Present-day thought on the notion of species is troubled by a mistaken understanding of the nature of the issue: while the species problem is commonly understood as concerning the epistemology and ontology of one single scientific concept, I argue that in fact there are multiple distinct concepts at stake. An approach to the species problem is presented that interprets the term ‘species’ as the placeholder for four distinct scientific concepts, each having its own role in biological theory, and an explanation (...) is given of the concepts involved. To illustrate how these concepts are commonly conflated, two widely accepted ideas on species are criticized: species individualism and species pluralism. I argue that by failing to distinguish between the four concepts and their particular roles in contemporary biological theory, these ideas stand in the way of a final resolution of the species problem. (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.

Species are generally considered to be the basic units of evolution, and hence to constitute spatio-temporally bounded entities. In addition, it has been argued that species also instantiate a natural kind. Evolution is fundamentally about change. The question then is how species can remain the same through evolutionary change. Proponents of the species qua individuals thesis individuate species through their unique evolutionary origin. Individuals, or spatio-temporally located particulars in general, can be bodies, objects, events, or processes, or a combination of (...) these. It is here argued that species are best understood as open or closed, causally integrated processual systems that also instantiate an historically conditioned homeostatic property cluster natural kind. (shrink)

This paper takes a hierarchical approach to the question whether species are individuals or natural kinds. The thesis defended here is that species are spatiotemporally located complex wholes (individuals), that are composed of (i.e., include) causally interdependent parts, which collectively also instantiate a homeostatic property cluster (HPC) natural kind. Species may form open or closed genetic systems that are dynamic in nature, that have fuzzy boundaries due to the processual nature of speciation, that may have leaky boundaries as is manifest (...) in lateral gene transfer and introgression, that may be of multiple origins through hybridization, and that may split and merge and split again over time. The identity conditions of species qua individuals will have to be anchored in their history, rather than in their unique evolutionary origin. Species qua historically conditioned HPC natural kinds requires the kind to be mereologically structured, subject to the part-whole relation rather than the membership relation. This implies that there can be more than one kind of natural kinds. (shrink)

abstract This article attempts to illustrate the continuing need to pay attention to ontological issues connected with the conduct of empirical research and subsequent policy making. Failure to do so leads to the conflation of social constructions with ideas about the thesis of an independent reality. Such category mistakes often lead to dilemmas in which culturally sensitive constructs may, on the one hand, be worthy of study because they do tell us how socially constructed categories do predict social phenomena; but, (...) on the other hand, such constructs may illustrate an unwillingness on the part of the research community to recognize the objective nature of such constructs. Some recommendations are suggested for addressing the social policy consequences of these dilemmas. (shrink)

Species are central to biology, but there is currently no agreement on what the adequate species concept should be, and many have adopted a pluralist stance: different species concepts will be required for different purposes. This thesis is a multidimensional analysis of species pluralism. First I explicate how pluralism differs monism and relativism. I then consider the history of species pluralism. I argue that we must re-frame the species problem, and that re-evaluating Aristotle's role in the histories of systematics can (...) shed light on pluralism. Next I consider different forms of pluralism: evolutionary and extra-evolutionary species pluralism, which differ in their stance on evolutionary theory. I show that pluralism is more than a debate about the species category, but a debate about which concepts are legitimate and a claim about how they interact with one another. Following that, I consider what sort of ontology is required for different forms of species pluralism. I argue that pluralists who deny the unity of biology will require a further plurality of frameworks, while those that ground their pluralism in evolution need only one framework. Finally, I consider what pluralism means for biological practice. I argue that species concepts are tools, and reflect on how pluralism can illuminate the way systematists approach the discovery of new species of yeast. Pluralism can make sense of the way species concepts are used, and can be developed to aid researchers in thinking about how to use the right tools for the right jobs. (shrink)