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.

Imbalanced speciation pulses sustain the radiation of mammals

The evolutionary histories of major clades, including mammals, often comprise changes in their diversification dynamics, but how these changes occur remains debated. We combined comprehensive phylogenetic and fossil information in a new "birth-death diffusion" model that provides a detailed characterization of variation in diversification rates in mammals. We found an early rising and sustained diversification scenario, wherein speciation rates increased before and during the Cretaceous-Paleogene (K-Pg) boundary. The K-Pg mass extinction event filtered out more slowly speciating lineages and was followed by a subsequent slowing in speciation rates rather than rebounds. These dynamics arose from an imbalanced speciation process, with separate lineages giving rise to many, less speciation-prone descendants. Diversity seems to have been brought about by these isolated, fast-speciating lineages, rather than by a few punctuated innovations.

Genome-wide diversity, population structure and signatures of inbreeding in the African buffalo in Mozambique

The African buffalo, Syncerus caffer, is a key species in African ecosystems. Like other large herbivores, it plays a fundamental role in its habitat acting as an ecosystem engineer. Over the last few centuries, African buffalo populations have declined because of range contraction and demographic decline caused by direct or indirect human activities. In Mozambique, historically home to large buffalo herds, the combined effect of colonialism and subsequent civil wars has created a critical situation that urgently needs to be addressed. In this study, we focused on the analysis of genetic diversity of Syncerus caffer caffer populations from six areas of Mozambique. Using genome-wide SNPs obtained from ddRAD sequencing, we examined the population structure across the country, estimated gene flow between areas under conservation management, including national reserves, and assessed the inbreeding coefficients. Our results indicate that all studied populations of Syncerus caffer caffer are genetically depauperate, with a high level of inbreeding. Moreover, buffaloes in Mozambique present a significant population differentiation between southern and central areas. We found an unexpected genotype in the Gorongosa National Park, where buffaloes experienced a dramatic population size reduction, that shares a common ancestry with southern populations of Catuane and Namaacha. This could suggest the past occurrence of a connection between southern and central Mozambique and that the observed population structuring could reflect recent events of anthropogenic origin. All the populations analysed showed high levels of homozygosity, likely due to extensive inbreeding over the last few decades, which could have increased the frequency of recessive deleterious alleles. Improving the resilience of Syncerus caffer caffer in Mozambique is essential for preserving the ecosystem integrity. The most viable approach appears to be facilitating translocations and re-establishing connectivity between isolated herds. However, our results also highlight the importance of assessing intraspecific genetic diversity when considering interventions aimed at enhancing population viability such as selecting suitable source populations.

Would future climate warming cause zoonotic diseases to spread over long distances?

Dipus sagitta is a major rodent found in arid environments and desert areas. They feed on plant seeds, young branches and some small insects, and have hibernating habits. Peak Dipus sagitta numbers impact the construction of the plant community in the environment, but also have a human impact as these rodents carry a variety of parasitic fleas capable of spreading serious diseases to humans. Based on 216 present distribution records of Dipus sagitta and seven environmental variables, this article simulates the potential distribution of Dipus sagitta during the Last Glacial Maximum, the mid-Holocene, the present and the future (2070s, RCP4.5, RCP8.5). This study also analyzes the geographic changes of the population distribution and evaluates the importance of climate factors by integrating contribution rate, replacement importance value and the jackknife test using the MaxEnt model. In this study, we opted to assess the predictive capabilities of our model using the receiver operating characteristic (ROC) and partial receiver operating characteristic (pROC) metrics. The findings indicate that the AUC value exceeds 0.9 and the AUC ratio is greater than 1, indicating superior predictive performance by the model. The results showed that the main climatic factors affecting the distribution of the three-toed jerboa were precipitation in the coldest quarter, temperature seasonality (standard deviation), and mean annual temperature. Under the two warming scenarios of the mid-Holocene and the future, there were differences in the changes in the distribution area of the three-toed jerboa. During the mid-Holocene, the suitable distribution area of the three-toed jerboa expanded, with a 93.91% increase in the rate of change compared to the Last Glacial Maximum. The size of the three-toed jerboa's habitat decreases under both future climate scenarios. Compared to the current period, under the RCP4.5 emission scenario, the change rate is -2.96%, and under the RCP8.5 emission scenario, the change rate is -7.41%. This indicates a trend of contraction in the south and expansion in the north. It is important to assess changes in the geographic population of Dipus sagitta due to climate change to formulate population control strategies of these harmful rodents and to prevent and control the long-distance transmission of zoonotic diseases.

Worldwide Late Pleistocene and Early Holocene population declines in extant megafauna are associated with Homo sapiens expansion rather than climate change

The worldwide extinction of megafauna during the Late Pleistocene and Early Holocene is evident from the fossil record, with dominant theories suggesting a climate, human or combined impact cause. Consequently, two disparate scenarios are possible for the surviving megafauna during this time period - they could have declined due to similar pressures, or increased in population size due to reductions in competition or other biotic pressures. We therefore infer population histories of 139 extant megafauna species using genomic data which reveal population declines in 91% of species throughout the Quaternary period, with larger species experiencing the strongest decreases. Declines become ubiquitous 32-76 kya across all landmasses, a pattern better explained by worldwide Homo sapiens expansion than by changes in climate. We estimate that, in consequence, total megafauna abundance, biomass, and energy turnover decreased by 92-95% over the past 50,000 years, implying major human-driven ecosystem restructuring at a global scale.

North American pollen records provide evidence for macroscale ecological changes in the Anthropocene

Recent global changes associated with anthropogenic activities are impacting ecological systems globally, giving rise to the Anthropocene. Critical reorganization of biological communities and biodiversity loss are expected to accelerate as anthropogenic global change continues. Long-term records offer context for understanding baseline conditions and those trajectories that are beyond the range of normal fluctuation seen over recent millennia: Are we causing changes that are fundamentally different from changes in the past? Using a rich dataset of late Quaternary pollen records, stored in the open-access and community-curated Neotoma database, we analyzed changes in biodiversity and community composition since the end Pleistocene in North America. We measured taxonomic richness, short-term taxonomic loss and gain, first/last appearances (FAD/LAD), and abrupt community change. For all analyses, we incorporated age-model uncertainty and accounted for differences in sample size to generate conservative estimates. The most prominent signals of elevated vegetation change were seen during the Pleistocene-Holocene transition and since 200 calendar years before present (cal YBP). During the Pleistocene-Holocene transition, abrupt changes and FADs were elevated, and from 200 to -50 cal YBP, we found increases in short-term taxonomic loss, FADs, LADs, and abrupt changes. Taxonomic richness declined from ~13,000 cal YBP until about 6,000 cal YBP and then increased until the present, reaching levels seen during the end Pleistocene. Regionally, patterns were highly variable. These results show that recent changes associated with anthropogenic impacts are comparable to the landscape changes that took place as we moved from a glacial to interglacial world.

Pre-Younger Dryas megafaunal extirpation at Rancho La Brea linked to fire-driven state shift

The cause, or causes, of the Pleistocene megafaunal extinctions have been difficult to establish, in part because poor spatiotemporal resolution in the fossil record hinders alignment of species disappearances with archeological and environmental data. We obtained 172 new radiocarbon dates on megafauna from Rancho La Brea in California spanning 15.6 to 10.0 thousand calendar years before present (ka). Seven species of extinct megafauna disappeared by 12.9 ka, before the onset of the Younger Dryas. Comparison with high-resolution regional datasets revealed that these disappearances coincided with an ecological state shift that followed aridification and vegetation changes during the Bølling-Allerød (14.69 to 12.89 ka). Time-series modeling implicates large-scale fires as the primary cause of the extirpations, and the catalyst of this state shift may have been mounting human impacts in a drying, warming, and increasingly fire-prone ecosystem.

Megafaunal extinctions, not climate change, may explain Holocene genetic diversity declines in Numenius shorebirds

Understanding the relative contributions of historical and anthropogenic factors to declines in genetic diversity is important for informing conservation action. Using genome-wide DNA of fresh and historic specimens, including that of two species widely thought to be extinct, we investigated fluctuations in genetic diversity and present the first complete phylogenomic tree for all nine species of the threatened shorebird genus Numenius, known as whimbrels and curlews. Most species faced sharp declines in effective population size, a proxy for genetic diversity, soon after the Last Glacial Maximum (around 20,000 years ago). These declines occurred prior to the Anthropocene and in spite of an increase in the breeding area predicted by environmental niche modeling, suggesting that they were not caused by climatic or recent anthropogenic factors. Crucially, these genetic diversity declines coincide with mass extinctions of mammalian megafauna in the Northern Hemisphere. Among other factors, the demise of ecosystem-engineering megafauna which maintained open habitats may have been detrimental for grassland and tundra-breeding Numenius shorebirds. Our work suggests that the impact of historical factors such as megafaunal extinction may have had wider repercussions on present-day population dynamics of open habitat biota than previously appreciated.

Evolutionary history of the extinct wolf population from France in the context of global phylogeographic changes throughout the Holocene

Phylogeographic patterns in large mammals result from natural environmental factors and anthropogenic effects, which in some cases include domestication. The grey wolf was once widely distributed across the Holarctic, but experienced phylogeographic shifts and demographic declines during the Holocene. In the 19th-20th centuries, the species became extirpated from large parts of Europe due to direct extermination and habitat loss. We reconstructed the evolutionary history of the extinct Western European wolves based on the mitogenomic composition of 78 samples from France (Neolithic-20th century) in the context of other populations of wolves and dogs worldwide. We found a close genetic similarity of French wolves from ancient, medieval and recent populations, which suggests the long-term continuity of maternal lineages. MtDNA haplotypes of the French wolves showed large diversity and fell into two main haplogroups of modern Holarctic wolves. Our worldwide phylogeographic analysis indicated that haplogroup W1, which includes wolves from Eurasia and North America, originated in Northern Siberia. Haplogroup W2, which includes only European wolves, originated in Europe ~35 kya and its frequency was reduced during the Holocene due to an expansion of haplogroup W1 from the east. Moreover, we found that dog haplogroup D, currently restricted to Europe and the Middle East, was nested within the wolf haplogroup W2. This suggests European origin of haplogroup D, probably as a result of an ancient introgression from European wolves. Our results highlight the dynamic evolutionary history of European wolves during the Holocene, with a partial lineage replacement and introgressive hybridization with local dog populations.

Disruption of trait-environment relationships in African megafauna occurred in the middle Pleistocene

Mammalian megafauna have been critical to the functioning of Earth's biosphere for millions of years. However, since the Plio-Pleistocene, their biodiversity has declined concurrently with dramatic environmental change and hominin evolution. While these biodiversity declines are well-documented, their implications for the ecological function of megafaunal communities remain uncertain. Here, we adapt ecometric methods to evaluate whether the functional link between communities of herbivorous, eastern African megafauna and their environments (i.e., functional trait-environment relationships) was disrupted as biodiversity losses occurred over the past 7.4 Ma. Herbivore taxonomic and functional diversity began to decline during the Pliocene as open grassland habitats emerged, persisted, and expanded. In the mid-Pleistocene, grassland expansion intensified, and climates became more variable and arid. It was then that phylogenetic diversity declined, and the trait-environment relationships of herbivore communities shifted significantly. Our results divulge the varying implications of different losses in megafaunal biodiversity. Only the losses that occurred since the mid-Pleistocene were coincident with a disturbance to community ecological function. Prior diversity losses, conversely, occurred as the megafaunal species and trait pool narrowed towards those adapted to grassland environments.

Anthropogenic predictors of varying Holocene occurrence for Europe's large mammal fauna

Understanding how species respond to different anthropogenic pressures is essential for conservation planning. The archaeological record has great potential to inform extinction risk assessment by providing evidence on past human-caused biodiversity loss, but identifying specific drivers of past declines from environmental archives has proved challenging. We used 17 684 Holocene zooarchaeological records for 15 European large mammal species together with data on past environmental conditions and anthropogenic activities across Europe, to assess the ability of environmental archives to determine the relative importance of different human pressures in shaping faunal distributions through time. Site occupancy probability showed differing significant relationships with environmental covariates for all species, and nine species also showed significant relationships with anthropogenic covariates (human population density, % cropland, % grazing land). Across-species differences in negative relationships with covariates provide ecological insights for understanding extinction dynamics: some mammals (red deer, aurochs, wolf, wildcat, lynx, pine marten and beech marten) were more vulnerable to past human-environmental interactions, and differing single and synergistic anthropogenic factors influenced likelihood of past occurrence across species. Our results provide new evidence for pre-industrial population fragmentation and depletion in European mammals, and demonstrate the usefulness of historical baselines for understanding species' varying long-term sensitivity to multiple threats.

Kill site database: A unified dataset on human-megafauna interactions across time and space

The database presented in this data article is related to the paper "Megafauna kill sites in South America: a critical review" [1]. It includes a list of 134 publications on human-megafauna interaction, with 69 archaeological sites showing human-megafauna interaction. From these sites, 44 present a minimum human-megafauna association, from which up to 17 megafauna kill sites were classified, with up to 15 exploited extinct megafauna taxa. It also provides a list of current taxonomic classifications of extinct megafauna that humans have exploited according to empirical evidence presented in the related paper. The megafauna kill sites were classified based on five restrictive criteria according to Grayson and Meltzer's (2015, 2002), Borrero's (2009) and Mothé et al.'s (2020) protocol. The kill sites database reflects the empirical evidence on megafauna exploitation by humans available in scientific literature and is useful to understand the human-megafauna interactions in the late Quaternary. Finally, we also provide our online repository (www.killsitedatabase.com), an initiative to unify the evidence on megafauna kill sites (and their related data) worldwide, starting in South America.

Limited co-benefits of protected areas in southwest China under current climate change and human modification

An ambitious new Post-2020 Global Biodiversity Framework "Kunming-Montreal Global Biodiversity Framework" has been developed. However, the combined effects of climate change and human modification can undermine the potential benefits of the global post-2020 conservation efforts. The co-benefits of stabilizing the climate, conserving biodiversity, and maintaining intact wilderness areas may help to persuade the general public of the need to quickly expand existing protected areas (PAs). To maximize the co-benefits after 2020, the careful optimization of existing (PAs) network and scientific identification of conservation targets are both essential. Here, we mapped hotspots of biodiversity, climate vulnerability, and wilderness in Southwest China (SWC). By analyzing the representativeness and gaps of the existing PAs network in SWC, we devised post-2020 conservation targets and highlighted their implications for decision-makers. Our results showed that the incongruence between hotspots of different species exists, indicating that habitats suitable for one taxon may not fully harbor other taxa. According to our assessment, the five jurisdictions of SWC have warmed on average by 0.4°C-1.1 °C over the past 60 years alone. In particular, biodiversity hotspots in SWC are undergoing stark climatic changes. We uncovered prominent conservation gaps in SWC's network of PAs, especially in terms of climate vulnerability and biodiversity. Due to their insufficient number and unreasonable spatial distribution, the PAs network in SWC may be not capable of meeting its biodiversity, climate vulnerability, and wilderness conservation objectives. To rectify this, we proposed a 3-step mission: milestone 2025, milestone 2030, and goal 2050, which aims to protect 23%, 28%, and 60% of the terrestrial area in SWC, respectively. Taken together, our study derived conservation priority areas with relatively clear spatial boundaries and importance levels, thus providing detailed, timely information for decision-makers to expand the PAs network and implement conservation measures varying in strictness in post-2020 conservation practice.

Climate-driven habitat shifts of high-ranked prey species structure Late Upper Paleolithic hunting

Changing climates in the past affected both human and faunal population distributions, thereby structuring human diets, demography, and cultural evolution. Yet, separating the effects of climate-driven and human-induced changes in prey species abundances remains challenging, particularly during the Late Upper Paleolithic, a period marked by rapid climate change and marked ecosystem transformation. To disentangle the effects of climate and hunter-gatherer populations on animal prey species during the period, we synthesize disparate paleoclimate records, zooarchaeological data, and archaeological data using ecological methods and theory to test to what extent climate and anthropogenic impacts drove broad changes in human subsistence observed in the Late Upper Paleolithic zooarchaeological records. We find that the observed changes in faunal assemblages during the European Late Upper Paleolithic are consistent with climate-driven animal habitat shifts impacting the natural abundances of high-ranked prey species on the landscape rather than human-induced resource depression. The study has important implications for understanding how past climate change impacted and structured the diet and demography of human populations and can serve as a baseline for considerations of resilience and adaptation in the present.

The Yale Geochronometric Laboratory and the Rewriting of Global Environmental History

Beginning in the nineteenth century, scientists speculated that the Pleistocene megafauna-species such as the giant ground sloth, wooly mammoth, and saber-tooth cat-perished because of rapid climate change accompanying the end of the most recent Ice Age. In the 1950s, a small network of ecologists challenged this view in collaboration with archeologists who used the new tool of radiocarbon dating. The Pleistocene overkill hypothesis imagined human hunting, not climate change, to be the primary cause of megafaunal extinction. This article situates the Pleistocene overkill hypothesis in a broader history of the emergence of historical ecology as a distinct sub-discipline of paleoecology. Tracing the work of the Yale Geochronometric Laboratory and an interdisciplinary research network that included Paul Sears, Richard Foster Flint, Edward Deevey, Kathryn Clisby, and Paul S. Martin, it reveals how both the methods and the meaning of studying fossil pollen shifted between the 1910s and 1960s. First used as a tool for fossil fuel extraction, fossil pollen became a means of envisioning climatic history, and ultimately, a means of reimagining global ecological history. First through pollen stratigraphy and then through radiocarbon dating, ecologists reconstructed past biotic communities and rethought the role of humans in these communities. By the 1980s, the discipline of historical ecology would reshape physical environments through the practice of ecological restoration.

The Exceptional Presence of Megaloceros giganteus in North-Eastern Iberia and Its Palaeoecological Implications: The Case of Teixoneres Cave (Moià, Barcelona, Spain)

In this article we announce the discovery of the first remains of Megaloceros giganteus found in Catalonia (north-eastern Iberia) from the Late Pleistocene: a fragment of maxillary. Dated between 35,000 and 37,000 cal BP, it is also among the youngest occurrence of this taxon in the Iberian Peninsula, while its last known occurrence is dated to the Neolithic period. Through a comparison with the giant deer of the northern Pyrenees, we analyzed the herbivore guilds in which this taxon was associated to understand the context in which it was able to enter the Iberian Peninsula. By comparing its diet with those of specimens from Northern Europe, we detail the ecological adaptations of this taxon in this new environment. We suggest that Megaloceros accompanied the migrations of cold-adapted species by taking advantage of the opening of corridors on both sides of the Pyrenees during the coldest periods of the Late Pleistocene. The diet of the Iberian individuals, which is oriented towards abrasive plants, suggests an adaptation to a different ecological niche than that found in Northern European individuals. The northern Iberian Peninsula may have been an extreme in the geographical expansion of M. giganteus. More specimens will be needed in the future to establish the variability of the southern Megaloceros populations.

How cougars and feral donkeys change desert wetlands: Novel interactions between native predators and non-native megaherbivores shape trophic cascades in the Anthropocene

Research Highlight: Lundgren, E. J., Ramp, D., Middleton, O. S., Wooster, E. I. F., Kusch, E., Balisi, M., Ripple, W. J., Hasselerharm, C. D., Sanchez, J. N., Mills, M. & Wallach, A. D. (2022) A novel trophic cascade between cougars and feral donkeys shapes desert wetlands. Journal of Animal Ecology, (91, 2010-2022). https://doi.org/10.1111/1365-2656.13766. Despite being absent from most regions of the contemporary world, megafauna species dominated the dynamics of ecological communities until the late Pleistocene. Trophic rewilding is a promising approach to restoring megafauna interactions, their functional roles and the consequent trophic cascades. Unintentional rewilding with large non-native herbivores, such as equids, offers outstanding opportunities for ecologists to understand the outcomes of using replacement species to restore the ecological functions of extinct native megafauna. In this context, it is relevant to understand the extent to which extant native predators can impose top-down control on non-native megaherbivores and how trophic cascades arising from novel predator-prey interactions influences biodiversity and ecosystem functions. In Death Valley National Park (United States), Lundgren et al. depict a natural experiment showing compelling evidence of native cougars overcoming ecological naïveté-that is, the mismatches between predator and prey species that do not share a common evolutionary history-and are now successfully preying on younger individuals of feral donkeys. These non-native donkeys, whose growing wild populations threaten the native biota, became cougars' most frequent dietary item in that region. In areas with cougars, donkeys changed their spatiotemporal foraging patterns, becoming diurnal and less active. On the other hand, donkeys remain more active and forage throughout the day and night in areas without cougars. The cougar-donkey interaction triggered a behaviourally mediated trophic cascade emerging from a 'landscape of fear', that is, from the perception of spatial heterogeneity in predation risk by donkeys. Areas with cougars have less trampled ground, fewer donkey trails, and much more canopy cover and vegetation around water. Donkeys concentrate their activity mostly in topologically plain terrains lacking proper sites for the ambush behaviour of cougars and with more intense human presence, likely acting as a shield against the predators. Lundgren et al. present a promising model system for studying the effects of fearful grazers on community structure in the context of novel ecological interactions being established in the Anthropocene. Whether the emerging cascade is transient or persistent, the relative roles of consumptive and non-consumptive effects as underlying mechanisms, and their consequences for food web structure, functioning and stability, are questions of general interest. Addressing them can help us to elucidate the costs and benefits of using non-native megaherbivores in the functional restoration of permanently invaded ecosystems.

Quaternary megafauna extinctions altered body size distribution in tortoises

The late Quaternary is characterized by the extinction of many terrestrial megafauna, which included tortoises (Family: Testudinidae). However, limited information is available on how extinction shaped the phenotype of surviving taxa. Here, based on a global dataset of straight carapace length, we investigate the temporal variation, spatial distribution and evolution of tortoise body size over the past 23 million years, thereby capturing the effects of Quaternary extinctions in this clade. We found a significant change in body size distribution characterized by a reduction of both mean body size and maximum body size of extant tortoises relative to fossil taxa. This reduction of body size occurred earlier in mainland (Early Pleistocene 2.588-0.781 Ma) than in island tortoises (Late Pleistocene/Holocene 0.126-0 Ma). Despite contrasting body size patterns between fossil and extant taxa on a spatial scale, tortoise body size showed limited variation over time until this decline. Body size is a fundamental functional trait determining many aspects of species ecologies, with large tortoises playing key roles as ecosystem engineers. As such, the transition from larger sized to smaller sized classes indicated by our findings likely resulted in the homogenization of tortoises' ecological functions and diminished the role of tortoises in structuring the vegetation community.

Clinal variation as a tool to understand climate change

Clines are observable gradients that reflect continuous change in biological traits of species across geographical ranges. Clinal gradients could vary at geographic scales (latitude and altitude). Since clinal variations represent active genomic responses at the population level they (clines) provide an immense power to address questions related to climatic change. With the fast pace of climate change i.e. warming, populations are also likely to exhibit rapid responses; at both the phenotypic and genotypic levels. We seek to understand how clinal variation could be used to anticipate climatic responses using Drosophila, a pervasively used inter-disciplinary model system owing to its molecular repertoire. The genomic information coupled with the phenotypic variation greatly facilitates our understanding of the Drosophilidae response to climate change. We discuss traits associated with clinal variation at the phenotypic level as well as their underlying genetic regulators. Given prevailing climatic conditions and future projections for climate change, clines could emerge as monitoring tools to track the cross-talk between climatic variables and organisms.

Local chronicles reveal the effect of anthropogenic and climatic impacts on local extinctions of Chinese pangolins (Manis pentadactyla) in mainland China

Anthropogenic and climatic factors affect the survival of animal species. Chinese pangolin is a critically endangered species, and identifying which variables lead to local extinction events is essential for conservation management. Local chronicles in China serve as long‐term monitoring data, providing a perspective to disentangle the roles of human impacts and climate changes in local extinctions. Therefore, we established generalized additive models to identify factors leading to local extinction with historical data from 1700–2000 AD in mainland China. Then we decreased the time scale and constructed extinction risk models using MaxEnt in a 30‐year transect (1970–2000 AD) to further assess extinction probability of extant Chinese pangolin populations. Lastly, we used principal component analysis to assess variation of related anthropogenic and climatic variables. Our results showed that the extinction probability increased with global warming and human population growth. An extinction risk assessment indicated that the population and distribution range of Chinese pangolins had been persistently shrinking in response to highly intensive human activities (main cause) and climate change. PCA results indicated that variability of climatic variables is greater than anthropogenic variables. Overall, the factors causing local extinctions are intensive human interference and drastic climatic fluctuations which induced by the effect of global warming. Approximately 28.10% of extant Chinese pangolins populations are confronted with a notable extinction risk (0.37 ≤ extinction probability≤0.93), specifically those in Southeast China, including Guangdong, Jiangxi, Zhejiang, Hunan and Fujian Provinces. To rescue this critically endangered species, we suggest strengthening field investigations, identifying the exact distribution range and population density of Chinese pangolins and further optimizing the network of nature reserves to improve conservation coverage on the landscape scale and alleviate human interference. Conservation practices that concentrate on the viability assessment of scattered populations could help to improve restoration strategies of the Chinese pangolin.

Late Pleistocene megafauna extinction leads to missing pieces of ecological space in a North American mammal community

The conservation status of large-bodied mammals is dire. Their decline has serious consequences because they have unique ecological roles not replicated by smaller-bodied animals. Here, we use the fossil record of the megafauna extinction at the terminal Pleistocene to explore the consequences of past biodiversity loss. We characterize the isotopic and body-size niche of a mammal community in Texas before and after the event to assess the influence on the ecology and ecological interactions of surviving species (>1 kg). Preextinction, a variety of C₄ grazers, C₃ browsers, and mixed feeders existed, similar to modern African savannas, with likely specialization among the two sabertooth species for juvenile grazers. Postextinction, body size and isotopic niche space were lost, and the δ¹³C and δ¹⁵N values of some survivors shifted. We see mesocarnivore release within the Felidae: the jaguar, now an apex carnivore, moved into the specialized isotopic niche previously occupied by extinct cats. Puma, previously absent, became common and lynx shifted toward consuming more C₄-based resources. Lagomorphs were the only herbivores to shift toward C₄ resources. Body size changes from the Pleistocene to Holocene were species-specific, with some animals (deer, hare) becoming significantly larger and others smaller (bison, rabbits) or exhibiting no change to climate shifts or biodiversity loss. Overall, the Holocene body-size-isotopic niche was drastically reduced and considerable ecological complexity lost. We conclude biodiversity loss led to reorganization of survivors and many "missing pieces" within our community; without intervention, the loss of Earth's remaining ecosystems that support megafauna will likely suffer the same fate.

Lost, gained, and regained functional and phylogenetic diversity of European mammals since 8000 years ago

Mammals have experienced high levels of human-mediated extirpations but have also been widely introduced to new locations, and some have recovered from historic persecution. Both of these processes-losses and gains-have resulted in concern about functional losses and changes in ecological communities as new ecological states develop. The question of whether species turnover inevitably leads to declines in functional and phylogenetic diversity depends, however, on the traits and phylogenetic distinctiveness of the species that are lost, gained, or regained. Comparing ~8000 years ago with the last century, we show that extirpations and range retractions have indeed reduced the functional and phylogenetic diversity of mammals in most European regions (countries and island groups), but species recoveries and the introduction of non-native species have increased functional and phylogenetic diversity by equivalent or greater amounts in many regions. Overall, across Europe, species richness increased in 41 regions over the last 8000 years and declined in 1; phylogenetic diversity increased in 33 and declined in 12, while functional diversity results showed 20 increases and 25 decreases. The balance of losses (extirpations) and gains (introductions, range expansions) has, however, led to net increases in functional diversity on many islands, where the original diversity was low, and across most of western Europe. Historically extirpated mega- and mesofaunal species have recolonized or been reintroduced to many European regions, contributing to recent functional and phylogenetic diversity recovery. If conservation rewilding projects continue to reintroduce regionally extirpated species and domestic descendants of "extinct" species to provide replacement grazing, browsing, and predation, there is potential to generate net functional and phylogenetic diversity gains (relative to 8000 years ago) in most European regions.

The antique genetic plight of the Mediterranean monk seal (Monachus monachus)

Disentangling the impact of Late Quaternary climate change from human activities can have crucial implications on the conservation of endangered species. We investigated the population genetics and demography of the Mediterranean monk seal (Monachus monachus), one of the world's most endangered marine mammals, through an unprecedented dataset encompassing historical (extinct) and extant populations from the eastern North Atlantic to the entire Mediterranean Basin. We show that Cabo Blanco (Western Sahara/Mauritania), Madeira, Western Mediterranean (historical range) and Eastern Mediterranean regions segregate into four populations. This structure is probably the consequence of recent drift, combined with long-term isolation by distance (R2 = 0.7), resulting from prevailing short-distance (less than 500 km) and infrequent long-distance dispersal (less than 1500 km). All populations (Madeira especially), show high levels of inbreeding and low levels of genetic diversity, seemingly declining since historical time, but surprisingly not being impacted by the 1997 massive die-off in Cabo Blanco. Approximate Bayesian Computation analyses support scenarios combining local extinctions and a major effective population size decline in all populations during Antiquity. Our results suggest that the early densification of human populations around the Mediterranean Basin coupled with the development of seafaring techniques were the main drivers of the decline of Mediterranean monk seals.

A 14,000-year-old genome sheds light on the evolution and extinction of a Pleistocene vulture

The New World Vulture [Coragyps] occidentalis (L. Miller, 1909) is one of many species that were extinct by the end of the Pleistocene. To understand its evolutionary history we sequenced the genome of a 14,000 year old [Coragyps] occidentalis found associated with megaherbivores in the Peruvian Andes. occidentalis has been viewed as the ancestor, or possibly sister, to the extant Black Vulture Coragyps atratus, but genomic data shows occidentalis to be deeply nested within the South American clade of atratus. Coragyps atratus inhabits lowlands, but the fossil record indicates that occidentalis mostly occupied high elevations. Our results suggest that occidentalis evolved from a population of atratus in southwestern South America that colonized the High Andes 300 to 400 kya. The morphological and morphometric differences between occidentalis and atratus may thus be explained by ecological diversification following from the natural selection imposed by this new and extreme, high elevation environment. The sudden evolution of a population with significantly larger body size and different anatomical proportions than atratus thus constitutes an example of punctuated evolution.

14,000 year old DNA reveals the evolutionary dynamics and adaptations of South American vultures.

Late quaternary biotic homogenization of North American mammalian faunas

Biotic homogenization—increasing similarity of species composition among ecological communities—has been linked to anthropogenic processes operating over the last century. Fossil evidence, however, suggests that humans have had impacts on ecosystems for millennia. We quantify biotic homogenization of North American mammalian assemblages during the late Pleistocene through Holocene (~30,000 ybp to recent), a timespan encompassing increased evidence of humans on the landscape (~20,000–14,000 ybp). From ~10,000 ybp to recent, assemblages became significantly more homogenous (>100% increase in Jaccard similarity), a pattern that cannot be explained by changes in fossil record sampling. Homogenization was most pronounced among mammals larger than 1 kg and occurred in two phases. The first followed the megafaunal extinction at ~10,000 ybp. The second, more rapid phase began during human population growth and early agricultural intensification (~2,000–1,000 ybp). We show that North American ecosystems were homogenizing for millennia, extending human impacts back ~10,000 years.

Biotic homogenization, which is increased similarity in the composition of species among communities, is rising due to human activities. Using North American mammal fossil records from the past 30,000 years, this study shows that this phenomenon is ancient, beginning between 12,000 and 10,000 years ago with the extinction of the mammal megafauna.

Anthropogenic disruptions to longstanding patterns of trophic-size structure in vertebrates

Diet and body mass are inextricably linked in vertebrates: while herbivores and carnivores have converged on much larger sizes, invertivores and omnivores are, on average, much smaller, leading to a roughly U-shaped relationship between body size and trophic guild. Although this U-shaped trophic-size structure is well documented in extant terrestrial mammals, whether this pattern manifests across diverse vertebrate clades and biomes is unknown. Moreover, emergence of the U-shape over geological time and future persistence are unknown. Here we compiled a comprehensive dataset of diet and body size spanning several vertebrate classes and show that the U-shaped pattern is taxonomically and biogeographically universal in modern vertebrate groups, except for marine mammals and seabirds. We further found that, for terrestrial mammals, this U-shape emerged by the Palaeocene and has thus persisted for at least 66 million years. Yet disruption of this fundamental trophic-size structure in mammals appears likely in the next century, based on projected extinctions. Actions to prevent declines in the largest animals will sustain the functioning of Earth's wild ecosystems and biomass energy distributions that have persisted through deep time.

Changing surface ocean circulation caused the local demise of echinoid Scaphechinus mirabilis in Taiwan during the Pleistocene-Holocene transition

Abundant fossil specimens of Scaphechinus mirabilis, now occurring mostly in temperate waters, have been found in the Toukoshan Formation (Pleistocene) in Miaoli County, Taiwan. Environmental changes leading to its extirpation (local extinction) have thus far been elusive. Here, we reconstruct past environmental and oceanic conditions off northwest Taiwan by analyzing clumped isotopes, as well as stable oxygen isotopes, of well-preserved fossil echinoid tests collected from the Toukoshan Formation. Radiocarbon dates suggest that these samples are from Marine Isotope Stage 3 (MIS 3). Paleotemperature estimates based on clumped isotopes indicate that fossil echinoids were living in oceanic conditions that range from 9 to 14 °C on average, comparable with the estimate derived for a modern sample from Mutsu Bay, Japan. Notably, this temperature range is ~ 10 °C colder than today’s conditions off northwest Taiwan. The substantially lower temperatures during ~ 30 ka (MIS 3) compared to the modern conditions might be due to the rerouting of surface currents off northwest Taiwan when the sea level was ~ 60 m lower than today, in addition to the cooling caused by a lower atmospheric CO₂ level during the Last Glacial Period. Colder waters brought here by the China Coastal Current (CCC) and the existence of shallow subtidal zones termed “Miaoli Bay” (mainly located in the present-day Miaoli county) during MIS 3 plausibly sustained generations of S. mirabilis, yielding tens of thousands of fossil specimens in the well-preserved fossil beds. The likely extirpation driver is the drastic change from a temperate climate to much warmer conditions in the shallow sea during the Pleistocene–Holocene transition.

Ancient mitochondrial and modern whole genomes unravel massive genetic diversity loss during near extinction of Alpine ibex

Population bottlenecks can have dramatic consequences for the health and long-term survival of a species. Understanding of historic population size and standing genetic variation prior to a contraction allows estimating the impact of a bottleneck on the species genetic diversity. Although historic population sizes can be modelled based on extant genomics, uncertainty is high for the last 10-20 millenia. Hence, integrating ancient genomes provides a powerful complement to retrace the evolution of genetic diversity through population fluctuations. Here, we recover 15 high-quality mitogenomes of the once nearly extinct Alpine ibex spanning 8601 BP to 1919 CE and combine these with 60 published modern whole genomes. Coalescent demography simulations based on modern whole genomes indicate population fluctuations coinciding with the last major glaciation period. Using our ancient and historic mitogenomes, we investigate the more recent demographic history of the species and show that mitochondrial haplotype diversity was reduced to a fifth of the pre-bottleneck diversity with several highly differentiated mitochondrial lineages having co-existed historically. The main collapse of mitochondrial diversity coincides with elevated human population growth during the last 1-2 kya. After recovery, one lineage was spread and nearly fixed across the Alps due to recolonization efforts. Our study highlights that a combined approach integrating genomic data of ancient, historic and extant populations unravels major long-term population fluctuations from the emergence of a species through its near extinction up to the recent past.

Small brains predisposed Late Quaternary mammals to extinction

The Late Quaternary witnessed a dramatic wave of large mammal extinctions, that are usually attributed to either human hunting or climatic change. We hypothesized that the large mammals that survived the extinctions might have been endowed with larger brain sizes than their relatives, which could have conferred enhanced behavioral plasticity and the ability to cope with the rapidly changing Late Quaternary environmental conditions. We assembled data on brain sizes of 291 extant mammal species plus 50 more that went extinct during the Late Quaternary. Using logistic, and mixed effect models, and controlling for phylogeny and body mass, we found that large brains were associated with higher probability to survive the Late Quaternary extinctions, and that extant species have brains that are, on average, 53% larger when accounting for order as a random effect, and 83% when fitting a single regression line. Moreover, we found that models that used brain size in addition to body size predicted extinction status better than models that used only body size. We propose that possessing a large brain was an important, yet so far neglected characteristic of surviving megafauna species.

A Myth for the Sixth Mass Extinction: Telling Noah’s Story during a Climate Crisis

Myths are open storylines that invite elaboration and modification. The flood narrative of Genesis 6–9, for example, has been readily employed to motivate endangered species protection and to reflect on the rising seas and mass extinctions associated with climate change. The distinctive features of any retelling of the Noah’s ark story reflect the needs of historically situated and culturally embedded audiences. This paper focuses on four versions of Noah’s story: in Genesis, in the Qur’an, at Ark Encounter theme park, and in Darren Aronofsky’s film Noah. Analysis identifies the narrative choices that align each telling with its cultural context and draws out insights for adapting the story for the contemporary climate crisis. A conclusion addresses issues of race and racial injustice in traditional interpretations of Noah’s story, and highlights approaches to redress those inequities in new imaginings of the flood narrative.

Biodiversity crisis or sixth mass extinction?: Does the current anthropogenic biodiversity crisis really qualify as a mass extinction?: Does the current anthropogenic biodiversity crisis really qualify as a mass extinction?

Human actions have caused an increasing number of species to go extinct. Do the available data support concerns about a new mass extinction event?

Late Quaternary dynamics of Arctic biota from ancient environmental genomics

During the last glacial-interglacial cycle, Arctic biotas experienced substantial climatic changes, yet the nature, extent and rate of their responses are not fully understood1-8. Here we report a large-scale environmental DNA metagenomic study of ancient plant and mammal communities, analysing 535 permafrost and lake sediment samples from across the Arctic spanning the past 50,000 years. Furthermore, we present 1,541 contemporary plant genome assemblies that were generated as reference sequences. Our study provides several insights into the long-term dynamics of the Arctic biota at the circumpolar and regional scales. Our key findings include: (1) a relatively homogeneous steppe-tundra flora dominated the Arctic during the Last Glacial Maximum, followed by regional divergence of vegetation during the Holocene epoch; (2) certain grazing animals consistently co-occurred in space and time; (3) humans appear to have been a minor factor in driving animal distributions; (4) higher effective precipitation, as well as an increase in the proportion of wetland plants, show negative effects on animal diversity; (5) the persistence of the steppe-tundra vegetation in northern Siberia enabled the late survival of several now-extinct megafauna species, including the woolly mammoth until 3.9 ± 0.2 thousand years ago (ka) and the woolly rhinoceros until 9.8 ± 0.2 ka; and (6) phylogenetic analysis of mammoth environmental DNA reveals a previously unsampled mitochondrial lineage. Our findings highlight the power of ancient environmental metagenomics analyses to advance understanding of population histories and long-term ecological dynamics.

Wild and trapped: a history of Colombian zoos and its revelations of animal fortunes and State entanglements, 1930s-1990s

This article presents the first history of Colombian zoos and one of the few contributions to the history of these institutions in Latin America. It proposes that in this region's zoos native animals tended to predominate, signaling the increasing transformation of forests and other native ecosystems into croplands and pasturelands, as well as the growing distance between people and natural environments. Colombian zoos additionally underscore the limitations of the State in its period of most rapid expansion. They reveal how private interests overshadowed the State by providing public amenities, but also how they offered unconventional solutions to certain hurdles of State formation.

Humans, megafauna and landscape structure – Rock engravings from Namibia encourage a comparative approach to central Europe and southern Africa

This paper deals with reflections that arose after observing prehistoric rock engravings at different locations in Namibia. These observations stimulated comparative considerations with focus on southern Africa and central Europe. Similar to the Aurignacian rock art of European origin, the most common motifs in the Namibian rock engravings are large animals. While in Europe, the species that served as a blueprint for the illustration of Aurignacian rock art have mostly disappeared, the megafauna illustrated on the rock engravings in Namibia can still be found in the immediate vicinity of the rock art. Against this background, we discuss and further develop a comparative regional approach. We reconstruct and evaluate the suitability of African savannas and still-existing megafauna communities as an appropriate reference-frame for natural European grassland systems and extinct associated warm-adapted megafauna (Eemian Interglacial megafauna). Special attention is laid on the unique situation in Africa in the light of a global extinction wave of megafauna following increasing human activity in the Late Quaternary. This leads us to discuss the use of domesticated ungulates as surrogate taxa to fulfill ecosystem functions in Europe as part of concepts termed “rewilding” or “naturalistic grazing”. After critically examining these concepts, we conclude that using domesticated forms as representatives of extinct or locally disappeared species in Europe has its justification to some extent. If, however, the naturally occurring megaherbivore community still exists (Africa), these naturally occurring species should be given priority due to their organismic abilities and limitations adapted to the harsh conditions in their specific environment. Finally, we discuss the application of (transboundary) protected areas as effective instruments to mitigate human-wildlife conflicts. A holistic approach, including nature conservation and preservation of cultural achievements (domesticated forms, grazing systems), appears promising for the effective protection of the natural African savanna ecosystems with their unique fauna elements, as illustrated in rock engravings that inspired us to write this paper.

Thinking about the Biodiversity Loss in This Changing World

Extinction of species has been a recurrent phenomenon in the history of our planet, but it was generally outweighed in the course of quite a long geological time by the appearance of new species, except, especially, for the five geologically short times when the so-called “Big Five” mass extinctions occurred. Could the current decline in biodiversity be considered as a signal of an ongoing, human-driven sixth mass extinction? This note briefly examines some issues related to: (i) The hypothesized current extinction rate and the magnitude of contemporary global biodiversity loss; (ii) the challenges of comparing them to the background extinction rate and the magnitude of the past Big Five mass extinction events; (iii) briefly considering the effects of the main anthropogenic stressors on ecosystems, including the risk of the emergence of pandemic diseases. A comparison between the Pleistocene fauna dynamics with the present defaunation process and the cascading effects of recent anthropogenic actions on ecosystem structure and functioning suggests that habitat degradation, ecosystem fragmentation, and alien species introduction are important stressors increasing the negative impact on biodiversity exerted by anthropogenic-driven climate changes and their connected effects. In addition, anthropogenic ecological stressors such as urbanization, landscapes, and wildlife trade, creating new opportunities for virus transmission by augmenting human contact with wild species, are among the main factors triggering pandemic diseases.

Late Holocene spread of pastoralism coincides with endemic megafaunal extinction on Madagascar

Recently expanded estimates for when humans arrived on Madagascar (up to approximately 10 000 years ago) highlight questions about the causes of the island's relatively late megafaunal extinctions (approximately 2000-500 years ago). Introduced domesticated animals could have contributed to extinctions, but the arrival times and past diets of exotic animals are poorly known. To conduct the first explicit test of the potential for competition between introduced livestock and extinct endemic megafauna in southern and western Madagascar, we generated new radiocarbon and stable carbon and nitrogen isotope data from the bone collagen of introduced ungulates (zebu cattle, ovicaprids and bushpigs, n = 66) and endemic megafauna (pygmy hippopotamuses, giant tortoises and elephant birds, n = 68), and combined these data with existing data from endemic megafauna (n = 282, including giant lemurs). Radiocarbon dates confirm that introduced and endemic herbivores briefly overlapped chronologically in this region between 1000 and 800 calibrated years before present (cal BP). Moreover, stable isotope data suggest that goats, tortoises and hippos had broadly similar diets or exploited similar habitats. These data support the potential for both direct and indirect forms of competition between introduced and endemic herbivores. We argue that competition with introduced herbivores, mediated by opportunistic hunting by humans and exacerbated by environmental change, contributed to the late extinction of endemic megafauna on Madagascar.

Genome-wide diversity in the California condor tracks its prehistoric abundance and decline

Due to their small population sizes, threatened and endangered species frequently suffer from a lack of genetic diversity, potentially leading to inbreeding depression and reduced adaptability.¹ During the latter half of the twentieth century, North America's largest soaring bird,² the California condor (Gymnogyps californianus; Critically Endangered³), briefly went extinct in the wild. Though condors once ranged throughout North America, by 1982 only 22 individuals remained. Following decades of captive breeding and release efforts, there are now >300 free-flying wild condors and ∼200 in captivity. The condor's recent near-extinction from lead poisoning, poaching, and loss of habitat is well documented,⁴ but much about its history remains obscure. To fill this gap and aid future management of the species, we produced a high-quality chromosome-length genome assembly for the California condor and analyzed its genome-wide diversity. For comparison, we also examined the genomes of two close relatives: the Andean condor (Vultur gryphus; Vulnerable³) and the turkey vulture (Cathartes aura; Least Concern³). The genomes of all three species show evidence of historic population declines. Interestingly, the California condor genome retains a high degree of variation, which our analyses reveal is a legacy of its historically high abundance. Correlations between genome-wide diversity and recombination rate further suggest a history of purifying selection against linked deleterious alleles, boding well for future restoration. We show how both long-term evolutionary forces and recent inbreeding have shaped the genome of the California condor, and provide crucial genomic resources to enable future research and conservation.

Exploring the phylogeography and population dynamics of the giant deer (Megaloceros giganteus) using Late Quaternary mitogenomes

Late Quaternary climatic fluctuations in the Northern Hemisphere had drastic effects on large mammal species, leading to the extinction of a substantial number of them. The giant deer (Megaloceros giganteus) was one of the species that became extinct in the Holocene, around 7660 calendar years before present. In the Late Pleistocene, the species ranged from western Europe to central Asia. However, during the Holocene, its range contracted to eastern Europe and western Siberia, where the last populations of the species occurred. Here, we generated 35 Late Pleistocene and Holocene giant deer mitogenomes to explore the genetics of the demise of this iconic species. Bayesian phylogenetic analyses of the mitogenomes suggested five main clades for the species: three pre-Last Glacial Maximum clades that did not appear in the post-Last Glacial Maximum genetic pool, and two clades that showed continuity into the Holocene. Our study also identified a decrease in genetic diversity starting in Marine Isotope Stage 3 and accelerating during the Last Glacial Maximum. This reduction in genetic diversity during the Last Glacial Maximum, coupled with a major contraction of fossil occurrences, suggests that climate was a major driver in the dynamics of the giant deer.

Towards quantifying the mass extinction debt of the Anthropocene

To make sense of our present biodiversity crises, the modern rate of species extinctions is commonly compared to a benchmark, or 'background,' rate derived from the fossil record. These estimates are critical for bounding the scale of modern diversity loss, but are yet to fully account for the fundamental structure of extinction rates through time. Namely, a substantial fraction of extinctions within the fossil record occurs within relatively short-lived extinction pulses, and not during intervals characterized by background rates of extinction. Accordingly, it is more appropriate to compare the modern event to these pulses than to the long-term average rate. Unfortunately, neither the duration of extinction pulses in the geological record nor the ultimate magnitude of the extinction pulse today is resolved, making assessments of their relative sizes difficult. In addition, the common metric used to compare current and past extinction rates does not correct for large differences in observation duration. Here, we propose a new predictive metric that may be used to ascertain the ultimate extent of the ongoing extinction threat, building on the observation that extinction magnitude in the marine fossil record is correlated to the magnitude of sedimentary turnover. Thus, we propose that the ultimate number of species destined for extinction today can be predicted by way of a quantitative appraisal of humanity's modification of ecosystems as recorded in sediments-that is, by comparing our future rock record with that of the past. The ubiquity of habitat disruption worldwide suggests that a profound mass extinction debt exists today, but one that might yet be averted by preserving and restoring ecosystems and their geological traces.

Relative demographic susceptibility does not explain the extinction chronology of Sahul's megafauna

The causes of Sahul’s megafauna extinctions remain uncertain, although several interacting factors were likely responsible. To examine the relative support for hypotheses regarding plausible ecological mechanisms underlying these extinctions, we constructed the first stochastic, age-structured models for 13 extinct megafauna species from five functional/taxonomic groups, as well as 8 extant species within these groups for comparison. Perturbing specific demographic rates individually, we tested which species were more demographically susceptible to extinction, and then compared these relative sensitivities to the fossil-derived extinction chronology. Our models show that the macropodiformes were the least demographically susceptible to extinction, followed by carnivores, monotremes, vombatiform herbivores, and large birds. Five of the eight extant species were as or more susceptible than the extinct species. There was no clear relationship between extinction susceptibility and the extinction chronology for any perturbation scenario, while body mass and generation length explained much of the variation in relative risk. Our results reveal that the actual mechanisms leading to the observed extinction chronology were unlikely related to variation in demographic susceptibility per se, but were possibly driven instead by finer-scale variation in climate change and/or human prey choice and relative hunting success.

Vulnerabilities of protected lands in the face of climate and human footprint changes

Protected areas (PAs) play a pivotal role in maintaining viable populations of species and minimizing their habitat loss. Globally, there are currently over 200,000 PAs that cover approximately 15% of land area. The post-2020 global biodiversity framework aims to expand this coverage to 30% by 2030. However, focusing only on the percentage coverage of PAs without evaluating their effectiveness may fail to achieve conservation goals. Here, we use a multidimensional approach incorporating species, climate and anthropogenic vulnerabilities to assess the threat levels in over 2500 PAs in China. We identify nearly 10% of PAs as the most threatened PAs in China and about one-fifth PAs as hotspots of climate and anthropogenic vulnerabilities. We also find high climate instability in species vulnerability hotspots, suggesting an elevated likelihood of species' extirpation therein. Our framework could be useful in assessing resiliency of global protected lands and also in selecting near optimal areas for their future expansion.

The evolution of the human trophic level during the Pleistocene

The human trophic level (HTL) during the Pleistocene and its degree of variability serve, explicitly or tacitly, as the basis of many explanations for human evolution, behavior, and culture. Previous attempts to reconstruct the HTL have relied heavily on an analogy with recent hunter-gatherer groups' diets. In addition to technological differences, recent findings of substantial ecological differences between the Pleistocene and the Anthropocene cast doubt regarding that analogy's validity. Surprisingly little systematic evolution-guided evidence served to reconstruct HTL. Here, we reconstruct the HTL during the Pleistocene by reviewing evidence for the impact of the HTL on the biological, ecological, and behavioral systems derived from various existing studies. We adapt a paleobiological and paleoecological approach, including evidence from human physiology and genetics, archaeology, paleontology, and zoology, and identified 25 sources of evidence in total. The evidence shows that the trophic level of the Homo lineage that most probably led to modern humans evolved from a low base to a high, carnivorous position during the Pleistocene, beginning with Homo habilis and peaking in Homo erectus. A reversal of that trend appears in the Upper Paleolithic, strengthening in the Mesolithic/Epipaleolithic and Neolithic, and culminating with the advent of agriculture. We conclude that it is possible to reach a credible reconstruction of the HTL without relying on a simple analogy with recent hunter-gatherers' diets. The memory of an adaptation to a trophic level that is embedded in modern humans' biology in the form of genetics, metabolism, and morphology is a fruitful line of investigation of past HTLs, whose potential we have only started to explore.