Femora nutrient foramina and aerobic capacity in giant extinct xenarthrans.

Nutrient foramina are small openings in the periosteal surface of the mid-shaft region of long bones that traverse the cortical layer and reach the medullary cavity. They are important for the delivery of nutrients and oxygen to bone tissue and are crucial for the repair and remodeling of bones over time. The nutrient foramina in the femur's diaphysis are related to the energetic needs of the femur and have been shown to be related to the maximum metabolic rate (MMR) of taxa. Here, we investigate the relationship between nutrient foramen size and body mass as a proxy to the aerobic capacity of taxa in living and extinct xenarthrans, including living sloths, anteaters, and armadillos, as well as extinct xenarthrans such as glyptodonts, pampatheres, and ground sloths. Seventy femora were sampled, including 20 from extant taxa and 50 from extinct taxa. We obtained the blood flow rate (Q̇) based on foramina area and performed PGLS and phylogenetic ANCOVA in order to explore differences among mammalian groups. Our results show that, among mammals, taxa commonly associated with lower metabolism like living xenarthrans showed relatively smaller foramina, while the foramina of giant extinct xenarthrans like ground sloths and glyptodonts overlapped with non-xenarthran placentals. Consequently, Q̇ estimations indicated aerobic capacities comparable to other placental giant taxa like elephants or some ungulates. Furthermore, the estimation of the MMR for fossil giant taxa showed similar results, with almost all taxa showing high values except for those for which strong semi-arboreal or fossorial habits have been proposed. Moreover, the results are compatible with the diets predicted for extinct taxa, which indicate a strong consumption of grass similar to ungulates and in contrast to the folivorous or insectivorous diets of extant xenarthrans. The ancestral reconstruction of the MMR values indicated a lack of a common pattern for all xenarthrans, strongly supporting the occurrence of low metabolic rates in extant forms due to their particular dietary preferences and arboreal or fossorial habits. Our results highlight the importance of considering different evidence beyond the phylogenetic position of extinct taxa, especially when extinct forms are exceptionally different from their extant relatives. Future studies evaluating the energetic needs of giant extinct xenarthrans should not assume lower metabolic rates for these extinct animals based solely on their phylogenetic position and the observations on their extant relatives.

Anthropic cut marks in extinct megafauna bones from the Pampean region (Argentina) at the last glacial maximum.

The initial peopling of South America is a topic of intense archaeological debate. Among the most contentious issues remain the nature of the human-megafauna interaction and the possible role of humans, along with climatic change, in the extinction of several megamammal genera at the end of the Pleistocene. In this study, we present the analysis of fossil remains with cutmarks belonging to a specimen of Neosclerocalyptus (Xenarthra, Glyptodontidae), found on the banks of the Reconquista River, northeast of the Pampean region (Argentina), whose AMS 14C dating corresponds to the Last Glacial Maximum (21,090-20,811 cal YBP). Paleoenvironmental reconstructions, stratigraphic descriptions, absolute chronological dating of bone materials, and deposits suggest a relatively rapid burial event of the bone assemblage in a semi-dry climate during a wet season. Quantitative and qualitative analyses of the cut marks, reconstruction of butchering sequences, and assessments of the possible agents involved in the observed bone surface modifications indicate anthropic activities. Our results provide new elements for discussing the earliest peopling of southern South America and specifically for the interaction between humans and local megafauna in the Pampean region during the Last Glacial Maximum.

The role of epistasis in evolutionary rescue.

The process by which adaptive evolution preserves a population threatened with extinction due to environmental changes is known as evolutionary rescue. Several factors determine the fate of those populations, including demography and genetic factors, such as standing genetic variation, gene flow, availability of de novo mutations, and so on. Despite the extensive debate about evolutionary rescue in the current literature, a study about the role of epistasis and the topography of the fitness landscape on the fate of dwindling populations is missing. In the current work, we aim to fill this gap and study the influence of epistasis on the probability of extinction of populations. We present simulation results, and analytical approximations are derived. Counterintuitively, we show that the likelihood of extinction is smaller when the degree of epistasis is higher. The reason underneath is twofold: first, higher epistasis can promote mutations of more significant phenotypic effects, but also, the incongruence between the maps genotype-phenotype and phenotype-fitness turns the fitness landscape at low epistasis more rugged, thus curbing some of its advantages.

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.

Experimental evidence of climate change extinction risk in Neotropical montane epiphytes.

Climate change is conjectured to endanger tropical species, particularly in biodiverse montane regions, but accurate estimates of extinction risk are limited by a lack of empirical data demonstrating tropical species' sensitivity to climate. To fill this gap, studies could match high-quality distribution data with multi-year transplant experiments. Here, we conduct field surveys of epiphyte distributions on three mountains in Central America and perform reciprocal transplant experiments on one mountain across sites that varied in elevation, temperature and aridity. We find that most species are unable to survive outside of their narrow elevational distributions. Additionally, our findings suggest starkly different outcomes from temperature conditions expected by 2100 under different climate change scenarios. Under temperatures associated with low-emission scenarios, most tropical montane epiphyte species will survive, but under emission scenarios that are moderately high, 5-36% of our study species may go extinct and 10-55% of populations may be lost. Using a test of tropical species' climate tolerances from a large field experiment, paired with detailed species distribution data across multiple mountains, our work strengthens earlier conjecture about risks of wide-spread extinctions from climate change in tropical montane ecosystems.

'Miraculous' plant spotted on famed Ecuador ridge.

The former biodiversity hot spot had become a classic example of extinction.

A global map of species at risk of extinction due to natural hazards.

An often-overlooked question of the biodiversity crisis is how natural hazards contribute to species extinction risk. To address this issue, we explored how four natural hazards, earthquakes, hurricanes, tsunamis, and volcanoes, overlapped with the distribution ranges of amphibians, birds, mammals, and reptiles that have either narrow distributions or populations with few mature individuals. To assess which species are at risk from these natural hazards, we combined the frequency and magnitude of each natural hazard to estimate their impact. We considered species at risk if they overlapped with regions where any of the four natural hazards historically occurred (n = 3,722). Those species with at least a quarter of their range subjected to a high relative impact were considered at high risk (n = 2,001) of extinction due to natural hazards. In total, 834 reptiles, 617 amphibians, 302 birds, and 248 mammals were at high risk and they were mainly distributed on islands and in the tropics. Hurricanes (n = 983) and earthquakes (n = 868) affected most species, while tsunamis (n = 272), and volcanoes (n = 171) affected considerably fewer. The region with the highest number of species at high risk was the Pacific Ring of Fire, especially due to volcanoes, earthquakes, and tsunamis, while hurricane-related high-risk species were concentrated in the Caribbean Sea, Gulf of Mexico, and northwestern Pacific Ocean. Our study provides important information regarding the species at risk due to natural hazards and can help guide conservation attention and efforts to safeguard their survival.

Understanding evolutionary rescue and parallelism in response to environmental stress.

Evolutionary rescue, the process by which populations facing environmental stress avoid extinction through genetic adaptation, is a critical area of study in evolutionary biology. The order in which mutations arise and get established will be relevant to the population's rescue. This study investigates the degree of parallel evolution at the genotypic level between independent populations facing environmental stress and subject to different demographic regimes. Under density regulation, 2 regimes exist: In the first, the population can restore positive growth rates by adjusting its population size or through adaptive mutations, whereas in the second regime, the population is doomed to extinction unless a rescue mutation occurs. Analytical approximations for the likelihood of evolutionary rescue are obtained and contrasted with simulation results. We show that the initial level of maladaptation and the demographic regime significantly affect the level of parallelism. There is an evident transition between these 2 regimes. Whereas in the first regime, parallelism decreases with the level of maladaptation, it displays the opposite behavior in the rescue/extinction regime. These findings have important implications for understanding population persistence and the degree of parallelism in evolutionary responses as they integrate demographic effects and evolutionary processes.

An extinct north American porcupine with a South American tail.

New World porcupines (Erethizontinae) originated in South America and dispersed into North America as part of the Great American Biotic Interchange (GABI) 3-4 million years ago.1 Extant prehensile-tailed porcupines (Coendou) today live in tropical forests of Central and South America.2,3 In contrast, North American porcupines (Erethizon dorsatum) are thought to be ecologically adapted to higher-latitude temperate forests, with a larger body, shorter tail, and diet that includes bark.4,5,6,7 Limited fossils8,9,10,11,12,13 have hindered our understanding of the timing of this ecological differentiation relative to intercontinental dispersal during the GABI and expansion into temperate habitats.14,15,16,17,18 Here, we describe functionally important features of the skeleton of the extinct Erethizon poyeri, the oldest nearly complete porcupine skeleton documented from North America, found in the early Pleistocene of Florida. It differs from extant E. dorsatum in having a long, prehensile tail, grasping foot, and lacking dental specializations for bark gnawing, similar to tropical Coendou. Results from phylogenetic analysis suggest that the more arboreal characteristics found in E. poyeri are ancestral for erethizontines. Only after it expanded into temperate, Nearctic habitats did Erethizon acquire the characteristic features that it is known for today. When combined with molecular estimates of divergence times, results suggest that Erethizon was ecologically similar to a larger species of Coendou when it crossed the Isthmus of Panama by the early Pleistocene. It is likely that the range of this more tropically adapted form was limited to a continuous forested biome that extended from South America through the Gulf Coast.

Short-term extinction predicted by population viability analysis for a Neotropical salt marsh endemic bird.

Salt marshes pose challenges for the birds that inhabit them, including high rates of nest flooding, tipping, and predation. The impacts of rising sea levels and invasive species further exacerbate these challenges. To assess the urgency of conservation and adequacy of new actions, researchers and wildlife managers may use population viability analyses (PVAs) to identify population trends and major threats. We conducted PVA for Formicivora acutirostris, which is a threatened neotropical bird species endemic to salt marshes. We studied the species' demography in different sectors of an estuary in southern Brazil from 2006 to 2023 and estimated the sex ratio, longevity, productivity, first-year survival, and mortality rates. For a 133-year period, starting in 1990, we modeled four scenarios: (1) pessimistic and (2) optimistic scenarios, including the worst and best values for the parameters; (3) a baseline scenario, with intermediate values; and (4) scenarios under conservation management, with increased recruitment and/or habitat preservation. Projections indicated population decline for all assessment scenarios, with a 100% probability of extinction by 2054 in the pessimistic scenario and no extinction in the optimistic scenario. The conservation scenarios indicated population stability with 16% improvement in productivity, 10% improvement in first-year survival, and stable carrying capacity. The disjunct distribution of the species, with remnants concentrated in a broad interface with arboreal habitats, may seal the population decline by increasing nest predation. The species should be considered conservation dependent, and we recommend assisted colonization, predator control, habitat recovery, and ex situ conservation.

The reorganization of predator-prey networks over 20 million years explains extinction patterns of mammalian carnivores.

Linking the species interactions occurring at the scale of local communities to their potential impact at evolutionary timescales is challenging. Here, we used the high-resolution fossil record of mammals from the Iberian Peninsula to reconstruct a timeseries of trophic networks spanning more than 20 million years and asked whether predator-prey interactions affected regional extinction patterns. We found that, despite small changes in species richness, trophic networks showed long-term trends, gradually losing interactions and becoming sparser towards the present. This restructuring of the ecological networks was driven by the loss of medium-sized herbivores, which reduced prey availability for predators. The decrease in prey availability was associated with predator longevity, such that predators with less available prey had greater extinction risk. These results not only reveal long-term trends in network structure but suggest that prey species richness in ecological communities may shape large scale patterns of extinction and persistence among predators.

Potential effects of brown howler monkey extinction on dispersal services in fragmented forests void of large dispersers.

The dispersal of large-seeded species strongly depends on medium-sized and large frugivores, such as primates, which are highly susceptible to population declines. In the Atlantic Forest, brown howler monkeys Alouatta guariba are medium-sized folivorous-frugivorous species that are likely to occur in small to large fragments where the largest frugivores are extinct. However, populations of this primate have been suffering from forest fragmentation, habitat loss, hunting, and the direct and indirect effects of yellow fever outbreaks, which increase the importance of understanding their role as seed dispersers and the impacts of their potential loss. The richness and abundance of large-seeded species might also be reduced in smaller fragments, which could directly affect the magnitude of the potential impact of disperser extinction on plant recruitment. Here, we tested the following mutually exclusive predictions on the effect of fragment size on plant richness and relative density of medium- and large-seeded species consumed by brown howler monkeys in fragments smaller than 1500 ha: the number and the relative density of plant species potentially affected by the local extinction of these monkeys will be (1) directly related to forest fragment size, or (2) not related to forest fragment size. Plant richness and the relative density of large- and medium-sized seed species consumed by brown howler monkeys did not vary with fragment size, corroborating our second prediction. Thus, the local extinction of brown howler monkeys would have a similar potentially negative impact on plant regeneration for the range of tested fragment sizes. We discuss the limitations of our results and suggest other lines of enquiry for the refinement of our conclusions.

Using historical habitat loss to predict contemporary mammal extirpations in Neotropical forests.

Understanding which species will be extirpated in the aftermath of large-scale human disturbance is critical to mitigating biodiversity loss, particularly in hyperdiverse tropical biomes. Deforestation is the strongest driver of contemporary local extinctions in tropical forests but may occur at different tempos. The 2 most extensive tropical forest biomes in South America-the Atlantic Forest and the Amazon-have experienced historically divergent pathways of habitat loss and biodiversity decay, providing a unique case study to investigate rates of local species persistence on a single continent. We quantified medium- to large-bodied mammal species persistence across these biomes to elucidate how landscape configuration affects their persistence and associated ecological functions. We collected occurrence data for 617 assemblages of medium- to large-bodied mammal species (>1 kg) in the Atlantic Forest and the Amazon. Analyzing natural habitat cover based on satellite data (1985-2022), we employed descriptive statistics and generalized linear models (GLMs) to investigate ecospecies occurrence patterns in relation to habitat cover across the landscapes. The subregional erosion of Amazonian mammal assemblage diversity since the 1970s mirrors that observed since the colonial conquest of the Atlantic Forest, given that 52.8% of all Amazonian mammals are now on a similar trajectory. Four out of 5 large mammals in the Atlantic Forest were prone to extirpation, whereas 53% of Amazonian mammals were vulnerable to extirpation. Greater natural habitat cover increased the persistence likelihood of ecospecies in both biomes. These trends reflected a median local species loss 63.9% higher in the Atlantic Forest than in the Amazon, which appears to be moving toward a turning point of forest habitat loss and degradation. The contrasting trajectories of species persistence in the Amazon and Atlantic Forest domains underscore the importance of considering historical habitat loss pathways and regional biodiversity erosion in conservation strategies. By focusing on landscape configuration and identifying essential ecological functions associated with large vertebrate species, conservation planning and management practices can be better informed.

Uso de la pérdida histórica de hábitat para predecir la desaparición de mamíferos contemporáneos en los bosques neotropicales Resumen Tener conocimiento de cuáles especies desaparecerán después de una perturbación humana es de suma importancia para mitigar la pérdida de la biodiversidad, particularmente en los biomas híper diversos. La deforestación es la principal causante de las extinciones locales contemporáneas en los bosques tropicales, aunque puede ocurrir en diferentes tiempos. Los dos bosques tropicales más extensos de América del Sur ­ el Bosque Atlántico y la Amazonia ­ han experimentado formas históricamente divergentes de pérdida de hábitat y decadencia de biodiversidad, lo que proporciona un caso único de estudio para investigar las tasas de persistencia de las especies locales en un solo continente. Cuantificamos la persistencia de las especies de mamíferos de talla mediana a grande en estos dos bosques para aclarar cómo la configuración del paisaje afecta su persistencia y las funciones ecológicas asociadas. Recolectamos datos de presencia de 617 ensambles de especies de mamíferos de talla mediana a grande (>1 kg) en el Bosque Atlántico y en la Amazonia. Analizamos la cobertura natural del hábitat con base en datos satelitales (1985­2022) y empleamos estadística descriptiva y modelos lineales generalizados (MLG) para investigar los patrones de presencia de las eco especies en relación con la cobertura del hábitat en los distintos paisajes. La erosión subregional de la diversidad de ensambles de mamíferos en la Amazonia desde los 70s es igual a la observada en el Bosque Atlántico desde la conquista colonial, dado que 52.8% de todos los mamíferos amazónicos se encuentran en una trayectoria similar. Cuatro de los cinco grandes mamíferos en el Bosque Atlántico estaban propensos a desaparecer, mientras que el 53% de los mamíferos amazónicos estaban vulnerables a desaparecer. Una mayor cobertura natural del hábitat incrementó la probabilidad de persistencia de las eco especies en ambos bosques. Estas tendencias reflejaron una pérdida mediana de especies locales 63.9% mayor en el Bosque Atlántico que en la Amazonia, lo cual parece dirigirse hacia un momento decisivo para la degradación y pérdida del hábitat del bosque. Las trayectorias contrastantes de la persistencia de especies en el Bosque Atlántico y la Amazonia destacan la importancia de considerar dentro de las estrategias de conservación las maneras en las que se ha perdido históricamente el hábitat y la erosión de la biodiversidad regional. Si nos enfocamos en la configuración del paisaje y en la identificación de las funciones ecológicas esenciales asociadas con las especies grandes de vertebrados, podemos informar de mejor manera a la planeación de la conservación y las prácticas de manejo.

The Clade Replacement Theory: a framework to study age-dependent extinction.

There is no scientific consensus about whether and how species' evolutionary age, or the elapsed time since their origination, might affect their probability of going extinct. Different age-dependent extinction (ADE) patterns have been proposed in theoretical and empirical studies, while the existence of a consistent and universal pattern across the tree of life remains debated. If evolutionary age predicts species extinction probability, then the study of ADE should comprise the elapsed time and the ecological process acting on species from their origin to their extinction or to the present for extant species. Additionally, given that closely related species share traits associated with fitness, evolutionary proximity could generate similar ADE patterns. Considering the historical context and extinction selectivity based on evolutionary relatedness, we build on previous theoretical work to formalize the Clade Replacement Theory (CRT) as a framework that considers the ecological and evolutionary aspects of species age and extinction probability to produce testable predictions on ADE patterns. CRT's domain is the diversification dynamics of two or more clades competing for environmental space throughout time, and its propositions or derived hypotheses are as follows: (i) incumbency effects by an early arriving clade that limit the colonization and the diversification of a younger clade leading to a negative ADE scenario (younger species more prone to extinction than older ones) and (ii) an ecological shift triggered by an environmental change that imposes a new selective regime over the environmental space and leads to a positive ADE scenario (extinction probability increasing with age). From these propositions, we developed the prediction that the ADE scenario would be defined by whether an ecological shift happens or not. We discuss how the CRT could be tested with empirical data and provide examples where it could be applied. We hope this article will provide a common ground to unify results from different fields and foster new empirical tests of the mechanisms derived here while providing insights into CRT theoretical structuration.

Exploring the effects of competition and predation on the success of biological invasion through mathematical modeling.

Biological invasions are a major cause of species extinction and biodiversity loss. Exotic predators are the type of introduced species that have the greatest negative impact, causing the extinction of hundreds of native species. Despite this, they continue to be intentionally introduced by humans. Understanding the causes that determine the success of these invasions is a challenge within the field of invasion biology. Mathematical models play a crucial role in understanding and predicting the behavior of exotic species in different ecosystems. This study examines the effect of predation and competition on the invasion success of an exotic generalist predator in a native predator-prey system. Considering that the exotic predator both consumes the native prey and competes with the native predator, it is necessary to study the interplay between predation and competition, as one of these interspecific interactions may either counteract or contribute to the impact of the other on the success of a biological invasion. Through a mathematical model, represented by a system of ordinary differential equations, it is possible to describe four different scenarios upon the arrival of the exotic predator in a native predator-prey system. The conditions for each of these scenarios are described analytically and numerically. The numerical simulations are performed considering the American mink (Mustela vison), an invasive generalist predator. The results highlight the importance of considering the interplay between interspecific interactions for understanding biological invasion success.

Interrelationships among Early Triassic faunas of Western Gondwana and Laurasia as illuminated by a new South American benthosuchid temnospondyl.

The End-Permian Mass Extinction marked a critical turning point in Earth's history, and the biological recovery that followed the crisis led to the emergence of several modern vertebrate and invertebrate taxa. Even considering the importance of the Early Triassic biotic recovery for the evolution of modern faunas and floras, our knowledge of this event is still hindered by the sparse sampling of crucial geological formations. This leaves our understanding of Early Triassic ecosystems fundamentally biased toward productive and historically well-explored geological units. Recent surveys in poorly known Gondwanan localities, such as those within the Sanga do Cabral Formation in southern Brazil, have unveiled insights into Early Triassic terrestrial ecosystems, shedding light on a diverse and previously unknown tetrapod fauna. Here, we report the discovery of a new temnospondyl genus and species in the Lower Triassic Sanga do Cabral Formation. The new taxon can be confidently assigned to the Benthosuchidae, a stereospondyl clade with a distribution previously restricted to the East European Platform. Phylogenetic analysis confirms the relationship of the new genus to the trematosaurian lineage, being closely related to the genus Benthosuchus. Our results raise questions about the biogeographical history of stereospondyls after the End-Permian Mass Extinction and suggest a potential connection between Russian and South American Early Triassic faunas. Further investigations are needed to thoroughly explore the potential dispersal routes that may explain this seemingly unusual biogeographical pattern.

The bat man takes a stand.

Mexican biologist Rodrigo Medellín Legorreta is fighting political headwinds to preserve his country's natural heritage-and his own legacy.

Deadly avian flu hits Galápagos.

Concerns rise for boobies, finches, and other endemic species.

To rewire or not to rewire: To what extent rewiring to surviving partners can avoid extinction?

Research Highlight: Leimberger, K.G., Hadley, A.S., & Betts, M.G. (2023). Plant-hummingbird pollination networks exhibit minimal rewiring after experimental removal of a locally abundant plant species. Journal of Animal Ecology, https://doi.org/10.1111/1365-2656.13935. In this paper, Leimberger, Hadley and Betts (2023) explore the effects of removing a locally abundant plant species on plant-hummingbird pollination networks. They experimentally prevented access of hummingbirds to flowers of Heliconia tortuosa and assessed subsequent changes in the interactions between plants and hummingbirds. Their main hypothesis postulated that the loss of a highly connected species would lead to interaction rewiring and niche expansions by hummingbirds, decreasing individual, species and network specialization. However, they found that the overall structure of the plant-hummingbird networks remains mostly unaltered, with limited rewiring and minimal changes in specialization. The main contributions of this study can be summarized as (i) it adds to a limited number of manipulative studies on the capacity of species to rewire their interactions following the loss of partners, and importantly, it is the first study from the tropics and with vertebrate pollinators, for which experimental studies at appropriate scales is intrinsically more challenging; and (ii) innovates by evaluating change in specialization for the individual level, carried out through pollen sampling on the body of hummingbirds. The limited change in species interactions highlights that network stability through interaction rewiring may have been overestimated in previous studies, calling for further manipulative studies in the field. At the same time, it also indicated that even the loss of a highly abundant plant species has an overall small effect on network structure. Thus, this study contributes timely findings regarding the capacity of ecological communities to respond to species extinctions.

Mutilation of the tree of life via mass extinction of animal genera.

Mass extinctions during the past 500 million y rapidly removed branches from the phylogenetic tree of life and required millions of years for evolution to generate functional replacements for the extinct (EX) organisms. Here we show, by examining 5,400 vertebrate genera (excluding fishes) comprising 34,600 species, that 73 genera became EX since 1500 AD. Beyond any doubt, the human-driven sixth mass extinction is more severe than previously assessed and is rapidly accelerating. The current generic extinction rates are 35 times higher than expected background rates prevailing in the last million years under the absence of human impacts. The genera lost in the last five centuries would have taken some 18,000 y to vanish in the absence of human beings. Current generic extinction rates will likely greatly accelerate in the next few decades due to drivers accompanying the growth and consumption of the human enterprise such as habitat destruction, illegal trade, and climate disruption. If all now-endangered genera were to vanish by 2,100, extinction rates would be 354 (average) or 511 (for mammals) times higher than background rates, meaning that genera lost in three centuries would have taken 106,000 and 153,000 y to become EX in the absence of humans. Such mutilation of the tree of life and the resulting loss of ecosystem services provided by biodiversity to humanity is a serious threat to the stability of civilization. Immediate political, economic, and social efforts of an unprecedented scale are essential if we are to prevent these extinctions and their societal impacts.