Species

262 Species

excluding names and species made by bird watchers and gardeners. Darwin himself

in several places made this sort of definition, particularly in his Natural Selection:

In the following pages I mean by species, those collections of individuals, which have

been so designated by naturalists.^50

It is interesting to note that Regan refers to “communities.” This word typically
has been used to apply to ecological communities; that is, ecosystems,^51 but in this
case and at this time it is more likely to refer to what we now call a “deme,” or a
“Mendelian population.” If this is so, then Regan is conflating two well-known ideas
in our history here: that of a reproductive element and a diagnostic one. In short,
Regan might very well have been putting forward an “operative”^52 notion of the
generative species conception we have so often encountered. A less biological ver-
sion of this view, which he calls the “cynical” species concept, is presented by Philip
Kitcher:

Species are those groups of organisms which are recognized as species by competent

taxonomists.^53

Here the operationalist aspect of the concept is primary. Species are made by

acts of recognition by experts. Whether or not it includes a strong element of the

biological (that is, reproductively isolated) nature of species, conventionalism takes

seriously Locke’s claim that species are made for communication, and objections to

the recent Phylocode proposal (many by strict cladists, no less) are in part founded

on the idea that higher taxa, at least, should be convenient, since they are artificial

taxa anyway.^54

Replacementism: LITUs (Least Inclusive Taxonomic Units)

Frederick Pleijel, a leading specialist on polychaete worms (bristleworms), has

proposed doing away with the notion of species altogether. Instead, he proposes to

replace it with the neutral term least inclusive taxonomic unit, or LITU (in homage

to the OTU of phenetics). Pleijel’s and Rouse’s “definition” of the LITU runs

(^50) Darwin and Stauffer 1975, 98, cited by McOuat 2001, 4n10.
(^51) Taylor 1992.
(^52) The term “operational” is taken from the philosopher of physics (and physicist) Percy Bridgman
[1927]. Operationalism, the view named by him, is the view that the only meaning of a scientific
concept is the set of measurements and operations that can be done to define it [Chang 2009].
(^53) Kitcher 1984, 308.
(^54) The Phylocode proposes to replace all Linnaean ranks with rankless strictly monophyletic taxa based
on the best cladograms [Cantino and de Queiroz 2010]. It has been supported by eliminativists like
Ereshefsky and Pleijel and Rouse [Pleijel and Rouse 2003], but some pattern cladists, such as Norman
Platnick and Gareth Nelson (pers. comm.) oppose it due to its disruption of scientific communication
and meaninglessness, as in their view cladograms are only hypotheses and are subject to revision.
Others [Benton 2000, Berry 2002, Bryant and Cantino 2002, Forey 2002, Carpenter 2003, Gao and
Sun 2003, Nixon et al. 2003, Kojima 2003, Keller et al. 2003] attack the proposal for a range of rea-
sons, ranging from a personal distaste to a rejection of cladism. Most think that named monophyletic
higher taxa are not going to be stable as new results come in.