturing speciation, extinction, and dispersal processes across geographical gradients. Furthermore, we provide evidence of how parametric biogeographic methods can improve our inference of past events and, therefore, our conclusions about the evolutionary processes driving biodiversity patterns. We recommend that further studies include several approaches simultaneously (e.g., spatial diversification modeling, parametric biogeographic methods, simulations) to disentangle the relative role of speciation, extinction, and dispersal in the generation and maintenance of species richness gradients at regional and global scales.