Re: Quote Mine Project - Part II

gen2rev wrote:

> On Wed, 10 Sep 2003 03:19:04 +0000 (UTC), John Harshman
> <[EMAIL PROTECTED]> wrote:
> 
> 
>>
>>gen2rev wrote:
>>
>>
>>>On Mon, 8 Sep 2003 02:05:43 +0000 (UTC), catshark <[EMAIL PROTECTED]>
>>>wrote:
>>>
>>[snip[
>>
>>
>>
>>>>>"Although Archaeopteryx is often proposed as a transitional form, "its
>>>>>fossils do not count." Punctuated Equilibria, 1977.
>>>>>
>>>>>
>>>>Don't know if this is separate or somehow linked to the above quotes.  If
>>>>nothing else this idiot won't make it easy.
>>>>
>>>>
>>>Gould (and Eldredge, 1977) didn't write the passage quoted above. What
>>>they *did* write is:
>>>
>>>     At the higher level of evolutionary transition between basic
>>>     morphological designs, gradualism has always been in trouble,
>>>     though it remains the "official" position of most Western
>>>     evolutionists. Smooth intermediates between _Bauplane_ are
>>>     almost impossible to construct, even in thought experiments;
>>>     there is certainly no evidence for them in the fossil record
>>>     (curious mosaics like _Archaeopteryx_ do not count).
>>>
> 
> Note: the term "Bauplane" is actually spelled "Bäuplane", but I wasn't
> sure how "ä" (that's an "a" with two dots on top) would appear on OSs
> other than Windoze, or even on my own computer after it's been through
> Usenet. I guess I'm going to find out...


Looks fine to me, though it may vary among readers.

>>>It's now obvious that Gould and Eldredge weren't arguing against
>>>_Archaeopteryx_ being a transitional form, but arguing that it wasn't an
>>>example of a gradual change between body plans. They state that it's a
>>>mosaic, a mixture of both primitive and advanced features. But did Gould
>>>believe that _Archaeopteryx_ was a transitional form? He did indeed, as
>>>can be seen in his article "The Tell-tale Wishbone" (Gould 1980).
>>
>>I think they're making even less of an argument than you say. I think 
>>they're saying it's not a smooth intermediate, meaning a creature 
>>exactly intermediate in all respects. The creationist caricature 
>>requires that each and every character evolve at exactly the same rate, 
>>instead of different characters changing at different times and at 
>>different rates. Because Archaeopteryx (together with its various more 
>>primitive and derived relatives) *is* evidence for a gradual change 
>>between body plans, and one that was caught more or less in the middle.


Actually, this depends on what you mean by "gradual", which Gould has 
never properly defined except by caricature. Phyletic gradualism was 
taken to mean that if we observe two endpoints, all morphologies in 
between, in time, should also be proportionately in between, in 
morphospace. And you can indeed find such expectations occasionally in 
the old paleo literature. Even in punk eek, speciation (and therefore 
evolutionary change according to the theory) takes thousands of years 
and proceeds by ordinary selection within populations. And major body 
plan alterations don't happen in a single speciation event, but are 
spread over millions of years, as with the evolution of birds within 
theropods.

> While Archaeopteryx is certainly an intermediate, I'm not sure that it's
> evidence for a change in body plans. Of course, it depends on which body
> plans we're talking about. As you know, at least one specimen of
> Archaeopteryx was initially mistaken as an example of Compsognathus,
> since they have pretty much identical body plans, which are unlike those
> of modern birds.
> 
> But the body plans of "non-avian theropods" are in turn unlike those of
> lizards, if only because theropods are bipedal, so Archaeopteryx could
> be considered to be in the middle, between "lizard" and bird.
> 
> It did occur to me that Gould and Eldredge were making the argument that
> you say they are, but why single out Archaeopteryx? When they used the
> term "mosaic" I translated that as "a theropod with feathers and a
> reversed big toe". But if they're making the argument that you say they
> are, wouldn't every transitional creature be a mosaic?


Yes. Which is their point, I think. Creationist caricatures of 
intermediates (or what amounts to the same thing, Gould's caricature of 
what "gradualism" implies) are generally lacking in the fossil record, 
and in most cases wouldn't make biological sense. I believe they were 
using Archaeopteryx just as a well-known example of what real 
intermediates look like.

("Bauplan" is an overused term. It's unclear just how much of a 
difference is required before a lineage gets to a different bauplan. I 
believe the term was originally applied to phyla. But I digress.)

>>>REFERENCES
>>>
>>>Gould, S. J. 1980. The Tell-tale Wishbone. In "The Panda's Thumb: More
>>>Reflections in Natural History", pp 267-277. New York: W. W. Norton &
>>>Company, Inc. (Originally published in the November, 1977 edition of
>>>Natural History)
>>>
>>>Gould, S. J., & Eldredge, N. 1977. Punctuated equilibria: the tempo and
>>>mode of evolution reconsidered. Paleobiology 3:115-151.
>>>
>>>
>>>[snip the rest]
>>>
>>>
>>>
>