In addition to the distinction between species as a category and speciesas a taxon, the word species is ambiguous in a very different butequally important way, namely the temporal distinction between horizontal andvertical species. Although often found in the relevant literature, thisdistinction has thus far remained vague and undefined. In this paper the use ofthe distinction is explored, an attempt is made to clarify and define it, andthen the relation between the two dimensions and the implications of thatrelation are examined. (...) Using Darwin's analogy of language evolution forspeciesevolution, and by appealing to a major change in the conception of languagebetween 19th- and 20th-century linguistics, it is argued that the horizontaldimension has priority (pragmatic, epistemological, logical, and ontological)over the vertical dimension. This has immense ramifications for the modernspecies problem. Fundamentally, it favors horizontal species concepts oververtical ones. In so doing it places species realism on a much more securefoundation and largely undercuts species pluralism. In addition it raises aserious problem for the increasingly popular family of phylogenetic speciesconcepts, which generally suffer from a dimensionality confusion. However,thereis a recent trend within this family that attempts to restore the priority ofthe horizontal dimension. It is concluded that this trend should be affirmedandthat the species-as-individuals view should be abandoned. (shrink)

Joseph Hooker first learned that Charles Darwin believed in the transmutation of species in 1844. For the next 14 years, Hooker remained a "nonconsenter" to Darwin's views, resolving to keep the question of species origin "subservient to Botany instead of Botany to it, as must be the true relation." Hooker placed particular emphasis on the need for any theory of species origin to support the broad taxonomic delimitation of species, a highly contentious issue. His always provisional support for special creation (...) waned during the 1850s as he lost faith in its expediency for coordinating the study of plant geography, systematics and physiology. In 1858, Hooker embraced Darwin's "considerable revolution in natural history," but only after Darwin had carefully molded his transmutationism to meet Hooker's exacting specifications. (shrink)

The view that species are individuals, as developed by Ghiselinand Hull, has been touted as explaining the role of type specimens intaxonomy. The kinship of this explanation with the Kripke-Putnam theoryof names has long been recognized. In light of this kinship, however,Hull's account of type specimens can be seen to entail two relatedinscrutability problems – unreasonable limits placed on the natureand extent of biological knowledge. An appreciation for these problemsinvites us to consider the proper relation between metaphysical andepistemological inquires in (...) the philosophy of science. (shrink)

Joseph Hooker first learned that Charles Darwin believed in the transmutation of species in 1844. For the next 14 years, Hooker remained a "nonconsenter" to Darwin's views, resolving to keep the question of species origin "subservient to Botany instead of Botany to it, as must be the true relation." Hooker placed particular emphasis on the need for any theory of species origin to support the broad taxonomic delimitation of species, a highly contentious issue. His always provisional support for special creation (...) waned during the 1850s as he lost faith in its expediency for coordinating the study of plant geography, systematics and physiology. In 1858, Hooker embraced Darwin's "considerable revolution in natural history," but only after Darwin had carefully molded his transmutationism to meet Hooker's exacting specifications. (shrink)