R: Being "scientific" about segnosaurs[quite long]

["calzola" <calzola@iol.it>]

Mr. Kinman wrote:
>But I am forming a
> falsifiable hypothesis of coelurosaurian phylogeny that will be testable.
> If it fails scientific scrutiny, I'll admit it and accept it.

Ok, what might these falsifying clues be? How may they be recognized as
such?
The base of your hyotheisis is the non acceptance of some cladistic
criteria.This hypothesis, while  of some interest, has already been
questioned, because of the non-consideration of some characters ; now, the
problem is, IMHO, that there's no objective criterion on which  base such a
choice. You've been thinking of choosing the SLC as characteristic of your
enlarged AVES, with the consequence of excluding almost all "segnosaurs"
from this group, albeit the presence of quite a big  amount of characters
inidicating a close relationship with oviraptorosaurians. If you've decided
that you like the possibility that these characters are indeed homoplasic
and therefore indipendently acquired by "segnosaurs", what, ON EARTH, may
lead you to decide that it's not a good idea?? Another subjective intuition
or dubt?
I don't wanna say that it's not good to formulate new hypothesis having a
suspect that they may be objectively supported by some evidence, but there
must be _some_ evidence.
Furthermore, having to deal with one another (cladists and eclecticists) we
need some common theoretical ground to work on.....the lack of such a
"space" means the impossibility of working on the same hypothesis. While
denying the importance of some principles(however  extremist they may seem
to you), you erase the common base on wich it's possible to elaborate.
It's like asking a meteorologist to work with my grandmom and her knee to do
weather forecasts without using satellite images and all the rest of his
high-tech tools(here representing the achievementes of his field of
expertise...) or to ask my grandmom to look at satellite images to know what
the weather will be like (in case you don't like eclecticism being compared
to a 80y.o 's. knee:)


But please > don't brand it as unscientific just because it challenges the
holophyly of
> "enigmosauria".

-----we've not been questioning your hypothesis because it potentially
denies "enigmosaurian" monophily, but for the approach it reflects.
Accepting it, in light of the rest of the evidence indicating the contrary,
would be a contraddiction.


[...]If I'm wrong, and
> "enigmosauria" is holophyletic, so be it.
------Again, what may lead you to a different conclusion? if this hypothesis
of yours excludes us from discussion, I think that any further element
brought in by you (as possibly denying you own hypothesis) would just be as
well uncosiderable; and this only because you move from different
assumptions about the importance of parsimony and the relative importance of
characters.

 Until then, I will be seriously
> considering the possibility that "enigmosauria" is based on homoplasies
and
> is probably paraphyletic.
-----On what basis? I think it's just that , willing to enlarge Aves and
necessitating a commonly shared characters, and possibly found it in the
form of SLC, you've just decided that the "enigmosaurian" condition is
trouble-causing and that all the characters uniting "enigmosaurs" with
oviraptorosaurians have been acquired independently. This is _exaclty_ what
results from your emails and nothing may lead me to think it's an acceptable
series of considerations,despite your efforts to make them seem like they
need consideration.I'm sorry.

 It's a very tricky part of the coelurosaur tree,
> and am I just pursuing the problem in a more eclectic manner.

---now, i'd just like to know what exactly "eclecticism" means......your
approach lacks any costantly applied principle on which eventually base a
hypothesis; I mean ,today a set of characters may be considered homoplasic
because their presence is "unneeded" and tomorrow used differently....
If you have a condition implying two steps, you'd better consider the one
needing only one, since it's more parsimonious; however faulty may be,
considering parsimony as the common  trait of all evolutionary processes is
the simplest way to consider two different processes and compare
them.Otherwise you're lost in the  "subjective space"....



Filippo Calzolari
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