Extinction Research Articles

Predicting the responses of European grassland communities to climate and land cover change.

European grasslands are among the most species-rich ecosystems on small spatial scales. However, human-induced activities like land use and climate change pose significant threats to this diversity. To explore how climate and land cover change will affect biodiversity and community composition in grassland ecosystems, we conducted joint species distribution models (SDMs) on the extensive vegetation-plot database sPlotOpen to project distributions of 1178 grassland species across Europe under current conditions and three future scenarios. We further compared model accuracy and computational efficiency between joint SDMs (JSDMs) and stacked SDMs, especially for rare species. Our results show that: (i) grassland communities in the mountain ranges are expected to suffer high rates of species loss, while those in western, northern and eastern Europe will experience substantial turnover; (ii) scaling anomalies were observed in the predicted species richness, reflecting regional differences in the dominant drivers of assembly processes; (iii) JSDMs did not outperform stacked SDMs in predictive power but demonstrated superior efficiency in model fitting and predicting; and (iv) incorporating co-occurrence datasets improved the model performance in predicting the distribution of rare species. This article is part of the theme issue 'Ecological novelty and planetary stewardship: biodiversity dynamics in a transforming biosphere'.

A new species of Eocene soldier beetle, a Malthodes (Coleoptera: Cantharidae: Malthininae) in Baltic amber

ABSTRACT A new species of soldier beetle (Cantharidae) from Eocene Baltic amber, Malthodes maierae sp. nov., is described and illustrated from a male specimen discovered in Russia. The new species differs from the hundreds of known extant and extinct species of Malthodes Kiesenwetter, 1852. The last abdominal segments, which are substantially modified on the male to hold the female during mating, differ considerably in Malthodes species and are very important diagnostic elements for this genus. The exact evolutionary forces driving these manifold modifications are unknown, but they are likely related to sexual selection, mate recognition, antagonistic coevolution, or varying habitats, or a combination of these factors. The Zoobank LSID for this is: urn:lsid:zoobank.org:pub:DC13FC31-BD71-4C3D-9536-B70AF65FB699

Germination niche of co-occurring threatened native and alien species: a case study in Lindernia procumbens and L. dubia

AbstractPlant invasions have a negative impact on biodiversity and lead to species loss. Although studies on traits promoting invasiveness have been largely developed, comparative studies on germination traits of closely related native versus alien invasive species, which also take into account threatened species, are lacking. We analysed the germination requirements of two congeneric Lindernia species inhabiting paddy field in Northern Italy. Germination tests were conducted exposing seeds of both species across a broad range of temperature and conditions (i.e., cold-wet stratification, dark condition, alternate temperature, gibberellic acid). The invasive L. dubia showed higher and faster germination, occurring over a broader range of temperatures compared to the native threatened L. procumbens, along with a lighter non-deep physiological dormancy. These results show a competitive advantage of the alien species already in the early stages of plant regeneration and provide a comprehensive overview of the germination requirements, necessary for the development of future conservation and management plans.

Preventing Loss of Animal Species Under Human-Caused Climate Change

Preventing Loss of Animal Species Under Human-Caused Climate Change

The global pattern of epiphytic liverwort disparity: insights from Frullania

The geographical and ecological patterns of morphological disparity are crucial to understand how species are assembled within communities in the context of the evolutionary history, morphological evolution and ecological interactions. However, with limited exceptions, rather few studies have been conducted on the global pattern of disparity, particularly in early land plants. Here we explored the spatial accumulation of disparity in a morphologically variable and species rich liverwort genus Frullania in order to test the hypothesis of latitude disparity gradient. We compiled a morphological data set consisting of eight continuous traits for 244 currently accepted species, and scored the species distribution into 19 floristic regions worldwide. By reconstructing the morphospace of all defined regions and comparisons, we identified a general Gondwana-Laurasia pattern of disparity in Frullania. This likely results from an increase of ecological opportunities and / or relaxed constraints towards low latitudes. The lowest disparity occurred in arid tropical regions, largely due to a high extinction rate as a consequence of paleoaridification. There was weak correlation between species diversity and disparity at different spatial scales. Furthermore, long-distance dispersal may have partially shaped the present-day distribution of Frullania disparity, given its frequency and the great contribution of widely distributed species to local morphospace. This study not only highlighted the crucial roles of paleoenvironmental changes, ecological opportunities, and efficient dispersal on the global pattern of plant disparity, but also implied its dependence on the ecological and physiological function of traits.

Managing Forests for Biodiversity Conservation and Climate Change Mitigation.

We include biodiversity impacts in forest management decision making by incorporating the countryside species area relationship model into the partial equilibrium model GLOBIOM-Forest. We tested three forest management intensities (low, medium, and high) and limited biodiversity loss via an additional constraint on regional species loss. We analyzed two scenarios for climate change mitigation. RCP1.9, the higher mitigation scenario, has more biodiversity loss than the reference RCP7.0, suggesting a trade-off between climate change mitigation, with increased bioenergy use, and biodiversity conservation in forests. This trade-off can be alleviated with biodiversity-conscious forest management by (1) shifting biomass production destined to bioenergy from forests to energy crops, (2) increasing areas under unmanaged secondary forest, (3) reducing forest management intensity, and (4) reallocating biomass production between and within regions. With these mechanisms, it is possible to reduce potential global biodiversity loss by 10% with minor changes in economic outcomes. The global aggregated reduction in biodiversity impacts does not imply that biodiversity impacts are reduced in each ecoregion. We exemplify how to connect an ecologic and an economic model to identify trade-offs, challenges, and possibilities for improved decisions. We acknowledge the limitations of this approach, especially of measuring and projecting biodiversity loss.

Weaving feathers of intangible and tangible knowledge: Historical records and human‐bird interactions in the Marquesas Islands

AbstractBirds fulfilled an essential role in ancient Polynesian cultures. They were prized for their bones and colourful feathers, fat, and protein; their cultural importance is further highlighted in Polynesian oral histories. This research investigates the dynamics of human‐bird interactions over time in the Marquesas Archipelago as known from archaeology, oral histories, ethnohistorical records, and museum collections. I analyse the range of avian taxa represented across the various datasets and their cultural uses. The results demonstrate that while some species are represented across one or more datasets, understanding the full extent of species’ cultural roles and use requires more than one thread of analysis, particularly for those taxa with limited or no archaeological signature. Two forms of managed resource use emerge from this study. One is tapu (prohibition of use), and the second is the conservative use of birds as a resource such as restricted feather collecting. Red feathers, represented in museum objects and historical accounts, highlight multiple taxa being used for specific adornment types. The combined analyses provide insights into the loss and persistence of species, as well as aspects of Marquesan cultural management.

The rediscovery of a relict unlocks the first global phylogeny of whip spiders (Amblypygi).

Asymmetrical rates of cladogenesis and extinction abound in the Tree of Life, resulting in numerous minute clades that are dwarfed by larger sister groups. Such taxa are commonly regarded as phylogenetic relicts or "living fossils" when they exhibit an ancient first appearance in the fossil record and prolonged external morphological stasis, particularly in comparison to their more diversified sister groups. Due to their special status, various phylogenetic relicts tend to be well-studied and prioritized for conservation. A notable exception to this trend is found within Amblypygi ("whip spiders"), a visually striking order of functionally hexapodous arachnids that are notable for their antenniform first walking leg pair (the eponymous "whips"). Paleoamblypygi, the putative sister group to the remaining Amblypygi, is known from Late Carboniferous and Eocene deposits, but is survived by a single living species, Paracharon caecus Hansen, 1921, that was last collected in 1899. Due to the absence of genomic sequence-grade tissue for this vital taxon, there is no global molecular phylogeny for Amblypygi to date, nor a fossil-calibrated estimation of divergences within the group. Here, we report a previously unknown species of Paleoamblypygi from a cave site in Colombia. Capitalizing upon this discovery, we generated the first molecular phylogeny of Amblypygi, integrating ultraconserved element sequencing with legacy Sanger datasets and including described extant genera. To quantify the impact of sampling Paleoamblypygi on divergence time estimation, we performed in silico experiments with pruning of Paracharon. We demonstrate that the omission of relicts has a significant impact on the accuracy of node dating approaches that outweighs the impact of excluding ingroup fossils, which bears upon the ancestral range reconstruction for the group. Our results underscore the imperative for biodiversity discovery efforts in elucidating the phylogenetic relationships of "dark taxa", and especially phylogenetic relicts in tropical and subtropical habitats. The lack of reciprocal monophyly for Charontidae and Charinidae leads us to subsume them into one family, Charontidae, new synonymy.

Evaluating dynamic tree-species-shifting and height development caused by ungulate browsing in forest regeneration using a process-based modeling approach

Ungulate browsing can prevent the successful regeneration and development of forest-owner-intended and climate-resilient admixed tree species, compromising the future provision of multiple ecosystem services. A reduction of the height increment of palatable tree species caused by ungulate browsing results in a competition shift in favor of less palatable species. While this key process of losing admixed tree species is well understood, forest growth models have not yet captured its full complexity. Therefore, our objectives were to simulate (i) the loss of susceptible tree species from different browsing regimes and its impact on stand development, (ii) changes in the height increment of saplings and trees, and (iii) the shifts in social status during stand development without pre-defined limits a sapling can resist browsing. To address these objectives, we used the process-based model iLand to simulate the exposure of Norway spruce, Silver fir, and European beech stands to varying browsing densities. We successfully reproduced expected dynamic shifts in species composition and height development 24 years after establishment, depending on ungulate pressure and species-specific competitive strength. Stand composition and growth differences already occur with slight changes in ungulate density. When saplings remained in stand structure, independent of the number being browsed, our results led to more individuals with substantially smaller dimensions. We found that dynamic tree species shifting can be simulated realistically by a process-based modeling approach, which can be used to show the strong impact of ungulates on stand development.

Extinction selectivity obscures patterns of trait‐dependent endangerment in Columbiformes

AbstractAimUnderstanding how extinction has occurred in the recent past is crucial to unravel its main drivers as well as to implement effective conservation practices to minimize global biodiversity loss. It has long been hypothesized that extinction risk is not randomly distributed among traits of species. However, the actual traits making species more prone to extinction may have been overlooked because already extinct species are often not considered in comparative analyses of extinction risk. We characterized the drivers of extinction in a cosmopolitan bird clade, including Holocene and contemporary extinctions potentially related to human impacts and provided evidence of an ‘extinction selectivity’ in species traits.LocationGlobal.Time periodAnthropocene.Major taxa studiedColumbiformes clade, pigeons and doves.MethodsWe constructed a new phylogenetic hypothesis of the Columbiformes, a cosmopolitan bird clade consisting of 33 recently extinct and 351 extant species. Then, we integrated data on geography, behaviour and morphology to reveal the drivers of extinction risk. We used phylogenetic generalized least square models to test the effect of geography, behaviour and morphology in the risk of extinction and identified differences in the drivers of extinction when including versus excluding recently extinct species.ResultsOur analysis revealed that Columbiformes endemic to islands with ground‐foraging habits, weak flying abilities, migratory behaviour and larger body sizes are more vulnerable to extinction. Our results also show that excluding recently extinct species identifies extinction drivers different from those when including recently extinct species.Main conclusionsOnly by accurately identifying the traits that increase extinction risk we can develop targeted conservation measures that promote the long‐term persistence of threatened species. Extinction selectivity has important implications for the conservation of biological communities and ultimately ecosystem functioning, considering the critical role Columbiformes often play as seed dispersers.

Neoliberalism, World-System Position, and Biodiversity Loss

Several studies provide evidence that social, economic, political, and conservation-related factors impact cross-national biodiversity loss. One theoretical argument concerning biodiversity loss that has not been directly assessed involves the relationship between species loss and neoliberalism. Generally, neoliberalism promotes free markets. This has become a dominant philosophy across nations (though the strength of neoliberalism varies cross-nationally) and affects how nations interact with one another as resource users and providers. Given how neoliberal policies work to integrate nations into a single global capitalist economy, we assess neoliberalism’s effects on threatened species alongside a nation’s position in the global world-system. The current study examines nine sets of negative binomial regression models analyzing the effect of neoliberalism, world-system position, and a set of control variables on species biodiversity loss across a sample of 104 countries for which all relevant data were available. We find some support that neoliberalism increases biodiversity loss in fully assessed species (birds and amphibians). We also find support for the hypothesis that there is more biodiversity loss in the periphery and semi-periphery of the world-system (compared with core countries) in fully assessed threatened species. We argue that the results support previous research showing the sociological drivers of biodiversity loss.

Interactive effects of drought and deforestation on multitrophic communities and aquatic ecosystem functions in the Neotropics-a test using tank bromeliads.

Together with the intensification of dry seasons in Neotropical regions, increasing deforestation is expected to exacerbate species extinctions, something that could lead to dramatic shifts in multitrophic communities and ecosystem functions. Recent studies suggest that the effects of habitat loss are greater where precipitation has decreased. Yet, experimental studies of the pure and interactive effects of drought and deforestation at ecosystem level remain scarce. Here, we used rainshelters and transplantation from rainforest to open areas of natural microcosms (the aquatic ecosystem and microbial-faunal food web found within the rainwater-filled leaves of tank bromeliads) to emulate drought and deforestation in a full factorial experimental design. We analysed the pure and interactive effects of our treatments on functional community structure (including microorganisms, detritivore and predatory invertebrates), and on leaf litter decomposition in tank bromeliad ecosystems. Drought or deforestation alone had a moderate impact on biomass at the various trophic level, but did not eliminate species. However, their interaction synergistically reduced the biomass of all invertebrate functional groups and bacteria. Predators were the most impacted trophic group as they were totally eliminated, while detritivore biomass was reduced by about 95%. Fungal biomass was either unaffected or boosted by our treatments. Decomposition was essentially driven by microbial activity, and did not change across treatments involving deforestation and/or drought. Our results suggest that highly resistant microorganisms such as fungi (plus a few detritivores) maintain key ecosystem functions in the face of drought and habitat change. We conclude that habitat destruction compounds the problems of climate change, that the impacts of the two phenomena on food webs are mutually reinforcing, and that the stability of ecosystem functions depends on the resistance of a core group of organisms. Assuming that taking global action is more challenging than taking local-regional actions, policy-makers should be encouraged to implement environmental action plans that will halt habitat destruction, to dampen any detrimental interactive effect with the impacts of global climate change.

Ancient mitogenomes reveal evidence for the Late Miocene dispersal of mergansers to the Southern Hemisphere

Abstract Mergansers are riverine and coastal piscivorous ducks that are widespread throughout North America and Eurasia but uncommon in the Southern Hemisphere. One species occurs in South America and at least two extinct species are known from New Zealand. It has been proposed that these Southern Hemisphere merganser lineages were founded by at least two independent dispersal events from the Northern Hemisphere. However, some morphological and behavioural evidence suggests that Southern Hemisphere mergansers may form a monophyletic clade that descended from only a single dispersal event from the Northern Hemisphere. For example, Southern Hemisphere mergansers share several characteristics that differ from Northern Hemisphere mergansers (e.g. non-migratory vs. migratory, sexual monochromatism vs. sexual dichromatism, long vs. short pair bonds). We sequenced complete mitogenomes from the Brazilian merganser and an extinct merganser from New Zealand—the Auckland Island merganser. Our results show that the Brazilian and Auckland Island mergansers are not sister-taxa, and probably descend from two separate colonization events from the Northern Hemisphere at least 7 Mya. Nuclear (palaeo)genomic data may help to further resolve the relationship between living and extinct mergansers, including merganser fossils from New Zealand that have not been subjected to palaeogenetic analysis.

Creativity in Health Communication to Promote Blood Lead Testing in Children.

Low rates of blood lead level screening among young children persist as a public health issue in the United States, including in Texas where levels remain below the national average. This article describes a multiyear, multipartner initiative aimed at increasing screening rates through a creative, community-informed social media campaign. Interviews with parents, providers, and state health department staff revealed a common perception that lead poisoning was a relic of the past. Using these insights, the team developed humorous social media messaging comparing extinct animals to lead poisoning to capture attention and change attitudes about lead's current relevance. The "#GetLeadCheckedTexas" campaign ran on state health department channels during National Lead Poisoning Prevention Week in October 2020. Colorful graphics depicted extinct creatures like dinosaurs along with their babies, playing on childhood enthusiasm for such animals while evoking protective feelings in parents. Messaging highlighted lead's dangers for young children and encouraged viewers to discuss testing with providers. Website analytics showed the campaign drove substantial increases in page views for lead screening resources, particularly among providers. While originally designed with a parent audience in mind, the campaign seemed to resonate more with providers, likely due to timing during an awareness week and use of official health department channels. The initiative demonstrates the value of creative communications approaches employed in traditional advertising to raise awareness and promote public health priorities. Audience research, thoughtful use of humor, and designing human-focused messaging helped cut through information clutter and drive engagement with an important childhood health issue.

Testing seed germination from herbaria: Application of seed quality enhancement techniques and implication for plant resurrection and conservation

AbstractHerbaria are an important source of data and material useful in many fields, including plant conservation. Seeds preserved in herbarium specimens may have the potential to germinate, although few studies focused on this topic. Here, the first systematic assessment of six techniques, including priming techniques and melatonin application, aimed at improving the germination of seeds from herbarium specimens is presented. Seed germination of 26 species common in Europe, some of which congeneric to extinct species, collected in herbaria and in the wild (20,549 seeds in total, including 19,509 from 297 herbarium specimens from 8 different herbaria) was tested with the following treatments: exogenous melatonin addition to the germination medium, priming with melatonin, osmopriming, hydropriming for 24 and 48 hours, standard soil, heat sterilization and gibberellins addition. More than 85% of the fresh seeds and 1% of the seeds collected in herbaria germinated, including seeds older than 50 years. Data show that treatment with exogenous melatonin had a positive effect on the germination of fresh seeds, but a negative effect on the germination of herbarium‐derived seeds. Furthermore, osmopriming treatment had a slightly positive effect on the germination of herbarium‐derived seeds. Osmopriming and exogenous melatonin addition seem to be promising techniques that need further investigation and improvement and might be useful for the development of an optimal germination protocol for old and herbarium‐derived seeds. The germination of seeds from herbaria could be an important tool in plant conservation, with the aim of reversing the extinction trend of many species through de‐extinction, safeguarding biodiversity, and genetic variability. This study provides preliminary data for the development of germination protocols, especially for old seeds of species of conservation interest, to maximise the chance of recovering lost genetic diversity and leading to the first de‐extinction ever.

Conservation Action Tracker: A tool to identify and monitor conservation actions for tree species

AbstractPremiseThe GlobalTree Portal, hosted by Botanic Gardens Conservation International, provides access to information on the approximately 58,000 tree species worldwide. Included in the GlobalTree Portal is the Conservation Action Tracker, a dynamic and collaborative database to identify and monitor conservation actions for tree species globally.MethodsThe Conservation Action Tracker collates conservation action information at the species level, including species recovery/action plans, ex situ collections, propagation protocols, in situ management, species protection policy, and education/awareness campaigns.ResultsTo date, the Conservation Action Tracker contains conservation action information for 4126 tree species, including 2161 threatened species, of which 659 are classified as Vulnerable, 783 as Endangered, and 719 as Critically Endangered. It covers conservation action information for at least one tree species in every country; however, more information is needed for 89% of Vulnerable, 87% of Endangered, and 77% of Critically Endangered tree species.DiscussionMonitoring species conservation actions can support the prioritization and scaling up of conservation practices by sharing knowledge, increasing collaboration, enabling the identification of conservation gaps, and making the information available to be used by decision‐makers. Tracking conservation actions at the species level is, therefore, essential to guide future conservation efforts. Increasing the amount of data in the Conservation Action Tracker will improve the tool's ability to guide future conservation efforts and avoid the extinction of tree species.

PSII-7 Effect of endophyte-infected tall fescue on body weight, vital signs, and liver function of beef heifers

Abstract Tall fescue was first introduced to the United States over 70 years ago. Since then, it has become the most common forage source for beef cattle in the Southeastern region of the US. Most tall fescue establishes a symbiotic relationship with a toxic fungal endophyte (Epichloë coenophiala), which contributes to the improved vigor of the plant due to acquired resistance to grazing, insects, heat, and drought. However, when consumed by cattle, it may cause fescue toxicosis, a condition characterized by reduced feed intake, body weight (BW) loss, vasoconstriction, and impaired reproductive performance in livestock species. Therefore, the aim of this study was to investigate the effect of endophyte-infected tall fescue consumption on growth performance and health-related traits in beef cattle. For this purpose, 24 Simmental x Angus heifers were divided into two dietary treatments, in which 12 heifers received endophyte-free tall fescue seeds (E-) and 12 heifers were fed with endophyte-infected tall fescue seeds (E+, 6,764 ppb of ergovaline) mixed with the diet for 45 d. The E+ heifers received a daily dose of 20 μg of ergovaline per kg of BW. The E- heifers received the same quantity of seeds as the E+ heifers. For each heifer, phenotypes related to growth (BW), vital signs (respiration rate [RR], and body temperature [TEMP]), and liver functions (serum albumin [ALB], alkaline phosphatase [ALP], aspartate aminotransferase [AST], gamma-glutamyltransferase [GGT], cholesterol [COL], bilirubin [BIL], and triglycerides [TRI]) were analyzed at the end of the experiment. Phenotypes were analyzed using a linear model in R with diet included as a fixed effect. For analysis of BW, the BW at the beginning of the trial was included in the model as a covariate. Results showed that COL and ALP were significantly less (P < 0.05) in the E+ heifers compared with the E- (-32.92 ± 11.16 mg/dL and -32.33 ± 13.95 U/L, respectively). Conversely, E+ heifers had greater (P < 0.05) BW, RR, TEMP, and AST when compared with E- heifers (-17.82 ± 5.12 kg, 25.83 ± 5.52 breaths/min, 0.56 ± 0.12 oC, and 5.83 ± 2.18 U/L, respectively). Measurements of ALB, BIL, GGT, and TRI were not different between E+ and E- heifers. Our results suggest that heifers consuming endophyte-infected tall fescue have compromised vital signs and metabolically altered liver, which may impair growth performance. This study increases our understanding of the biological mechanisms affected by the fescue toxin in beef cattle.

Effect of artisanal gold mining on woody plant diversity in Western Burkina Faso

Although artisanal gold mining strongly contribute to enhance people incomes in West Africa, this activity can lead to habitat fragmentation and loss of woody species. Therefore, studying the impact of artisanal gold mining on woody plant diversity is needed for efficient management of forest resources. In this study, we investigated the impact of artisanal gold mining on woody plant diversity and dynamics in the Kari classified forest in Western Burkina Faso. Forest inventories were carried out at two sites including a gold panning site and a control site, following a systematic sampling design. We identified all woody species and measured all woody species with a diamtere at breast height ≥5 cm. A total 60 plots of 900 m² were surveyed. Diversity indices and dendrometric parameters were calculated and compared between the two sites. The results showed a higher species richness (59 woody species distributing in 39 genera and 18 families) in the control site compared to the gold panning site (38 species distributing in 25 genera and 12 families). The mean values of the number of species per plot and the Shannon diversity index were higher in the control site (15.50 ± 8.80; 2.16 ± 0.43, respectively) than in the artisal mining site (5.47 ± 2.71; 1.40 ± 0.53, respectively), showing that the control site is more diverse than the site that is under gold panning. The control site also had the highest density (683.33 ± 262.99 ft/ha) and stable woody stands compared to the less gold panning site (137.41 ± 102.31 ft/ha) where unstable woody stands were found. While the gold-panning site was characterised by biophysical impacts such as destruction of the plant cover and soil excavation, no visible impact was observed at the control site.Theses findings highlight the negative impact of artisanl gold mining on woody species diversity and structure. The study provides essential information for decision-making on sustainable forest management in the context of mining boom in Burkina Faso's.

Competitive relationships due to similar nutrient preferences reshape soil bacterial metacommunities

Paddy soil, as an ecosystem with alternating drained and flooded conditions, microorganisms in it can maintain the stability of the ecosystem by regulating the composition and diversity of its species when disturbed by external biotic or abiotic factors, and the regulatory mechanism in this process is a controversial topic in ecological research. In this study, we investigate the effects of pigeon feces addition on bacterial communities in three textured soils, two conditions (drained and flooded) based on microcosm experiment using high-throughput sequencing techniques. Our results show that pigeon feces addition reduced environmental heterogeneity and community diversity, both under flooded and drained conditions and in all textured soils, thereby decreasing the effectiveness of environmental selection and increasing diffusion limitations among bacterial communities. Bacterial communities are altered by environmental factors including total organic carbon, available nitrogen, total phosphorus, available phosphorus and available potassium, resulting in the formation of new community structures and dominant genera. Bacteria from pigeon feces did not colonize the original soil in large numbers, and the soil bacterial community structure changed, with some species replaced the indigenous ones as new dominant genera. As nutrient diffusion increases the nutrient content of the soil, this does not lead to species extinction; however, nutrient diffusion creates new nutrient preferences of the bacterial community, which causes direct competition between species, and contributes to the extinction and immigration species. Our results suggest that species replacement is an adaptive strategy of soil bacterial community in response to dispersal of pigeon feces, and that bacterial community regulate diversity and abundance of the community by enhancing species extinction and immigration, thereby preventing bacteria in pigeon feces from colonizing paddy soils and maintaining ecosystem stability.

Selection by differential survival among marine animals in the Phanerozoic

The Gaia hypothesis posits that the Earth and its biosphere function as a single self-stabilizing system, but a key challenge is explaining how this could have arisen through Darwinian evolution. One theory is that of “selection by differential survival,” in which a clade’s extinction probability decreases with age as it accumulates adaptations resisting environmental disturbances. While this is hard to assess during early Earth history, we can assess whether this process operated among marine animal genera throughout the Phanerozoic. To that end, we analyzed time ranges of 36,117 extinct animal genera using fossil occurrence data from the Paleobiology Database in order to calculate marine metazoan extinction age selectivity, extinction rates, and speciation rates over the Phanerozoic. We identify four signatures of selection by differential survival: lower extinction rates among older lineages, heritability and taxonomically nested propagation of extinction resistance, reduced age selectivity during rare environmental perturbations, and differential extinction rather than speciation as the primary driver of the phenomenon. Evidence for this process at lower taxonomic levels also implies its possibility for life as a whole – indeed, the possibility of Gaia.