[Taxacom] PhyloCode & ICZN to "duke it out"?

Doug Yanega dyanega at ucr.edu
Fri Oct 5 13:36:50 CDT 2007

Rich Pyle wrote:

>  > Imagine, e.g., that an internal specifier of a "converted"
>>  family name is found to belong to a rather distant family.
>>  Everybody agrees on this, and there are no particular
>>  lumper/splitter problems. However :
>>  - As per PhyloCode rules, the "converted" name then makes a
>>  big jump upwards, and ends up covering a larger clade
>>  equivalent to, say, a suborder; we now need to devise a new
>>  name if we still want to refer to the clade made of the
>>  former family minus this specifier.
>I'm not sure I understand how this is different from subjective synonymy for
>Linnaean nomenclature (other than the rank thing, which is not relevant in
>the context of Phylocode nomenclature anyway).  Maybe my tired brain is
>missing something fundamental here. Perhaps you're worried about reversal of
>hierarchy of pre-existing names?  I haven't thought this through entirely,
>so there may well be a concern that I'm missing here.  But I guess it would
>depend on how often the problem came up.
>>  - As per IC*N rules, unless that specifier is the type of the
>>  family, it is simply transferred to the family where it
>  > belongs;

It is this point that I think I consider the most problematic aspect 
of the Phylocode; unless I'm wrong about how it works, when the 
constituency of a named clade is changed in subsequent phylogenies, 
in MANY cases this change will require that a NEW NAME be coined for 
the re-defined clade; under the Linnaean system, the name does not 
need to be changed, specifically because it *is* defined by a "point" 
rather than a "set" (to continue Rich's analogy).

In essence, the difference between how the Phylocode and Linnaean 
systems treat a change in the circumscription of a group is: (1) in 
the Phylocode, you just create a new name, because the group which 
defined the older name no longer *exists*, and that older name cannot 
be used for a group with a different set of constituents. Therefore, 
any given name is extremely stable (it cannot be redefined), BUT when 
there are changes within a group, it prompts the creation of new 
names. (2) In the Linnaean system, all that one does is say that the 
name now has a broader/narrower definition, modified to 
include/exclude certain constituents that used to be treated 
differently. Therefore, the *usage* of a name is not stable, but the 
same name continues to be used, regardless.

The end result is that in the Linnaean system, over a long period of 
time, one will see lots of familiar family names in the literature, 
for example, but find upon examination that what one author 
historically treated as a member of family X is presently placed in 
family Y, and that other former families are now subfamilies or 
vice-versa; it's all not the same, but it's all still fundamentally 
recognizable. Learning a new definition is required, but not learning 
a new name. In the Phylocode system, over a long period of time, 
entirely new lists of names will develop, as older names vanish 
completely and irrevocably from usage. Learning new names is required 
PLUS learning their definitions. To me, the latter is a FAR inferior 
approach, and it makes it much harder to track the history of 
classification, and connect past research to the present.

Then one has the problem of synonymy; under a typological 
classification, the issue of synonymy is rather straightforward; no 
matter how old or obscure a name is, one can generally track it down 
and figure out where it is presently placed. It is not nearly so 
straightforward a proposition under the Phylocode.

Don't underestimate the power of familiarity in communication and 
understanding; note also that I'm not saying that Linnaean names 
cannot also fall so far out of use that they become unfamiliar, just 
that the SCALE of name turnover, both in absolute numbers and in the 
rapidity with which it occurs, is intrinsically vastly greater under 
the Phylocode, and to me that is extremely unappealing. How many 
presently named clades do you honestly think will remain unchanged 
for the next 100 years? Bear in mind that as en entomologist, this 
concerns me more, I'm sure, than someone who may work on mammals or 
such, because there aren't new high-level mammal phylogenies 
published every week. The number of insect groups for which we have 
robust and stable phylogenies from genus level on up is *incredibly* 
tiny, meaning any Phylocode assignment of names to insects is 
virtually guaranteed to be completely undone every single time a new 
phylogeny is published. Of course, if a formal phylogeny has to exist 
before Phylocode names can be used, many insects would not have 
Phylocode names below what would effectively be the subfamily level 
within our lifetimes.

The proliferation of names is therefore not simply a matter - as Rich 
suggested - of assigning names to every node; it also results from 
the more rigid definition OF names, such that new names are required 
whenever a group is redefined in a manner inconsistent with how the 
original name was applied. As to whether this would be a common 
problem or not, one only has to look at recent history; simply 
perform the mental experiment of imagining that the Phylocode had 
been instituted back in, say, 1967. Imagine that all the Linnaean 
names in use back then were re-cast as Phylocode names, and given 
definitions following Phylocode protocols. How many of these names 
would have survived to the present day? Maybe 20-30%, across all 
kingdoms? That'd be a helluva lot of replacement names for us all to 

Finally, I have to confess that I find it intrinsically appealing to 
be able to look at different names, such as Lygaeus, Lygaeidae, and 
Lygaeoidea, and KNOW, even if I'm not familiar with the publications 
defining them, that they are nested taxa. Or, if I am informed that a 
beetle I have in hand is in the superfamily Scirtoidea, then even if 
I know nothing about beetles, I know that somewhere out there is a 
family Scirtidae with a genus Scirtus in it, and I could go to a 
museum, or library, and look up Scirtus there, maybe even turning up 
research or specimens dating back to the 1700's. Or if I'm told I 
have a specimen in the genus Passalus, then I could reasonably expect 
that If I located the descriptions of every species placed in that 
genus, I could become familar with whatever species I had, plus ALL 
of its closest relatives: even a taxonomically naive person has 
someplace to start searching for additional information when names 
possess that sort of information content. I'm not particularly 
comfortable with the idea that if I see a name, I have no idea what 
it might represent until and unless I also can see a copy of a tree 
on which it appears.

To me, the Phylocode offers more drawbacks than advantages.


Doug Yanega        Dept. of Entomology         Entomology Research Museum
Univ. of California, Riverside, CA 92521-0314        skype: dyanega
phone: (951) 827-4315 (standard disclaimer: opinions are mine, not UCR's)
   "There are some enterprises in which a careful disorderliness
         is the true method" - Herman Melville, Moby Dick, Chap. 82

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