STEVENS, PETER F. Department of Biology, University of Missouri St Louis, St Louis, MO 63121-4499, and Missouri Botanical Garden, P.O. Box 299, St Louis, MO 63166-0299. - Organisms, form and characters.
In the development of phylogenetic systematics over the last decade
our approach to morphological characters has remained at a
preDarwinian level, even as we use ever more sophisticated tools for
looking at plants. A largely neglected area is that of the
relationship between characters, their states, and organisms. One
especially problematic set of issues concerns the documentation of
morphological observations and their general availability, whether as
measurements, s.e.m.s, etc. (cf. gene sequences in GenBank, and
associated voucher specimens). Another concerns the relationships
between the observer, observations, characters, and their states. Are
there alternative ways an organism can be atomised into characters
that would aid our understanding (perhaps think of the monocot flower
here)? Are there alternative ways a character can be atomised into
states? How can we justify one atomisation over another in any
particular situation? Do we have to? Does terminology constrain our
vision of the world and, if so, how? Is seeing forgetting the name a
thing is called? What is the relationship between the purely
morphological and systematic approaches to studying plants? We will
discuss these and related issues as they arise during the session.
Key words: character states, characters, morphology, observation, systematic theory, terminology