The twentieth century witnessed a dramatic increase in the use of statistics by biologists, including systematists. The modern synthesis and new systematics stimulated this development, particularly after World War II. The rise of "the statistical frame of mind " resulted in a rethinking of the relationship between biological and mathematical points of view, the roles of objectivity and subjectivity in systematic research, the implications of new computing technologies, and the place of systematics among the biological disciplines.

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)

In Unifying Biology, Smocovitis offers a series of claimsregarding the relationship between key actors in the synthesisperiod of evolutionary studies and positivism, especially claimsentailing Joseph Henry Woodger and the Unity of Science Movement.This commentary examines Woodger''s possible relevance to key synthesis actors and challenges Smocovitis'' arguments for theexplanatory relevance of logical positivism, and positivism moregenerally, to synthesis history. Under scrutiny, these arguments areshort on evidence and subject to substantial conceptual confusion.Though plausible, Smocovitis'' minimal interpretation – that somegeneralised form of Comtean (...) positivism had a role in synthesishistory – requires more of an evidential basis and must engageexisting scholarship on epistemic reforms in the biological sciencesprior to the synthesis period. Smocovitis is right to investigateepistemology in the synthesis period of evolutionary studies and tolook for links to wider changes in science and philosophy. However,in its present form, Unifying Biology fails to support herbasic interpretation. (shrink)

(1995). Synthesizing disciplinary narratives: George Gaylord Simpson's tempo and mode in evolution. Social Epistemology: Vol. 9, Boundary Rhetorics and the Work of Interdisciplinarity, pp. 113-150.

Species can be defined as a lineage of populations among which was never set up an micro-evolutionary isolation, and what is meant by ‘micro-evolutionary isolation’ is this: two populations are micro-evolutionarily isolated, if and only if, the micro-evolutionary processes affecting one of them (namely: natural selection, genetic drift, sexual selection, mutation and/or migration) cannot reach the other. This is a delimitation of the evolutionary species concept that is compatible and solidary with the conceptual division of labor that some authors have (...) proposed to solve the problem raised by the definition of species. (shrink)

The dichotomy between ‘typological thinking’ and ‘population thinking’ features in a range of debates in contemporary and historical biology. The origins of this dichotomy are often traced to Ernst Mayr, who is said to have coined it in the 1950s as a rhetorical device that could be used to shield the Modern Synthesis from attacks by the opponents of population biology. In this two-part essay, I argue that the origins of the typology/population dichotomy are considerably more complicated and more interesting (...) than is commonly thought. In the first part, I argued that Mayr's dichotomy was based on two distinct type/population contrasts that had been articulated much earlier by George Gaylord Simpson and Theodosius Dobzhansky. Their distinctions made eminent sense in their own, isolated contexts. In this second part, I will show how Mayr conflated these type/population distinctions and blended in some of his own, unrelated concerns with ‘types’ of a rather different sort. Although Mayr told his early critics that he was merely making “a temporary oversimplification,” he ended up burdening the history and philosophy of biology with a troubled dichotomy. (shrink)