Extinction Research Articles

Amaranthus pakai (Amaranthaceae), a New Critically Endangered Species from the Hawaiian Islands

Amaranthus pakai Faccenda & N. Bayón (Amaranthaceae), a new Hawaiian endemic species from the main islands, is described. It is most probably closely related to A. brownii Cristoph. & Caum, an extinct species from Nihoa Island. It also morphologically resembles A. interruptus R. Br. and A. viridis L. Amaranthus pakai differs from these species in its leaves with elliptical lamina, and pistillate flowers with three widely spathulate sepals, which are longer than the fruits. The first collections date back to the 19th century and suggest that this species was formerly rather widespread across the main Hawaiian Islands, but the population probably crashed during the 1800s. However, these early specimens were misidentified until recently. Amaranthus pakai was last seen in the wild in 2014 and, following its assessment against the IUCN criteria, is considered Critically Endangered, as only 30 to 40 plants were seen at that time.

Subfossils suggest worse-than-realised losses of small-bodied mammals in northern Australia

Context Examining Australia’s late Quaternary subfossil record can be valuable in assessing whether the current diversity of small-bodied mammals seen across some parts of northern Australia is ‘normal’. Such records are important for establishing baselines for measuring historic changes in communities today and into the future. These datasets are becoming increasingly important, given trajectories in current global climate change, and predicted habitat losses and other potential anthropogenic impacts. Aims The main aim of this study is to utilise the local subfossil record from north-eastern Australia to establish a natural baseline for assessing changes in small mammal communities post-European colonisation. Methods Subfossils of vertebrates and other taxa were recovered from surface deposits adjacent to cave entrances at Broken River, near Greenvale in north-eastern Queensland, and were subjected to taxonomic, taphonomic and statistical analyses. These were then compared with local faunal records from modern surveys to compare differences in faunal communities between past and present. Key results Radiocarbon dating showed that these subfossils are geologically young, dating to approximately the time of European colonisation. We provide evidence for the former presence of extinct species of hopping mice (Notomys spp.) and rabbit rats (Conilurus spp.) in the region. Additional locally extirpated taxa such as Cape York bandicoot (Isoodon peninsulae) and Shark Bay mouse (Pseudomys gouldii) demonstrated considerable range contractions since the deposits accumulated, compared with their current distribution. Independent evidence from subfossil land snails recovered from these deposits is, with two exceptions, all modern-day vine thicket, karst-dwelling species indicating a long-term maintenance of vine thicket habitat. Thus, the loss of several mammal species is unlikely to be the result of habitat loss. Conclusions Analysis of the surface deposits showed that local historic small-mammal communities were much more diverse than are the region’s extant faunas recorded by modern surveys. Many extinctions and extirpations evidently occurred prior to such faunas being recorded as local inhabitants of the region. Implications Our data suggested that post-European colonisation small-mammal losses are likely to be substantially worse than previously realised.

Climate change threatens amphibians and species representation within protected areas in tropical wetlands

Abstract Protected areas (PAs) are crucial for biodiversity conservation, yet climate change threatens their long‐term effectiveness by displacing species distributions. Among the most climate‐threatened organisms are the amphibians, highly dependent on water and wetlands. The world's largest continuous tropical wetland, the Pantanal and surroundings, is situated in the Upper Paraguay River Basin (UPRB) in South America. Of the 74 amphibian species found there, 4% are threatened. Less than 5% of the basin is within PAs. Recurrent droughts and increasing human pressures further endanger the region's semiaquatic fauna if adequate protection measures are not implemented. Using Ensemble of Small Models, we mapped habitat suitability of amphibian species and projected amphibian richness and composition across the UPRB. We applied null models to evaluate the representation of amphibian ranges within the current PA network under both current and future climate scenarios. To prioritize areas for PA network expansion under climate change scenarios, we used a systematic conservation planning algorithm. By 2100, over 80% of amphibian species from the study area are projected to lose suitable habitat, with 99% of amphibian assemblages facing climate‐driven species loss. Although the existing PA network had limited species representation, protecting on average less than 5% of amphibian ranges. However, 13.7% of PAs are expected to shelter more amphibian species than expected by chance under future climate conditions. Highlands, particularly in the northern and southeastern boundaries of the UPRB, are identified priority areas for PA network expansion due to their high projected changes in amphibian biodiversity. Synthesis and applications. Our findings reveal the extensive impacts of climate change on a major semiaquatic group in the world's largest tropical wetland. Although the current PA network in the Pantanal and surroundings safeguards fewer amphibians than expected, its limited coverage provides opportunities for systematic, data‐driven expansion to achieve the Post‐2020 Global Biodiversity Framework's 30 by 30 target. Expanding PAs is urgent, but addressing drivers of environmental degradation, including unsustainable practices in agriculture and livestock farming, is equally critical for conserving this biodiverse ecosystem.

Potential plant extinctions with the loss of the Pleistocene mammoth steppe

During the Pleistocene-Holocene transition, the dominant mammoth steppe ecosystem across northern Eurasia vanished, in parallel with megafauna extinctions. However, plant extinction patterns are rarely detected due to lack of identifiable fossil records. Here, we introduce a method for detection of plant taxa loss at regional (extirpation) to potentially global scale (extinction) and their causes, as determined from ancient plant DNA metabarcoding in sediment cores (sedaDNA) from lakes in Siberia and Alaska over the past 28,000 years. Overall, potential plant extinctions track changes in temperature, in vegetation, and in megafauna extinctions at the Pleistocene-Holocene transition. Estimated potential plant extinction rates were 1.7–5.9 extinctions per million species years (E/MSY), above background extinction rates but below modern estimates. Major potential plant extinction events were detected around 17,000 and 9000 years ago which lag maximum vegetation turnover. Our results indicate that herbaceous taxa and taxa contributing less to beta diversity are more vulnerable to extinction. While the robustness of the estimates will increase as DNA reference libraries and ancient sedaDNA data expand, the available data support that plants are more resilient to environmental changes than mammals.

EutherianCoP. An integrated biotic and climate database for conservation paleobiology based on eutherian mammals

We present a new database, EutherianCoP, of fossil mammals which lived globally from the Late Pleistocene to the Holocene. The database includes 13,972 fossil occurrences of 786 extant or recently extinct placental mammal species, plus 155,198 current occurrences for those of them which survived to the present. The occurrences are correlated with radiometric age information. For all species, we provide 32 different traits, inclusive of taxonomic, phenotypic, life history, biogeographic and phylogenetic information. Differently from any other compilation, the occurrences are complemented with estimates of past climatic conditions, including site-interpolated monthly and annual precipitation and temperature, leaf area index, megabiome type and net primary productivity, which are derived from transient paleo model simulations conducted with the Community Earth System Model 1.2 and the BIOME4 vegetation model. All data are further downloadable for further investigation.

Assessments of the earliest bats from the Quaternary of Serra da Mesa (Goiás, Brazil): phylogenetic insights and biogeographic modelling on the new extinct species of Rhinophylla, the first fossil record of the subfamily Rhinophyllinae (Chiroptera, Mammalia)

ABSTRACT Recovered from Quaternary deposits in Carneiro Cave (Serra da Mesa, Brazil), associated with a clayey-sandy sedimentary influx older than the overlying calcite layer, which has been dated to 182.8 ± 1.2 ka, a new extinct species of Rhinophylla is described based on a proximal radio fragment. This discovery represents one of the three oldest occurrences of Chiroptera in the exposed stratigraphic profile. The fossil record of Chiroptera consists of 1,117 bone fragments, distributed across Pleistocene and Holocene sedimentary packages. The chronology of this sedimentary sequence is established using dated layers, all of which are fully consistent with their order of deposition. A comparative study of the radioulnar morphology was conducted to determine the taxonomic identity of the new fossil bat. A strict consensus tree for phyllostomids was obtained, surprisingly consistent with recent molecular phylogenies, unequivocally places the new fossil in the subfamily Rhinophyllinae. Biogeographic modelling of Rhinophylla, typically characterised by an ecomorphology of small specialised epiphytic frugivores, suggests that around 200 ka (the fossil’s age reference) the genus may have had a broader distribution across Central Brazil than is observed today. This is consistent with the fact that Rhinophylla is currently absent in the surrounding region of the Carneiro Cave.

Comparative diversification analyses of Hydrangeaceae and Loasaceae reveal complex evolutionary history as species disperse out of Mesoamerica.

The movement of lineages into novel areas can promote ecological opportunity and adaptive radiation, leading to significant species diversity. Not all studies, however, have identified support for ecological opportunity associated with novel intercontinental colonizations. To gain key insights into the drivers of ecological opportunity, we tested whether intercontinental dispersals resulted in ecological opportunity using the Hydrangeaceae-Loasaceae clade, which has numerous centers of diversity across the globe. A time-calibrated phylogeny was reconstructed from four molecular markers. We tested for bursts of speciation rates followed by a decrease as expected phylogenetic patterns under an ecological opportunity model. Ancestral ranges were estimated using historical biogeographic analyses to examine the relationships of ancestral distributions and habitats with speciation and extinction rates. Hydrangeaceae and Loasaceae originated in arid Mesoamerica, then dispersed into South America, Eurasia, and eastern North America. Six clades experienced increased diversification rates, but those increases were not associated with transitions into new continental areas. Mentzelia section Bartonia was the only clade that exhibited a burst of speciation followed by a decrease. Both families originated in arid environments and experienced multiple transitions into mesic and tropical environments, but Loasaceae experienced a higher speciation-to-extinction ratio than Hydrangeaceae in the western Nearctic. Dispersal between continents did not trigger speciation rate shifts in Loasaceae and Hydrangeaceae. Instead, shifts occurred in regions inhabited by intrafamilial relatives and were likely driven by climate change in the Miocene, where species in drier microhabitats diversified into newly created habitats.

Assessment of Different Conventional and Biofortified Wheat Genotypes Based on Biology and Damage Pattern of Rhyzopertha dominica and Trogoderma granarium

The lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) and khapra beetle, Trogoderma granarium E. (Coleoptera: Dermestidae) are primary stored-grain insect pests. Differences in certain biological and physical parameters of both pest species and wheat genotypes were investigated under laboratory conditions. Zinc (Zn)-biofortified (Zincol-2016 and Akbar-2019) and conventional (Arooj-2022, Nawab-2021, Dilkash-2021, Bhakkar Star-2019) wheat genotypes were used in this study. Zn-biofortified genotypes outperformed the conventional ones, with significant differences observed in fecundity, percent adult emergence, total developmental duration, percent grain damage, and weight loss of both insect species. The results further revealed that the fecundity of R. dominica and T. granarium were lowest on Akbar-2019 in both the free-choice test (42.50 and 33.17) and no-choice test (35.50 and 32.50), respectively. Similarly, percent adult emergence of both insect species was also lowest on Akbar-2019 in both the free-choice test (69.78 and 70.28%) and no-choice test (67.38 and 70.71%). The total developmental period also showed significant variation among the tested genotypes. The longest developmental period was recorded in Akbar-2019, i.e., 44.33 and 58.83 days, for R. dominica and T. granarium, respectively. Similarly, percent grain damage (13.23 and 10.33%) and weight loss (3.62 and 2.12%) were found to be minimum in Akbar-2019 for both pest species, respectively. Additionally, a positive correlation was observed between grain moisture content and damage parameters, suggesting that the higher moisture content may aggravate the percent grain damage and weight loss. These findings indicate that the nutritional qualities of Zn-biofortified wheat genotypes negatively affected the development of both insect species; thus, it can be an efficacious approach not only for ensuring food security but also for protecting grains against storage pests.

FOGS: A SNPSTR Marker Database to Combat Wildlife Trafficking and a Cell Culture Bank for Ex-Situ Conservation.

Illegal wildlife trade is a growing problem internationally. Poaching of animals not only leads to the extinction of populations and species but also has serious consequences for ecosystems and economies. This study introduces a molecular marker system that authorities can use to detect and substantiate wildlife trafficking. SNPSTR markers combine short tandem repeats with single nucleotide polymorphisms within an amplicon to increase discriminatory power. Within the FOGS (Forensic Genetics for Species Protection) project, we have established SNPSTR marker sets for 74 vertebrate species. On average, each set consists of 19 SNPSTR markers with 82 SNPs per set. More than 1300 SNPSTR markers and over 300 STR markers were identified. Also, through its biobanking pipeline, the FOGS project enabled the cryopreservation of somatic cells from 91 vertebrate species as well as viable tissues for later cell initiation from a further 109 species, providing future strategies for ex situ conservation. In addition, many more fixed tissues and DNA samples of endangered species were biobanked. Therefore, FOGS was an interdisciplinary study, combining molecular wildlife forensics and conservation tools. The SNPSTR sets and cell culture information are accessible through the FOGS database (https://fogs-portal.de/data) that is open to scientists, researchers, breeders and authorities worldwide to protect wildlife from illegal trade.

The genetic structure of the ash obligate moth prays fraxinella suggests that it is not affected by current habitat fragmentation

Tree diseases may cause the extirpation or functional extinction of a common tree species on large spatial scales. For example, ash dieback (Hymenoscyphus fraxineus) is expected to cause widespread loss of European ash (Fraxinus excelsior). This type of widespread loss of a tree species may have consequences for the ability of some insects to move between woodlands, particularly obligate species (species reliant on one tree species for food). Our aim was to use ddRAD-seq genetic data to determine the population structure of Prays fraxinella (ash bud moth), an ash-obligate micro-moth, and to assess its ability to maintain connectivity across fragmented patches of native broadleaf woodlands. We found no evidence of genetic structuring at local (up to 44 km) spatial scales, and no evidence of inbreeding. At regional scales (up to 426 km), we found evidence of mixed ancestry and long-distance dispersal. Our research highlights that given its ability to maintain gene flow in areas where woodlands have historically been very fragmented, P. fraxinella may continue to maintain connectivity under moderate future tree losses under ongoing ash dieback outbreaks. Implications for insect conservation: Our research highlights the potential indirect impacts of ash-dieback through losses in connectivity. This approach should be extended to other ash-obligate species, under various levels of existing fragmentation, to inform conservation strategies more fully for managing ash dieback.

Accounting for functionality in the identification of global conservation priorities: promises and pitfalls.

Whereas preventing species extinctions remains a central objective of conservation efforts, it must be complemented by the long-term preservation of functional ecosystems and of the benefits humans derive from them. Here, I review recent approaches that explicitly account for functionality in setting large-scale conservation priorities, discussing their promise while highlighting challenges and pitfalls. Crossing data on species' distributions and ecological traits has enabled the mapping of global patterns of functional diversity and functional rarity and the identification of species that stand out for their functional distinctiveness. However, the priorities identified through these general indices do not directly address ecosystem functionality, instead, they are methods for ensuring the representation of individual functional traits as intrinsically valuable biodiversity elements. Three other approaches integrate functionality into large-scale priorities by taking into account the specific context of each ecosystem, site or species: the International Union for Conservation of Nature's Red List of Ecosystems, Key Biodiversity Areas and the Green Status of Species. Currently at various stages of development, testing and implementation, these approaches are playing an increasingly important role in the definition, implementation and monitoring of global- and national-scale conservation strategies to ensure the long-term persistence of ecosystem functions and associated ecosystem services.This article is part of the discussion meeting issue 'Bending the curve towards nature recovery: building on Georgina Mace's legacy for a biodiverse future'.

Bisphenol S induced endothelial dysfunction via mitochondrial pathway in the vascular endothelial cells, and detoxification effect of albumin binding.

As a replacement of bisphenol A, bisphenol S (BPS) is commonly used in the wrappers and food containers of daily life. Epidemiological studies demonstrate a close link between BPS exposure and vascular diseases, where the biological activities of BPS remain scarcely known. Herein, the effects of BPS on endothelial function as well as the underlying mechanism were investigated in human umbilical vein endothelial cells (HUVECs) and mouse arteries. It was found that exposure of BPS dose-dependently induced endothelial dysfunction (i.e., decline of nitric oxide (NO) formation) in HUVECs, accompanied by the increase of reactive oxygen species (ROS) production and loss of mitochondria membrane potential. Mitochondria-specific antioxidant (Mito-Tempol) or superoxide scavenger (tiron) abolished the harmful effects of BPS, while superoxide dismutase (SOD)-specific siRNA exhibited negative influence, suggesting that mitochondrial ROS was responsible for BPS-induced endothelial dysfunction and SOD was a sensitive target of BPS. Consistently, plasma NO formation and endothelium-dependent vasodilation was significantly impaired in mice exposed to dietary BPS. In addition, the binding of bovine serum albumin (BSA, the most abundant protein in blood) to BPS considerably alleviated ROS formation and endothelial dysfunction in HUVECs. BPS primarily interacted with Sudlow site I of albumin to generate BSA-BPS complex through static mechanism, in which the hydrogen bonds and electrostatic forces played important roles. Altogether, dietary exposure to emerging BPS would disrupt vascular homeostasis via the induction of mitochondrial ROS formation and consequent endothelial dysfunction, highlighting the detoxification impact of albumin protein on the hazardous effects of environmental pollutants.

Effects of water and sediment chemistry variables on aquatic macroinvertebrate community structuring in a subtropical Austral river system.

Riverine physical and chemical characteristics are influencing ecosystem integrity while shaping and impacting species richness and diversity. Changes in these factors could potentially influence community structuring through competition, predation and localised species extinctions. In this study, eight sampling sites over multiple seasons were assessed along the streams draining the City of Nelspruit, South Africa, to examine river health based on water and sediment quality, while using macroinvertebrates as bioindicators for pollution. All water variables with the exception for salinity were found to be significantly different among seasons, with sites having significant differences among all water variables. All sediment chemistry variables were also found to be significantly different among sites and seasons, with the exception of K for sites and Zn and Ca for seasons. The PCA factor loadings and two-cluster analysis identified two groupings, i.e. group 1 that consisted of all metals apart from K and Na and group 2 with K and Na metals. A total of 4470 macroinvertebrate taxa were identified, with Crustacea Caridina nilotica and Diptera Chironominae being dominant across seasons, with macroinvertebrate communities being found to be significantly different among sites and seasons. The most common functional feeding groups across sites were the collector-gatherers (52.2%), followed by collector-filters (26.8%), predators (16.4%), scrapers (4.4%) and shredders (0.1%). Boosted regression trees indicated that high variation in species richness occurred with change in resistivity, P, water pH, ORP, conductivity and S concentrations. These results evidence a strong linkage among the sediment, water quality, substratum embeddedness and habitat structure and community structure. It is important to protect the integrity of aquatic ecosystems through effective monitoring due to the increasing water and sediment quality pressures that arise from various anthropogenic activities.

IUCN Red List criteria fail to recognise most threatened and extinct species

Many species have benefited from management actions associated with listing as threatened on the IUCN Red List, resulting in fewer extinctions relative to business as usual. Red List criteria used to categorise threat status have, however, been designed with primary focus on higher vertebrates, and consequently produce inconsistent and deficient threat assessments for other taxa. Equally valid decisions on population trend shape, generation length, period of assessment, and habitat quality can result in threat status determinations ranging from Least Concern to Critically Endangered. Moreover, inconspicuous species exhibiting catastrophic population decline to below detection limits can ultimately be regarded as Data Deficient, thus categorised as neither extinct nor threatened. Under-estimation of extinction frequency biases our understanding of global environmental change and the urgent need for societal action. Improved extinction risk assessments can be achieved with changes and simplification of Red List criteria, and detailed case examples that guide progress through decision-points.

Calcium and strontium isotopes in extant diapsid reptiles reflect dietary tendencies-a reference frame for diet reconstructions in the fossil record.

Dietary preferences of extant reptiles can be directly observed, whereas diet reconstruction of extinct species typically relies on morphological or dental features. More specific information about the ingested diet is contained in the chemistry of hard tissues. Stable isotopes of calcium and strontium show systematic fractionations between diet and skeletal bioapatite, which is applied for diet and trophic-level reconstructions of extant and extinct vertebrate species. Here, we present the first comprehensive analysis of stable calcium and strontium isotopes of bones and teeth from 28 extant reptiles, including lepidosaurs and archosaurs (crocodilians) with distinct herbivorous to faunivorous feeding behaviour, establishing a dietary reference frame. Both calcium and strontium isotopes exhibit systematic offsets between dietary groups, with insectivores having the highest, herbivores intermediate and carnivores the lowest calcium and strontium isotope values. Although the isotopic trophic-level effect is similar to mammals, the absolute calcium isotope values in reptiles are more positive in each diet category. Combining isotopic data with dental microwear texture analysis enables a refined understanding of reptile feeding ecology and the identification of durophagous diets. This toolbox opens new possibilities for improved dietary reconstructions of extinct taxa, such as dinosaurs and other non-mammalian species in the fossil record.

Genomic data reveal that the Cuban blue-headed quail-dove (Starnoenas cyanocephala) is a biogeographic relict.

Islands are well known for their unique biodiversity and significance in evolutionary and ecological studies. Nevertheless, the extinction of island species accounts for most human-caused extinctions in recent time scales, which have accelerated in recent centuries. Pigeons and doves (Columbidae) are noteworthy for the high number of island endemics, as well as for the risks those species have faced since human arrival. On Caribbean islands, no other columbid has generated more phylogenetic interest and uncertainty than the blue-headed quail-dove, Starnoenas cyanocephala. This endangered Cuban endemic has been considered more similar, both behaviourally and phenotypically, to Australasian species than to the geographically closer 'quail-dove' (Geotrygon s.l.) species of the Western Hemisphere. Here, we use whole genome sequencing from Starnoenas and other newly sequenced columbids in combination with sequence data from previous publications to investigate its relationships. Phylogenomic analyses, which represent 35 of the 51 genera currently comprising the Columbidae, reveal that the blue-headed quail-dove is the sole representative of a lineage diverging early in the radiation of columbids. Starnoenas is sister to the species-rich subfamily Columbinae, which is found worldwide. As a highly distinctive evolutionary lineage lacking close modern relatives, we recommend elevating the conservation priority of Starnoenas.

Ecological and anthropogenic drivers of local extinction and colonization of giant pandas over the past 30 years

AbstractUnderstanding the patterns and drivers of species range shifts is essential to disentangle mechanisms driving species' responses to global change. Here, we quantified local extinction and colonization dynamics of giant pandas (Ailuropoda melanoleuca) using occurrence data collected by harnessing the labor of >1000 workers and >60,000 worker days for each of the three periods (TP1: 1985–1988, TP2: 1998–2002, and TP3: 2011–2014), and evaluated how these patterns were associated with (1) protected area, (2) local rarity/abundance, and (3) abiotic factors (i.e., climate, land‐use, and topography). We documented a decreased rate (from 0.433 during TP1–TP2 to 0.317 during TP2–TP3) of local extinction and a relatively stable rate (from 0.060 during TP1–TP2 to 0.056 during TP2–TP3) of local colonization through time. Furthermore, the occupancy gains have exceeded losses by a ratio of approximately 1.5 to 1, illustrating an expansion of panda's range at a rate of 1408.3 km2/decade. We also found that pandas were more likely to become locally extinct outside of protected areas, when locally rare in surrounding areas, and when certain biotic conditions were not met (e.g., increased forest cover). Local colonization was less likely in areas with high local rarity, challenging biotic conditions and unprotected area status. As the network of panda reserves expanded and the forest matured, the relative importance of other factors such as climate, biotic factors, and land‐use became more influential in determining patterns of local extinction and colonization. Our findings provide insights into the factors governing the expansion of panda's range and illustrate how the relative influence of biotic and abiotic factors can change over time, indicating that effective conservation intervention may be able to mitigate some of the negative impacts of climate change and habitat degradation. This insight extends beyond pandas and highlights the role of conservation interventions can play in building resilience under a changing climate.

Beyond the Hayflick limit: How microbes influence cellular aging.

Cellular senescence, a complex biological process resulting in permanent cell-cycle arrest, is central to aging and age-related diseases. A key concept in understanding cellular senescence is the Hayflick Limit, which refers to the limited capacity of normal human cells to divide, after which they become senescent. Senescent cells (SC) accumulate with age, releasing pro-inflammatory and tissue-remodeling factors collectively known as the senescence-associated secretory phenotype (SASP). The causes of senescence are multifaceted, including telomere attrition, oxidative stress, and genotoxic damage, and they extend to influences from microbial sources. Research increasingly emphasizes the role of the microbiome, especially gut microbiota (GM), in modulating host senescence processes. Beneficial microbial metabolites, such as short-chain fatty acids (SCFAs), support host health by maintaining antioxidant defenses and reducing inflammation, potentially mitigating senescence onset. Conversely, pathogenic bacteria like Pseudomonas aeruginosa and Helicobacter pylori introduce factors that damage host DNA or increase ROS, accelerating senescence via pathways such as NF-κB and p53-p21. This review explores the impact of bacterial factors on cellular senescence, highlighting the role of specific bacterial toxins in promoting senescence. Additionally, it discusses how dysbiosis and the loss of beneficial microbial species further contribute to age-related cellular deterioration. Modulating the gut microbiome to delay cellular senescence opens a path toward targeted anti-aging strategies. This work underscores the need for deeper investigation into microbial influence on aging, supporting innovative interventions to manage and potentially reverse cellular senescence.

A Highly Divergent Mitochondrial Genome in Extant Cape Buffalo From Addo Elephant National Park, South Africa.

The reduced cost of next-generation sequencing (NGS) has allowed researchers to generate nuclear and mitochondrial genome data to gain deeper insights into the phylogeography, evolutionary history and biology of non-model species. While the Cape buffalo (Syncerus caffer caffer) has been well-studied across its range with traditional genetic markers over the last 25 years, researchers are building on this knowledge by generating whole genome, population-level data sets to improve understanding of the genetic composition and evolutionary history of the species. Using publicly available NGS data, we assembled 40 Cape buffalo mitochondrial genomes (mitogenomes) from four protected areas in South Africa, expanding the geographical range and almost doubling the number of mitogenomes available for this species. Coverage of the mitogenomes ranged from 154 to 1036X. Haplotype and nucleotide diversity for Kruger National Park (n = 15) and Mokala National Park (n = 5) were similar to diversity levels in southern and eastern Africa. Hluhluwe-iMfolozi Park (n = 15) had low levels of genetic diversity, with only four haplotypes detected, reflecting its past bottleneck. Addo Elephant National Park (n = 5) had the highest nucleotide diversity of all populations across Africa, which was unexpected, as it is known to have low nuclear diversity. This diversity was driven by a highly divergent mitogenome from one sample, which was subsequently identified in another sample via Sanger sequencing of the cytochrome b gene. Using a fossil-calibrated phylogenetic analysis, we estimated that this lineage diverged from all other Cape buffalo lineages approximately 2.51 million years ago. We discuss several potential sources of this mitogenome but propose that it most likely originated through introgressive hybridisation with an extinct buffalo species, either S. acoelotus or S. antiquus. We conclude by discussing the conservation consequences of this finding for the Addo Elephant National Park population, proposing careful genetic management to prevent inbreeding depression while maintaining this highly unique diversity.

Supporting Wildlife Restoration in Eastern States via State Wildlife Action Plans

ABSTRACTThe biodiversity crisis is driven by extinction at two scales: the global extinction of species and the local extirpation of populations (i.e., range contraction). Local extirpations are especially acute in the eastern United States, which has lost a substantial portion of its native mammalian fauna. Species restoration in the U.S., therefore, should be utilised more to revitalise and restore degraded systems. State wildlife agencies can elevate discussions about species restoration and facilitate internal capacity to conduct restoration projects by including locally extirpated species in State Wildlife Action Plans, which are currently under revision, and will guide state conservation programs for the next 10 years.