Taxa and homologues can in our view be construed both as kinds and as individuals. However, the conceptualization of taxa as natural kinds in the sense of homeostatic property cluster kinds has been criticized by some systematists, as it seems that even such kinds cannot evolve due to their being homeostatic. We reply by arguing that the treatment of transformational and taxic homologies, respectively, as dynamic and static aspects of the same homeostatic property cluster kind represents a good perspective for (...) supporting the conceptualization of taxa as kinds. The focus on a phenomenon of homology based on causal processes (e.g., connectivity, activity-function, genetics, inheritance, and modularity) and implying relationship with modification yields a notion of natural kinds conforming to the phylogenetic-evolutionary framework. Nevertheless, homeostatic property cluster kinds in taxonomic and evolutionary practice must be rooted in the primacy of epistemological classification (homology as observational properties) over metaphysical generalization (series of transformation and common ancestry as unobservational processes). The perspective of individuating characters exclusively by historical-transformational independence instead of their developmental, structural, and functional independence fails to yield a sufficient practical interplay between theory and observation. Purely ontological and ostensional perspectives in evolution and phylogeny (e.g., an ideographic character concept and PhyloCode’s ‘individualism’ of clades) may be pragmatically contested in the case of urgent issues in biodiversity research, conservation, and systematics. (shrink)

Despite the traditional focus on metaphysical issues in discussions of natural kinds in biology, epistemological considerations are at least as important. By revisiting the debate as to whether taxa are kinds or individuals, I argue that both accounts are metaphysically compatible, but that one or the other approach can be pragmatically preferable depending on the epistemic context. Recent objections against construing species as homeostatic property cluster kinds are also addressed. The second part of the paper broadens the perspective by considering (...) homologues as another example of natural kinds, comparing them with analogues as functionally defined kinds. Given that there are various types of natural kinds, I discuss the different theoretical purposes served by diverse kind concepts, suggesting that there is no clear-cut distinction between natural kinds and other kinds, such as functional kinds. Rather than attempting to offer a unique metaphysical account of ‘natural’ kind, a more fruitful approach consists in the epistemological study of how different natural kind concepts are employed in scientific reasoning. (shrink)

Ernst Mayr's typological/population distinction is a conceptual thread that runs throughout much of his work in systematics, evolutionary biology, and the history and philosophy of biology. Mayr himself claims that typological thinking originated in the philosophy of Plato and that population thinking was first introduced by Charles Darwin and field naturalists. A more proximate origin of the typological/population thinking, however, is found in Mayr's own work on species. This paper traces the antecedents of the typological/population distinction by detailing Mayr's changing (...) views of species between 1942 and 1955. During this period, Mayr struggles to refine the biological species concept in the face of tensions that exist between studying species locally and studying them as geographically distributed collections of variable populations. The typological/population distinction is first formulated in 1955, when Mayr generalizes from the type concept versus the population concept in taxonomy to typological versus population thinking in biology more generally. Mayr's appeal to the more general distinction between typological and population thinking coincides with the waning status of natural history and evolutionary biology that occurs in the early 1950s and the distinction plays an important role in Mayr's efforts to legitimate the natural historical sciences. (shrink)

To cite this Article: Ereshefsky, Marc , 'Foundational Issues Concerning Taxa and Taxon Names', Systematic Biology, 56:2, 295 - 301 To link to this article: DOI: 10.1080/10635150701317401 URL: http://dx.doi.org/10.1080/10635150701317401..

Most biologists use the Linnaean system for constructing classifications of the organic world. The Linnaean system, however, has lost its theoretical basis due to the shift in biology from creationist and essentialist tenets to evolutionary theory. As a result, the Linnaean system is both cumbersome and ontologically vacuous. This paper illustrates the problems facing the Linnaean system, and ends with a brief introduction to an alternative approach to biological classification.

Homeostatic Property Cluster (HPC) theory suggests that species and other biological taxa consist of organisms that share certain similarities. HPC theory acknowledges the existence of Darwinian variation within biological taxa. The claim is that “homeostatic mechanisms” acting on the members of such taxa nonetheless ensure a significant cluster of similarities. The HPC theorist’s focus on individual similarities is inadequate to account for stable polymorphism within taxa, and fails properly to capture their historical nature. A better approach is to treat distributions (...) of traits in species populations as irreducible facts, explained in terms of selection pressures, genealogy, and other evolutionary factors. We call this view Population Structure Theory (PST). PST accommodates the view, implicit in biological systematics, that species are identified by reference to particular historical populations. (shrink)

In this paper I explore Aristotle’s views on natural kinds and the compatibility of pluralism and realism, a topic that has generated considerable interest among contemporary philosophers. I argue that, when it came to zoology, Aristotle denied that there is only one way of organizing the diversity of the living world into natural kinds that will yield a single, unified system of classification. Instead, living things can be grouped and regrouped into various cross-cutting kinds on the basis of objective similarities (...) and differences in ways that subserve the explanatory context. Since the explanatory aims of zoology are diverse and variegated, the kinds it recognizes must be equally diverse and variegated. At the same time, there are certain constraints on which kinds can be selected. And those constraints derive more from the causal structure of the world than from the proclivities of the classifier (hence the realism). This distinguishes Aristotle’s version of pluralistic realism from those contemporary versions (like Dupré’s “promiscuous realism”) that treat all or most classifications of a given domain as equally legitimate and not just a sub-set of kinds recognized by the science that studies it. By contrast, Aristotle privileges scientifically important kinds on the basis of their role in causal investigations. On this picture natural kinds are those kinds with the sort of causal structure that allows them to enter into scientific explanations. In the final section I argue that Aristotle’s zoology should remain of interest to philosophers and biologists alike insofar as it combines a pluralistic form of realism with a rank-free approach to classification. (shrink)

Cognitive definitions cannot accommodate fear as it occurs in species incapable of sophisticated cognition. Some think that fear must, therefore, be noncognitive. This paper explores another option, arguably more in line with evolutionary theory: that like other "biological universals" fear admits of variation across and within species. A paradigm case of such universals is species: it is argued that they can be defined by ostension in the manner of Putnam and Kripke without implying that they must have an invariable essence. (...) Emotions can be defined in this way too, in principle, but the theoretical understanding of homology necessary to do so is lacking at present. (shrink)

The purpose of this paper is to test the contemporary concept of biological species against some of the problems caused by treating species as spatiotemporally extended entities governed by criteria of persistence, identity, etc. After outlining the general problem of symmetric division in natural objects, I set out some useful distinctions (section 1) and confirm that species are not natural kinds (section 2). Section 3 takes up the separate issue of species definition, focusing on the Biological Species Concept (BSC). Sections (...) 4 and 5 examine the matter of species identity over space and time respectively, as determined by the BSC. Both gradualistic and punctuated equilibrium models of speciation are discussed. In section 6 I argue that the BSC fails to determine adequate criteria for dealing with certain kinds of speciation. Section 7 moves speculatively beyond the BSC to a brief examination of alternatives. (shrink)

The vision of natural kinds that is most common in the modern philosophy of biology, particularly with respect to the question whether species and other taxa are natural kinds, is based on a revision of the notion by Mill in A System of Logic. However, there was another conception that Whewell had previously captured well, which taxonomists have always employed, of kinds as being types that need not have necessary and sufficient characters and properties, or essences. These competing views employ (...) different approaches to scientific methodologies: Mill’s class-kinds are not formed by induction but by deduction, while Whewell’s type-kinds are inductive. More recently, phylogenetic kinds (clades, or monophyletic-kinds) are inductively projectible, and escape Mill’s strictures. Mill’s version represents a shift in the notions of kinds from the biological to the physical sciences. (shrink)

"--Joel Cracraft, American Museum of Natural History "This is not the potted history that one usually finds in texts and review articles.

Defining Species: A Sourcebook from Antiquity to Today provides excerpts and commentary on the definition of «species from source material ranging from the ...

Essentialism is widely regarded as a mistaken view of biological kinds, such as species. After recounting why (sections 2-3), we provide a brief survey of the chief responses to the “death of essentialism” in the philosophy of biology (section 4). We then develop one of these responses, the claim that biological kinds are homeostatic property clusters (sections 5-6) illustrating this view with several novel examples (section 7). Although this view was first expressed 20 years ago, and has received recent discussion (...) and critique, it remains underdeveloped and is often misrepresented by its critics (section 8). (shrink)