On the Nature of Species and the Moral Significance of their Extinction Oxford Handbooks Online On the Nature of Species and the Moral Significance of their Extinction Russell Powell The Oxford Handbook of Animal Ethics Edited by Tom L. Beauchamp and R. G. Frey Print Publication Date: Oct 2011 Subject: Philosophy, Moral Philosophy, Philosophy of Science Online Publication Date: May DOI: 10.1093/oxfordhb/9780195371963.013.0022 2012 Abstract and Keywords This article begins by noting that in the history of life, every species up to presently existing species has become extinct. Complex life itself has been on the brink of annihilation at various points in the evolutionary process. A problem, given this history, is whether we should regard the causing or the permitting of the extinction of species as a bad outcome to be avoided. It notes that so-called common-sense intuitions about these matters are not trustworthy and often do not hold up to theoretical scrutiny. Using the evolutionary and ecological sciences, the discussion takes the currently received view that species should be analyzed in terms of individual lineages and not as a temporal natural kinds. Keywords: extinction, life history, evolution, ecological sciences WE owe our existence to an unbroken chain of reproduction that began with the inception of life some 3.5 billion years ago. Rejoicing in the fortuity of our genealogy, however, can obscure an equally salient but far less auspicious pattern in the history of life—namely, the extinction of nearly every species that has ever existed. There have been geological moments, and one in particular about 250 million years ago, when complex life itself teetered on the brink of annihilation. Yet the fragility of animal life per se pales in comparison to that of individual taxa.1 The mean duration of species is around four million years—an incomprehensibly vast interval to the human mind, but a mere pittance geologically speaking. And as we will see, species do not seem to get any better over time at not going extinct. What is more, if it were not for the most recent mass extinction, mammals might still be relegated to a small, nocturnal existence in the ecological shadow of dinosauria. Why, then, should we think that causing or permitting the extinction of species is a bad thing? In claiming that it is prima facie wrong for humans to contribute to or fail to prevent the extinction of species, environmental ethicists have often relied on the intuition that species qua species have moral value. This intuitively attractive idea has been notoriously difficult to justify, however. And unlike moral judgments about fairness, lying, and torturing the innocent, intuitions about the value of species are not sufficiently robust across persons and cultures to serve as the lynchpin (p. 604) for an ethical framework, especially one that aims to influence public policy. Another reason to avoid hanging an ethical theory of species conservation on untutored moral intuitions is that folk judgments about biological entities have a less-than-stellar track record. As recently as the eighteenth century, it was still commonly believed that organisms are composed of various ratios of the four elements identified by Aristotle, that living things are driven by vital forces, and that species reflect eternal, immutable essences around which biological variation gravitates. While commonsense intuitions have an important role to play in philosophical ethics, many folk judgments in the biological realm, such as our attitudes toward genetically modified organisms or invasive species, are often premised on certain presuppositions about the causal structure of the living world that may or may not hold up to theoretical scrutiny.2 Just as our considered moral-status judgments about comatose patients should be informed 3 Page 1 of 19 PRINTED FROM OXFORD HANDBOOKS ONLINE (www.oxfordhandbooks.com). (c) Oxford University Press, 2015. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a title in Oxford Handbooks Online for personal use (for details see Privacy Policy). Subscriber: Harvard University Library; date: 24 August 2015 On the Nature of Species and the Moral Significance of their Extinction by neuroscientific findings regarding the functional specialization of different regions of the human brain,3 so too should environmental ethics be constrained by the ontological landscape that is sketched by the evolutionary and ecological sciences. This is not to imply that the relationship between descriptive biology and normative environmental ethics is a unilateral one; ethicists can draw the attention of scientists to the types of entities or causal relations that are deemed to be of moral significance, and scientists in turn can go out and look for these objects or properties in the blooming, buzzing confusion of the biological world. In this chapter I will consider several moral justifications for the conservation of species in light of what we know about the ontology and evolution of species and their interrelations.4 The discussion will be structured as follows. In section 1, I consider the nature of species and their role in evolutionary theory. Although there are many species concepts available in contemporary evolutionary biology, I believe that for the purposes of ethical analysis there is sufficient overlap between these to avoid systemic conflicts in our individuation of species. The dominant view in biology and the philosophy of science, and the one that I support, is that species should be thought of as individual lineages, rather than as atemporal, natural kind classes. That we regard species as concrete individuals that evolve in space and time has important ramifications for the value that we might ascribe to them. Nevertheless, in section 2 I show that a species is not the sort of individual that exhibits properties thought to create morally relevant interests, such as sentience or goal-directedness, and I conclude therefore that species are not promising candidates for intrinsic moral value. I move on to consider theories that regard species as valuable not as moral patients, but because of their relation to morally considerable beings. I suggest a number of ways that species and even higher taxa could have both final and instrumental value that is not reducible to their constituent parts, focusing on informational, evolutionary, and ecological properties and the organizational levels at which they are manifest. In section 3, I examine metaphysical and epistemic arguments against prioritizing species for conservation, including those grounded in the “seamless web” and “delicate balance of nature” metaphors that often motivate environmental law and policy. I find these arguments unpersuasive on both theoretical and empirical grounds. (p. 605) Finally, in the conclusion, I consider whether there is a morally important difference between human- caused extinctions and those that result from “natural” evolutionary processes. I suggest that the degree of “badness” that is added to some state of affairs because a culpable moral agent is implicated is minimal, and thus should not significantly affect our conservation priorities. 1. The Ontology of Species What Is a Species? The aim of this essay is to determine whether species are proper objects of moral concern. To make this determination, we first need to be clear on the ontological status of species, which in turn requires that we examine the theoretical role that the species concept plays in contemporary evolutionary science. As far as we can tell, all life on Earth shares a common ancestor. Despite this evolutionary continuity, biological variation is not smoothly distributed in space and time. There are fairly discrete clusters of variation at all levels of the nested biological hierarchy, a clumping of form that generally reflects evolutionary relationships and which taxonomic classification intends to capture. Among taxonomic categories (see note 1), the most theoretically fundamental is the species. Nearly all biologists and philosophers of science agree that species are comprised of geographically distributed populations of organisms with varying levels of gene exchange. Yet there is no single, widely accepted definition of the term “species.” Probably the most influential formulation is the “biological species concept,” according to which a species is the maximally inclusive set of potentially interbreeding organisms that are reproductively isolated from other such groups.5 This definition is far from canonical, however, and the species concept remains highly contested in biology and philosophy.6 Indeed, the last few decades have witnessed a proliferation of species concepts, sometimes complementary but often conflicting, with different groups of biologists attuned to properties that are of particular relevance to their Page 2 of 19 PRINTED FROM OXFORD HANDBOOKS ONLINE (www.oxfordhandbooks.com). (c) Oxford University Press, 2015. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a title in Oxford Handbooks Online for personal use (for details see Privacy Policy). Subscriber: Harvard University Library; date: 24 August 2015 On the Nature of Species and the Moral Significance of their Extinction subfield of study, such as evolutionary history, morphology, inter-fertility, or ecological role, to name a few. This conceptual and methodological discord has led many authors to embrace some form of theoretical pluralism regarding the species concept.7 This poses a problem: if biologists and philosophers of science cannot agree on what the term “species” refers to, or which groupings of organisms or populations it picks out, then how can ethicists talk meaningfully about preserving such entities? Fortunately, the space of disagreement between alternative accounts of species is small enough to avoid prejudicing ethical discussions concerning the moral value of species. The reason for this optimism is that regardless of which properties they deem relevant to or necessary for species membership, all contemporary species concepts (p.