On biological species, species concepts and individuation in the natural world

I am a realist and argue that biological species exist in nature. I also argue that the validity of ¢ndings of the many disciplines within the natural sciences employing biological species in their endeavours of inquiry are unequivocally linked to the accuracy of the species used in experiments. Few scientists today see the fundamental importance of taxonomic and systematic studies in both addressing accuracy of diversity and the delineation of species diversity for other areas of science. The basic controversial issues in the debate revolve around opinions regarding the nature of species as either Individuals or Classes, confusion of Species as a taxonomic category and as entities in nature, the varied practitioners studying diversity, a general lack of a Lineage perspective and a gross chauvinistic perspective on the types of data worthy of exposing and delineating diversity. I argue that species in nature are Individuals and form Lineages .A sIndividuals, they cannot be de¢ned but can only be diagnosed in time. The category Species is a Class with a de¢nition. The di⁄culties realised by scientists studying biodiversity in ‘de¢ning’ a species hinges upon the fact that as natural entities they cannot be de¢ned. Recognizing and understanding the origins of characters in species is further complicated if one views species in nature as Classes and lacks an appreciation for the Lineage and the origin and retention of traits through time. This forms an interesting paradox that many scientists have fallen victim to wherein species are viewed as Classes (hence de¢nable, but immutable) yet are used to understand the process of descent that involves lineages and Individuals! The pre-Darwinian Class perspective of species, combined with a common chauvinistic perspective on characters ultimately delays progress and places a ‘glass ceiling’ on species diversity for planet Earth. One resolution to the species and species concept issue is to view the concepts in a hierarchical manner of primary (theoretical) and secondary (operational) concepts. Interestingly, the issue of Individuals versus Classes for naturally occurring entities is much more widespread and exists in many other scienti¢c ¢elds. Thus, a hierarchical perspective of having a primary, nonoperational concept for natural entities and multiple operational concepts serving as ‘tools’ for discovering natural things consistent with the primary concept is a heuristic methodology that is applicable to the advancement of many areas of science.

[1]  J. Winston Describing Species: Practical Taxonomic Procedure for Biologists , 1999 .

[2]  J Mallet,et al.  A species definition for the modern synthesis. , 1995, Trends in ecology & evolution.

[3]  J. R. Stauffer,et al.  Behaviour: an important diagnostic tool for Lake Malawi cichlids , 2002 .

[4]  R. Waples Pacific Salmon, Oncorhynchus spp., and the Definition of "Species" Under the Endangered Species Act , 1991 .

[5]  R L Mayden,et al.  Consilience and a hierarchy of species concepts: advances toward closure on the species puzzle. , 1999, Journal of nematology.

[6]  Ernst Mayr,et al.  Species Concepts and Definitions , 1976 .

[7]  D. Hull Are Species Really Individuals , 1976 .

[8]  Joel Cracraft,et al.  Species Concepts and Speciation Analysis , 1983 .

[9]  L. V. Valen,et al.  Ecological Species, Multispecies, and Oaks , 1976 .

[10]  A. Kluge,et al.  A CONSIDERATION OF EPISTEMOLOGY IN SYSTEMATIC BIOLOGY, WITH SPECIAL REFERENCE TO SPECIES , 1994 .

[11]  P. Sneath,et al.  PHENETIC TAXONOMY AT THE SPECIES LEVEL AND ABOVE , 1976 .

[12]  D. Hillis,et al.  Species in concept and practice : herpetological applications , 1990 .

[13]  T. Dobzhansky Mendelian Populations and Their Evolution , 1950, The American Naturalist.

[14]  D. Rosen Fishes from the uplands and intermontane basins of Guatemala : revisionary studies and comparative geography. Bulletin of the AMNH ; v. 162, article 5 , 1979 .

[15]  George Gaylord Simpson,et al.  Principles of Animal Taxonomy , 1961 .

[16]  Native Trout of Western North America , 1994 .

[17]  C. Lydeard,et al.  Species Delineation and the Identification of Evolutionarily Significant Units: Lessons from the Freshwater Mussel Genus Potamilus (Bivalvia: Unionidae) , 1998 .

[18]  E. Wiley,et al.  On Species Individualism: A New Defense of the Species-as-Individuals Hypothesis , 2001, Philosophy of Science.

[19]  Rudolf Meier,et al.  Species Concepts and Phylogenetic Theory , 2000 .

[20]  Kevin J. Gaston,et al.  Biodiversity : a biology of numbers and difference , 1996 .

[21]  T. Dobzhansky Speciation as a Stage in Evolutionary Divergence , 1940, The American Naturalist.

[22]  P. Kitcher Some Puzzles About Species , 1989 .

[23]  L. Maxson,et al.  Biochemical evolution in the slimy salamanders of the Plethodon glutinosus Complex in the Eastern United States , 1989 .

[24]  P. Kitcher Ghostly whispers: Mayr, Ghiselin, and the “Philosophers” on the ontological status of species , 1987 .

[25]  Michael T. Ghiselin,et al.  Metaphysics and the origin of species , 1997 .

[26]  H. Paterson,et al.  Evolution and the Recognition Concept of Species: Collected Writings , 1992 .

[27]  M. Ghiselin Individuality, History and Laws of Nature in Biology , 1989 .

[28]  Ernst Mayr,et al.  Principles of systematic zoology , 1969 .

[29]  R. Waples Evolutionarily Significant Units and the Conservation of Biological Diversity under the Endangered' Species Act , 1995 .

[30]  R. Chesser,et al.  MODES OF SPECIATION IN BIRDS: A TEST OF LYNCH'S METHOD , 1994, Evolution; international journal of organic evolution.

[31]  H. Bart,et al.  Diversity, distribution, and conservation status of the native freshwater fishes of the Southern United States , 2000 .

[32]  W. Hennig Phylogenetic Systematics , 2002 .

[33]  What Is a Planet? , 2001, Science.

[34]  E. Wiley,et al.  The Evolutionary Species Concept Reconsidered , 1978 .

[35]  G. Shull THE SPECIES CONCEPT FROM THE POINT OF VIEW OF A GENETICIST , 1923 .

[36]  Daniel J. Howard,et al.  Endless Forms: Species and Speciation , 1998 .

[37]  George Gaylord Simpson,et al.  CRITERIA FOR GENERA, SPECIES, AND SUBSPECIES IN ZOOLOGY AND PALEOZOOLOGY , 1943 .

[38]  B. Collette,et al.  Systematics, Historical Ecology, and North American Freshwater Fishes. , 1993 .

[39]  E. Wiley Phylogenetics: The Theory and Practice of Phylogenetic Systematics , 1981 .

[40]  M. Ghiselin A Radical Solution to the Species Problem , 1974 .

[41]  T. Kuhn,et al.  The Structure of Scientific Revolutions. , 1964 .

[42]  Mark Ridley,et al.  The cladistic solution to the species problem , 1989 .

[43]  Robert M. Zink,et al.  Species Concepts in Ornithology , 1988 .

[44]  E. Wilson,et al.  The Diversity of Life , 1993, Politics and the Life Sciences.

[45]  R. Mayden,et al.  Systematics, species concepts, and the evolutionarily significant unit in biodiversity and conservation biology , 1995 .

[46]  K. Nixon,et al.  AN AMPLIFICATION OF THE PHYLOGENETIC SPECIES CONCEPT , 1990 .

[47]  J. Mallet A species definition for the modern synthesis Trends in Ecology and Evolution 10: 294-299 (1995) , 1995 .

[48]  Gerald R. Smith,et al.  REPRODUCTIVE ISOLATION AND INTROGRESSION BETWEEN NOTROPIS CORNUTUS AND NOTROPIS CHRYSOCEPHALUS (FAMILY CYPRINIDAE): COMPARISON OF MORPHOLOGY, ALLOZYMES, AND MITOCHONDRIAL DNA , 1989, Evolution; international journal of organic evolution.

[49]  A. Cronquist Once again, what is a species?. , 1978 .

[50]  J. Cracraft THE SPECIES OF THE BIRDS‐OF‐PARADISE (PARADISAEIDAE): APPLYING THE PHYLOGENETIC SPECIES CONCEPT TO A COMPLEX PATTERN OF DIVERSIFICATION , 1992, Cladistics : the international journal of the Willi Hennig Society.

[51]  Niles Eldredge,et al.  Phylogenetic Patterns and the Evolutionary Process: Method and Theory in Comparative Biology , 1981 .

[52]  D. Kitts,et al.  Biological Species as Natural Kinds , 1979, Philosophy of Science.

[53]  Michael T. Ghiselin,et al.  On Psychologism in the Logic of Taxonomic Controversies , 1966 .

[54]  D. Rosen Vicariant Patterns and Historical Explanation in Biogeography , 1978 .

[55]  James D. Williams,et al.  Extinctions of North American Fishes During the past Century , 1989 .

[56]  John Alroy,et al.  Principles of genealogical concordance in species concepts and biological taxonomy , 1990 .

[57]  E. Mayr Speciation Phenomena in Birds , 1940, The American Naturalist.