The concept of mimesis is not very often used in the contemporary semiotic dialogue. This article introduces several views on this concept, and on the basis of these, mimesis is comprehended as a phenomenon of communication. By highlighting different semantic dimensions of the concept, mimesis is seen as being composed of phases of communication and as such, it is connected with imitation, representation, iconicity and other semiotic concepts.

Cooption and modularity are informative concepts in evolutionary developmental biology. Genes function within complex networks that act as modules in development. These modules can then be coopted in various functional and evolutionary contexts. Hormonal signaling, the main focus of this review, has a modular character. By regulating the activities of genes, proteins and other cellular molecules, a hormonal signal can have major effects on physiological and ontogenetic processes within and across tissues over a wide spatial and temporal scale. Because of (...) this property, we argue that hormones are frequently involved in the coordination of life history transitions (LHTs) and their evolution (LHE). Finally, we promote the usefulness of a comparative, non-model system approach towards understanding how hormones function and guide development and evolution, highlighting thyroid hormone function in echinoids as an example. BioEssays 27:64–75, 2005. © 2004 Wiley Periodicals, Inc. (shrink)

In biosemiotics, living beings are not conceived of as the passive result of anonymous selection pressures acted upon through the course of evolution. Rather, organisms are considered active participants that influence, shape and re-shape other organisms, the surrounding environment, and eventually also their own constitutional and functional integrity. The traditional Darwinian division between natural and sexual selection seems insufficient to encompass the richness of these processes, particularly in light of recent knowledge on communicational processes in the realm of life. Here, (...) we introduce the concepts of semiotic selection and semiotic co-option which in part represent a reinterpretation of classical biological terms and, at the same time, keep explanations sensitive to semiosic processes taking place in living nature. We introduce the term ‘semiotic selection’ to emphasize the fact that actions of different semiotic subjects (selectors) will produce qualitatively different selection pressures. Thereafter, ‘semiotic co-option’ explains how semiotic selection may shape appearance in animals through remodelling existing forms and relations. Considering the event of co-option followed by the process of semiotic selection enables us to describe the evolution of semantic organs. (shrink)

The importance of evolutionary parallelisms and their differences from evolutionary convergences have been historically underappreciated, as recently noticed in Gould's last book `The structure of evolutionary history'. In that book, Gould make an effort to distinguish and to reinterpret these concepts in the light of the new discoveries of the last decades on developmental biology and genetics, presenting the elegant metaphor of `Pharaonic bricks versus Corinthian columns'. In this paper I will briefly discuss these concepts, and will argue that, despite (...) the advances that have been made to define them in theory, it is rather hard to differentiate them in a practical phylogenetic context. In order to do so, I will provide some few examples from my own empirical studies on the last years of one of the most morphologically and taxonomically diverse groups of Vertebrates, the catfishes. (shrink)