Re: Signor-Lipps points

From
Date
Reply-To
Responding to Chris Little's question regarding sources of the
Signor-Lipps effect:

Keep in mind that deposition, preservation, and exposure of
fossils are all essentially forms of sampling.  They are all
components of the Signor-Lipps effect.  To work past the effect,
I think it may be useful, nay necessary, to construct formal
hypotheses in which the action and influence of each source of
sampling (and ultimately the putative underlying causes) is
considered explicitly and quantitatively.  It is in addressing
the problem of underlying causes (that we all want to know) 
that we draw a link between the Signor-Lipp effect and general
questions of whether, for instance, taxon turnover at the K/T
boundary was catastrophic or not, abrupt or gradual, stepwise
or smooth.  To evaluate total evidence means to engage in the
practice of "reciprocal illumination" (sensu Hennig 1966, the
landmark book that launched cladistics).  That is, just as we
use data to evaluate hypotheses, we must use hypotheses to 
evaluate data, in all possible combinations.  The goal is to
look as closely and as creatively as possible, from every
angle, at the scientific problems before us.  The history of
the K/T boundary story is, I think, a perfect illustration of
the power of this complex and lengthly process. 

Stepping up into metadiscussion for a moment, I would like to
suggest, if you're not comfortable using "Signor-Lipps effect",
using the term "underestimation problem" instead.  That is as
close as I have been able to come, after several days thinking
about the equivalent problems in ecology (and statistics in
general), to an intelligible term.  Better ideas are welcome!

I started quite an avalanche by bringing up the "missing meter"
question here, and I recall Norm McLeod expressed trepidation
about it.  I suppose he anticipated a nasty argument and bad
feelings all around and, frankly, I also worried that it might
come out badly.  I am been very impressed with the geniality
and effort that so many people have put into this discussion.
I've been following one electronic forum or another for a full
decade now, and I assure you that PALEONET has so far been an
exemplar of a cordial and productive discussion forum.  It is
not unique, but it is uncommonly good.  I suspect this has to
do with the paleontology community in general;  I'm fairly new
to paleontology, but I have found the PALAEOBOTANY mailing
list, not to mention the many paleo researchers I've met, to
be an exceptionally friendly and courteous group of people.

Regards,