History, action and identity: Revisiting the ‘Second’ Great Debate and assessing its importance for Social Theory

Este artículo aborda el tema de la naturaleza del conocimiento en los asuntos prácticos. Tradicionalmente esta cuestión ha sido abordada recurriendo a la construcción teórica [“theory-building”] y poniendo en juego una serie de criterios epistemológicos independientes que, supuestamente, garantizan los postulados formulados dentro de un marco teórico. En este contexto, la universalidad, entendida como generalidad, y la fiabilidad de los “datos” a lo largo de la historia son criterios particularmente poderosos que establecen la “verdad” de las proposiciones teóricas por medio de “tests” y, así, contribuyen a acumular “conocimiento”. Pero este ideal del conocimiento “teórico” malinterpreta de forma significativa tanto el tipo de conocimiento que necesitamos para adoptar decisiones prácticas, como el de la “historia” para constituirnos en agentes. Al utilizar el argumento de Bull del segundo debate como contrapunto, y al revisar también las controversias relativas a la paz democrática y al papel de los estudios macro-históricos, primero me centro en la naturaleza de la “historicidad” y la situacionalidad [situatedness] de todo el conocimiento práctico. En segundo lugar, intento clarificar cómo el conocimiento del pasado que se relaciona con las elecciones prácticas en esa “historia” no es simplemente un almacén de datos fijos, sino un producto de la memoria, la cual está profundamente implicada tanto en nuestras construcciones de la identidad como de los proyectos políticos que perseguimos. En tercer lugar, esbozaré los criterios para la generación de conocimiento que son más apropiados cuando afrontamos problemas prácticosThis article raises the issue about the nature of knowledge in practical matters. Traditionally this question has been answered by pointing to ‘theory-building’ and to field independent epistemological criteria that are supposed to provide the knowledge warrants for the assertions made within a theoretical framework. In this context universality, i.e. generality and transhistorical reliability of the ‘data’, are particularly powerful criteria that establish the ‘truth’ of theoretical propositions through ‘tests’ and thus contribute to cumulative ‘knowledge’. But this ideal of ‘theoretical’ knowledge significantly misunderstands both the type of knowledge we need when we make practical choices and that of ‘history’ in constituting us as agents. In using Bull’s argument in the second debate as a foil, and in revisiting also the controversies concerning the democratic peace and the role of macro-historical studies I first elaborate on the nature of the ‘historicity’ and situatedness of all practical knowledge. In a second step, I attempt to clarify how the knowledge of the past relates to practical choices in that ‘history’ is not simply a storehouse of fixed data, but a product of memory, which in turn is deeply involved in our constructions of identity and of the political projects we pursue. In a third step I adumbrate the criteria for knowledge generation that are more appropriate when we face practical problem

Christine Absmeier, Das schlesische Schulwesen im Zeitalter der Reformation. Ständische Bildungsreformen im Geiste Philipp Melanchthons. Stuttgart: Franz Steiner 2011 (371 S.) [Rezension]

Rezension von: Christine Absmeier, Das schlesische Schulwesen im Zeitalter der Reformation. Ständische Bildungsreformen im Geiste Philipp Melanchthons (Contubernium. Tübinger Beiträge zur Universitäts- und Wissenschaftsgeschichte, Band 74). Stuttgart: Franz Steiner 2011 (371 S.; ISBN 978-3-515-09814-4

Fragile DNA contributes to repeated evolution

Sequence features that affect DNA fragility might facilitate fast, repeated evolution by elevating mutation rates at genomic hotspots.Non peer reviewe

Neural innervation as a potential trigger of morphological color change and sexual dimorphism in cichlid fish

Many species change their coloration during ontogeny or even as adults. Color change hereby often serves as sexual or status signal. The cellular and subcellular changes that drive color change and how they are orchestrated have been barely understood, but a deeper knowledge of the underlying processes is important to our understanding of how such plastic changes develop and evolve. Here we studied the color change of the Malawi golden cichlid (Melanchromis auratus). Females and subordinate males of this species are yellow and white with two prominent black stripes (yellow morph; female and non-breeding male coloration), while dominant males change their color and completely invert this pattern with the yellow and white regions becoming black, and the black stripes becoming white to iridescent blue (dark morph; male breeding coloration). A comparison of the two morphs reveals that substantial changes across multiple levels of biological organization underlie this polyphenism. These include changes in pigment cell (chromatophore) number, intracellular dispersal of pigments, and tilting of reflective platelets (iridosomes) within iridophores. At the transcriptional level, we find differences in pigmentation gene expression between these two color morphs but, surprisingly, 80% of the genes overexpressed in the dark morph relate to neuronal processes including synapse formation. Nerve fiber staining confirms that scales of the dark morph are indeed innervated by 1.3 to 2 times more axonal fibers. Our results might suggest an instructive role of nervous innervation orchestrating the complex cellular and ultrastructural changes that drive the morphological color change of this cichlid species.Peer reviewe

East African cichlid fishes

Cichlid fishes are a very diverse and species-rich family of teleost fishes that inhabit lakes and rivers of India, Africa, and South and Central America. Research has largely focused on East African cichlids of the Rift Lakes Tanganyika, Malawi, and Victoria that constitute the biodiversity hotspots of cichlid fishes. Here, we give an overview of the study system, research questions, and methodologies. Research on cichlid fishes spans many disciplines including ecology, evolution, physiology, genetics, development, and behavioral biology. In this review, we focus on a range of organismal traits, including coloration phenotypes, trophic adaptations, appendages like fins and scales, sensory systems, sex, brains, and behaviors. Moreover, we discuss studies on cichlid phylogenies, plasticity, and general evolutionary patterns, ranging from convergence to speciation rates and the proximate and ultimate mechanisms underlying these processes. From a methodological viewpoint, the last decade has brought great advances in cichlid fish research, particularly through the advent of affordable deep sequencing and advances in genetic manipulations. The ability to integrate across traits and research disciplines, ranging from developmental biology to ecology and evolution, makes cichlid fishes a fascinating research system.Peer reviewe

Building and Managing a Tropical Fish Facility: A Do-It-Yourself Guide

At the core of most research in zoological disciplines, ranging from developmental biology to genetics to behavioral biology, is the ability to keep animals in captivity. While facilities for traditional model organisms often benefit from well-established designs, construction of a facility for less commonly studied organisms can present a challenge. Here, we detail the process of designing, constructing, and operating a specialized 10,000-liter aquatic facility dedicated to housing cichlid fishes for research purposes. The facility, comprising 42 aquaria capable of division into up to 126 compartments, a flow-through rack for juveniles, egg tumblers for eggs and embryos, and a microinjection setup, provides a comprehensive environment for all life stages of cichlid fishes. We anticipate that a similar design can be also used also for other tropical teleost fishes. This resource is designed to promote increased efficiency and success in cichlid fish breeding and research, thereby offering significant insights for aquatic research labs seeking to build or optimize their own infrastructures.Comment: 14 pages, 9 figures, 2 table

Developmental and Cellular Basis of Vertical Bar Color Patterns in the East African Cichlid Fish Haplochromis latifasciatus

The East African adaptive radiations of cichlid fishes are renowned for their diversity in coloration. Yet, the developmental basis of pigment pattern formation remains largely unknown. One of the most common melanic patterns in cichlid fishes are vertical bar patterns. Here we describe the ontogeny of this conspicuous pattern in the Lake Kyoga species Haplochromis latifasciatus. Beginning with the larval stages we tracked the formation of this stereotypic color pattern and discovered that its macroscopic appearance is largely explained by an increase in melanophore density and accumulation of melanin during the first 3 weeks post-fertilization. The embryonal analysis is complemented with cytological quantifications of pigment cells in adult scales and the dermis beneath the scales. In adults, melanic bars are characterized by a two to threefold higher density of melanophores than in the intervening yellow interbars. We found no strong support for differences in other pigment cell types such as xanthophores. Quantitative PCRs for twelve known pigmentation genes showed that expression of melanin synthesis genes tyr and tyrp1a is increased five to sixfold in melanic bars, while xanthophore and iridophore marker genes are not differentially expressed. In summary, we provide novel insights on how vertical bars, one of the most widespread vertebrate color patterns, are formed through dynamic control of melanophore density, melanin synthesis and melanosome dispersal.Peer reviewe