I respond to Michał Chaberek’s and Robert A. Delfino’s criticisms of my argument that evolution is compatible with Aristotelian-Thomistic metaphysics. Biological species, as secondary substances, are beings of reason founded in the natures of their instances. They are traceable to God’s creative intent, but not to universal exemplars. Aquinas teaches that concepts are derived from sensible accidents. Thus, evolution’s directed variation of such accidents will eventually require new species concepts. This accords with projective realism, which allows diverse, well-founded concepts based (...) on the multiple perspectives and conceptual spaces of knowing subjects. Charges that this is nominalism, not moderate realism, are rebutted; however, it is relativism because knowledge is a subject-object relation. Other metaphysical issues are considered. Chaberek’s thesis that species cannot evolve naturally fails because he: (1) reifies the species concept, (2) misrepresents the motivation, structure and conclusions of evolution, (3) confuses Aristotle’s four causes and (4) limits God’s creative omnipotence. Finally, Chaberek is out of step with contemporary theology. (shrink)

We argue that the logical outcome of the cladistics revolution in biological systematics, and the move towards rankless phylogenetic classification of nested monophyletic groups as formalized in the PhyloCode, is to eliminate the species rank along with all the others and simply name clades. We propose that the lowest level of formally named clade be the SNaRC, the Smallest Named and Registered Clade. The SNaRC is an epistemic level in the classification, not an ontic one. Naming stops at that level (...) because there is no currently acceptable evidence for clades within it, not because no smaller clades exist. Later, included clades may be named. They would then become the SNaRCs, while the original SNaRC would keep its original name. We argue that all theoretical tasks of biology, in evolution and ecology, as well as practical tasks such as conservation assessment, are better approached using this rankless phylogenetic approach. (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)

The purpose of this paper is to contribute to the ongoing analyses that aim to confront the problem of marked variation. Negatively marked differences are those natural variations that are used to cleave human beings into different categories (e.g., of disablement, of medicalized pathology, of subnormalcy, or of deviance). The problem of marked variation is: Why are some rather than other variations marked as epistemically or culturally significant or as a diagnostic of pathology, and What is the epistemic background that (...) makes these—rather than other variations—marked as subnormal? For Wilson (2018a), critical examination of the problem of marked variation is central to understanding the epistemology of medicalized pathology that made the history of eugenics possible. My aim is to explore the role marked variation plays in eugenic and other problematic classifications and the inferences they appear to license. I pay particular attention to the normative valuations of marked variations, how these valuations affect the inferences that are made by others about those possessing the variation, and how those possessing the variation perceive themselves. In the final sections, I illustrate this by critically discussing three putative kinship conceptions of race. I rely on these to extend the scope of the puzzle of marked variation from the context of historic and current markings of an individual’s variation as disability in the eugenics movement to historic and current markings for assigning putative racial ascriptions to individuals and groups. Lastly, I suggest that the problem of marked variation is a problem that looms over any epistemic account that is dependent upon sorting or classifying. (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)

Species pluralism allows for multiple species concepts. Given the overwhelming number of such concepts, this seems like an obvious interpretation of how `species' is used in contemporary biology. But why has it taken so long for this approach to be considered? I argue that part of the reason pluralism was overlooked due to the widespread use of a particular rhetorical strategy developed by Ernst Mayr. This strategy provided a framework for debates about the correct conception of species. That is, the (...) strategy offered a means of comparing modern concepts with a monistic-essentialist understanding of species. I ask what would happen if we replaced this concept with Aristotle's own pluralist-essentialist understanding of species. As recent scholarship shows, Aristotle's philosophy of biology allows for an approach to classification that is in practice highly pluralistic. From this new framework we can understand what sort of assumptions are at stake between modern forms of species pluralism. My analysis shows that the essentialist story told by Mayr and others left us asking the wrong questions about how to conceive of species in an evolutionary world. Having a deeper understanding of Aristotle's approach to the classification of animals allows us to shift focus from the so-called species problem in order to raise four issues that are relevant to current debates. These are questions about: the explanatory power of taxonomic ranks, the importance of the species category problem, whether species are constituted by intrinsic or extrinsic properties, and how to interpret the ``cross-cutting'' metaphor endemic to the pluralist literature. In order to get to these questions I will first explain what sort of claim species pluralism is at the most general level, and a gloss on the standard interpretation of the historical shift from species monism to species pluralism. (shrink)