Species Problem – A Philosophical Analysis

Abstract

The ‘species problem’ is that there are multiple ways to conceive species that divide up biodiversity in inconsistent ways. Monistic responses to the species problem seek a single universal species concept, no single concept seems adequate though. Pluralistic responses recognise multiple species concepts, based on differences across biodiversity, theoretical interests or the functioning of concepts. But if what counts as a species taxon depends on human interests it isn't clear that species concepts divide biodiversity into real units and ‘cut nature at its joints’ in a straightforward way. The reality of species also seems to depend on their metaphysical status: what basic kinds of things are they? Some argue that species are sets of organisms, based on real essences, clusters of properties or historical relations. Others argue that they are spatiotemporally restricted individuals analogous to organisms. Key Concepts: The species problem is the use of multiple inconsistent species concepts that divide biodiversity in different ways. Monism is the view that correctly understood, there is only one kind of species thing. Natural kinds are groupings that are independent of human conventions and preferences, and are studied by science. Pluralism is the view that there are two or more kinds of species things. Pragmatic pluralism is the view that organisms can be grouped into species on the basis of different research interests. Realism is the view that species taxa are real and independent of human conventions. The species‐as‐individuals thesis is that species are historical individuals with beginnings, endings, change over time and cohesion. Organisms are ‘parts’ of a species. The species‐as‐sets thesis is that species are sets of organisms, where set inclusion is determined by intrinsic or extrinsic properties. Organisms are ‘members’ of a species.

Crossing species boundaries : the hybrid histories of the true geese

“…The former concept is popular among philosophers, probably because thinking in terms of natural kinds has a long tradition in philosophy. Biologists, on the other hand, mostly adhere to the species-as-individuals concept, because it is more coherent with evolutionary theory (Richards, 2010). However, both concepts emphasize the importance of (evolutionary) history in the species problem.…”

“…It is often stated that Darwin killed essentialism in biology (e.g., Dennett, 1995, Mayr, 1982. But this so-called "essentialism story" is misleading: many pre-Darwinian naturalists, including Aristotle and Linnaeus, did not adhere to a strict species essentialist philosophy (see Richards, 2010 for a nuanced version of the essentialism story). Regardless of this historical issue, two approaches that try to reconcile the contradiction between species essentialism and evolutionary change are most promising, namely species as historical natural kinds (LaPorte, 2004) and species as "individuals" that change over time (Ghiselin, 1969).…”

“…The debate on the definition of a species, commonly known as the species problem (Richards, 2010), has produced an insurmountable quantity of literature and yet there is still no proper definition of a species. Darwin (1859, p.44) nicely formulated the species problem, a description that still holds today: "No one definition has yet satisfied all naturalists; yet every naturalist knows vaguely what he means when he speaks of a species. "…”

Concealed diversity : taxonomical, phytogeographical and phytosociological notes on brambles (Rubus L. subgen. Rubus) in north-west Europe

“…This "Essentialism Story" was adopted by many authors, but questioned from the beginning by a minority (see Richards 2010 chapters 3 and 4 for an overview). Recently also Richards (2010) and Wilkins (2009bWilkins ( , 2010 Wilkins (2009b) and Richards (2010) is that the investigators in the pre-Darwinian period had ideas on what species are, namely "the generation of similar form" (Wilkins 2009b, p. 232), or, as John Ray (the father of natural history in Britain) has put in 1686, "progeny resembling their parents" (Ray 1686). This was named the Generative Notion (or Conception) of Species by Wilkins (2009b, p. 195;, and I will return to this later.…”

“…A short history of the species problem As was elucidated by Richards (2010), the species problem as experienced today has both its philosophical and biological roots in the understanding of Aristotelian philosophy, and the interpretation of the species ideas of early naturalists like John Ray and Carolus Linnaeus. The traditional view, which was developed by Cain, Mayr and Hull in the mid-twentieth century, claims that until the "Origin of Species" by Charles Darwin both philosophy and biology considered species as invariable natural kinds with essential features.…”