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RE: Princeton Field Guide



Greg Paul wrote:

<One person challanged me to define genus as though that point has critical 
meaning. It is not possible to define species either, but species are real. It 
is not possible to define life, but it is real. There is no way to precisely 
define battleship versus battlecruiser (HMS HOOD for example) versus heavy 
cruiser (Alaska class for example). Many terms are approximations, it does not 
mean that they cannot be used to describe and distinguish basic, comparable 
types.>

  Species are not real. I think this is where so many systematists get "it" 
wrong. You cannot enter a world where you can determine what is and what is not 
a species without running into the various hundreds of potential concepts that 
allow scientists and philosophers to argue about species. Some species concepts 
are comparable to classical "kinds" or the newer term "baramin," which I am 
sure Greg is familiar with, but he is loathe I am sure to regard these as true 
concepts. If so, then Greg can reject an idea of "species," and this can only 
be extended to any other. Greg must therefore have a special, "true" version of 
species at his disposal, but if he does, he's not shared it. This must then 
extend to Genus, and by extension of his argument, Greg must think a genus is 
real, too.

  So when Greg talks about the nature of "species" and "genus," it is due to 
the need of a basic, innate level by which varying organisms may be compared, 
even if that level is superficial and in truth nonexistent. Humans crave 
categories, and last time I met Greg (shook his hand) I was fairly sure he was 
human. Greg is challenged solely on the fact that he has made sometimes 
contradictory philosophical statements on what should or should not be a 
"genus," and Greg does not answer this question above, but instead infers the 
question as meaningless. He is incorrect when he says it is impossible to 
define species, because there are various published, and competing definitions 
available. Perhaps Greg should read the literature on the subject. John 
Wilkins, over at http://evolvingthoughts.net/, studies the subject in 
particular, and is purportedly writing a book on it. I recommend visiting that 
site regardless. And of course, by extension, Greg is incorrect by extension 
when it is inferred that there are no definitions of "genus;" there are, and 
they are used incompatibly with some species concepts, which makes for fun 
times when dealing with bacteriological, botanical and zoological systematics 
(especially when comparing them to one another).

Cheers,

  Jaime A. Headden
  The Bite Stuff (site v2)
  http://qilong.wordpress.com/

"Innocent, unbiased observation is a myth." --- P.B. Medawar (1969)


"Ever since man first left his cave and met a stranger with a
different language and a new way of looking at things, the human race
has had a dream: to kill him, so we don't have to learn his language or
his new way of looking at things." --- Zapp Brannigan (Beast With a Billion 
Backs)



> Date: Tue, 19 Oct 2010 18:01:57 -0400
> From: GSP1954@aol.com
> To: dinosaur@usc.edu
> Subject: Re: Princeton Field Guide
> 
> Some additional comments on the too often unrealistic discussion of the 
> field guide. 
> 
> It is of course not possible to provide an extensive description for each 
> dinosaur species. In field guides for extant organisms the descriptions are 
> entirely superficial descriptions of visually filed spottable identification 
> markings and shapes (detailed technical morphology is not discussed), and 
> these are consistently available for each species so the descriptions are 
> similar in length for every species. The amount of information for dinosaurs 
> ranges from almost as good as for living animals in those few cases in which 
> feathers and their color patterns have been preserved and documented, to 
> virtually nothing for many poorly known species, so the amount of information 
> that can accompany the species ranges from extensive to zero. There is of 
> course no need to include with each theropod species that it was bipedal, 
> that 
> was noted in the description for the entire group. Same for most of them 
> being 
> tridatcyl. Each species description includes only those features limited to 
> that species that can be used to distinguish it from other species. In some 
> cases there is no special features available so they are either "standard 
> for the group" or "insufficient information." For example, what nontechnical 
> feature/s suitable for a popular field guide distingush/es Argentinosaurus  
> it from other giant titanosaurs? Suggestions, anyone?    
> 
> One person challanged me to define genus as though that point has critical 
> meaning. It is not possible to define species either, but species are real. 
> It is not possible to define life, but it is real. There is no way to 
> precisely define battleship versus battlecruiser (HMS HOOD for example) 
> versus 
> heavy cruiser (Alaska class for example). Many terms are approximations, it 
> does not mean that they cannot be used to describe and distinguish basic, 
> comparable types. 
> 
> Canis poses an interesting problem for the current use in dinosaurology of 
> genus as just a few species that form a monophyletic grade. Canis is a large 
> genus with many fossil and extant species that vary considerably in size, 
> anatomy and lifestyles. The living species can all interbreed easily and 
> produce reproductlively viable hybirds (as per the new eastern coyote, which 
> has 
> considerable wolf in it so it is bigger, more social and can take down 
> deer), so it is unlikely that the genus will be split up. So lets consider 
> the 
> consequences if a clade of fossil canids was found that was way too 
> anatomically different to be in the genus Canis, or to have interbred with 
> Canis 
> species. Also that the different genus has clearly evolved from derived Canis 
> species in a way that rendered Canis paraphyletic. Would it then be required 
> to split living Canis into multiple genera despite their ability to 
> interbreed?   
> 
> The chasmosaurine cladogram in the new PLos One Sampson et al paper 
> illustrates the potential problem in a dinosaur group. The chart is 
> suspiciously 
> progressive, with a series of chasmosaur taxa eventually leading over time to 
> Anchiceratops, Arrhinoceratops and then the ultimate Triceratops clade. 
> Because the chasmosaurs from Chasmosaurus to Vegaceratops appear to be 
> paraphyletic they have to be split into a bevy of genera despite varying only 
> in 
> cranial adornments. This may well be an artifact of the cladogram based on 
> the 
> characters that happen to be analyzed, it is quite likely that the 
> Chasmosaurus to Vegaceratops chasmosaurs are their own clade with minor 
> variations in 
> display organs that constitute a typical, multispecies genus. Assume that in 
> the future some but not all cladograms find that Chasmosaurus belli and 
> russeli are paraphyletic relative to a more derived and very distinctive 
> chasmosaurine, while other chasmosaurs are monophyletic? How would that be 
> handled 
> at the genus level? 
> 
> I am also unpleased that the fragmentary Mexican chasmosaurine was given a 
> genus name, Coahuilaceratops would have been better left incertae sedis. 
> When I was in Spain I came across a bunch of iguanodonts that are clearly new 
> taxa but they are too incomplete to name. 
> 
> At the SVP meeting it was interesting that some of the new work is 
> emphasizing the importance of stratigraphy in determining taxa, a conclusion 
> I came 
> to while doing the book. The stratigraphic factor threatens to sink a number 
> of genera in oversplit dinosaur groups. Phylogeny alone is not sufficient.  
> 
> Some of Z Armstrong comments are particularly inept in a naive, armchair 
> critic manner so they need rebuttal. He claims that Huabeisaurus is very 
> incomplete when most of the skeleton, including the vital shoulder girdles 
> are 
> figured by Glut in his suppl 2. His spurious speculation that I used photos 
> of 
> a grossly incomplete mounted skeleton is based on ignorance, and is the 
> sort of idle misinformation that uninformed persons with keyboards and 
> internet 
> access have no apparent qualm distributing despite their lack of knowledge 
> and because of their laziness (he didn't ask me). Huabeisaurus is the best 
> basal titanosaur yet published, too bad we don't know what kind of skull it 
> had. Malawisaurus and Phuwiangosaurus are less well known and in some cases 
> lacking major shoulder and pelvic elements so I did not find them worth the 
> production time available (I was particularly reluctant to do new skeletons 
> when the pelvis is not known). The information I have is that the super 
> mamenchisaur skeleton is much more complete than the very incomplete 
> Argentinosaurus. Hopefully the size of Futalognkosaurus will be pinned down 
> soon, 
> information I have seen indicates it is in the 50-60 tonne class (its 
> relative 
> proportions also helps show that none of the S Amer supertitanosaurs 
> approached 
> 100 tonnes as was commonly thought). 
> 
> As anyone who actually does lots of skeletal restorations knows, it is not 
> always possible to tell what bones are and are not preserved in a specimen 
> or species, so it is not practical to do every skeleton or species composite 
> showing only the elements preserved, and one ends up doing a complete 
> skeleton. Ergo, it is not viable to do a book in which there is consistency 
> in 
> showing only bones that are preserved. In the case of the field guide I used 
> a 
> combination of new work, and restorations already done in the past to keep 
> the work and time load in reasonable limits, some of the latter were complete 
> restorations although some elements are missing.   
> 
> It should be understood that it is possible to put only so much time and 
> labor into writing and illustrating a given book. The advance was far larger 
> than for any other type of adult market dinosaur book in order to make the 
> hundreds of drawings possible, but it placed limits on what was doable form a 
> business perspective. Producing dinosaur skeletal restorations plus side 
> views is much more time and labor intensive than generating 
> semi-standardized, 
> surface only illustrations of birds or sharks. As it was I put as much 
> effort into the book as was feasible. There are also marketing constraints, 
> and a 
> longer book would have been more expensive. 
> 
> There are the annoying errors in the book, am particularly vexed that I 
> sent on old version of the Apatosaurus rearing and feeding in a tree full 
> scene. And missed a few new taxa that had been described before the cut off 
> date, 
> which is hard to avoid with so much stuff coming out. 
> 
> GSPaul
> 
> </HTML>