What really hampers taxonomy and conservation? A riposte to Garnett and Christidis (2017)

Abstract

Responding to purported taxonomic anarchy, in an article published in the widely read journal Nature, Garnett & Christidis (2017) [hereafter GC] opined on the need for “standardized global species lists”, at the behest of conservationists, and proposed the construction of a judicial committee to “restrict … freedom of taxonomic action” and promote taxonomic stability. Here we reflect on this perspective and contest that the view of GC conflicts with some basic and indisputable principles underpinning the philosophy of science, most notably: it must be free. They appear to believe that taxonomic revisions should be based on political, economic and conservation concerns, and they treat species as fixed real entities, instead of refutable scientific hypotheses. In addition to such theoretical misconceptions, GC did not consider important practical aspects of what they term taxonomic anarchy, most significantly the participation of conservationists as authors of taxonomic works, and the importance of alternative management units, a well-established discussion in conservation biology.

Full text

Accepted by A. Minelli: 19 Jul. 2017; published: 1 Sept. 2017
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What really hampers taxonomy and conservation? A riposte to Garnett and
Christidis (2017)
MARCOS A. RAPOSO
1,2
, RENATA STOPIGLIA
3,4
, GUILHERME RENZO R. BRITO
1,5
, FLÁVIO A.
BOCKMANN
3,6
, GUY M. KIRWAN
1,7
, JEAN GAYON
2
& ALAIN DUBOIS
4
1
Setor de Ornitologia, Departamento de Vertebrados, Museu Nacional, Universidade Federal do Rio de Janeiro, Quinta da Boa Vista,
s/n, 20940–040 Rio de Janeiro, RJ, Brazil. raposo@mn.ufrj.br (MAR), grenzobrito@gmail.com (GRRB), gmkirwan@aol.com (GMK)
2
UMR 8590, IHPST–Institut d'Histoire et de Philosophie des Sciences et des Techniques, UMR 8590, Université Paris 1 Panthéon-
Sorbonne & CNRS, 13 rue du Four, 75006 Paris, France. jean.gayon@univ-paris1.fr (JG)
3
Laboratório de Ictiologia de Ribeirão Preto, Departamento de Biologia, FFCLRP, Universidade de São Paulo, Av. dos Bandeirantes
3900, 14040–901 Ribeirão Preto, SP, Brazil. renata.stopiglia@usp.br (RS), fabockmann@ffclrp.usp.br (FAB)
4
Institut de Systématique, Évolution, Biodiversité, ISYEB – UMR 7205 – CNRS, MNHN, UPMC, EPHE, Muséum national d’Histoire
naturelle, Sorbonne Universités, 25 rue Cuvier, CP 30, 75005, Paris, France. adubois@mnhn.fr (AD).
5
Departamento de Zoologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho, 373, 21941-
902, Rio de Janeiro, RJ, Brazil.
6
Programa de Pós-Graduação em Biologia Comparada, FFCLRP, Universidade de São Paulo, Av. dos Bandeirantes 3900, 14040–
901, Ribeirão Preto, SP, Brazil.
7
Research Associate, Field Museum of Natural History, 1400 South Lakeshore Drive, Chicago, IL 60605, USA.
Abstract
Responding to purported taxonomic anarchy, in an article published in the widely read journal Nature, Garnett & Chris-
tidis (2017) [hereafter GC] opined on the need for “standardized global species lists”, at the behest of conservationists,
and proposed the construction of a judicial committee to “restrict … freedom of taxonomic action” and promote taxonomic
stability. Here we reflect on this perspective and contest that the view of GC conflicts with some basic and indisputable
principles underpinning the philosophy of science, most notably: it must be free. They appear to believe that taxonomic
revisions should be based on political, economic and conservation concerns, and they treat species as fixed real entities,
instead of refutable scientific hypotheses. In addition to such theoretical misconceptions, GC did not consider important
practical aspects of what they term taxonomic anarchy, most significantly the participation of conservationists as authors
of taxonomic works, and the importance of alternative management units, a well-established discussion in conservation
biology.
Key words: Taxonomy, freedom, science, philosophy, conservation
Introduction
The journal Nature has historically published important contributions on biodiversity, evolution and taxonomy, the
science behind the classification of living organisms. One such was Bremer et al. (1990) who wrote persuasively:
“Taxonomists should pursue their scientific venture and stop worrying about instability in classification. Taxonomy
is not a service function for labeling organisms, but a science of its own, dealing with variation, relationships and
phylogeny” (see also Dubois 1998; Carvalho et al. 2007). These views are aligned with modern concepts of science
and freedom of expression. However, the opinion of Garnett & Christidis (2017) [GC hereafter] expressed in an
article published in the same journal appears to blatantly contradict these principles, by arguing for “standardized
global species lists”, supposedly at the behest of conservationists, and proposing a structure to “restrict the freedom
of taxonomic action” and promote taxonomic stability. Interestingly, Bremer et al. (1990) had also stated: “to
establish some international peer-review system to approve or reject proposed modifications overlooks the benefits
of change in taxonomy”.

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Here we reflect on these perspectives following two necessary lines of thought: a theoretical one, where we
concentrate on different philosophical aspects of their propositions and statements; and a practical approach, where
we analyse, based on GC’s examples, the consistency of their statements as true representation of the current
taxonomic universe.
Theoretical perspective
The dispute between those who need, for practical ends, stable lists of existing species and those who classify and
catalogue life is old
(e.g. Crisp & Fogg 1988) and motivated Bremer et al. (1990) to write in defence of taxonomic
work. Twenty-seven years later GC (but see also Thiele & Yeates 2002; Godfray 2007) brought back to the widely
read journal Nature a pragmatic view of the function of taxonomy, demonstrating that the debate is far from over
and revealing the necessity of more profound reflections and clarification.
GC commence by stating that “The assumption that species are fixed entities underpins every international
agreement on biodiversity conservation, all national environmental legislation …[etc.]”. The statement that
species are “fixed entities” goes back to Linnaeus (vide Zachos 2016: 30) and is unacceptable from a modern
evolutionary viewpoint. Furthermore, this belief goes against the very widespread conception of science whose aim
is not a search for definitive or ‘fixed truth’, but to produce rational and testable hypotheses, and the replacement
via refutation of once-adopted hypotheses by better ones until they are in their turn subject to modification or
rejection. Thus is science and, particularly in taxonomy, stability is ignorance, as well expressed by Gaffney
(1979), Dominguez & Wheeler (1997) and Dubois (2005).
Species are scientific hypotheses and their definition and limits should change whenever scientists judge this
necessary. We will refrain from discussing whether species hypotheses refer to real entities or not (see Dubois
2007; Raposo & Kirwan 2017), because under either perspective (existing or non-existent), they represent
hypotheses and consequently are not static.
Some of the consequences of such a misguided notion of species and the role played by scientific hypotheses
are better understood by examining GC’s statement that “Paradoxically, finer splitting could also make certain
species more vulnerable”. To claim that finer splitting renders species more vulnerable is inconsistent with facts
and logic. From the perspective that a species is a human intellectual construct, it can only be endangered once it
has gained existence through formal taxonomic procedures, such as description or validation. If species should be
regarded as pre-existing real entities, the splitting action becomes even more important as it equips the
conservation community with the appropriate knowledge to take specific measures to protect these entities. On the
other hand, ignorance or omission leads to real risk of extinction simply because it is impossible to preserve what is
unknown.
Another common misunderstanding is their apparent belief that taxonomists should be driven by conservation
and economic goals, and not otherwise. Although we are sensitive to some of these consequences, at least in theory,
a better understanding of the natural world will always positively impact conservation policy. The few examples
mentioned by GC attest to this and not to the contrary as they purport. For example, according to GC, a taxonomic
revision of the “central Asian argali wild sheep (Ovis ammon), turned one species into nine, and overnight
Kazakhstan had five mountain sheep species in need of protection, not just one”. Apparently, following this
taxonomic revision we discovered that the group’s conservation was much more problematic than previously
thought. This line of reasoning provides response to virtually all of the examples presented by GC. There is no
option but to find the hypothesis that best approaches our conception of reality under present knowledge.
More seriously, GC confound science and politics stating that the “community’s failure to govern taxonomy
threatens the effectiveness of global efforts to halt biodiversity loss, damages the credibility of science and is
expensive to society.” Following this line of reasoning, the authors complain that “a single taxonomic paper can
affect whole conservation programmes, tourist enterprises and employment opportunities.” But should taxonomists
try to predict future economic or political disputes when reviewing taxonomy? Such considerations would discredit
taxonomy as a scientific enterprise. The idea that a taxonomist should not validate species that might be
endangered or should not refute as inadequate hypotheses insufficiently robust species or, much less to create a
“judicial committee” to analyse the political impacts of taxonomic works before accepting them is scientifically
unacceptable and ethically reprehensible. Such a body would transform taxonomy into a merely political tool for

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guiding economic decisions that are not necessarily aligned with species preservation policies. The authors refer to
the International Union of Microbiological Societies (IUMS) as an example of success, but criticise it because of
the statement “Nothing in this Code may be construed to restrict the freedom of taxonomic action.” GC are
apparently impervious to what lies behind such an important ruling, the only really indisputable truth in science: it
must be free.
The authors also attest that the International Union of Biological Sciences (IUBS) should restrict the freedom
of taxonomists. This is anti-scientific and would result in science “losing its soul” with significant negative results,
as demonstrated by Trofim Lysenko’s rejection of Mendelian genetic inheritance theory, which gained the support
of Joseph Stalin, described in Leone’s (1952: 379) words thus “Science cannot long remain unfettered in a social
system which seeks to exercise strict control over the whole spiritual and intellectual life of a nation. The
correctness of a scientific theory can never be adjudged by its readiness to give the answers desired by political
leadership” (see also Hołynski 2017). In this sense, taxonomists should struggle to maintain their “freedom of
taxonomic thought or action”, as noted in the preamble to the International Code of Zoological Nomenclature
(Anonymous 1999, hereafter ‘the Code’; see also Minelli 2000).
Practical perspective: who is really demanding stability?
The main argument motivating GC is the putative demand for stability by conservationists. To illustrate this, they
provide a diagram demonstrating supposedly anarchic avian taxonomy. At this point, a detailed look at the very
specific case reported by the authors becomes important.
Among the taxon Aves, the most recently published world checklist (del Hoyo & Collar 2014, 2016)
recognises 4,372 species of non-passerines and 6,592 species of passerines, versus totals of 4,016 and 6,005
species, respectively, in the well-respected Howard & Moore checklist (Dickinson & Remsen 2013; Dickinson &
Christidis 2014). Thus, del Hoyo & Collar chose to recognise overall 943 more species, sometimes as a result of
different responses to taxonomic works published in peer-reviewed literature. However, a substantial measure of
the discrepancy in totals is the result of del Hoyo & Collar attempting to apply an operational method governing
use of morphological and vocal characters towards species delimitation (Tobias et al. 2010) to as many taxa as
possible that were thought might require revision. Nevertheless, in common with other prior published works, del
Hoyo & Collar chose to treat as species quite a number of taxa, e.g. among Procellariforms, that would not have
“passed” the Tobias criteria for recognition. At least in some of these cases, they considered that the conservation
benefits outweighed the negatives of recognising additional species, many of them breeding on oceanic islands at
high risk from introduced predators. This fact directly contradicts GC’s baseline hypothesis.
What might be surprising to readers of GC is that one of the co-authors of that operational approach (Tobias et
al. 2010 [Collar]) and the just-mentioned checklist (del Hoyo & Collar 2014, 2016), has worked in international
bird conservation for 40 years, with a special focus on the compilation of Red Data books. Furthermore, all of the
other authors of the Tobias criteria are primarily avian ecologists or conservation biologists. The motivation for
undertaking a revision of the taxonomy of the world’s birds is clearly explained in del Hoyo & Collar (2014: 19–
20): “Given that conservation very largely takes the species as its unit of concern, and that the future of many taxa
might in part depend on their recognition or not as species …, it has become increasingly frustrating to have to
wait—frequently in vain—for authoritative decisions from other sources over whether form A or form B is a species
or subspecies”. The del Hoyo & Collar checklist was developed in collaboration with BirdLife International, the
body responsible for assigning IUCN threat categories to birds, and its taxonomy has been adopted in full by the
same organisation. Furthermore, various legislative bodies have also quickly elected to work with this checklist,
including the EU and the UN Convention on the Conservation of Migratory Species of Wild Animals. In other
words, one influential bird conservationist had to some extent “lost patience” in waiting for the input of
professional taxonomists and elected to “do it himself”. The resulting taxonomic inflation (almost 10%) seems to
have been of no concern at least to some conservationists.
We will not discuss here the quality of the taxonomy employed by del Hoyo & Collar (2014, 2016), which is
unimportant in the present context, but, contradicting GC, it demonstrates that real conservationists, at least in
ornithology, do not, of necessity, require stability. They demand more and better taxonomy and are, in fact, behind
what GC consider taxonomic anarchy, as illustrated by their own diagram. It also illustrates that there is no

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necessary polarization between conservationists and taxonomists. But it raises one important question: who, after
all, is demanding stability?
Furthermore, still considering their example, authorities must understand the difference between online lists
and genuine taxonomic revisions. Species lists are useful for some practical purposes (e.g. to stimulate the general
interest of the public in citizen science programmes), but they are obviously unscientific and should never serve as
the base (data matrix) for any kind of serious research (see Nemésio et al. 2014 for a specific case). GC base their
conclusion on a comparison between some of these online lists and the Howard & Moore checklist. Appropriate
sources of information are always taxonomic revisions produced group by group. It is more difficult, but authors
really interested to produce robust science should do so themselves, or invite a taxonomist to assist.
Even if the GC example of Aves taxonomy was true, the use of anecdotal observations to draw general
assumptions is quite dangerous. In the present case, other examples from vertebrate taxonomy could easily be used
to contradict that claim. For example, fishes, which possess a strong conservation appeal, including for economic
reasons, currently number 34,401 valid species as of 31 May 2017, of which 3,924 have been described in the last
ten years (Eschmeyer & Fong 2017). Despite the increasing rate of species descriptions, fish taxonomy can in no
way be termed “anarchic”, because cases of conflict are relatively rare, probably due to the standards of excellence
established by the ichthyological community. Therefore, before accepting the conclusions of GC, it is necessary to
perform thorough research that attests to the solidity of their statements.
Concluding remarks
Ending their paper with the phrase “Vagueness is not compatible with conservation”, GC threaten the credibility of
conservation biology as a science. The evolution of all sciences implies the constant revision of concepts in an
effort to make scientific discourse best reflect our understanding of the natural world, and this is also valid for
conservation biology, which has debated which entities represent the best targets for protection for more than 30
years. The case is sufficiently complex that the Moritz (1994) paper on the importance of alternative management
units (Evolutionary Significant Units and Management Units) to species has been heavily cited since its
publication. This debate is crucial to resolve the problems highlighted by GC’s paper, but these authors appear to
avoid or ignore the maturity achieved by conservation biology, as exemplified by Avise (1989) who predicted that
“An up-dated taxonomy that includes input from molecular genetics should provide a firmer foundation for the
proper recognition and hence management of biotic diversity… Management personnel will have to keep an open
mind regarding the prospect of taxonomic revision, particularly in groups that have been problematic or poorly
studied. Most systematists are well aware of the provisional nature of existing taxonomic assignments, particularly
at the subspecies and species levels… Inevitably, conflicts will occasionally arise when multiple data bases are
used to assess taxonomic and evolutionary relationships.”
In fact, part of this problem stems from the embarrassing fact that, contrary to its introductory statement, the
zoological Code indeed partly infringes on the freedom of taxonomic thought and action in forbidding to name taxa
at ranks below subspecies (e.g., variety or form). This precludes the possibility to include such taxa in Red Lists
and official juridical text, unlike the case in botany. Such lower ranks could very well be used for such alternative
management units. Both taxonomists and conservationists have so far proved unable to explore these possibilities,
despite recommendations that they do so (Dubois 2006, 2011: 43–44) (see also Daugherty et al. 1990 and May
1990 for the emblematic case of the extinctions of tuatara Sphenodon populations, or Valbuena-Ureña et al. 2013
for the newt genus Calotriton).
Finally, it is important that taxonomists reflect on the permanence of this discourse in scientific journals. It is
clear that it has no philosophical or factual consistency. Yet, it would be a mistake for us to believe the discussion is
futile. Taxonomy is a complex and strongly empirical science. Particularly in groups of great visual appeal, as in
the case of vertebrates, the taxonomist responds, on the one hand, to the simpler demand of the ordinary citizen to
know what merits a name and on the other hand, to Popper, Peirce and the many other philosophers of science, who
demand the difficult goal of deductibility. It endeavours to identify unique clades that represent hypotheses of
discontinuity in a fluid and continuous world. It is backed by reasonability and historical process, rather than by the
formal logic that is supposed to characterize other sciences (Raposo & Kirwan 2017).
Under this scenario, there are no alternatives other than to constantly seek to improve the theoretical quality of

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our science and our discourse. This is part of the refinement of concepts important to the structure of our
knowledge, as is the case of the concept of species, which taxonomists should acclaim as proof of maturity and not
the opposite (GC’s total misunderstanding of this was well tackled by Hołyński 2017).
As Kierkegaard (1841) remarked in the introduction to his “On the Concept of Irony with Continual Reference
to Socrates”: “The observer ought to be an amorist; he must not be indifferent to any feature, any factor. But on the
other hand he ought to have a sense of his own predominance—but should use it only to help the phenomenon
obtain its full disclosure. Therefore, even if the observer does bring the concept along with him, it is still of great
importance that the phenomenon remain inviolate and that the concept be seen as coming into existence
[tilblivende] through the phenomenon.” For this, taxonomy requires time, work, academic recognition, positions,
funding and historical balance, nothing more, or less.
Acknowledgements
The authors received research funding from the following agencies, for which they are deeply grateful: Fundação
de Amparo à Pesquisa do Estado de São Paulo (Proc. # 2016/18963-8 to RS); Conselho Nacional de
Desenvolvimento Científico e Tecnológico (Proc. # 312067/2013-5 to FAB) and Coordenação de Aperfeiçoamento
de Pessoal de Nível Superior (PNPD fellowship to GRRB).
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