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Occam's Bull



Chapter I: So Here We Are 

Kris writes: > Yes... It does seem to be a really good idea that simple 
feathers evolved first [...] However... Homeotics don't play that type of game 
peoples. < 

David Marjanovic writes: >> Looks like they do, almost. That recent Nature 
paper by Yu et al. messed around with gene expression to find out just that. < 
< 

Excuse me... Simple question here from the back of the class... How many times 
in the history of science have we found that evidence seemed to point one way 
(especially if thats what they were looking for), but later on new evidence 
pops up to show otherwise? It is the reasons we have Piltdown men as well as 
*Archaeoraptors* on our own front... It's not that *Microraptor*, as well as 
the Enantio that it was fused to, do not pay a close resemblance to actual 
fossils that we have now since found, and were in many ways, predicted to have 
actually existed by various hypotheses on avian evolution... The main 
problem... The Beast... resides in the thinking. This type of thinking is the 
same as the people who think elephant legs are trees, and so they started 
looking at the bark on the ground as evidences of their original idea... 
instead of wondering why the tree just moved. I myself have ideas very close to 
the ideas being stated on the many different fronts, but in no way would !
I try and say the evidence in suport of these ideas are much better than âif 
the glove donât fit!â. To say we are attacking the ideas themselves is 
completely missing the point, like a blind kid coming up to bat... Many of 
theses ideas are very close to those who do not like the "Case Closed!" style 
of dogma that goes on once an idea seems to have any evidence backing it for 
more than a weekend. 

Kris Writes: > Evolutionary "stages" are not viewing themselves as part of a 
series. They are just looking for more immediate reproductive success. < 

David Marjanovic writes: >> Of course, of course. Has been forgotten very 
often. Doesn't contradict the above. << 

Actually it does... and the reason it is not  being seen is central to the 
problem. It seems to be inherent in the first place to look at the 
hypothesis.... to start off small... and go big. When a study is done with this 
as a mind set, it is very easy for people to put ovale blocks in round holes. 

Kris writes: > It is a fools game to play "Lets guess what variations in 
homeotic gene expression can do!". < 

David Marjanovic writes: >> Fully correct. "Let's _try_ what variations in 
homeotic gene expression can do!" is not, however. This is a scientist's game. 
(OK, OK. Not that there weren't some foolish scientists. :-) ) << 

Kris writes: > If we think about skulls and trends... The number one trend 
seems to have been a reduction in complexity... Not an increase. < 

David Marjanovic writes: >>  Yeah. And? Bad news for those who believed in 
progress in evolution and equated more skull bones with progress. I doubt 
anyone ever did both, however. << 

No one ever did you say? And how exactly could that be? Go around and ask 
people not in the know about the subject. Take a nice old fashion head count of 
100 people... Make sure they do not know about the fossils and then ask them 
which seems to be the way a skull would evolve? More bones over time... Or less 
bones over time?......... I..... on the other hand...... don't need to do such 
a silly thing because I already know the answer. I have met many of these 
people who would say âMore bones over time right? What do you mean less?... 
How is that evolution?" 

Simple fact... It is ONLY by way of the evidence that we know a reduction in 
the dermal elements did indeed take place. Because it is known so well now, it 
may seem to some as being obvious... Touble is... It is not... Just as it was 
only after the fossils were found did the idea of big brains in humans coming 
before bipedism go up in flames. 

For us... It is not that we do not have fossils... The big issue here is that 
we do not have fossils that show a series. This leaves those with ideas which 
are not found as evidence to be able to sometimes see things that are not 
actually there. For example... BPM 1-3-13 was said by Norell to show evidence 
that pinnate style feathers evolved before flight. Then low and behold, here 
comes another fossil called, and quite appropriately I might add,   
*Cryptovolans pauli*... And what happens???? Here we have an animal that seems 
to look shockingly like BPM 1-3-13,  yet it shows feathers in such a way as to 
scream flier. What I am saying is how about letting the fossil record show us 
what is what this time around ok? Most had claimed dromaeosaurs as a pre-flight 
version of the theropods that were related to the early fliers... Is this so 
certain now? If so, are you ready to take that wager with fossils yet to 
come??? 

------------------------------------------------------------

Chapter II: Occam's Bulldozer Cometh 

It seems that some in the pool are still treading water and do not know just 
what is meant by "Occam's Bulldozer"... and what is being implied. Others 
seemed to have their water-wings on and have picked up on it right away. 

The key here is the same with the term in general; Interpretation. 
Interpretation is the main issue underlining most all of the said disscusions 
on cladistics. 

Older versions of human interpretation, as in what was seen in the Burgess 
Shales with say... *Anomalocaris*and how its earlier versions were separated as 
different fossil animals.... is a classic example of seeing more than what is 
shown in the fossils. 

This was not only an idea of interpreting the fossils themselves, but it showed 
how the whole subject of evolution itself was being interpreted as showing an 
increase in body plans over time.  We now see it as a decrease in body plans 
over time, with the winners diversifying from there. 

The fear that we have of being so biased in the future is thought to be 
removed, at least in part, by the impartial method of "just the facts ma'am". 
This is what we call Cladistics. 

Cladistics, we believe, are a great tool to help us sort out the mess, but they 
are still in their infancy. It seems people believe the errors of human 
interpretation are not an issue when we use this method because all we are 
doing is adding up the so called facts and letting a computer do the rest. 

Cladistics can be too black and white in its current methods. This is not to 
say that cladistics in general are a bad idea, as some have stated, but we do 
need to, in my mind, make the traits a little more expressive of their true 
nature. Of course this leaves us with a whole other bag of worms left open on 
the table; Individual interpretation of those traits in issue. This is what 
unavoidably happens when we use such an overly simplified version of a trait 
and rating them as 0, 1, 2 ect... 

Most used to state that how reversed a pubic shaft was in theropods was 
something that dictated how "bird-like" that theropod was. This made it all 
simple... Troodonts and oviraptors were not as bird-like as dromaeosaurs and so 
on. 

This looks odd since we now see that *Archaeopteryx* most likely had a vertical 
pubic shaft and dromaeosaurs in some cases had a much more reversed pubic 
shaft. 

Yes... Truth be told... This may be reversals in some groups and it could be 
possible  that covergent evolution happened in closley related groups. What it 
also can show is just what the rating of this trait is claimed to show; 
Dromaeosaurs being more derived than *Archaeopteryx* in the direction of either 
modern birds, or a side branch that is still further along than *Archaeopteryx* 
was. 

One of the ways we have tried to work around this, is to let the gods of chaos 
work their magic by adding up other traits that seem not to be correlated to 
one another in any special way. This is done by adding up all the traits in 
question that may change over time and rating them. This is done with as many 
traits as possible that might help us correlate relationships between the 
organisms in question. 

For example, when we look at the list of characters for the phylogenetic 
analysis of *Sapeornis* and other birds by Norell and Clarke (2001) in Nature, 
we can see that trait number 159 reads; "Preacetabular ilii: (0) approach on 
midline, open, or cartilaginous connection; (1) co-ossified, dorsal closure of 
"iliosynsacral canals"". 

Now, the iliosynsacral canal is a canal formed by the iliosynsacral crest and 
each canal is separated by the dorsal synsacral crest from one another. We see 
the iliosynsacral crest as a median ridge formed by the fusion of the right and 
left dorsal iliac crests with the dorsal crest of the synsacrum. Each canal is 
roofed by the preacetabular wing of the ilium from its side and contains 
epaxial musculature. The ventral wall of each canal is made up of the 
transverse lamina which is the fused transverse processes of the synsacral 
vertebrae. 

What is important in all of this is not all modern birds have this dorsal 
fusion and sometimes this region is left open as it is in both pigeons and 
crows. 

The iliosynsacral sulcus, when present, is a furrow between the central 
synsacral crest and right and left dorsal iliac crests. This is the same region 
where the iliosynsacral crest is found in other birds that are no more derived 
than pigeons and crows. 

Let's think about this though... What rating should a pigeon or a crow get as 
to maybe a seagull??? Should the first two be considered any less derived than 
the last? What does (1) imply over (0)? 

It is our belief this can be done with most of the traits that are used, and if 
not, at least enough to throw off the final outcome by miles. 

In short, when we warm up the ol' computers and put in the traits, they are not 
adding up known facts... They are adding up opinions in style!!! 

This is what is meant by "Occam's bulldozer"... The ability to think you are 
being unbiased, but instead, you are just driving your opinions under the guise 
of impartial facts. 

Kris