Species

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)

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)

I spell out and update the individuality thesis, that species are individuals, and not classes, sets, or kinds. I offer three complementary presentations of this thesis. First, as a way of resolving an inconsistent triad about natural kinds; second, as a phylogenetic systematics theoretical perspective; and, finally, as a novel recursive account of an evolved character. These approaches do different sorts of work, serving different interests. Presenting them together produces a taxonomy of the debates over the thesis, and isolates ways (...) it has been productive. This goes to the larger point of this paper: a defense of the individuality thesis in terms of its utility, and an update of it in light of recent theoretical developments and empirical work in biology. (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 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 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)

Over the last 150 years the number of hominin fossils discovered has increased, and with it the taxonomic diversity recognised. There are currently claims for at least 26 hominin species. I consider here the challenge posed by this diversity, and how we can determine, through comparative modelling, whether it is a real evolutionary signal or an artefact of our procedures, and also the opportunities provided to make the science of human evolution a more comparative one.

This paper aims to offer a new argument in defence bacterial species pluralism. To do so, I shall first present the particular issues derived from the conflict between the non-theoretical understanding of species as units of classification and the theoretical comprehension of them as units of evolution. Secondly, I shall justify the necessity of the concept of species for the bacterial world, and show how medicine and endosymbiotic evolutionary theory make use of different concepts of bacterial species due to their (...) distinctive purposes. Finally, I shall show how my argument provides a new source of defence for bacterial pluralism. (shrink)

Any biological species of biparental organisms necessarily includes, and is fundamentally dependent on, sign processes between individuals. In this case, the natural category of the species is based on family resemblances, which is why a species is not a natural kind. We describe the mechanism that generates the family resemblance. An individual recognition window and biparental reproduction almost suffice as conditions to produce species naturally. This is due to assortativity of mating which is not based on certain individual traits, but (...) on the difference between individuals. The biosemiotic model described here explains what holds a species together. It also implies that boundaries of a species are fundamentally fuzzy, and that character displacement occurs in case of sympatry. Speciation is a special case of discretisation that is an inevitable result of any communication system in work. The biosemiotic mechanism provides the conditions and communicative restrictions for the origin and persistence of diversity in the realm of living systems. (shrink)

The present study examined the effects of semantic structure on simple inductive judgments about category members. For a particular category, subjects were told that one of the species had a given property and were asked to estimate the proportion of instances in the other species that possessed the property. The results indicated that category structure—in particular, the typicality of the species—influenced subjects' judgments. These results were interpreted by models based on the following assumption: When little is known about the underlying (...) distribution of a property, subjects assume that the distribution mirrors that of better-known properties. For this reason, if subjects learn that an unknown property is possessed by a typical species, they are more likely to generalize than if the same fact had been learned about an atypical species. (shrink)

Resumo Neste artigo, vamos considerar o recente debate na metafísica da evolução, no que diz respeito tanto à persistência como à “mudança” em espécies biológicas, segundo a tese que considera a espécie como o agregado de indivíduos. Centrar-nos-emos na proposta de Thomas Reydon, que argumenta que em biologia, o termo “espécie” refere-se a duas entidades biológicas, por si denominadas evolverons e phylons, que desempenham vários papéis epistemológicos em pelo menos duas disciplinas diferentes, nomeadamente na biologia sistemática e na biologia evolutiva. (...) Em particular, analisamos criticamente a alegação de Reydon, que estas duas entidades biológicas geraram um problema para a tese que sustém a equivalência entre duas teorias de persistência, desenvolvidas pela metafísica analítica contemporânea: o tri–Dimensionalismo e tetra–Dimensionalismo. Neste artigo, pretende-se restaurar a tese da equivalência metafísica, recorrendo a uma tripla estratégia: promover a ideia de que os evolverons e os “phylons” são duas dimensões de uma mesma realidade; recorrer a uma noção menos problemática noção de endurantismo e, por último, destacar alguns problemas que surgem dos exemplos biológicos empregues por Reydon para basear o desenvolvimento dos seus argumentos. Palavras-chave : conceito de espécie, endurantismo, equivalência metafísica entre 3D e 4D, espécies biológicas sincrónicas e diacrónicas, persistênciaIn this paper we revise a recent debate on the metaphysics of evolution pertaining to both the persistence and change of biological species, and the species-as-individuals thesis. We focus on Thomas Reydon’s proposal that, in biology, the term “species” refers to two different biological entities, which he calls evolverons and phylons, and plays different epistemological roles in at least two different disciplines in which it is used, namely, evolutionary and systematic biology. In particular, we critically revise Reydon’s claim that these two biological entities raise a problem for the thesis of the equivalence between the two theories of persistence developed in contemporary analytic metaphysics: three–dimensionalism and four–dimensionalism. In this paper, we aim to reinstate the thesis of metaphysical equivalence by a threefold strategy: motivation of the idea that evolverons and phylons are two dimensions of the same entity, shifting to a less problematic notion of endurance, and an exploration of doubts about the particular biological examples upon which Reydon bases his arguments. Keywords : 3D / 4D metaphysical equivalence, endurantism, persistence, species concept, synchronic and diachronic biological species. (shrink)