Species

Prior to the advent of whole-genome sequencing in ancient humans, the likelihood that Homo sapiens and Neanderthals admixed has long been debated, mostly on the basis of phenotypic assessments alone. Today, evidence for archaic hominin admixture is being documented in an increasing number of studies, expanding the evidential basis of the debate on whether Homo sapiens and Neanderthals merit separate specific taxonomic status. Here we argue that while new evidence has provided us with a finer-grained picture of ancient intra- and (...) intergroup demographic dynamics, it does not yet justify merging the Neanderthals in an expanded concept of Homo sapiens or abandoning specific taxonomies. We approach this issue and the apparent conflict between molecular and morphology-based taxonomies from a diachronic perspective on lineage divergence, highlighting how different taxonomic properties are expected to arise at different points in time, and from an integrative perspective on different species conceptions and delimitation criteria. We argue that in light of similar “invasions” of the genome among other animal taxa, full reproductive isolation as the final, litmus test for distinct species status should be rather considered a biologically misplaced expectation. Therefore, we suggest that specific nomenclature should not be perceived with embarrassment but rather be justifiably applied in human paleogenomic publications, maintaining congruence with zoological literature. We then briefly consider and problematize recent suggestions that human evolutionary diversification should now be best represented by a ‘braided stream” or a network. We conclude by putting our paleoanthropological case study in the broader context of species delimitation in the genomic era. (shrink)

-/- Species lists play an important role in biology and practical domains like conservation, legislation, biosecurity and trade regulation. However, their effective use by non-specialist scientific and societal users is sometimes hindered by disagreements between competing lists. While it is well-known that such disagreements exist, it remains unclear how prevalent they are, what their nature is, and what causes them. In this study, we argue that these questions should be investigated using methods based on taxon concept rather than methods based (...) on Linnaean names, and use such a concept-based method to quantify disagreement about bird classification and investigate its relation to research effort. We found that there was disagreement about 38% of all groups of birds recognized as a species, more than three times as much as indicated by previous measures. Disagreement about the delimitation of bird groups was the most common kind of conflict, outnumbering disagreement about nomenclature and disagreement about rank. While high levels of conflict about rank were associated with lower levels of research effort, this was not the case for conflict about the delimitation of bird groups. This suggests that taxonomic disagreement cannot be resolved simply by increasing research effort. (shrink)

Some plausibly necessary a posteriori theoretical claims include ‘water is H 2 O’, ‘gold is the element with atomic number 79’, and ‘cats are animals’. In this paper I challenge the necessity of the third claim. I argue that there are possible worlds in which cats exist, but are not animals. Under any of the species concepts currently accepted in biology, organisms do not belong essentially to their species. This is equally true of their ancestors. In phylogenetic systematics, monophyletic clades (...) such as the animal kingdom are composed of an ancestral stem species and all of its descendants. If the stem species had not existed, neither would the clade. Thus it could have been the case that all the organisms which actually belong to the animal kingdom might have existed yet not have been animals. (shrink)

Abstract:Should we use modern bioengineering techniques to design species? An instrumentalist account of species’ value offers permissive guidance. But what if species exemplify final value? Is it always very good to create new species? Is it always very wrong to blend or modify existing species? In this paper, I argue that both extremes are implausible. However, final value theories struggle to deliver a flexible, moderate treatment of these issues, and so the ethics of designing species presents a challenge for final (...) value theorists. Fortunately, a design-based account of the value of species has the resources to offer plausible, nuanced, context-sensitive guidance on the ethics of designing species. It holds that designing species is sometimes very bad, sometimes quite good, and sometimes neither very good nor very bad. The plausibility of these results lends credibility to the design-based framework, and gives final value theorists reason to prefer the design-based approach. (shrink)

This review provides an overview of the ethics of extinctions with a focus on the Western analytical environmental ethics literature. It thereby gives special attention to the possible philosophical grounds for Michael Soulé’s assertion that the untimely ‘extinction of populations and species is bad’. Illustrating such debates in environmental ethics, the guiding question for this review concerns why – or when – anthropogenic extinctions are bad or wrong, which also includes the question of when that might not be the case (...) (i.e. which extinctions are even desirable). After providing an explanation of the disciplinary perspective taken (section “Introduction”), the concept of extinction and its history within that literature are introduced (section “Understanding extinction”). Then, in section “Why (or when) might anthropogenic extinctions be morally problematic?”, different reasons for why anthropogenic extinctions might be morally problematic are presented based on the loss of species’ value, harm to nonhuman individuals, the loss of valuable biological variety and duties to future generations. This section concludes by also considering cases where anthropogenic extinctions might be justified. Section “How to respond to extinctions?” then addresses a selection of topics concerning risks and de-extinction technologies. Finally, the section on “Extinction studies” introduces other viewpoints on the ethics of extinction from the extinction studies literature, followed by the “Conclusion”. (shrink)

Pluralistic approaches in the philosophy of biological individuality suggest that reality is divisible into multiple types of biological individuals (evolutionary, genetic, physiological, etc.). In this research I will argue in favor of this pluralistic ontology. Inspired mainly by John Dupré’s processual metaphysics, Ronald Giere’s perspectivism, and Hasok Chang’s active realism, I will suggest that: (i) biological individuals are temporarily stable nexuses in a flow of causal processes, (ii) individuations in biology represent real individuals only under the scientific perspectives that support (...) them, (iii) biology’s ability to recognize diverse types of individuals comes from epistemically successful individuation practices. These practices not only contact us with multiple sites of reality, but also invite us to embrace pluralism as an effective way to increase our scientific knowledge of nature. (shrink)

Should we kill animals to save animals? This question lies at the heart of this case study. Sovereign nations have an interest in protecting and conserving their natural resources, and in particular their distinctive flora and fauna. As they seek to promote these interests, they inevitably face the economic question of how they are going to finance their conservation efforts. One way of answering this question is to engage in the practice of selling big game hunting licenses and using the (...) revenues to fund conservation programs. This strategy is counterintuitive (and to some, morally repellent); but it has a partial track record of success in places such as Namibia, South Africa, and the United States. Despite its successes, there are some who believe that the moral objections to such a strategy outweigh any potential benefits. This case study provides the student with an opportunity to explore the tension between the desire to save endangered animals and the possibility that the best way to do that involves killing some of them. (shrink)

Species, or ‘the Species Problem’, is a topic in science, in the philosophy of science, and in general philosophy. There is not one, but many, species problems, and these are dealt with in this volume. Species are often thought of as units of biology, to be used in ecology, conservation, classification, and theory. The chapters in this book present opposing views on the current philosophical and conceptual issues of the Species Problem in biology. -/- Divided into four sections Theories and (...) Concepts, Practice and Methods, Ranks, Trees and Names, and Metaphysics and Epistemologies, the book is authored by systematists, philosophers, historians and working biologists, many leaders in their fields. Topics include Essentialism and individuals, speciation modes, theory and the species rank, nomenclature and diagnosis, scale of species, and ecology, conservation, and species. -/- Species Problems and Beyond aims to clarify the contemporary issues of the Species Problem. It is ideal for use in upper-level seminars and courses in Evolutionary Biology, Philosophy of Science, Philosophy of Biology, Systematics and Taxonomy, and Phylogenetics/Cladistics, and for any scholar in these fields. (shrink)

Evolutionary conceptions of species place special weight on each species having dynamic independence as a unit of evolution. However, the idea that species have their own historical fates, tendencies, or roles has resisted systematic analysis. Growing evidence from population genomics shows that many paradigm species regularly engage in hybridization. How can species be defined in terms of independent evolutionary identities if their genomes are dynamically coupled through lateral exchange? I introduce the concept of a “composite lineage” to distinguish species and (...) subspecies on the basis of the proportion of a group’s heritable traits that are uncoupled from reproductive exchange. (shrink)

One primary goal for metaphysical theories of natural kinds is to account for their epistemic fruitfulness. According to cluster theories of natural kinds, this epistemic fruitfulness is grounded in the regular and stable co- occurrence of a broad set of properties. In this paper, I defend the view that such a cluster theory is insufficient to adequately account for the epistemic fruitfulness of kinds. I argue that cluster theories can indeed account for the projectibility of natural kinds, but not for (...) several other epistemic operations that natural kinds support. Natural kinds also play a role in scientific explanations and categorizations. A theory of natural kinds can only account for these additional kind-based epistemic practices if it also analyzes their causal structure. (shrink)

Most philosophical discussions of disagreement have used idealized disagreements to draw conclusions about the nature of disagreement. I closely examine an actual, non-idealized disagreement in dinosaur paleobiology and show that it can not only teach us about the features of some of our real world disagreements, but can help us to argue for the possibility of reasonable real world disagreement.

Lists of species underpin many fields of human endeavour, but there are currently no universally accepted principles for deciding which biological species should be accepted when there are alternative taxonomic treatments (and, by extension, which scientific names should be applied to those species). As improvements in information technology make it easier to communicate, access, and aggregate biodiversity information, there is a need for a framework that helps taxonomists and the users of taxonomy decide which taxa and names should be used (...) by society whilst continuing to encourage taxonomic research that leads to new species discoveries, new knowledge of species relationships, and the refinement of existing species concepts. Here, we present 10 principles that can underpin such a governance framework, namely (i) the species list must be based on science and free from nontaxonomic considerations and interference, (ii) governance of the species list must aim for community support and use, (iii) all decisions about list composition must be transparent, (iv) the governance of validated lists of species is separate from the governance of the names of taxa, (v) governance of lists of accepted species must not constrain academic freedom, (vi) the set of criteria considered sufficient to recognise species boundaries may appropriately vary between different taxonomic groups but should be consistent when possible, (vii) a global list must balance conflicting needs for currency and stability by having archived versions, (viii) contributors need appropriate recognition, (ix) list content should be traceable, and (x) a global listing process needs both to encompass global diversity and to accommodate local knowledge of that diversity. We conclude by outlining issues that must be resolved if such a system of taxonomic list governance and a unified list of accepted scientific names generated are to be universally adopted. (shrink)

The main claim of this thesis is that value-judgments should play a profound role in the construction and evaluation of species classifications. The arguments for this claim will be presented over the course of five chapters. These are divided into two main parts; part one, which consists of the two first chapters, presents an argument for a radical form of species pluralism; part two, which comprises the remaining chapters, discusses the implications of radical species pluralism for the role of values (...) in species classification. The content of the five chapters is as follows. Chapter 1 starts with a discussion of the theoretical assumptions concerning species and natural kinds that form the broad framework within which the arguments of the thesis are placed. The aim of this chapter is to introduce a set of relatively uncontroversial assumptions that frame the rest of the thesis. On the basis of these assumptions, chapter 2 presents an argument for radical species pluralism. The chapter substantiates this argument with a broad range of examples, and compares this position to other forms of species pluralism. Chapter 3 returns to the main interest of the thesis, namely, the role of values in species classification. It introduces the notion of values and presents an argument for the value-ladenness of taxonomy on the basis of the considerations in the first two chapters. It then sketches three important views on values in science in the literature. Chapter 4 argues that the case presented in chapter 3 provides strong support for one of these views, called the ‘Aims View’, and against two other prominent views, called the ‘Epistemic Priority View’ and the ‘Value-Free Ideal’. The resulting view, in line with the Aims View, is that value-judgments should play a particularly substantial role in species classification. Chapter 5 then considers the popular assumption that these value-judgments in taxonomy commonly take the shape of generally accepted classificatory norms, and argues that this assumption is not tenable. Finally, a brief concluding chapter points at some implications of the claims and arguments in this thesis. (shrink)

The species concept is one of the central concepts in biological science. Although modern systematics speculates about the existence of a complex hierarchy of nested taxa, biological species are considered particularly important for the active role they play in evolution. However, neither theoretical biologists nor philosophers of biology have come to an agreement about what a species is. In this chapter, we address two questions pertaining to biological species: (1) are they individuals or universals? and (2) are they bona fide (...) or fiat entities? In section The Species-as-Individuals View, we illustrate the reasons that have led many scholars to support the view that species are individuals. In the next two sections, we show that the relational concepts of species – on which the species-as-individuals view is based – provide neither necessary nor sufficient conditions for species membership. This seriously undermines the species-as-individuals view. In the section A Conceptualist Model for the Metaphysics of Species, we advance the proposal that species are fiat concepts (and thus, universal entities partially dependent on the human mind) carved in a multi-dimensional space representing the properties that the biological organisms possess. The final section concludes. (shrink)

Moderate pluralism is a popular position in contemporary philosophy of biology. Despite its popularity, various authors have argued that it tends to slide off off into a radical form of pluralism that is both normatively and descriptively ueptable. This paper looks at at the case of biological species classification, and evaluates a popular way of avoiding radical pluralism by relying on the shared aims and norms of a discipline. The main contention is that while these aims and norms may play (...) an important role in the legitimacy of species classifications, they fail to fend off radical pluralism. It follows from this that the legitimacy of species classifications is also determined by local decisions about the aims of research and how to operationalize and balance these. This is important, I argue, because it means that any acceptable view on the legitimacy of classification should be able to account for these local decisions. (shrink)

Garnett and Christidis (2017) [hereafter GC] recently proposed that the International Union of the Biological Sciences should centrally regulate the taxonomy of complex organisms. Their proposal was met with much criticism (e.g. Hołyński 2017; Thomson et al., 2018), and perhaps most extensively from Raposo et al. (2017) in this journal. The main target of this criticism was GC’s call to, first, “restrict the freedom of taxonomic action”, and, second, to let social, political and conservation values weigh in on species classification. (...) Some commentators even went as far as to draw a comparison with the infamous Lysenko-case of state-controlled and heavily restricted science (Raposo et al. 2017, 181; Hołyński 2017, 12). This comment will argue, without thereby endorsing GC’s position, that these two aspects of their views need not be as threatening as this comparison suggests, and indeed are very reasonable. (shrink)

The concept of species is one of the core concepts in biology and one of the cornerstones of evolutionary biology, yet it is rife with conceptual problems. Philosophers of biology have been discussing the concept of species for decades, and in doing so they sometimes appeal to the views of biologists. However, their statements as to what biologists think are seldom supported by empirical data. In order to investigate what biologists actually think about the key issues related to the problem (...) of species, we have conducted a survey on the sample of 193 biologists from the population of biologists from over 150 biology departments at universities in the US and the EU. This article presents and discusses the results of the survey. Some results confirm and others falsify the reiterated statements of philosophers of biology as to what biologists think, but all results we obtained should be informative and relevant for future discussions of the problem of species. (shrink)

We present the first comprehensive taxonomic revision and review the biology of the olingos, the endemic Neotropical procyonid genus Bassaricyon, based on most specimens available in museums, and with data derived from anatomy, morphometrics, mitochondrial and nuclear DNA, field observations, and geographic range modeling. Species of Bassaricyon are primarily forest-living, arboreal, nocturnal, frugivorous, and solitary, and have one young at a time. We demonstrate that four olingo species can be recognized, including a Central American species (Bassaricyon gabbii), lowland species with (...) eastern, cis-Andean (Bassaricyon alleni) and western, trans-Andean (Bassaricyon medius) distributions, and a species endemic to cloud forests in the Andes. The oldest evolutionary divergence in the genus is between this last species, endemic to the Andes of Colombia and Ecuador, and all other species, which occur in lower elevation habitats. Surprisingly, this Andean endemic species, which we call the Olinguito, has never been previously described; it represents a new species in the order Carnivora and is the smallest living member of the family Procyonidae. We report on the biology of this new species based on information from museum specimens, niche modeling, and fieldwork in western Ecuador, and describe four Olinguito subspecies based on morphological distinctions across different regions of the Northern Andes. (shrink)

Certain lines of reasoning common in evolutionary taxonomy have been termed viciously circular. They are quite obviously not logically circular. They do give the superficial appearance of epistemological circularity. This appearance arises from the method of successive approximation used by evolutionary taxonomists. It is argued that this method is not epistemologically circular, even when the only evidence that the taxonomist has to go on is the phenetic similarity of contemporary forms. The important criticism of evolutionary taxonomy is rather that in (...) the absence of fossil evidence phyletic reconstructions are not warranted. It is argued that this charge stems initially from a misunderstanding of the kind of certainty possible in empirical science. When this criticism is couched in appropriate terms, it may be seen to have some force. Many phyletic inferences are not as warranted as one might wish. However, there is a great deal of difference between arguing that a line of reasoning is unwarranted and arguing that it is viciously circular. (shrink)

Mosquito-borne diseases represent a significant global disease burden, and recent outbreaks of such diseases have led to calls to reduce mosquito populations. Furthermore, advances in ‘gene-drive’ technology have raised the prospect of eradicating certain species of mosquito via genetic modification. This technology has attracted a great deal of media attention, and the idea of using gene-drive technology to eradicate mosquitoes has been met with criticism in the public domain. In this paper, I shall dispel two moral objections that have been (...) raised in the public domain against the use of gene-drive technologies to eradicate mosquitoes. The first objection invokes the concept of the ‘sanctity of life’ in order to claim that we should not drive an animal to extinction. In response, I follow Peter Singer in raising doubts about general appeals to the sanctity of life, and argue that neither individual mosquitoes nor mosquitoes species considered holistically are appropriately described as bearing a significant degree of moral status. The second objection claims that seeking to eradicate mosquitoes amounts to displaying unacceptable degrees of hubris. Although I argue that this objection also fails, I conclude by claiming that it raises the important point that we need to acquire more empirical data about, inter alia, the likely effects of mosquito eradication on the ecosystem, and the likelihood of gene-drive technology successfully eradicating the intended mosquito species, in order to adequately inform our moral analysis of gene-drive technologies in this context. (shrink)

Transhumanism is the school of thought that advocates the use of technology to enhance the human species, to the point where some supporters consider that a new species altogether could arise. Even some critics think this at least a technological possibility. Some supporters also believe the emergence of a new, improved, superhuman species raises no special ethical questions. Through an examination of the metaphysics of species, and an analysis of the essence of the human species, I argue that the existence (...) of an embodied, genuinely superhuman species is a metaphysical impossibility. Finally, I point out an interesting ethical consideration that this metaphysical truth raises. (shrink)

In this paper, I address the charge that the category species should be abandoned in biological work. The widespread appeal to species in scientific discourse provides a presumption in favor of the category’s usefulness, but a defeasible presumption. Widely acknowledged troubles attend species: these troubles might render the concept unusable by showing that ‘species’ is equivocal or meaningless or in some similar way fatally flawed. Further, there might be better alternatives to species. I argue that the presumption in favor of (...) species is not defeated on these scores. Troubles attending species, which arise on account of contextual variation attending the use of ‘species’, do not indicate that the concept is unusable. And alternatives to the use of ‘species’, which have been proposed in connection with rank-free systematics and in connection with conservation efforts, fail to provide a proper replacement for species. (shrink)

This paper argues that the occurrence of a non-native species, such as purple loosestrife, on one's property does not constitute a nuisance in the context of background principles of common law. No one is injured by it. The control of non-native species, such as purple loosestrife, does not constitute a compelling public interest, moreover, but represents primarily the concern of an epistemic community of conservation biologists and ecologists. This paper describes a history of cases in agricultural law that establish that (...) a public authority may enter private property to destroy a tree or other species but only to protect a compelling public interest, such as the apple industry in Virginia or the citrus industry in Florida, and only if it pays all the costs including just compensation. The paper argues a fortiori that if a public authority enters private property to control non-native or “invasive” species it must pay all the costs and indemnify the owner—contrary to what many state laws contemplate and the Environmental Law Institute recommends. (shrink)

The organism is one of the fundamental concepts of biology and has been at the center of many discussions about biological individuality, yet what exactly it is can be confusing. The definition that we find generally useful is that an organism is a unit in which all the subunits have evolved to be highly cooperative, with very little conflict. We focus on how often organisms evolve from two or more formerly independent organisms. Two canonical transitions of this type—replicators clustered in (...) cells and endosymbiotic organelles within host cells—demonstrate the reality of this kind of evolutionary transition and suggest conditions that can favor it. These conditions include co-transmission of the partners across generations and rules that strongly regulate and limit conflict, such as a fair meiosis. Recently, much attention has been given to associations of animals with microbes involved in their nutrition. These range from tight endosymbiotic associations like those between aphids and Buchnera bacteria, to the complex communities in animal intestines. Here, starting with a reflection about identity through time, we consider the distinctions between these kinds of animal–bacteria interactions and describe the criteria by which a few can be considered jointly organismal but most cannot. (shrink)

RESUMEN: En el actual contexto científico que forma la concepción darwiniana de las especies aún persisten las interpretaciones esencialistas de los conceptos de especie. ¿Se trata aquí sólo de la ignorancia de la teoría biológica? O, más bien, ¿es posible comprender la persistencia de los enfoques esencialistas sobre la base de la potencialidad de estos enfoques para explicar el logro de ciertos valores epistémicos de los actuales conceptos de especie? Me propongo responder afirmativamente a esta última pregunta. En la sección (...) 1 argumento que Samir Okasha (2002) no logra mostrar que hay otras razones, distintas a la de la ignorancia de la biología, que motivan el error de Kripke y de Putnam acerca de las especies. En la sección 2 propongo mi respuesta a la pregunta inicial en términos de algunos valores epistémicos que comparten las ideas esencialistas acerca de las especies y algunos de los actuales conceptos de especie.ABSTRACT: In the current scientific context that forms Darwinian conception of species, essentialist interpretations of the species concept persist. Is this only because of an ignorance of the biological theory? Or rather, is it possible to understand the persistence of essentialist approaches on the basis of the potentiality of these approaches to account for the achievement of certain epistemic values of the current species concepts? I intend to give a positive answer to this second question. In Section 1, I argue that Samir Okasha (2002) does not succeed in demonstrating that there are other reasons, which are different from that one regarding the ignorance about biology, which cause Kripke and Putnam to be mistaken about the species. In Section 2, I put forward my answer to the initial question in terms of some epistemic values sharing the essentialist ideas about the species and some of the current species concepts. (shrink)

Can we be realists about a general category but pluralists about concepts relating to that category? I argue that paleobiological methods of delineating species are not affected by differing species concepts, and that this underwrites an argument that species concept pluralists should be species category realists. First, the criteria by which paleobiologists delineate species are ‘indifferent’ to the species category. That is, their method for identifying species applies equally to any species concept. To identify a new species, paleobiologists show that (...) interspecies processes, such as phenotypic plasticity, sexual dimorphism, or ontogenetic diversity, are a worse explanation of the variance between specimens than intraspecies processes. As opposed to operating under a single or plurality of species concepts, then, paleobiologists use abductive inferences, which would be required regardless of any particular species concept. Second, paleobiologists are frequently interested in large-scale, long-term morphological patterns in the fossil record, and resolving the fine-grained differences which result from different species concepts is irrelevant at those scales. I argue that this claim about paleobiological practice supports what I call ‘indifference realism’ about the species category. The indifference realist argues that when legitimate investigation is indifferent to a plurality of concepts, we should be realists about the category those concepts pertain to. (shrink)

This paper addresses the general problem of how to rationally choose an algorithm for phylogenetic inference. Specifically, the controversy between maximum likelihood (ML) and maximum parsimony (MP) perspectives is reframed within the philosophical issue of theory choice. A Kuhnian approach in which rationality is bounded and value-laden is offered and construed through the notion of a Style of Modeling. A Style is divided into four stages: collecting remnant models, constructing models of taxonomical identity, implementing modeling algorithms, and finally inferring and (...) confirming evolutionary trees or cladograms. The identification and investigation of styles is useful for exploring sociological and epistemological issues such as individuating scientific communities and assessing the rationality of algorithm choice. Regarding the last point, this paper suggests that the values motivating ML and MP perspectives are justified but only contextually; these algorithms also have normative force because they can be therapeutic by allowing us to rationally choose among several competing trees, nonetheless this force is limited and cannot be used in order to decide the controversy tout court. (shrink)