Deconstructing morphology

Abstract

Scholtz, G. 2010. Deconstructing morphology. -Acta Zoologica (Stockholm) 91: 44-63Morphology as the science of form is, in particular, related to the overwhelming diversity of animal forms. Due to its long pre-Darwinian tradition, organismic morphology is partly burdened by ahistorical typological views. On the other hand, the study of organismic form has always implied concepts of transformation, which helped to pave the way for evolutionary theories. This contradictory history and the fact that we need words to describe organismic form lead in many cases to morphological concepts implying a mixture of structural, functional, developmental, ecological, typological, and evolutionary aspects in current morphological approaches. Because these mixed views lead to contradictory and misleading interpretations of animal form, I stress the need to deconstruct morphological concepts at all levels. I propose a morphology that analyses transformation of animal forms strictly at the structural level in combination with genealogical thinking. Function and other biological aspects of form should be considered in an independent second analytical step. A comparative pattern approach, including developmental patterns, of animal structure in an evolutionary framework allows for the analysis of morphological change, in particular, phylogenetic reconstructions, homology assessment, and the recognition of evolutionary independent morphological units.

An Advanced Filter-Feeder Hypothesis for Urochordate Evolution

“…For example, the fate of A6.3 is restricted to endoderm and trunk lateral cells in ascidians, but it becomes the central nervous system in Oikopleura (see also Supplementary Figure S1). Such cases provide reasons to double check the results, but might also highlight interesting areas of research in which the mechanism responsible for an obvious evolutionary novelty could be deduced using a comparative approach (Scholtz, 2005(Scholtz, , 2010. Thus, careful and transparent argumentation in relation to homology hypotheses will clearly advance the burgeoning field of comparative cell lineage studies and identify interesting and relevant evolutionary novelties for future analysis.…”

Elucidating the phylogenetic position of Gnathostomulida and first mitochondrial genomes of Gnathostomulida, Gastrotricha and Polycladida (Platyhelminthes)

“…These three features of 474 the jaws have been regarded as separate characters in some mor-475 phological-cladistic analyses (Nielsen, 2001;Sørensen et al, 476 2000), but it is not certain if they constitute truly independent 477 identities allowing independent character coding (Jenner, 2004). 478 Nonetheless, if coded separately or not, these characters increase 479 the probability of homology of these jaw apparatuses based on a 480 homology complexity test (e.g., Scholtz, 2010). Another pharyngeal 481 character, which supported the Gnathifera hypothesis in morpho-482 logical-cladistic analyses, was an extended non-contractile region 483 of the pharyngeal musculature (Zrzavy, 2003).…”

Cheliceral Morphology in Solifugae (Arachnida): Primary Homology, Terminology, and Character Survey

“…The comparative approach, among the most important in biological research, requires data to be comparable and communicable (Edgecombe, 2008;Fusco, 2008;Bonato et al, 2010;Richter et al, 2010;Scholtz, 2010). Identified as "the core problem of morphological data" (Vogt et al, 2010: 309), unstandardized terminology among authors, studies and scientific communities, i.e.…”