What are biological species? Aristotelians and Lockeans agree that they are natural kinds; but, evolutionary theory shows that neither traditional philosophical approach is truly adequate. Recently, Michael Ghiselin and David Hull have argued that species are individuals. This claim is shown to be against the spirit of much modern biology. It is concluded that species are natural kinds of a sort, and that any 'objectivity' they possess comes from their being at the focus of a consilience of inductions.

This chapter contains sections titled: Historical and Current Views of Species Return to a Darwinian View of Species Practical Implications Postscript: Counterpoint References.

This chapter contains sections titled: Introduction Early Species Concepts—Linnaeus Biological Species Concepts Phylogenetic Species Concepts Species Concepts and Speciation Conclusions Postscript: Counterpoint References.

Stamos squarely confronts the problem of determining what a biological species is, whether species are real, and the nature of their reality. He critically considers the evolution of the major contemporary views of species and also offers his own solution to the species problem.

No question in theoretical biology has been more perennially controversial or perplexing than "What is a species?" Recent advances in phylogenetic theory have called into question traditional views of species and spawned many concepts that are currently competing for general acceptance. Once the subject of esoteric intellectual exercises, the "species problem" has emerged as a critically important aspect of global environmental concerns. Completion of an inventory of biodiversity, success in conservation, predictive knowledge about life on earth, management of material resources, (...) formulation of scientifically credible public policy and law, and more depend upon our adoption of the "right" species concept. Quentin D. Wheeler and Rudolf Meier present a debate among top systematic biology theorists to consider the strengths and weaknesses of five competing concepts. Debaters include (1) Ernst Mayr (Biological Species Concept), (2) Rudolf Meier and Rainer Willmann (Hennigian species concept), (3) Brent Mishler and Edward Theriot (one version of the Phylogenetic Species Concept), (4) Quentin Wheeler and Norman Platnick (a competing version of the Phylogenetic Species Concept), and (5) E. O. Wiley and Richard Mayden (the Evolutionary Species Concept). Each author or pair of authors contributes three essays to the debate: first, a position paper with an opening argument for their respective concept of species; second, a counterpoint view of the weakness of competing concepts; and, finally, a rebuttal of the attacks made by other authors. This unique and lively debate format makes the comparative advantages and disadvantages of competing species concepts clear and accessible in a single book for the first time, bringing to light numerous controversies in phylogenetic theory, taxonomy, and philosophy of science that are important to a wide audience. Species Concepts and Phylogenetic Theory will meet a need among scientists, conservationists, policy-makers, and students of biology for an explicit, critical evaluation of a large and complex literature on species. An important reference for professionals, the book will prove especially useful in classrooms and discussion groups where students may find a concise, lucid entrée to one of the most complex questions facing science and society. (shrink)

Stamos squarely confronts the problem of determining what a biological species is, whether species are real, and the nature of their reality. He critically considers the evolution of the major contemporary views of species and also offers his own solution to the species problem.

There is long-standing disagreement among systematists about how to divide biodiversity into species. Over twenty different species concepts are used to group organisms, according to criteria as diverse as morphological or molecular similarity, interbreeding and genealogical relationships. This, combined with the implications of evolutionary biology, raises the worry that either there is no single kind of species, or that species are not real. This book surveys the history of thinking about species from Aristotle to modern systematics in order to understand (...) the origin of the problem, and advocates a solution based on the idea of the division of conceptual labor, whereby species concepts function in different ways - theoretically and operationally. It also considers related topics such as individuality and the metaphysics of evolution, and how scientific terms get their meaning. This important addition to the current debate will be essential for philosophers and historians of science, and for biologists. (shrink)

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

The essentialism story is a version of the history of biological classification that was fabricated between 1953 and 1968 by Ernst Mayr, who combined contributions from Arthur Cain and David Hull with his own grudge against Plato. It portrays pre-Darwinian taxonomists as caught in the grip of an ancient philosophy called essentialism, from which they were not released until Charles Darwin's 1859 Origin of Species. Mayr's motive was to promote the Modern Synthesis in opposition to the typology of idealist morphologists; (...) demonizing Plato served this end. Arthur Cain's picture of Linnaeus as a follower of 'Aristotelian' (scholastic) logic was woven into the story, along with David Hull's application of Karl Popper's term, 'essentialism', which Mayr accepted in 1968 as a synonym for what he had called 'typological thinking'. Although Mayr also pointed out the importance of empiricism in the history of taxonomy, the essentialism story still dominates the secondary literature. The history of the first telling of the essentialism story exposes its scant basis in fact. (shrink)

The current picture of the history of taxonomy incorporates A. J. Cain's claim that Linnaeus strove to apply the logical method of definition taught by medieval followers of Aristotle. Cain's argument does not stand up to critical examination. Contrary to some published statements, there is no evidence that Linnaeus ever studied logic. His use of the words “genus” and “species” ruined the meaning they had in logic, and “essential” meant to him merely “taxonomically useful.” The essentialism story, a narrative that (...) has most pre-Darwinian biologists steeped in the world view of Plato and Aristotle, is ill-founded and improbable. (shrink)