[Annelida] Traditional taxonomy discussion
J. Kirk Fitzhugh
(by kfitzhugh from nhm.org)
Mon Feb 8 14:51:59 EST 2010
I'll try to place into some context the question I asked yesterday, "How
is 'traditional descriptive taxonomy' any less scientific than 'only
molecular taxonomists' [sic!]?" and my statement "None of us should
condone a world of 'only molecular taxonomists". Last week I had
extensive discussions about the Boreo paper with Sergio Salazar-Valejo.
Below is what I sent to Sergio, as this might make my concerns a bit
more clear. I've also added in some references where I have analyzed
these issues extensively:
Thank you for forwarding the article. I'll offer my own opinions on
the state of 'biodiversity' studies. I suggest that the problems
outlined by Boreo are not the real causes. The greater problems
include (1) the lack of emphasis on the scientific nature of
biological systematics (_not_ taxonomy), and (2) the inability of
the biological community to develop a rational consensus for what we
mean by terms like 'species' and 'taxon.' I suggest that it is
because systematists have failed to fully address these issues that
it is primarily the systematics community that must be blamed for
the current mess we find ourselves in with regard to 'biodiversity'
policies and practices.
Problem (1) is a great example of using words without any real focus
on what the words really mean. I'm a systematist, not a taxonomist
(Fitzhugh 2006a, 2008b). The difference is critically important.
Systematics is a field that is consistent with the broader goal of
doing science: to causally understand the objects and phenomena
around us (Fitzhugh 2005a, b, 2006a, b, 2008a, b, c, 2009a, in
review). Taxonomy deals with classification. Classification does not
necessarily entail causal ordering, and as such, none of us should
claim to be doing taxonomy if we are also claiming that what we do
is part of the more general endeavor of doing science.
Without solving problem (2), the term 'biodiversity' remains an
empty term. I wholly deny the characterization of species as things
in time and space, and I have published enough to justify my
position (Fitzhugh 2005b, 2009a). I don't study species. In fact, in
my entire career I've never seen a species, much less any other
taxon. The reason is simple: species, or taxa for that matter, are
not things that exist around us. Yet, we (including Boreo) speak as
if species are all around us and actually exist. We talk in terms of
'species diversity,' 'describing species,' or 'barcoding species.'
But if, as I have claimed, species and all taxa are nothing more
than our explanatory hypotheses we apply to the organisms we
observe, then we find that the entire industry of 'biodiversity'
rests on a myth.
But, doing science is a social affair. We want the acceptance of our
work by our peers. We need that acceptance to get funding and to
keep our jobs. The consequence is that our education system teaches
that to be a good scientist means to do things just like everyone
else does it. Copy what the 'good scientists' are doing because they
are the ones getting the money to do 'good' science. Don't question
why or how we should blindly follow the use of terms like
'biodiversity' or 'species' or 'barcoding' (Fitzhugh 2006d) It's
more important to get as many papers published as possible, because
everyone thinks that's what makes a scientist a 'good' scientist.
The consequence is that we use words and 'do' science without
critically thinking about why we are using those words or doing
activities in a particular way. Policies are only as good as the
foundations upon which they are built. My opinion is that the
foundations upon which 'biodiversity' and biological systematics are
built are so poorly formulated that it's time we realize that we
face a critical, long-term problem that will only become worse. I
claim that the solution is a fundamental reorganization of our
education system when it comes to actually teaching the nature of
science. A solution I strongly doubt will ever happen. The social
character of science won't allow it.
This then brings us back to the question I posed yesterday on Annelida,
"How is 'traditional descriptive taxonomy' any less scientific than
'only molecular taxonomists' [sic!]?" and my statement "None of us
should condone a world of 'only molecular taxonomists."
Systematics has as its goal the act of placing our observations of
objects and events into a causal framework, such that we increase our
opportunities to acquire understanding. This is the very reason we place
so much importance on the theories in evolutionary biology - those
theories are the conceptual bases for developing the explanatory
hypotheses we call cladograms and taxa (including species; Fitzhugh
2008b, 2009a). What we do is not classification. We are systematists,
not classificationists. Systematics falls squarely in line with what all
fields of science attempt to attain.
But, if it is our goal to explain the properties of the objects, i.e.
organisms, that we study, then we have to fully accept the implications.
And the biggest implication is that there is no rational procedure in
reasoning to actively disregard some relevant observations over other
relevant observations. I've raised this issue numerous times here on
Annelida and in my research (Fitzhugh 2006a, b, 2006d, 2008c, 2009b)
under the traditional phrase, 'requirement of total evidence.' For
instance, the goal of producing a cladogram via a computer program is
not just to get a 'tree' or 'phylogeny.' The intent is far, far more
encompassing. The very reason we make observations of the characters of
organisms is because we strive to provide explanations for those
observations. By the very nature of that action, the requirement of
total evidence precludes knowingly excluding some set of observations,
then producing a cladogram and recursively referring back to the
excluded characters. Yet, we see this done all the time, where one has a
set of DNA sequences and do not give consideration to all other
available characters. The consequence, as I've pointed out very often,
is that any sequence-based cladogram can say nothing about all of the
characters that were excluded from the analysis. Indeed, the veracity of
the hypothesis is compromised for the fact that all relevant evidence
has not been considered. This is the very reason why none of us should
ever accept as 'normal systematics' the process of violating the
requirement of total evidence. There simply are no principles of
reasoning that would support such a view, and the view is less than
So, between what we know of the goal of biological systematics as a
field in science, and the rules for rational reasoning that transcend
all the sciences, it is obvious that no particular, exclusive set of
characters can be used to make systematics a better science. DNA won't
save us, just as any other classes of characters won't. We need to move
away from the view that we need a 'tree of life." The goal of
systematics is to explain within the evolutionary context of organisms.
That goal cannot be attained by filtering out only the desired
characters to the exclusion of all others that are also relevant to
What is often referred to as descriptive taxonomy really isn't that at
all. It is, instead, a part of systematics, and as such has just as much
scientific merit as other endeavors to present explanatory hypotheses.
This becomes especially clear when we recognize that species are one
class of hypotheses that we develop in reaction to our observing
organisms, just as are all taxa a variety of such classes of hypotheses
(Fitzhugh 2008b, 2009a). As a consequence, I agree with Geoff that we do
need to worry about the ICZN, which for the most part is at odds with
our scientific endeavors (Fitzhugh 2008b, 2009a; Nogueira et al. in
review). But, in order to sort out ICZN problems, just as to sort out
the problems identified by Boreo, we need to address the more
foundational problems in systematics and the way our education system
teaches the nature of science.
Fitzhugh, K. 2005a. Les Bases Philosophiques de L'inférence
Phylogénétique: Une vue d'ensemble. Biosystema 24: 83-105.
Fitzhugh, K. 2005b. The inferential basis of species hypotheses: the
solution to defining the term 'species'. Marine Ecology 26: 155-165.
Fitzhugh, K. 2006a. The abduction of phylogenetic hypotheses. Zootaxa
Fitzhugh, K. 2006b. The 'requirement of total evidence' and its role in
phylogenetic systematics'. Biology & Philosophy 21: 309-351.
Fitzhugh, K. 2006c. The philosophical basis of character coding for the
inference of phylogenetic hypotheses. Zoologica Scripta 35: 261-286.
Fitzhugh, K. 2006d. DNA barcoding: an instance of technology-driven
science? BioScience 56: 462-463.
Fitzhugh, K. 2008a. Fact, theory, test and evolution. Zoologica Scripta
Fitzhugh, K. 2008b. Abductive inference: implications for 'Linnean' and
'phylogenetic' approaches for representing biological systematization.
Evolutionary Biology 35: 52-82.
Fitzhugh, K. 2008c. Clarifying the role of character loss in
phylogenetic inference. Zoologica Scripta 37: 561-569.
Fitzhugh, K. 2009a. Species as explanatory hypotheses: refinements and
implications. Acta Biotheoretica 57: 201-248.
Fitzhugh, K. 2009b. Between macro and molecular. BioScience 59:85-86.
Fitzhugh, K. in review. 'Evidence' for evolution versus 'evidence' for
intelligent design: parallel confusions. Acta Biotheoretica
Nogueira, J.M.M, K. Fitzhugh and M.C.S. Rossi. in review. A new genus of
Sabellinae (Polychaeta: Sabellidae) from Atlantic and Pacific Oceans.
Kirk Fitzhugh wrote:
> "Personally I tend to agree with the outsiders that traditional
> descriptive taxonomy has a weak claim to be real science. Soon only
> molecular taxonomists will exist. This is not a bad thing as long as
> they can also handle and include organism phenotype descriptions."
> How is 'traditional descriptive taxonomy' any less scientific than
> 'only molecular taxonomists' [sic!]? I'd be fascinated to know of the
> definitive text book on doing science that substantiates your claim
> that presenting hypotheses isn't a fundamental part of doing science.
> None of us should condone a world of 'only molecular taxonomists.' To
> do so would be a bastardization of the very principles of science.
> -----Original Message-----
> From: annelida-bounces from oat.bio.indiana.edu on behalf of Geoff Read
> Sent: Sun 2/7/2010 12:49 PM
> To: Annelida from magpie.bio.indiana.edu
> Subject: [Annelida] Traditional taxonomy discussion
> This commentary is being discussed. Personally I tend to agree with
> the outsiders that traditional descriptive taxonomy has a weak claim
> to be real science. Soon only molecular taxonomists will exist. This
> is not a bad thing as long as they can also handle and include
> organism phenotype descriptions. Many can't at the moment. I worry
> more about the problems with the Zoological Code, and lack of
> consensus on the way forward, and the energy wasted on futility of
> archaisms such as gender agreement, minutiae of revisionism in
> publication dates, obscure priorities, and especially keeping to
> print-only validity of names, and not registering all new names, than
> the issues raised here. Politics is everywhere.
> Boero F 2010. The Study of Species in the Era of Biodiversity: A Tale
> of Stupidity. Diversity 2: 115-126.
> [Open access]
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