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Re: Greg Paul is right (again); or "Archie's not a birdy"



On Thu, Aug 4, 2011 at 5:03 AM, David Marjanovic
<david.marjanovic@gmx.at> wrote:
>> > ...and open the way for unjustified inferences in the other
>> > direction, where plesiomorphies are extrapolated too close to the
>> > crown.
>>
>>  Curious to see some examples of this in the literature.
>
> How about "cold-blooded-ness" and a body covering of scales being
> extrapolated all the way to the *Archaeopteryx* node?

No, those are examples of unjustified inferences brought about due to
associating the most widely-familiar name with an arbitrary
"middle-ground" clade instead of with the crown group. This is a
failure of the "middle ground" approach, not the crown group approach!

> Another examples I can think of (I don't have any literature here with me)
> is in art: before the discovery of *Eoalulavis*, enantiornitheans were
> depicted as lacking alulae.

Was it assumed that they had none, or did the artist make a necessary
judgment call in the face of ambiguous evidence? (Remember that
illustrators are often forced to make guesses in cases where
scientists are not. You can build a case if they all consistently
guess one way, though.)

Here's the example you need to find: a case where a popular name is
associated with the crown, and that causes people to assume some
plesiomorphy exists closer to the crown than it was later found to be.
I'm having real trouble thinking of one.

>>  Again, though, what makes "Aves" so exceptional? So far the best
>>  argument I've seen is its homonymy with a vernacular word in certain
>>  languages. I don't find that argument terribly compelling, either,
>>  since the vernacular word is also primarily neontological in usage.
>
> Well, because one of these languages is Latin, Linnaeus simply called the
> birds "birds" (so he didn't have to invent a name like he did with Mammalia
> and Reptilia), and therefore the equation "Aves = birds" is stuck in the
> heads of pretty much everyone with an interest in biology.

And did the Romans call Archaeopteryx a bird?

I've sometimes thought it would be better to related the Latin term
"avis" to "fowl". (Although, I queried a "layperson" as to their usage
and found that "fowl" corresponded to _Galloanserae_ rather than
_Aves_. Vernacular meanings shift. I've also heard from someone who
deals with ratite ranchers who was under the impression that ratites
aren't birds.)

> This holds especially for biologists who don't normally think about
> biodiversity. A few years ago we discussed the Nature paper about "the
> ancestral vertebrate karyotype", where Vertebrata was used instead of
> Osteichthyes, Tetrapoda instead of Sarcopterygii, and so on... it's not
> really about crown vs. bigger, it's about well-known vs. accurate.

Well, no amount of nomenclatural assistance is going to help some people....

-- 
T. Michael Keesey
http://tmkeesey.net/