The Metaphysics of Species

Of those who believe that biological species are real, the dominant metaphysics of species is that they are individuals. While the arguments for this view have been thoroughly criticized in the last quarter thirty years, comparatively less effort has been spent trying to show that the view is actually false. My primary concern in the present paper is to detail a metaphysical problem for the species-as-individuals thesis that should at least give potential adherents great pause. Second, I will sketch a (...) “deflationary” approach to the metaphysics of species which requires us to swallow fewer contentious philosophical claims and yet still accommodate the intuitions that species are real. (shrink)

Abstract: Under traditional Jewish Law (halacha), assessment of human reproductive cloning (HRC) has been formulated along four lines of inquiry, which I discussed in Part I of this paper. Therein I also analyze five relevant doctrines of Talmudic Law, concluding that under with a risk-benefit analysis HRC fails to fulfill the obligation ‘to be fruitful and multiply’ and should be strictly prohibited. Here, I review of the topic from an exigetical Biblical and Kabbalistic perspective, beginning with exploring comments of the (...) Ramban (Nachmanides) which suggest Kabbalistic insights very much in keeping with current biology. In this Part II of the paper, I expand and annotate statements of the Ramban on the interrelationship of the reproductive faculties of an organism and its soul by examining the development of the spiritual states of plant, animal and human and noting the commensurate evolution with its reproductive facilities. Speculating that the reproductive mechanism of each species is indelibly related to its soul-state, I suggest that interfering with human sexual reproduction by HRC has the same effect the Ramban argues is the result of Kilayim (interbreeding), i.e., wrecking havoc with the Universe. In Part III, I postulate a biologic explanation for warnings found in the Golemic Literature and suggest that these allude to the importance of maintaining human genetic diversity through sexual reproduction. The conclusions I reached after evaluating the propriety of HRC under a Kabbalistic/metaphysical index comports with those I reached using a traditional legal /halachic inquiry in Part I. Thus, both systems arrive at the conclusion that HRC is in violation of the divine and natural order and constitute a distinct biological threat to the survival of the human species, a conclusions in accord with current scientific thinking. (shrink)

Cladism, today the dominant school of systematics in biology, includes a classification component – the view that classification ought to reflect phylogeny only, such that all and only taxa are monophyletic (i.e. consist of an ancestor and all its descendants) - and a metaphysical component – the view that all and only real groups or kinds of organisms are monophyletic. For the most part these are seen as amounting to much the same thing, but I argue they can and should (...) be distinguished, in particular that cladists about classification need not accept the typically cladist view about real groups or kinds. Cladists about classification can and should adopt an explanatory criterion for the reality of groups or kinds, on which being monophyletic is neither necessary nor sufficient for being real or natural. Thus the line of reasoning that has rightly led to cladism becoming dominant within systematics, and the attractive line of reasoning in the philosophical literature that advocates a more liberal approach to natural kinds, are seen to be, contrary to appearances, compatible. (shrink)

Katz denies that organisms created in a lab as part of a de-extinction attempt will be authentic members of the extinct species, on the basis that they will lack the original species’ defining biological and evolutionary history. Against Katz, I note that an evolutionary lineage is conferred on an organism through its inheriting genes from forebears already possessed of such a lineage, and that de-extinction amounts to a delayed, human-assisted reproductive process, in which genes are inherited from forebears long dead. (...) My conclusion is that de-extinct organisms can perfectly well have an ancient evolutionary history, contrary to what Katz claims. (shrink)

This afterword to Species and Beyond provides some reflections on species, with special attention to what I think the most significant developments have been in the thinking of biologists and philosophers working on species over the past 25 years, as well as some bad jokes.

It has been widely argued that words are analogous to species such that words, like species, are natural kinds. In this paper, I consider the metaphysics of word-kinds. After arguing against an essentialist approach, I argue that word-kinds are homeostatic property clusters, in line with the dominant approach to other biological and psychological kinds.

Organisms leave a variety of traces in the fossil record. Among these traces, vertebrate and invertebrate paleontologists conventionally recognize a distinction between the remains of an organism’s phenotype and the remains of an organism’s life activities. The same convention recognizes body fossils as biological structures and trace fossils as geological objects. This convention explains some curious practices in the classification, as with the distinction between taxa for trace fossils and for tracemakers. I consider the distinction between “parallel taxonomies,” or parataxonomies, (...) which privileges some kinds of fossil taxa as “natural” and others as “artificial.” The motivations for and consequences of this practice are inconsistent. By comparison, I examine an alternative system of classification used by paleobotanists that regards all fossil taxa as “artificially” split. While this system has the potential to inflate the number of taxa with which paleontologists work, the system offers greater consistency than conventional practices. Weighing the strengths and weaknesses of each system, I recommend that paleontologists should adopt the paleobotanical system more broadly. (shrink)

Biological lineages move through time, space, and each other. As they do, they diversify, diverge, and grade away from and into one another. One result of this is genealogical discordance; i.e., the lineages of a biological entity may have different histories. We see this on numerous levels, from microbial networks, to holobionts, to population-level lineages. This paper considers how genealogical discordance impacts our study of species. More specifically, I consider this in the context of three framing questions: (1) How, if (...) at all, does genealogical discordance challenge, modify, or revise how we conceive of species? (2) How has growing appreciation of genealogical discordance impacted scientific practice? Of systematics in particular? (3) How do lineages at different levels diverge and diversify? All told, genealogical discordance enriches and complicates our taxonomic ontology, as well as the practice of reconstructing phylogenies. This presents both challenges and opportunities for the study of divergence and diversification. (shrink)

This book offers a novel defence of a highly contested philosophical position: biological natural kind essentialism. This theory is routinely and explicitly rejected for its purported inability to be explicated in the context of contemporary biological science, and its supposed incompatibility with the process and progress of evolution by natural selection. Christopher J. Austin challenges these objections, and in conjunction with contemporary scientific advancements within the field of evolutionary-developmental biology, the book utilises a contemporary neo-Aristotelian metaphysics of "dispositional properties", or (...) causal powers, to provide a theory of essentialism centred on the developmental architecture of organisms and its role in the evolutionary process. By defending a novel theory of Aristotelian biological natural kind essentialism, Essence in the Age of Evolution represents the fresh and exciting union of cutting-edge philosophical insight and scientific knowledge. (shrink)

© The Author 2017. Published by Oxford University Press on behalf of The Scots Philosophical Association and the University of St Andrews. All rights reserved. For permissions, please e-mail: [email protected] A. Richards offers a comprehensive introduction to biological classification: ‘the comparison and grouping of organisms, the naming of these groups, the theoretical basis for grouping, and the philosophical foundations for systems of grouping’. This book functions as an introduction to philosophy for biologists, an introduction to biology for philosophers and an (...) introduction to the history of both suitable for a more general audience.In the first chapter, he considers the results of folk and ethno-taxonomy, and related studies in cognitive psychology and developmental linguistics. The results suggest that all humans classify hierarchically, and that there is some agreement between folk and ethno-taxonomy and scientific taxonomy. But, even with this agreement, there is still disagreement about the ‘naturalness’... (shrink)

Developments in genetic engineering may soon allow biologists to clone organisms from extinct species. The process, dubbed “de-extinction,” has been publicized as a means to bring extinct species back to life. For theorists and philosophers of biology, the process also suggests a thought experiment for the ongoing “species problem”: given a species concept, would a clone be classified in the extinct species? Previous analyses have answered this question in the context of specific de-extinction technologies or particular species concepts. The thought (...) experiment is given more comprehensive treatment here. Given the products of three de-extinction technologies, twenty-two species concepts are “tested” to see which are consistent with the idea that species may be resurrected. The ensuing discussion considers whether or not de-extinction is a conceptually coherent research program and, if so, whether or not its development may contribute to a resolution of the species problem. Ultimately, theorists must face a choice: they may revise their commitments to species concepts or they may recognize de-extinction as a means to make progress in the species problem. (shrink)

Natural kinds, real kinds, or, following J.S Mill simply, Kinds, are thought to be an important asset for scientific realists in the non-fundamental (or “special”) sciences. Essential natures are less in vogue. I show that the realist would do well to couple her Kinds with essential natures in order to strengthen their epistemic and ontological credentials. I argue that these essential natures need not however be intrinsic to the Kind’s members; they may be historical. I concentrate on assessing the merits (...) of historical essential natures in a paradigm case of Kinds in the non-fundamental sciences: species. I specify two basic jobs for essential natures: 1) offering individuation criteria, and 2) providing a causal explanation of the Kind’s multiple projectable properties. I argue that at least in the case of species historical essences are fit for both tasks. The principled resistance to Kinds with historical essences should also be cleared. (shrink)

Media reporters often announce that we are on the verge of bringing back the woolly mammoth, even while there is growing consensus among scientists that resurrecting the mammoth is unlikely. In fact, current “de-extinction” efforts are not designed to bring back a mammoth, but rather adaptations of the mammoth using close relatives. For example, Harvard scientists are working on creating an Asian elephant with the thick coat of a mammoth by merging mammoth and elephant DNA. But how should such creatures (...) be classified? Are they elephants, mammoths, or both? Answering these questions requires getting clear about the concept of reproduction. What I hope to show is that with an appropriate notion of reproduction—one for which I will argue—resurrecting a member of Mammuthus primigenius is a genuine possibility. (shrink)

A number of influential biologists are currently pursuing efforts to restore previously extinct species. But for decades, philosophers of biology have regarded “de-extinction” as conceptually incoherent. Once a species is gone, it is gone forever. We argue that a range of metaphysical, biological, and ethical grounds for opposing de-extinction are at best inconclusive and that a pragmatic stance that allows for its possibility is more appealing.

Features Covers the philosophical and historical development of the concept of "species" Documents that variation was recognized by pre-Darwinian scholars Includes a section on the debates since the time of the New Synthesis Better suited to non-philosophers Summary Over time the complex idea of "species" has evolved, yet its meaning is far from resolved. This comprehensive work is a fresh look at an idea central to the field of biology by tracing its history from antiquity to today. Species is a (...) benchmark exploration and clarification of a concept fundamental to the past, present, and future of the natural sciences. In this edition, a section is added on the debate over species since the time of the New Synthesis, and brings the book up to date. A section on recent philosophical debates over species has also been added. This edition is better suited non-specialists in philosophy, so that it will be of greater use for scientists wishing to understand how the notion came to be that living organisms form species. (shrink)

Contemporary biology has inherited two key assumptions from the Modern Synthesis about the nature of population lineages: sexual reproduction is the exemplar for how individuals in population lineages inherit traits from their parents, and random mating is the exemplar for reproductive interaction. While these assumptions have been extremely fruitful for a number of fields, such as population genetics and phylogenetics, they are increasingly unviable for studying the full diversity and evolution of life. I introduce the “mixture” account of population lineages (...) that escapes these assumptions by dissolving the Modern Synthesis’s sharp line separating reproduction and development and characterizing reproductive integration in population lineages by the ephemerality of isolated subgroups rather than random mating. The mixture account provides a single criterion for reproductive integration that accommodates both sexual and asexual reproduction, unifying their treatment under Kevin de Queiroz’s generalized lineage concept of species. The account also provides a new basis for empirically assessing the effect of random mating as an idealization on the empirical adequacy of population genetic models. (shrink)

The title of Beth Shapiro’s ‘How to Clone a Mammoth’ contains an implicature: it suggests that it is indeed possible to clone a mammoth, to bring extinct species back from the dead. But in fact Shapiro both denies this is possible, and denies there would be good reason to do it even if it were possible. The de-extinct ‘mammoths’ she speaks of are merely ecological proxies for mammoths—elephants re-engineered for cold-tolerance by the addition to their genomes of a few mammoth (...) genes. Shapiro’s denial that genuine species de-extinction is possible is based on her assumption that resurrected organisms would need to be perfectly indistinguishable from the creatures that died out. In this article I use the example of an extinct New Zealand wattlebird, the huia, to argue—contra Shapiro—that there are compelling reasons to resurrect certain species if it can be done. I then argue—again, contra Shapiro—that synthetically created organisms needn’t be perfectly indistinguishable from their genetic forebears in order for species de-extinction to be successful. (shrink)

Michael Ghiselin and David Hull’s individuality thesis is that biological species are individuals. Philosophers often treat the term “individual” as synonymous with “mereological sum” and characterize it in terms of mereology. It is easy to see how the biological project has been interpreted as a mereological one. This chapter argues that this is a mistake, that biological part/whole relations often violate the axioms of mereology. Conflating these projects confuses the central issues at stake in both, and makes the job of (...) evaluating either unnecessarily burdensome. Clarifying this helps identify the genuine metaphysical implications of the individuality thesis, which serves as an exemplar of scientifically informed metaphysics. (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)

This edited volume of 13 new essays aims to turn past discussions of natural kinds on their head. Instead of presenting a metaphysical view of kinds based largely on an unempirical vantage point, it pursues questions of kindedness which take the use of kinds and activities of kinding in practice as significant in the articulation of them as kinds. The book brings philosophical study of current and historical episodes and case studies from various scientific disciplines to bear on natural kinds (...) as traditionally conceived of within metaphysics. Focusing on these practices reveals the different knowledge-producing activities of kinding and processes involved in natural kind use, generation, and discovery. -/- Specialists in their field, the esteemed group of contributors use diverse empirically responsive approaches to explore the nature of kindhood. This groundbreaking volume presents detailed case studies that exemplify kinding in use. Newly written for this volume, each chapter engages with the activities of kinding across a variety of disciplines. Chapter topics include the nature of kinds, kindhood, kinding, and kind-making in linguistics, chemical classification, neuroscience, gene and protein classification, colour theory in applied mathematics, homology in comparative biology, sex and gender identity theory, memory research, race, extended cognition, symbolic algebra, cartography, and geographic information science. -/- The volume seeks to open up an as-yet unexplored area within the emerging field of philosophy of science in practice, and constitutes a valuable addition to the disciplines of philosophy and history of science, technology, engineering, and mathematics. -/- Contributions from a diverse group of established and junior scholars in the fields of Philosophy and History and Philosophy of Science including Hasok Chang, Jordi Cat, Sally Haslanger, Joyce C. Havstad, Catherine Kendig, Bernhard Nickel, Josipa Petrunic, Samuli Pöyhönen, Thomas A. C. Reydon, Quayshawn Spencer, Jackie Sullivan, Michael Wheeler, and Rasmus Grønfeldt Winther. (shrink)

According to the species-as-individuals thesis(hereafter S-A-I), species are cohesive entities. Barker and Wilson recently pointed out that the type of cohesion exhibited by species is fundamentally different from that of organisms (paradigmatic individuals), suggesting that species are homeostatic property cluster kinds. In this article, I propose a shift in how to approach cohesion in the context of S-A-I: instead of analyzing the different types of cohesion and questioning whether species have them, I focus on the role played by cohesion in (...) the identity of individuals. This shift allows us to recognize why cohesion matters to S-A-I, as well as to reconceive the analogy between species and organisms (paradigmatic individuals), and also allows us to highlight the context sensitivity of both ‘‘cohesion’’ and ‘‘individuals.’’ From this perspective, I identify two problems in Barker and Wilson’s argumentation. Firstly, the authors fail to recognize that species are individuals even if they do not have the same type of cohesion that organisms have. Secondly, their argument relies on a misinterpretation of S-A-I. I conclude that species cohesion is still best framed as a feature of species individuality rather than a feature of species as homeostatic property cluster kinds. The arguments presented here contribute to the re-articulation and reevaluation of S-A-I in the face of contemporary discussions. (shrink)

In _Realism and Naturalizing Knowledge_ (Keisho Shobo, 2013), Ryo Uehara carefully formulates the homeostatic property cluster theory of natural kinds and expands it by applying this framework to artifacts and knowledge and thereby drawing them in the naturalistic picture of the world. This is a substantial addition to the development of naturalistic philosophy in Japan. In this essay I shall make general comments on his account of natural kinds in the following respects: Uehara's distinction between real and nominal kinds, his (...) objection to the species-as-individual thesis, the relative lack of attention to the distinction between the realism of natural kinds and the scientific realism, and finally, races as possible natural kinds. (shrink)

John Wilkins and Malte Ebach respond to the dismissal of classification as something we need not concern ourselves with because it is, as Ernest Rutherford suggested, mere ‘‘stamp collecting.’’ They contend that classification is neither derivative of explanation or of hypothesis-making but is necessarily prior and prerequisite to it. Classification comes first and causal explanations are dependent upon it. As such it is an important (but neglected) area of philosophical study. Wilkins and Ebach reject Norwood Russell Hanson’s thesis that classification (...) relies on observation that is theory-laden and deny the need for aetiological assumptions and historical reconstruction to justify its arrangement. What they offer instead is a significant (albeit controversial) contribution to the philosophical literature on classification, a pre-theoretic natural classification based on the observation of patterns in data of ready-made phenomena. Their notion of ready-made phenomena rests on a conception of tacit knowledge or know-how. This is evident in their distinction between strong Theory-dependence and na ̈ıve theory-dependence. Their small t-theory-dependence permits patterns of observation that facilitate know-how but does not rely on a domain-specific explanatory theory of their aetiology. Wilkins and Ebach suggest classification differs from theory building in that it is passive (whereas theory building is active). Classification is possible just because it does not require the sieve of theory to capture classes that are ‘‘handed to you by your cognitive dispositions and the data that you observe’’ (p. 18). Finding regularities sans-theory is just something we do and can do without any prior theory about the underlying causes or origins of the resultant regularities. Luke Howard’s classification of clouds serves as an exemplar of a passive, theory-free classification system and the periodic table and the DSM help to illustrate this type of non-aetiological patterning. A recurrent theme is the nature of naturalness. For Wilkins and Ebach, the conception of naturalness is not one that is based on the generation or discovery of natural kind categories popular in both the traditional metaphysics of Mill and Wittgenstein as well as updated notions within philosophy of biology such as Boyd’s Homeostatic Property Cluster kinds. Instead, Wilkins and Ebach define the naturalness of classification as the falling into hierarchical patterns, aligning the search for natural arrangement with the aim of systematics, and as something that is grounded in a cognitive task or activity. However, they leave the question of realism v. antirealism open. ‘‘In natural classification...we must have real relations no matter how we might interpret ‘real’’’ (p. 70). There is tension with regard to their ontological commitments as they vacillate between constructive, operationalist, and realist approaches. Wilkins and Ebach initially define real as that which is causal and important (pp. 70–71), and later as that which ‘‘depends in no way upon a mind or observer’’ (p. 122). This makes their claim that there was ‘‘no real theory involved [in the pre-Darwinian classifications of Jussieu and Adanson]’’ (p. 64) difficult to interpret. Cont’d……. (shrink)

The aim of this article is to argue that ontological choices in scientific practice undermine common formulations of the value-free ideal in science. First, I argue that the truth values of scientific statements depend on ontological choices. For example, statements about entities such as species, race, memory, intelligence, depression, or obesity are true or false relative to the choice of a biological, psychological, or medical ontology. Second, I show that ontological choices often depend on non-epistemic values. On the basis of (...) these premises, I argue that it is often neither possible nor desirable to evaluate scientific statements independently of non-epistemic values. Finally, I suggest that considerations of ontological choices do not only challenge the value-free ideal but also help to specify positive roles of non-epistemic values in an often neglected area of scientific practice. (shrink)

I present and defend a novel version of the homeostatic property cluster account of natural kinds. The core of the proposal is a development of the notion of co-occurrence, central to the HPC account, along information-theoretic lines. The resulting theory retains all the appealing features of the original formulation, while increasing its explanatory power, and formal perspicuity. I showcase the theory by applying it to the problem of reconciling the thesis that biological species are natural kinds with the fact that (...) many such species are polymorphic. (shrink)

Biological taxonomists rely on the so-called ‘type method’ to regulate taxonomic nomenclature. For each newfound taxon, they lay down a ‘type specimen’ that carries with it the name of the taxon it belongs to. Even if a taxon’s circumscription is unknown and/or subject to change, it remains a necessary truth that the taxon’s type specimen falls within its boundaries. Philosophers have noted some time ago that this naming practice is in line with the causal theory of reference and its central (...) notion of rigid designation: a type specimen fixes the reference of a taxon name without defining it. Recently, however, this consensus has come under pressure in the pages of this journal. In a series of articles by Alex Levine, Joseph LaPorte, and Matthew Haber, it has been argued that type specimens belong only contingently to their species, and that this may bode problems for the relation between type method and causal theory. I will argue that this ‘contingency debate’ is a debate gone wrong, and that none of the arguments in defense of contingency withstand scrutiny. Taxonomic naming is not out of step with the causal theory, but conforms to it. However, I will also argue that this observation is itself in need of further explanation, since application of the type method in taxonomic practice is plagued by errors and ambiguities that threaten it with breaking down. Thus, the real question becomes why taxonomic naming conforms to the causal theory in the first place. I will show that the answer lies in the embedding of the type method into elaborate codes of nomenclature. (shrink)

Kripke argues for origin essentialism, the view that the same individual cannot have multiple origins. Sober hypothesises that Kripke's origin essentialism applies to biological species. This paper shows that Sober's hypothesis fails. Because Kripke's original argument is invalid, it cannot vindicate Sober's proposal. Salmon offers an influential reformulation of Kripke's argument but his argument fails to extend to species: the notion of an individual's origin is too narrow to apply to species, and Salmon's argument rests on a thought experiment that (...) conflicts with how species evolve. Thus, Sober and others are wrong to think that Kripke's origin essentialism can save species essentialism. (shrink)

This is an extended review of John Dupré's _Processes of Life_, a collection of essays. It clarifies Dupré's concepts of reductionism and anti-reductionism, and critically examines his associated discussions of downward causation, and both the context sensitivity and multiple realization of categories. It reviews his naturalistic monism, and critically distinguishes between his realism about categories and constructivism about classification. Challenges to his process ontology are presented, as are arguments for his pluralism about scientific categories. None of his main conclusions are (...) rejected; rather it is main arguments for them that are the focus. (shrink)

We argue for a new conventionalism about many kinds of evolutionary groups, including clades, cohesive units, and populations. This rejects a consensus, which says that given any one of the many legitimate grouping concepts, only objective biological facts determine whether a collection is such a group. Surprisingly, being any one kind of evolutionary group typically depends on which of many incompatible values are taken by suppressed variables. This is a novel pluralism underlying most any one group concept, rather than a (...) familiar pluralism claiming many concepts are legitimate. Consequently, we must help biological facts determine grouphood, even when given a single grouping concept. (shrink)

There has been much work on ontological dependence in recent literature. However, relatively little of it has been dedicated to the ways in which individual physical objects may depend on other distinct, non-overlapping objects. This paper gives several examples of such object-dependence and distinguishes between different types of it. The paper also introduces and refines the notion of an n-tet. N-tets (typically) occur when there are object-dependence relations between n objects. I claim that the identity (or, rather, what I call (...) the n-dentity) conditions for n-tets are not grounded in the individual identity conditions of each of the n objects, but instead are metaphysically basic. The paper then briefly discusses some ramifications of accepting object-dependence (and n-tets) on the philosophy of biology, ethics, and logic. (shrink)

Species concepts aim to define the species category. Many of these rely on defining species in terms of natural lineages and groupings. A dominant gene-centred metaconception has shaped notions of what constitutes both a natural lineage and a natural grouping. I suggest that relying on this metaconception provides an incomplete understanding of what constitute natural lineages and groupings. If we take seriously the role of epigenetic, behavioural, cultural, and ecological inheritance systems, rather than exclusively genetic inheritance, a broader notion of (...) what constitutes a natural grouping or lineage may be required. I conclude by outlining an alternative metaconception that is a de-centred metaschema for species. (shrink)

This chapter contains section titles: Introduction: Russell's Natural Kinds Is Biological Homeostasis Historical? Intrinsic Properties Redux Population Structure Conclusion: Are Species Duplicable?

Millikan and Her Critics offers a unique critical discussion of Ruth Millikan's highly regarded, influential, and systematic contributions to philosophy of mind and language, philosophy of biology, epistemology, and metaphysics. These newly written contributions present discussion from some of the most important philosophers in the field today and include replies from Millikan herself.

What are species? Are they objective features of the world? If so, what sort of features are they? Do everyday intuitions that species are real stand up to philosophical and scientific scrutiny? Two rival accounts of species' reality have dominated the discussion: that species are natural kinds defined by essential properties and that species are individuals. Unfortunately, neither account fully accommodates biological practice. In Are Species Real?, Slater presents a novel approach to this question aimed at accommodating the attractions to (...) both realism and antirealism about species. (shrink)

I argue that defenders of general duties of species preservation are faced with an impossible task. I distinguish derivative from non-derivative value and argue that the derivative value of species can yield only limited and contingent duties of preservation. There can be no general duty of species preservation unless all species have non-derivative value. Ongoing controversy over the ’species’ notion has not deterred some from claiming settled authority for whatever notion appears most conducive to their favored account of species value. (...) This is a mistake. The actual task is to state biologically plausible criteria for a ’species’ notion and to make the case that these criteria demarcate something of moral value. I argue that the task is made impossible by the same basic biological facts that led Darwin to the view that species are “merely artificial combinations made for convenience.‘. (shrink)

Over the last 2,300 years or so, many philosophers have believed that species are individuated by essences that are at least in part intrinsic. Psychologists tell us most folks also believe this view. But most philosophers of biology have abandoned the view, in light of evolutionary conceptions of species. In defiance, Michael Devitt has attempted in this journal to resurrect a version of the view, which he calls Intrinsic Biological Essentialism. I show that his arguments for the resurrection fail, and (...) I identify challenges that face anyone wishing to defend Intrinsic Biological Essentialism. (shrink)

A far-reaching and influential view in evolutionary biology claims that species are cohesive units held together by gene flow. Biologists have recognized empirical problems facing this view; after sharpening the expression of the view, we present novel conceptual problems for it. At the heart of these problems is a distinction between two importantly different concepts of cohesion, what we call integrative and response cohesion. Acknowledging the distinction problematizes both the explanandum of species cohesion and the explanans of gene flow that (...) are central to the view we discuss. We conclude by tracing four broader implications for the study and conceptualization of species. (shrink)

Several authors have argued that higher taxa are monophyletic homeostatic property cluster natural kinds. On the traditional definition of monophyly, this will not work: the emergence of taxon-defining homeostatic property clusters would not always correspond to unique speciation events. An alternative conception of monophyly is developed and advocated, which can accommodate the homeostatic property cluster proposal. Recent work in philosophy of science shows that it meets appropriate standards of objectivity and precision.

Biologists and philosophers that debate the existence of the species category fall into two camps. Some believe that the species category does not exist and the term 'species' should be eliminated from biology. Others believe that with new biological insights or the application of philosophical ideas, we can be confident that the species category exists. This paper offers a different approach to the species problem. We should be skeptical of the species category, but not skeptical of the existence of those (...) taxa biologists call 'species.' And despite skepticism over the species category, there are pragmatic reasons for keeping the word 'species.' This approach to the species problem is not new. Darwin employed a similar strategy to the species problem 150 years ago. (shrink)

Arguments against essentialism in biology rely strongly on a claim that modern biology abandoned Aristotle's notion of a species as a class of necessary and sufficient properties. However, neither his theory of essentialism, nor his logical definition of species and genus (eidos and genos) play much of a role in biological research and taxonomy, including his own. The objections to natural kinds thinking by early twentieth century biologists wrestling with the new genetics overlooked the fact that species have typical developmental (...) cycles and most have a large shared genetic component. These are the "what-it-is-to-be" members of that species. An intrinsic biological essentialism does not commit us to Aristotelian notions, nor even modern notions, of essence. There is a long-standing definition of "species" and its precursor notions that goes back to the Greeks, and which Darwin and pretty well all biologists since him share, that I call the Generative Conception of Species. It relies on there being a shared generative power that makes progeny resemble parents. The "what-it-is-to-be" a member of that species is that developmental type, mistakes in development notwithstanding. Moreover, such "essences" have always been understood to include deviations from the type. Finally, I shall examine some implications of the collapse of the narrative about essences in biology. (shrink)

-/- Because species names play an important role in scientific communication, it is more important that species be understood to be taxa than that they be equated with functional ecological or evolutionary entities. Although most biologists would agree that taxa are composed of organisms that share a unique common history, 2 major challenges remain in developing a species-as-taxa concept. First, grouping: in the face of genealogical discordance at all levels in the taxonomic hierarchy, how can we understand the nature of (...) taxa? Second, ranking: what criteria should be used to designate certain taxa in a nested series as being species? The grouping problem can be solved by viewing taxa as exclusive groups of organisms— sets of organisms that form a clade for a plurality of the genome (more than any conflicting set). However, no single objective criterion of species rank can be proposed. Instead, the species rank should be assigned by practitioners based on the semisubjective application of a set of species-ranking criteria. Although these criteria can be designed to yield species taxa that approximately match the ecological, evolutionary, and morphological entities that taxonomists have traditionally associated with the species rank, such a correspondence cannot be enforced without undermining the assumption that species are taxa. The challenge and art of monography is to use genealogical and other kinds of data to assign all organisms to one and only one species-ranked taxon. Various implications of the species-as-ranked-taxa view are discussed, including the synchronic nature of taxa, fossil species, the treatment of hybrids, and species nomenclature. I conclude that, although challenges remain, adopting the view that species are ranked taxa will facilitate a much-needed revolution in taxonomy that will allow it to better serve the biodiversity informatic needs of the 21st century. (shrink)

A major issue in philosophical debates on the species problem concerns the opposition between two seemingly incompatible views of the metaphysics of species: the view that species are individuals and the view that species are natural kinds. In two recent papers in this journal, Olivier Rieppel suggested that this opposition is much less deep than it seems at first sight. Rieppel used a recently developed philosophical account of natural kindhood, namely Richard Boyd’s “homeostatic property cluster” theory, to argue that every (...) species taxon can be conceived of as an individual that constitutes the single member of its own specific natural kind. In this paper I criticize Rieppel’s approach and argue that it does not deliver what it is supposed to, namely an account of species as kinds about which generalized statements can be made. (shrink)