The Development of the Philosophy of Species 331Species Definitions as Sociological Markers
A final observation: It is often remarked upon that the specialty of the investigator
has a marked effect upon the concept of species that they use. Microbiologists, for
example, tend to apply what could be seen as a “phenetic” notion of species since
gene exchange is not usually done by sex (in prokaryotes, at any rate), and what
genes are exchanged or moved laterally need not be between closely related taxa.
Ornithologists, on the other hand, have no issue with the reproductive isolation con-
ception, as no birds do not reproduce sexually, and hybridism tends to be ignored.^137
Similar concordances between specialties and definitions occur throughout biology.
However, there is a further correlation between definitions and theoretical tra-
ditions. Often adherence to a particular definition or conception is a statement of
adherence to a particular school or one leading figure over against other figures. For
example, many adherents of the Reproductive Isolation Species Conception (RISC)
(including those who are evolutionary systematists) use it as a tribal marker of those
who are non-cladists, while many cladists use their preferred version of the phylo-
species conceptions to identify against other cladists. The Hennig Convention in
particular is one such: it tends to be adopted by German-speaking Hennigians rather
than Anglophone systematists. De Queiroz’s General/Universal conception is also
often an academic marker in this way. I have noticed this happening for a while now.
Since philosophers are very often beholden to a particular biological writer or tradi-
tion (especially Mayr, who overcame his adversaries by the dual strategies of prolix-
ity and longevity), they tend to see the issues in terms specified by those particular
authorities.
This is not to say that such definitional boundary-work within science is indepen-
dent of real concerns and interests of the scientific work itself. I very much doubt
that any scientist adopts a view just because their advisors or mentors propound it.
However, the viciousness of the academic debate (as Wallace Stanley Sayre memo-
rably noted, vicious because the stakes are so low^138 ) over species means that the
intensity with which proponents defend and attack serves just such a social identity-
defining function within science.
Empirical work is still needed on how biologists actually do use species concepts,
if indeed they use them at all in their work, but a recent survey of biologists showed
some interesting results.^139 One is that the majority of specialists do not think there is
a monistic conception of species (124 of 155), and that it is not desirable to have one
(80 of 155). Even more interesting is that roughly the same number think species are
monothetically defined (80) as polythetically defined (76), and that roughly the same
number think species are real entities (70) as those who think they are not (71), while
a minority thinks they are conventional (nominalistic) labels (28). The notion that
(^137) However, hybridism in birds has been known for a long time [e.g., Elliot 1892, Suchetet 1897, Deane
1905, Ridgway 1909, Evans 1911] and even Mayr studied it [Mayr and Gilliard 1952].
(^138) Although the stakes could not be higher for a professional academic. Their careers, funding, status
and grants all depend on being of the “right” view. There is a tradeoff between marginality and
originality on the one hand, and the likelihood of professional advancement on the other. “Deviant”
views may pay off handsomely if successful, but more mainstream views have a higher chance of
return on investment, if a lower payoff expectation.
(^139) Pušić et al. 2 017.