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RE: PDF-request: Original description of Lagosuchus and/or Marasuchus
Dave, I was under the impression Bill had taken your issues into account with
his reply. If anything, Mike was too clarifying on the issue. It is not
contingent upon grad students to do research for others to benefit from, and in
many cases, interested parties can and have gone out to do the data collection
requested. I think this is even more important when the questioning party (you)
has specific interests that he claims are not being met, and is then acting as
though others should work towards alleviating this deficiency. I mean, really?
Mike's arguments are to the point; he picked a specific set of data that can
be observed from the literature, but then drew from the argument that it is not
sufficient to question said literature (although some data can only be produced
from said literature or its equivalent, such as quarry information, dates of
collection, etc.). Gone are the days when we were so limited that the
literature was to be taken for granted because travel was so restrictive. It is
possible for individuals to now travel from institute to institute and take
plent of first hand notes, photos, and other material noting their particular
interests (Phil Mannion has recently just published a work compiling data that
_could_ have been produced from the literature, but is richer because he chose
to use first-hand observation to invent a metric).
Mannion, P. D. and Upchurch, P. 2010. Completeness metrics and the
quality of the sauropodomorph fossil record through geological and
historical time. Paleobiology 36:283-302.
So what I got from both Mike's and Bill's replies to your arguments vis-à-vis
*Trialestes* was that 1) literature is not sufficient for some of the
information one might want to question phylogenies, 2) much less construct
them, and that 3) simply having other people do the work for you is going to
result in a lot of waiting time, meaning 4) it's often better to do the work
that you need to have done yourself.
Jaime A. Headden
The Bite Stuff (site v2)
"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
> Date: Sat, 10 Apr 2010 11:10:06 -0500
> From: email@example.com
> To: firstname.lastname@example.org
> CC: email@example.com; William_Parker@nps.gov
> Subject: Re: PDF-request: Original description of Lagosuchus and/or Marasuchus
> I appreciate your thoughts, but you're adding factors and suppositions not
> mentioned in Dr. Parker's original comments.
> You're also ignoring the key component in my comment: a priori taxon
> inclusion sets that are way too small for the gamut being tested in recent
> On Apr 10, 2010, at 10:56 AM, Mike Habib wrote:
>> On Apr 10, 2010, at 5:56 AM, David Peters wrote:
>>> To your point, if simply coding from the literature won't work this time it
>>> means the literature is not only wrong, it's>so< wrong that topology
>>> tumbles. And now is a good time to remind ourselves that the literature was
>>> written from>first hand observation<.
>>> So, what is your logic leaving us with? If first hand observation won't
>>> work (see above), plane tickets would be a waste of money. Right? Yes, it's
>>> a vicious unwinnable Catch-22 you are creating here.
>> Not quite. Bill Parker was indicating that coding from the literature is,
>> itself, the step of insufficiency. The literature was written from first
>> hand observation, but writing based on that literature is no longer first
>> hand observation. The best way to re-evaluate former first hand observation
>> is to make new first hand observations of our own - that is, go see the
>> specimens for ourselves.
>> The literature is important, of course, and it is completely sensible to
>> rely on it for many types of information. However, when coding a
>> phylogenetic reconstruction, using the literature can be tricky business.
>> Some methods do this exclusively of course (supertrees and supermatrices,
>> for example) but these methods often have goals other than supplying a
>> novel, robust topology (supertrees, for example, are mostly a method for
>> quantifying the historical record of published phylogenies up to that time,
>> often as a way of evaluating consensus in the literature. This is a
>> different goal than trying to actually reconstruct ancestry).
>> It is also worth pointing out that some methods of coding from the
>> literature are more robust than others. For example, if one is simply
>> adopting the data matrix supplied by another author, and combining it with
>> others (supermatrix), then you are only assuming that the prior authors were
>> accurate. This has its own set of problems, but can be workable in some
>> cases. However, trying to create new codings from the literature (say, for
>> example, by trying to code from a photograph or other second-hand source) is
>> exceptionally difficult to do accurately, and there will almost always be
>> features that are not accurately represented in a 2D photo or other such
>> representation. I believe this is what Parker was suggesting should be the
>> impetus to travel and observe specimens directly.
>> Michael Habib
>> Assistant Professor of Biology
>> Chatham University
>> Woodland Road, Pittsburgh PA 15232
>> Buhl Hall, Room 226A
>> (443) 280-0181
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