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

Conservation of poorly known species is challenging as lack of knowledge on their specific requirements may hamper effective strategies. Here, by integrating biogeographical and landscape analyses, we show that informed actions can be delineated for species with limited presence-only data available. We combine species distribution and connectivity models with temporal land cover changes to define priority areas for conservation of the endemic Brazilian three-banded armadillo, one of the most threatened xenarthrans that was once considered extinct in the wild. We revealed that areas of savanna and grassland are the most suitable habitats for the species and that uplands in the Caatinga ecoregion have a greater likelihood for dispersal. The few remnant armadillo populations are spatially associated with core areas of natural vegetation remnants. Worrisomely, 76% of natural core areas were lost in the past 30 years, mirroring the species’ severe population decline. Preserving the remnant core natural areas should be a high priority to ensure the species’ survival. We highlight key areas for proactive and reactive conservation actions for the three-banded armadillo that will benefit other threatened sympatric species. Our integrative framework provides a set of valuable information for guided conservation management that can be replicated for other poorly known species.

Language diversity is under threat, with between a third to a half of all languages considered endangered, and predicted rates of loss equivalent to one language per month for the rest of the century. Rather than reviewing the extensive body of linguistic research on endangered languages, this review focuses specifically on the interdisciplinary transfer of methods developed in conservation biology, macroecology and macroevolution to the study of language endangerment and loss. While the causes of language endangerment and loss are different to those for species, studying patterns of diversity of species and languages involves similar analytical challenges, associated with testing hypotheses and identifying causal relationships. Solutions developed in biology can be adapted to illuminate patterns in language endangerment, such as statistical methods that explicitly model phylogenetic nonindependence, spatial autocorrelation and covariation between variables, which may otherwise derail the search for meaningful predictors of language endangerment. However, other tools from conservation biology may be much less use in understanding or predicting language endangerment, such as metrics based on International Union for Conservation of Nature (IUCN) criteria, population viability analysis or niche modelling. This review highlights both the similarities and the differences in approaches to understanding the concurrent crises in loss of both linguistic diversity and biodiversity.

Deciding whether or not eradication of an invasive species has been successful is one of the main dilemmas facing managers of eradication programmes. When the species is no longer being detected, a decision must be made about when to stop the eradication programme and declare success. In practice, this decision is usually based on ad hoc rules, which may be inefficient. Since surveillance undertaken to confirm species absence is imperfect, any declaration of eradication success must consider the risk and the consequences of being wrong. If surveillance is insufficient, then eradication may be falsely declared (a Type I error), whereas continuation of surveillance when eradication has already occurred wastes resources (a Type II error). We review the various methods that have been developed for quantifying these errors and incorporating them into the decision-making process. We conclude with an overview of future developments likely to improve the practice of determining invasive species eradication success.

Prioritisation is about choice, and in the context of species extinction, it is about choosing what investments to make to prevent extinctions as opposed to assessing extinction risk, identifying species that are doomed to extinction, or mapping components of biodiversity. Prioritised investments may focus on conservation activities aimed at species protection or management, but they may also seek to acquire new knowledge to resolve uncertainties. Two core components of prioritisation are a clearly stated objective and knowledge of what activities can be undertaken, acknowledging that there are likely to be dependencies between these activities. As the natural environment and society change, so will the enabling conditions for conservation, hence the need to be adaptable and proactive into the future.

In this essay, we explore the philosophical and ethical issues concerning de-extinction. First, we will characterize what de-extinction is. This requires clarification of the process of extinction. Second, we consider whether de-extinction is even possible. There are a variety of arguments involving the nature of species that purport to show that once they have disappeared they cannot be resurrected. Third, we examine whether de-extinction is morally permissible. There are arguments that suggest we are obligated to do it based on restorative justice and biodiversity conservation. There are other arguments that conclude we are not permitted to do so based on considerations of animal welfare, hubris and the allocation of conservation resources.

The significant extinctions in Earth history have largely been unpredictable in terms of what species perish and what traits make species susceptible. The extinctions occurring during the late Pleistocene are unusual in this regard, because they were strongly size-selective and targeted exclusively large-bodied animals (i.e., megafauna, >1 ton) and disproportionately, large-bodied herbivores. Because these animals are also at particular risk today, the aftermath of the late Pleistocene extinctions can provide insights into how the loss or decline of contemporary large-bodied animals may influence ecosystems. Here, we review the ecological consequences of the late Pleistocene extinctions on major aspects of the environment, on communities and ecosystems, as well as on the diet, distribution and behavior of surviving mammals. We find the consequences of the loss of megafauna were pervasive and left legacies detectable in all parts of the Earth system. Furthermore, we find that the ecological roles that extinct and modern megafauna play in the Earth system are not replicated by smaller-bodied animals. Our review highlights the important perspectives that paleoecology can provide for modern conservation efforts.

The link between unsustainable harvest of species for the wildlife trade and extinction is clear in some cases, but little is known about the number of species across taxonomic groups that have gone extinct because of trade-related factors, or future risks for traded species. We conducted a rapid review of published articles and species assessments on the IUCN Red List of Threatened Species with the aim of recording examples of extinctions that were attributed to trade. We found reports of extinctions linked, at least in part, to wildlife trade for 511 unique taxa. These include 294 reports of global extinctions, 25 extinctions in the wild, and 192 local extinctions. The majority of global/in the wild extinctions linked to trade (230) involved ray-finned fishes, primarily due to predation by introduced commercial species. Seventy-one of the 175 reported local extinctions of animal taxa linked to trade were mammals. Twenty-two global/in the wild extinctions and 16 local extinctions of plants were reportedly linked to trade. One fungal species was reported locally extinct due to over-harvesting for trade. Furthermore, 340 species were reported to be near-extinct linked to trade, 269 of which were animals, including several high-profile megafauna. Extinctions were linked to direct harvesting and/or indirect threats such as bycatch or invasive species introduced for trade, but often it was not possible to determine the relative role of trade-related threats in extinctions. Our results highlight the need for better data collection on trade-related extinction risk to understand its impacts and to inform more effective wildlife trade policy.

Species that are evolutionarily distinct have long been valued for their unique and irreplaceable contribution to biodiversity. About 30 years ago, this idea was extended to the concept of phylogenetic diversity (PD): a quantitative, continuous-scale index of conservation value for a set of species, calculated by summing the phylogenetic branch lengths that connect them. This way of capturing evolutionary history has opened new opportunities for analysis, and has therefore generated a huge academic literature, but to date has had only limited impact on conservation practice or policy. In this review, I present a brief historical overview of PD research. I then examine the empirical evidence for the primary rationale of PD that it is the best proxy for “feature diversity,” which includes both known and unknown phenotypic characters, contributing to utilitarian value, ecosystem function, future resilience, and evolutionary potential. Surprisingly, it is only relatively recently that this rationale has been subject to systematic empirical scrutiny, and to date, there are mixed results on the connection between PD and phenotypic diversity. Finally, I examine the least well-studied, but potentially greatest challenge for PD: its dependence on the reliability of phylogenetic inference itself. The very few studies that have investigated this so far show that the ranking of species assemblages by their PD values can vary substantially under alternative, routine, phylogenetic methods and assumptions. If PD is to become more widely adopted into conservation decision-making, it will be important to better understand the conditions under which it performs well, and those under which it performs poorly.

Since the 1980s, the existence of one or more extinction events in the late Ediacaran has been the subject of debate. Discussion surrounding these events has intensified in the last decade, in concert with efforts to understand drivers of global change over the Ediacaran–Cambrian transition and the appearance of the more modern-looking Phanerozoic biosphere. In this paper we review the history of thought and work surrounding late Ediacaran extinctions, with a particular focus on the last 5 years of paleontological, geochemical, and geochronological research. We consider the extent to which key questions have been answered, and pose new questions which will help to characterize drivers of environmental and biotic change. A key challenge for future work will be the calculation of extinction intensities that account for limited sampling, the duration of Ediacaran ‘assemblage’ zones, and the preponderance of taxa restricted to a single ‘assemblage’; without these data, the extent to which Ediacaran bioevents represent genuine mass extinctions comparable to the ‘Big 5’ extinctions of the Phanerozoic remains to be rigorously tested. Lastly, we propose a revised model for drivers of late Ediacaran extinction pulses that builds off recent data and growing consensus within the field. This model is speculative, but does frame testable hypotheses that can be targeted in the next decade of work.

Around the world, countries have introduced laws and policies designed to prevent species extinction. While there have been some success stories, overall, these laws and policies are routinely failing. Extinction rates continue to climb. However, the law is necessary to regulate the human-environment interactions that form the basis of the drivers of extinction and biodiversity loss, including land-clearing, the discharge of greenhouse gases and the introduction of invasive species. The purpose of this paper is to evaluate the literature specifically on biodiversity conservation law, to review and describe the commonalities in laws and legal systems that can be considered successful, or unsuccessful. Laws for the conservation of biodiversity form a critical component for minimising the drivers of extinction, with species extinction being an extreme outcome of biodiversity loss. We reviewed 128 publications from around the world to ascertain and synthesise best practices in law and policy that aim to protect and conserve biodiversity (herein termed ‘biodiversity conservation law’). The literature demonstrated that when it comes to biodiversity conservation law, the concept of ‘best practice’ is elusive, and does not necessarily equate to a reversal in species decline. Further, most western countries utilise the same legal mechanisms (also known as policy tools) for biodiversity conservation, although some countries implement these laws more effectively than others. In this paper, we explore and explain several common legal mechanisms discussed across the range of literature, including species listing and recovery plans, protected area regulation, stewardship, restoration, and offset and no net loss schemes. We also explore the necessity of biodiversity and climate mainstreaming across all laws and highlight the need to engage in genuine partnerships and collaborations with First Nations communities. This paper, and the principles explored herein, should assist law and policymakers to regulate more effectively and explain to those in the conservation sciences where research should be directed to improve the science-policy interface.

The future of biodiversity lies not just in the strategies and mechanisms by which ecosystems and species are practically best protected from anthropogenic pressures. It lies also, and perhaps foremost, in the many billions of decisions that people make that, intentionally or otherwise, shape their impact on nature and the conservation policies and interventions that are implemented. Personalised ecology – the set of direct sensory interactions that each of us has with nature – is one important consideration in understanding the decisions that people make. Indeed, it has long been argued that people’s personalised ecologies have powerful implications, as captured in such concepts as biophilia, extinction of experience and shifting baselines. In this paper, we briefly review the connections between personalised ecology and the future of biodiversity, and the ways in which personalised ecologies might usefully be enhanced to improve that future.

Cardillo M (2023). Phylogenetic diversity in conservation: A brief history, critical overview, and challenges to progress. Cambridge Prisms: Extinction 1, e11.

There is growing evidence to suggest that there is an increase in species extinction occurring globally. In this article, we briefly review the literature on the economics of species extinction, examining what is meant by extinction before explaining how economics has conceptualised this. The initial economics literature on species extinction focuses largely on renewable resources, in particular fisheries, but has subsequently evolved to cover many aspects of biodiversity across all physical scales, employing an increasing array of methodological tools. We also consider aspects of cultural and societal extinctions (e.g. local languages, local knowledge) and how this is positively correlated with loss of biodiversity, as well as an economist’s outlook on the potential to re-capture value post-extinction.