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Re: The PhyloCode will not address the naming of species (Was The Papers That Ate Cincinnati)



On 5/8/07, Anthony Docimo <keenir@hotmail.com> wrote:

>Dinosauria has been everything from a suborder (original designation) >to a class. But why would the mere fact that his sort of thing goes on >a lot excuse it?

Why would the mere fact that it goes on, condemn it?

It doesn't. What condemns it is that it's meaningless.

but when you're talking to somebody, and you know you don't share a common
language (ie, "tiger"="tiger"/"tiger"="jaguar")...don't you *want* to use
scientific terms you both know and understand?

Yes! That's the whole point. The traditional codes have failed to achieve this result because they do not provide any way to unambiguously link a name to a group. For example, Family Hominidae is only defined as "the family including _Homo sapiens_"--authors can and do include only _Homo_ and its close extinct relatives, or _Homo_ as well as the great apes, or all apes.

But under the PhyloCode, you could, for example, define _Hominidae_ as
"the last common ancestor of _Pongo pygmaeus_ and _Homo sapiens_, and
all descendants thereof". Two researchers following the PhyloCode,
then, would be referring to the same entity when they talk about
_Hominidae_. Now, they may have different understandings as to what
belongs and what doesn't, but these would be actual disagreements
about the phylogeny, not subjective opinions about how inclusive a
"family" should be.

or are you suggesting that every country around the world *stops* its
biological and paleontological sciences, so that their scientists can learn
*another* international language (this time, PhyloCode) before being
permitted to resume their work?

The PhyloCode isn't intended to start over from scratch. For one thing, it leaves species to the current codes. For another, many of the names under it will be the same names as in other codes, but with new, rigorous definitions.

>Evolution is almost nothing *but* slippery slopes. But there are firm
>groupings we can attach names to.

"firm groupings"? like, oh, say, _bird_? ;)

"Bird" is an English vernacular term, and means whatever the English-speaking public wants it to mean. Names like _Aves_, _Avialae_, etc., though, can be given rigorous definitions. That there is currently some dispute as to which definitions would be best does not invalidate this.

>Identify an ancestor using any one
>of several methods (direct identification, node-based definition,
>branch-based definition, apomorphy-based definition, etc.),

like none of those are argued about nowadays. riiight. ;)

That's the goal of the PhyloCode--to end arguments about nomenclature so we can focus on the things we *should* be arguing about, like phylogeny.

>add all
>descendants of that ancestor, and, hey presto, you've got a natural,
>rigorously-defined clade.

"rigorously-defined"?

I've seen arguments - in this list and elsewhere - where people can't agree
if one fossil is a descendant of another, or if the first is a descendant of
the other's sibling species (which was never discovered)

The definition is still rigorous, even if the application is under question. It's the job of science (e.g., cladistic analysis) to determine how to apply the definition.

For example, Sereno defined _Tyrannoraptora_ as the last common
ancestor of _Tyrannosaurus rex_ and _Passer domesticus_ and all
descendants thereof. When he named it, he considered ornithomimosaurs
not to be tyrannoraptorans. Others, however, have done cladistic
analyses suggesting that ornithomimosaurs are tyrannoraptorans. The
clade still has the same definition, but our understanding of it is
under dispute. That's fine--the discussion is now about the actual
phylogeny (i.e., whether tyrannosauroids or ornithomimosaurs are
closer to avians), not about how different researchers feel that
_Tyrannoraptora_ should be expanded or contracted, or whether some
think it should be a microorder while others think it should be a
parvorder.

...such arguments then split the hairs of whether the first has derived
features from the second, or if it simply indicates a shared ancestor.

But those are arguments about actual facts. In other words, that's science. -- Mike Keesey