Oaks exemplify problems with the reproductive species concept which motivate a reconsideration of the use and nature of species. Ecology is important in the reconsideration. The species level is usually overemphasized in evolutionary thought; selection acts on phenotypes and any mutualistic units. Standard definitions tend to inhibit free conceptual progress. Multispecies, sets of broadly sympatric species that exchange genes, may occur among animals as well as plants and may conceivably bridge kingdoms. This phenomenon can be adaptively important. There may be (...) taxa without species. The degree of modality of adaptive zones can be investigated empirically. (shrink)

In birds and frogs, species pairs retain the capacity to produce viable hybrids for tens of millions of years, an order of magnitude longer than mammals. What accounts for these differences in relative rates of pre- and postzygotic isolation? We propose that reproductive mode is a critically important but previously overlooked factor in the speciation process. Viviparity creates a post-fertilization arena for genomic conflicts absent in egg-laying species. With viviparity, conflict can arise between: mothers and embryos; sibling embryos in the (...) womb, and maternal and paternal genomes within individual embryos. Such intra- and intergenomic conflicts result in perpetual antagonistic coevolution, thereby accelerating interpopulation postzygotic isolation. In addition, by generating intrapopulation genetic incompatibility, viviparity-driven conflict favors polyandry and limits the potential for precopulatory divergence. Mammalian diversification is characterized by rapid evolution of incompatible feto-maternal interactions, asymmetrical postzygotic isolation, disproportionate effects of genomically-imprinted genes, and “F2 hybrid enhancement.” The viviparity-driven conflict hypothesis provides a parsimonious explanation for these patterns in mammalian evolution. BioEssays 22:938–946, 2000. © 2000 John Wiley & Sons, Inc. (shrink)

Summary The common view has been that Darwin regarded species as artificial and arbitrary constructions of taxonomists, not as distinct natural units. However, in his transmutation notebooks he clearly subscribed to the reality of species, on the basis of the criterion of non-interbreeding. A consequence of this biological species concept was his identification of the acquisition of reproductive isolation as the mark of the completion of speciation. He developed in the notebooks a theory of geographic speciation on the grounds of (...) (a) an empirical correlation between barriers and the geographical distributions of allied species, (b) the analogy of artificial isolation in the formation of new domesticated varieties, and (c) the logical consequence of blending inheritance. A brief discussion of Darwin's species concept in later writings concludes the paper. (shrink)

The concept of individuality as applied to species, an important advance in the philosophy of evolutionary biology, is nevertheless in need of refinement. Four important subparts of this concept must be recognized: spatial boundaries, temporal boundaries, integration, and cohesion. Not all species necessarily meet all of these. Two very different types of pluralism have been advocated with respect to species, only one of which is satisfactory. An often unrecognized distinction between grouping and ranking components of any species concept is necessary. (...) A phylogenetic species concept is advocated that uses a grouping criterion of monophyly in a cladistic sense, and a ranking criterion based on those causal processes that are most important in producing and maintaining lineages in a particular case. Such causal processes can include actual interbreeding, selective constraints, and developmental canalization. The widespread use of the biological species concept is flawed for two reasons: because of a failure to distinguish grouping from ranking criteria and because of an unwarranted emphasis on the importance of interbreeding as a universal causal factor controlling evolutionary diversification. The potential to interbreed is not in itself a process; it is instead a result of a diversity of processes which result in shared selective environments and common developmental programs. These types of processes act in both sexual and asexual organisms, thus the phylogenetic species concept can reflect an underlying unity that the biological species concept can not. (shrink)

Since the 1970s, there has been a tremendous amount of literature on Ghiselin's proposal that species are individuals. After recalling the origins and stakes of this thesis in contemporary evolutionary theory, I show that it can also be found in the writings of the French naturalist Buffon in the 18th Century. Although Buffon did not have the conception that one species could be derived from another, there is an interesting similarity between the modern argument and that of Buffon regarding the (...) individuality of species. The analogy is strong enough to force us to recognize that genuine evolutionary (or Darwinian) questions might be of secondary importance in the discussion. In consequence, the third section of the paper proposes an alternative schema for the logical structure of the Darwinian concept of species. Darwin distinguished the problem of the designation of a concrete species, and the problem of its signification of species within his theory of descent? The resulting notion of species involves a logical structure based on the fusion of the logical operations of classification and ordering. The difficulty — and interest — is that this interpretation of species does not entail any precise operational definition of species; it can only tell us what the ultimate signification of classification is within the theory of descent with modification through natural selection. (shrink)

I defend a view of the species category, pluralistic realism, which is designed to do justice to the insights of many different groups of systematists. After arguing that species are sets and not individuals, I proceed to outline briefly some defects of the biological species concept. I draw the general moral that similar shortcomings arise for other popular views of the nature of species. These shortcomings arise because the legitimate interests of biology are diverse, and these diverse interests are reflected (...) in different legitimate approaches to the classification of organisms. In the final section, I show briefly how the pluralistic approach can help to illuminate some areas of biological and philosophical dispute. (shrink)

The fact that the names of biological species refer independently of identifying descriptions does not support the view of Ghiselin and Hull that species are individuals. Species may be regarded as natural kinds whose members share an essence which distinguishes them from the members of other species and accounts for the fact that they are reproductively isolated from the members of other species. Because evolutionary theory requires that species be spatiotemporally localized their names cannot occur in scientific laws. If natural (...) kind status is denied to species on this ground, it must also be denied to most classes of concrete entities which are now accorded such status. (shrink)

Biological species have been treated traditionally as spatiotemporally unrestricted classes. If they are to perform the function which they do in the evolutionary process, they must be spatiotemporally localized individuals, historical entities. Reinterpreting biological species as historical entities solves several important anomalies in biology, in philosophy of biology, and within philosophy itself. It also has important implications for any attempt to present an "evolutionary" analysis of science and for sciences such as anthropology which are devoted to the study of single (...) species. (shrink)

This paper takes up the cause of species pluralism. An argument for species pluralism is provided and standard monist objections to pluralism are answered. A new form of species pluralism is developed and shown to be an improvement over previous forms. This paper also offers a general foundation on which to base a pluralistic approach to biological classification.

This volume of twelve specially commissioned essays about species draws on the perspectives of prominent researchers from anthropology , botany, developmental psychology , the philosophy of biology and science, protozoology, and zoology . The concept of species has played a focal role in both evolutionary biology and the philosophy of biology , and the last decade has seen something of a publication boom on the topic (e.g., Otte and Endler 1989; Ereshefsky 1992b; Paterson 1994; lambert and Spence 1995; Claridge, Dawah, (...) and Wilson 1997; Wheeler and Meier 1999; Howard and Berlocher 1998). (shrink)

The question of whether biologists should continue to use the Linnaean hierarchy has been a hotly debated issue. Invented before the introduction of evolutionary theory, Linnaeus's system of classifying organisms is based on outdated theoretical assumptions, and is thought to be unable to provide accurate biological classifications. Marc Ereshefsky argues that biologists should abandon the Linnaean system and adopt an alternative that is more in line with evolutionary theory. He traces the evolution of the Linnaean hierarchy from its introduction to (...) the present. He illustrates how the continued use of this system hampers our ability to classify the organic world, and then goes on to make specific recommendations for a post-Linnaean method of classification. Accessible to a wide range of readers by providing introductory chapters to the philosophy of classification and the taxonomy of biology, the book will interest both scholars and students of biology and the philosophy of science. (shrink)

_This sweeping discussion of the philosophy of evolutionary biology is based on the revolutionary idea that species are not kinds of organisms but wholes composed of organisms._.

This 1983 book is a lively and clearly written introduction to the philosophy of natural science, organized around the central theme of scientific realism. It has two parts. 'Representing' deals with the different philosophical accounts of scientific objectivity and the reality of scientific entities. The views of Kuhn, Feyerabend, Lakatos, Putnam, van Fraassen, and others, are all considered. 'Intervening' presents the first sustained treatment of experimental science for many years and uses it to give a new direction to debates about (...) realism. Hacking illustrates how experimentation often has a life independent of theory. He argues that although the philosophical problems of scientific realism can not be resolved when put in terms of theory alone, a sound philosophy of experiment provides compelling grounds for a realistic attitude. A great many scientific examples are described in both parts of the book, which also includes lucid expositions of recent high energy physics and a remarkable chapter on the microscope in cell biology. (shrink)

Hilary Putnam deals in this book with some of the most fundamental persistent problems in philosophy: the nature of truth, knowledge and rationality. His aim is to break down the fixed categories of thought which have always appeared to define and constrain the permissible solutions to these problems.

"Legend is overdue for replacement, and an adequate replacement must attend to the process of science as carefully as Hull has done. I share his vision of a serious account of the social and intellectual dynamics of science that will avoid both the rosy blur of Legend and the facile charms of relativism.... Because of [Hull's] deep concern with the ways in which research is actually done, Science as a Process begins an important project in the study of science. It (...) is one of a distinguished series of books, which Hull himself edits."—Philip Kitcher, Nature "In Science as a Process, [David Hull] argues that the tension between cooperation and competition is exactly what makes science so successful.... Hull takes an unusual approach to his subject. He applies the rules of evolution in nature to the evolution of science, arguing that the same kinds of forces responsible for shaping the rise and demise of species also act on the development of scientific ideas."—Natalie Angier, New York Times Book Review "By far the most professional and thorough case in favour of an evolutionary philosophy of science ever to have been made. It contains excellent short histories of evolutionary biology and of systematics (the science of classifying living things); an important and original account of modern systematic controversy; a counter-attack against the philosophical critics of evolutionary philosophy; social-psychological evidence, collected by Hull himself, to show that science does have the character demanded by his philosophy; and a philosophical analysis of evolution which is general enough to apply to both biological and historical change."—Mark Ridley, Times Literary Supplement "Hull is primarily interested in how social interactions within the scientific community can help or hinder the process by which new theories and techniques get accepted.... The claim that science is a process for selecting out the best new ideas is not a new one, but Hull tells us exactly how scientists go about it, and he is prepared to accept that at least to some extent, the social activities of the scientists promoting a new idea can affect its chances of being accepted."—Peter J. Bowler, Archives of Natural History "I have been doing philosophy of science now for twenty-five years, and whilst I would never have claimed that I knew everything, I felt that I had a really good handle on the nature of science, Again and again, Hull was able to show me just how incomplete my understanding was.... Moreover, [Science as a Process] is one of the most compulsively readable books that I have ever encountered."—Michael Ruse, Biology and Philosophy. (shrink)

At least 22 concepts of species are in use today and many of these are notably incompatible in their accounts of biological diversity. Much of the traditional turmoil embodied in the species problem ultimately derives from the packaging of inappropriate criteria for species into a single concept. This results from a traditional conflation of function of concepts with their applications, definitions with concepts, taxonomic categories with groups, and the ontological status of real species with teleological approaches to recover them. Analogous (...) to classifications of supraspecific taxa, our forging inappropriate and ambiguous information relating to theoretical and operational discussions of species ultimately results in a trade-off between convenience, accuracy, precision, and the successful recovery of natural biological diversity. Hence, none of these expectations or intentions of species or classifications is attainable through composite, and possibly discordant, concepts of biological diversity or its descent. Reviewing and evaluating the concepts of species for their theoretical and operational qualities illustrates that a monistic, primary concept of species, applicable to the various entities believed to be species, is essential. This evaluation reveals only one theoretical concept as appropriate for species, the Evolutionary Species Concept. This conceptualization functions as a primary concept and is essential in structuring our ideas and perceptions of real species in the natural world. The remaining concepts are secondary, forming a hierarchy of definitional guidelines subordinate to the primary concept, and are essential to the study of species in practice. Secondary concepts should be used as operational tools, where appropriate, across the variance in natural diversity to discover entities in accord with the primary concept. Without this theoretical and empirical structuring of concepts of species our mission to achieve reconciliation and understanding of pattern and process of the natural world will fail. (shrink)

WE HAVE LEARNED in the preceding chapter that a revolutionary change of the species concept is in the making, a change which not only affects taxonomic procedure, but which also contributes considerably toward a better understanding of ...

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.

Gayon's recent claim that Buffon developed a concept of species as physical individuals is critically examined and rejected. Also critically examined and rejected is Gayon's more central thesis that as a consequence of his analysis of Buffon's species concept, and also of Darwin's species concept, it is clear that modern evolutionary theory does not require species to be physical individuals. While I agree with Gayon's conclusion that modern evolutionary theory does not require species to be physical individuals, I disagree with (...) his reasons and instead provide logical rather than historical reasons for the same conclusion. (shrink)

I adopt a cladistic view of species, and explore the possibility that there exists an equally valuable cladistic view of organismic traits. This suggestion seems to run counter to the stress on functional views of biological traits in recent work in philosophy and psychology. I show how the tension between these two views can be defused with a multilevel view of biological explanation. Despite the attractions of this compromise, I conclude that we must reject it, and adopt an essentially cladistic (...) conception of biological traits. (shrink)

Historically, naturalists who propose theories of evolution, including Darwin and Wallace, have done so in order to explain the apparent relationship of natural classification. This book begins by exploring the intimate historical relationship between patterns of classification and patterns of phylogeny. It is a circular argument, however, to use the data for classification and the concept of homology as evidence for evolution, when evolution is the theory explaining the phenomenon of natural classification. Alec Panchen presents other evidence for evolution in (...) the form of a historically-based but rigorously logical argument. This is then followed by a history of methods of classification and phylogeny reconstruction including current mathematical and molecular techniques. The author makes the important claim that if the hierarchical pattern of classification is a real phenomenon, then biology is unique as a science in making taxonomic statements. This conclusion is reached by way of historical reviews of theories of evolutionary mechanism and the philosophy of science as applied to biology. (shrink)

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.

In the face of argument to the contrary, it is shown that there is defensible middle ground available for entity realism, between the extremes of scientific realism and empiricist antirealism. Cartwright's ([1983]) earlier argument for defensible middle ground between these extremes, which depended crucially on the viability of an underdeveloped distinction between inference to the best explanation (IBE) and inference to the most probable cause (IPC), is examined and its defects are identified. The relationship between IBE and IPC is clarified (...) and a revised version of Cartwright's argument for defensible middle ground, which is free of the identified defects, is presented. (shrink)

Long before Charles Darwin undertook his first voyage, animal taxonomists had begun the scientific classification of animals, plants, and minerals. In the mid-1950s, taxonomist A. J. Cain summarized the state of knowledge about the structure of the living world in his major book Animal Species and Their Evolution. His work remains remarkably current today. Here Cain explains each of the terms by which scientists now classify all animals--from species through genus, family, order, class, and phylum. The work of the modern (...) taxonomist is dependent on the work of paleontologists, field biologists, ecologists, and other specialists who help piece together the puzzle of nature. This seminal text will interest students in each of these areas. It will also appeal to historians of science and to all amateur scientists with an interest in the animal kingdom. Originally published in 1993. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905. (shrink)