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Re: Say Hello To Occam's Bulldozer

Kris, this was a marvellous introduction to a concept
which, needless to say, should be more prevalent in
this forum. It is a source of solace that, with
well-preserved specimens, scholars such as Thomas
Holtz,  Mark Norell, Jeff Wilson,  and Julia Clarke et
al., are able to formulate paradigms of inferences, a
"snap-shot", as it were, of likelihoods based on
available data of pre-K/T in the absence of plastid
and nuclear DNA sequences from those dinosaurs. Can
one imagine how much a pint of tyrannosaur and
sauropod blood would reveal about saurischian 
phylogenetic systematics?
That was my frustration (a mental exercise, so to
speak) with Mr Crichton's laboratory sequences in his
second novel (setting aside the nonsensical screeds
from Ian Malcolm): rather than blithering, enough
computer data was available to present a phylogeny of
dinosaurs already cloned. There were opportunities for
rigorous field ecology and behavioural studies. In
2002, there is enormous amounts of information
available about living theropods, which can be checked
and re-checked. But...these are highly adapted clades
of those theropods which survived the K/T extinction
events (not event; the bollide impact did not "kill
off" all of the dinosaurs). For other dinosaur clades,
we are left with either putting one's hands in
pockets, or looking at the behavioural ecomorphologies
of mammalian taxa which live in the econiches of
pre-K/T dinosaurs (yes, yes, Qilongia: acknowledging
the formidable array of differences between pre-K/T
dinosaurs and extant mammalian mega- carnivores and
-herbivores). But...there is data from which one can
make guesses (sauropods, like giraffe, probably used
necks for both combat and mating rituals among females
and males; I doubt that heads flew off; sauropods,
like elephants, probably used infrasonics). Why not?
As you point out, Kris, limb development began among
ocean taxa for hunting and foraging. The processes of
evolution are more complex than many realize. For
example, "natural selection" is scientifically
meaningless: like Isaac Asimov's "hyperspace", it was
a buzzword in the absence of evidence... i.e.,
"natural selection" does not exist: Darwin, from a
failure of imagination, basically took his
contradictory inner struggles with "natural
philosophy" (the constipatory equivalence to
"intelligent design") and substituted words.  What
does exist are genomic engines, molecular genetics,
and processes of adaptations in fast-slow dynamical
And in the simplicity of complexity, life at the edge
of chaos on adaptative landscapes (to borrow without
shame from Stu Kauffman and Russell Lande) persists in
spite of it all.
Kris, you are a mensch!
--- MariusRomanus@aol.com wrote:
> I think the time is right to introduce all of you to
> the concept of "Occam's Bulldozer"...... 
> I believe that people have the tendency, and
> tenacity, to see ideas as supported facts
> (especially those of their own); Ideas which are
> really just speculations based on a partial fossil
> record. Yes... It does seem to be a really good idea
> that simple feathers evolved first and variations on
> these basal structures helped out in individual
> environments. For fliers, this apparently means
> those pennaceous-type feathers we all know and love,
> with secondary flightless versions of theropods
> inheriting the splendor. It sure would seem like
> this was the most likely path now doesn't it? It
> also would seem logical to us to develop things in
> this manner. However... Homeotics don't play that
> type of game peoples. Nature is a wicked old sod
> that often enjoys showing us that the simple root WE
> pick is not always best or correct root we thought
> it to be. Selection selects on changes that, as we
> all understand, are in response to the environment.
> This leaves little in the way of allowing us t!
> o establish the coveted "A logical development over
> time" scenario. Evolutionary "stages" are not
> viewing themselves as part of a series. They are
> just looking for more immediate reproductive
> success. If in the end, the results appear as
> "stages", which in hindsight we label as being a
> part of a series of logical steps, we most likely
> ended up with a picture colored by the human mind's
> need to see an overall reason that was actually not
> present during the actual selection events
> themselves to begin with. I liken this to painting
> by numbers... Trouble is... we only know how to
> count with whole numbers from 1 to 10... But the
> pictures we are trying to paint use decimals and
> fractions that go up to 1,000,000. 
> A perfect example of nature giving us black-eyes
> comes in the form of the evolution of the spiracle
> in fish. It was once thought that the spiracle
> developed by the increase in size of the mandibular
> arches which then restricted the first gill slit
> down to the size of the spiracle. Later, we were
> beaten with baseball bats when we saw that the
> fossil record showed the development of the spiracle
> FIRST, before the jaws. The spiracle was then
> believed to have been selected upon because of the
> organism's need to have a breathing vent of sorts
> while being buried in the mud. Other ideas have been
> tossed about as well... But the end result was our
> immaculate logical sequence being doused in gasoline
> and set on fire while the fossils laughed and made
> goggly-eyes at us while performing a stupid little
> dance. 
> Another simple example that comes to mind would of
> course be the new reasoning behind tetrapod limb
> development. Now we see limb evolution, not as
> elements to help the creature get about on land, but
> as the product of an organism dragging its still
> very fishy self through plants and rocks under water
> as it set up to be an ambush hunter. 
> We need to realize that most of our logically
> constructed sequences make sense only after we take
> into account a more complete fossil record, and not
> to try and derive ideas from a limited fossil record
> and pass them in goodness as facts. Let's sing all
> together now... "Little steps... Little steps...
> Homeotic genes do as they bloody well please." 
> It is a fools game to play "Lets guess what
> variations in homeotic gene expression can do!".
> Simple pathways are more for the human brain than
> for the actual events which had taken place. We like
> the idea that 1 becomes 2 and leads to 3. We like it
> so much that we have the bad habit of letting it
> rule science where it should not. As a good friend
> of mine so elegantly puts it, "We shall now call
> this type of thinking "Occam's Bulldozer"." 
> If we think about skulls and trends... The number
> one trend seems to have been a reduction in
> complexity... Not an increase. I'm sure that most of
> us could put together the pieces of a dog or human
> skull. But a basal fish?... Doubtful. I am not
> implying that this is the same case as in feather
> evolution. What we as a group are saying, is that
> parsimonious ideas are cool an all that... But!!!...
> Lets respect reality first OK?... Old Man Reality
> continually backs his Cadillac out of the driveway
> straight into and over us while we peddle our
> neato-keen bicycles. This is a simple reminder that
> nature does whatever it damn well pleases to do. We
> are left to hobble around with our legs in casts
> trying to make heads and tails out of how we ended
> up face down in the street with some crazy old man
> yelling that we shouldn't have been behind his car
> in the first place. 
> Kris 

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