From their earliest origins fishes have developed a suite of adaptations for locomotion in water. Even without data from behaviour, soft tissue, and extant relatives, it is possible to infer a wealth of palaeobiological and palaeoecological information. As in extant species, aspects of gross morphology such as streamlining, fin position and tail type are optimised even in the earliest fishes, indicating similar life strategies have been present throughout their evolutionary history. Drag-reducing riblets ornamenting the scales of fast-moving sharks have been subject to particularly intense research, but this has not been extended to extinct forms. The crowns of shark scales are exposed directly to the aquatic environment offering a unique opportunity to elucdate scale function in some of their long-extinct Palaeozoic relatives. This thesis is the first comprehensive study of scale function in fossil fishes, and demonstrates that sophisticated adaptations for drag-reduction existed at a remarkably early stage in fish evolution. It is shown that riblet spacing reflects swimming speed in modern sharks, and that drag-reduction morphology evolved in the denticles of the earliest vertebrates, including the oldest examples known (~460 million years ago). Comparative analysis between modern sharks and fossil taxa reveals distinct and diverse regionalisation of scale features across the body, as well as ontogenetic changes. In addition to riblet spacing, the variation of other scale features is investigated quantitatively in modern sharks, revealing the importance of riblet angle in overall drag reduction. Furthermore, experimental skin friction measurements of fossil fish scales demonstrate the potential drag reduction of a diverse range of morphologies, even without riblets.

A brief summary of previous literature on vertebrate chromatic responses is presented. The influence of pituitary preparations on the responses of the melanophores of teleosts and of other chromatic vertebrates is examined and a new classification of teleost melanophore responses proposed. The time relations of melanophore and erythrophore response in Phoxinus and melanophore responses in Ameiurus and Rana to injections of teleost pituitary material have been examined. A method of assay, using Phoxinus as test animal, for the melanophore-aggregating hormone is proposed. The distribution of minnow melanophore-aggregating and erythrophore-dispersing, and frog melanophore-dispersing activity in the minnow pituitary closely mirrors the distribution of the meta-adenohypophyseal cells. Experiments with peptic and tryptic digestion suggest that these factors are polypeptide in nature. The influence of alkaline extraction on these factors has been examined and it is suggested that the results can be interpreted in terms of a single polypeptide hormone. All three factors are substantially soluble in alcohol. Electrophoretic analysis of teleost pituitary material failed to separate the minnow melanophore-aggregating activity from the minnow erythrophore-dispersing and frog melanophore-dispersing factors. Similar results were obtained with paper and column chromatography. The responses of hypophysectomised spinal-sectioned Phoxinus are, qualitatively, the same as those of spinal-sectioned fish with intact pituitarios. The erythrophore response of Phoxinus is stronger in black-adapted than in white-adapted fish. The fbihumoral hypothesis' of Hogben and Slome (1931,1936) has been critically examined. The time relations of colour change provide no evidence in favour of a two-hormone control. It is concluded that the evidence in favour of a bihumoral control of teleost melanophores is insufficient to deny the possibility that these responses are in fact under the control of a single, polypeptide, hormone.

The structure and histology of the pituitary gland of two species of teleost, Herichthys cyanoguttatus and Cichlasoma nigrofasciatum, is described. Seven cell types can be recognised. Two groups of P.A.S.+ve, A.F.+ve cyanophils in the meso-adenohypophysis are associated with the production of the thyrotrophic and gonadotrophic hormones; it is suggested that the P.A.S.+ve acidophils in the metaadenohypophysis produce a chromatophorotrophic hormone. The blood supply of the pituitary in cichlids of different ages has been studied. The development of the pituitary of Herichthys and the time at which the cell-types become histologically differentiated is described; comparisons are drawn with the developing pituitary of Cichlasoma. Histological differentiation of the first thyrotrophs coincides with the initial secretion of colloid in the thyroid but the results of experiments in which specimens of Herichthys were reared in thiourea solution indicate that pituitary influence on thyroid activity is not established until a later stage. Thiourea treatment from an early age affects not only the development of the thyroid and thyrotrophs but also that of the swim-bladder, melanophores and skin. The mechanism of these disturbances is discussed. The effect on the pituitary of long-term adaptation to both white and black backgrounds has been studied in several species ofteleost and in Rana. Chromatic adaptation is accompanied by cytological changes in the pars intermedia of Rana, and in certain cells in the meta-adenohypophysis of Phoxinus, Salmo and Cichlasoma but not in Carassius or Ameiurus. The cell types in this region of the pituitary are not histologically comparable in different species; the cellular changes in Phoxinus and Rana can be related to the release of melanophore concentrating- and dispersing hormones respectively but such a correlation has not proved possible for other species. Interpretations of the cytological appearance of the meta-adenohypophysis and intermediate lobe under different conditions are suggested and the functions of the chromatophore-regulating hormone are discussed.

James C. Preisig. / Also issued as Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineeing and Woods Hole Oceanographic Institute, 1991. / Includes bibliographical references (p. 171-173). / Supported by DARPA. N00014-89-J-1489 Supported by NSF. MIP 87-14969 Supported by a General Electric Foundation Graduate Fellowship in Electrical Engineering, and a National Science Foudnation Graduate Fellowship.

The Middle Ordovician to Late Silurian represents an interval of approximately 50 million years, which has been recognised as the initial, cryptic, period in the evolutionary history of chondrichthyan fish. The fossil remains attributed to early chondrichthyans are dominated by isolated dermal scales that predate the appearance of undisputed chondrichthyan teeth and articulated skeletons in the Lower Devonian. Investigation of the inter-relationships of these scale taxa and their systematic position relative to high- ranked chondrichthyan clades has been hampered by the lack of developed scale-based classification schemes for jawed gnathostomes, coupled with the limited use of scale characters in phylogenetic studies of Palaeozoic Chondrichthyes. Here, all previously documented scale types of alleged Lower Palaeozoic chondrichthyans were examined using a combination of X-ray microtomography, SEM and Nomarski DIC optics. These were found to exhibit a set of characteristics (symmetrical trunk scales, areal crown growth and lack of hard-tissue resorption, cancellous bone and enamel) recognised as specific to the dermal skeleton of chondrichthyans among derived gnathostomes. The collected data permitted the establishment of a hierarchy of scale characters for separate taxonomic ranks, leading to the recognition of three Orders (Mongolepidida, Elegestolepida ordo nov. and Altholepida ordo nov.) of early chondrichthyans, differentiated by distinct types of scale-crown morphogenesis. A scale-based cladistic analysis of jawed gnathostomes corroborated these results by recovering a chondrichthyan clade that incorporates all examined taxa and ‘acanthodians’ with non-superpositional crown growth patterns. It is thus proposed that chondrichthyan dermoskeletal characters carry a phylogenetic signal, allowing to interpret the documented diverse types of scale morphogenesis as evidence for a major radiation of chondrichthyan lineages in the Lower Palaeozoic.

The Late Permian mass extinction occurring at 252.6 ± 0.2 Ma is the most severe Phanerozoic extinction event and was preceded and followed by additional disturbances. Patterns and processes of extinction and recovery of marine vertebrates have been little studied compared to marine invertebrates. This project focuses on Chondrichthyes, which, together with other marine fish, appeared to have been relatively unaffected by the extinction, while most of their supporting ecosystem collapsed. This study explores the authenticity of extinction among chondrichthyans and possible explanations for the observed patterns, because extinction severities on the taxonomic and ecological levels may be decoupled or the quality of the fossil record may be variable. The presented analyses are based on a newly compiled database that supercedes older compilations. It is supplemented by material obtained from numerous localities globally, which includes newly described taxa. Hence, this study attempts to be the most up-to-date and comprehensive analysis of patterns and trends in chondrichthyan diversity and distribution that is currently available. The data demonstrate that, despite some variability in the Permian–Triassic chondrichthyan fossil record, the Lopingian record is shown to be of adequate completeness and, furthermore, range-through genus diversity is not significantly correlated with the number of taxonomic occurrences. Genus diversity declined from the mid-Guadalupian following an increasing extinction rate, which intensified throughout the Lopingian and thus supports a combined overall extinction as a result of the end-Guadalupian and Late Permian events. Furthermore, global distribution of chondrichthyan diversity shifted away from tropical regions and particularly the Boreal Sea gained in diversity, tracking extinction and recovery in marine benthic invertebrates in both time and space. No significant dependence of extinction on taxonomic structure or palaeoecological traits exists, which suggests proportional losses, except during the end-Smithian crisis. Also, a significant size decrease is absent among Permian/Triassic boundary-crossing taxa, suggesting selective loss of large-sized chondrichthyans rather than adaptive size decrease. Ultimately, the Hybodontiformes, Neoselachii, Xenacanthiformes and Holocephali are identified as the survivors, which possessed a varying combination of characteristics such as moderate body-size, adaptation to brackish/freshwater environments, benthic or generalist littoral (clutching) feeding behaviour, and a wide palaeogeographic range.

L'elaboració d'aquesta tesi doctoral s'explica per l'apercebiment de la relació que s'ha establit, als últims anys, entre el llenguatge de la ciència i la tècnica i la llengua comuna, en bona mesura, pel protagonisme que ha adquirit la investigació científica a la societat occidental, en part reflectida als medis audiovisuals. Aquesta relació ha tingut la seva manifestació, a nivell lexicogràfic, en la inclusió de tecnicismes als diccionaris de llengua general.En aquest context, el principal objectiu d'aquest treball es comprovar quina presència té un sector de la terminologia científica: la física, en aquests diccionaris, en especial, al Diccionario de la Lengua Española de la Real Academia Española (DRAE), i quin és el seu tractament en quant a la forma i, sobre tot, al contingut, tractant de contemplar, a més, les diferències que es poguin donar respecte als diccionaris especialitzats. Tot això amb la finalitat de, partint del concepte de "diccionari de llengua general", fer una reflexió sobre la pertinença del tecnicismes en aquest tipus d'obres i justificar, en principi, un tractament lexicogràfic fora d'aquestes.Pel que respecta a l'estructura de la tesi, aquesta ha estat dividida en tres parts. A la primera, s'intenta caracteritzar la terminologia científica, essencialment, des de els punts de vista sociocultural-pragmàtic (capítol 1) i conceptual-semàntic (capítol 2), en oposició al vocabulari común. A la segona part, el interès s'enfoca cap a la relació entre terminologia científica i diccionaris, tant en el nivell macroestructural como en el microestructural, analitzant el vocabulari de la Física localitzat al DRAE en quant a l'entrada (capítol 3), a la definició (capítol 4) i a d'altres informacions, principalment les marques diatècniques (capítol 5). Aquesta segona parte termina amb una revisió d'altres diccionaris generals, a fi de contar amb una base més amplia sobre la qual fonamentar les nostres posteriors conclusions, així com de dos diccionaris especialitzats, a fi d'observar possibles diferències (capítol 6). La tercera part consisteix en un apèndix composat pel Corpus d'entrades y acepcions de la Física al DRAE, entre d'altres informacions, així como per un capítol en què s'explica la seva elaboració, labor per la qual es va fer imprescindible la consulta tant d'obres de referència (diccionaris especialitzats, enciclopèdies) com d'especialistes. / La elaboración de esta tesis doctoral se explica por la percatación de la relación que se ha establecido, en los últimos años, entre el lenguaje científico-técnico y la lengua común, en buena medida, por el protagonismo que ha adquirido la investigación científica en la sociedad occidental, en parte reflejada en los medios audiovisuales. Dicha relación ha tenido su manifestación, a nivel lexicográfico, en la inclusión de tecnicismos en los diccionarios de lengua general.En este contexto, el principal objetivo de este trabajo es comprobar qué presencia tiene un sector de la terminología científica: la física, en los estos diccionarios, en especial, el Diccionario de la Lengua Española de la Real Academia Española (DRAE), y cuál es su tratamiento en el plano formal y, sobre todo, en el conceptual, tratando de contemplar, además, las diferencias que puedan darse respecto a los diccionarios especializados. Todo ello con el fin de, a partir del concepto de "diccionario de lengua general", reflexionar acerca de la pertinencia de los tecnicismos en esta clase de obras y justificar, en principio, un tratamiento lexicográfico fuera de las mismas.Por lo que respecta a la estructura de la tesis, esta ha sido dividida en tres partes. En la primera se intenta caracterizar la terminología científica, esencialmente, desde los puntos de vista sociocultural-pragmático (capítulo 1) y conceptual-semántico (capítulo 2), en oposición al vocabulario común. En la segunda parte, el interés se enfoca hacia la relación entre terminología científica y diccionarios, tanto en el plano macroestructural como en el microestructural, analizando el vocabulario de la Física localizado en el DRAE en el nivel de la entrada (capítulo 3), de la definición (capítulo 4) y de otras informaciones, principalmente las marcas diatécnicas (capítulo 5). Esta segunda parte termina con una revisión de otros diccionarios generales, a fin de contar con una base más amplia en que fundamentar nuestras posteriores conclusiones, así como de dos diccionarios especializados, a fin de observar posibles diferencias (capítulo 6). La tercera parte consiste en un apéndice compuesto por el Corpus de entradas y acepciones de la Física del DRAE, entre otras informaciones, así como por un capítulo en que se explica su elaboración, labor en que fue imprescindible la consulta tanto de obras de referencia (diccionarios especializados, enciclopedias) como de especialistas. / The writing of this doctoral thesis is due to the perception about the relation that has been established in the last years, between scientific and technical language and common language. To a great extent, this is because of the prominence acquired by scientific research in western society, which is partly reflected by audiovisual media. At a lexicographic level, the inclusion of technical terms into general language dictionaries proves this relation. On the one hand, the chief aim of this work is to confirm which is the presence of a part of scientific terminology, the physical terminology, in some dictionaries, especially, the Diccionario de la Lengua Española by the Real Academia Española (DRAE). On the other hand, this work tries to confirm the terminology treatment from the formal perspective and, above all, from the conceptual perspective, moreover, it is intended to see the possible differences in opposition to specialized dictionaries. Taking into account the concept of "general language dictionary", this research aims to tackle the pertinence of the technical terms in this type of books and to justify, at a first stage, a lexicographic treatment out of them. With regard to the thesis structure, it has been divided into three parts. In the first one, it is attempted to characterise scientific terminology, basically, from a sociocultural-pragmatic (chapter 1) and conceptual-semantic (chapter 2) points of view, in opposition to common vocabulary. In the second part, the interest is focused on the relation between scientific terminology and dictionaries, at a macrostructural and microstructural levels, by analysing the Physics vocabulary located at DRAE at an entry level (chapter 3), definition level (chapter 4) and other informations, particularly, the diatechnical marks (chapter 5). This second parte finishes with a review of other general dictionaries in order to have a widest base on which we can find our later conclusions, as well as two specialized dictionaries in order to observe possible differences (chapter 6). The third part is an appendix that consists of the Physics entries and senses Corpus at DRAE, among other informations. It also consists of an explanation about its preparation, which needed the use of reference books (specialized dictionaries, encyclopaedies) and counselling from experts.

Les Ionoscopiformes sont un ordre de poissons actinoptérygiens fossiles avec de larges distributions temporelle et géographique, connus depuis le Trias moyen jusqu'au Crétacé supérieur, en Europe, Afrique, Asie et Amérique du Nord et du Sud. Les Ionoscopiformes sont composes des deux familles Ophiopsidae et Ionoscopidae, représentées par des espèces variées dont certaines ont leur anatomie encore mal connue. Bien que les Ionoscopiformes soient considérés comme un groupe monophylétique, les espèces d'Ophiopsidae et de Ionoscopidae diffèrent par plusieurs caractères, dont le type d'écaille et la structure de l'ornementation des os dermiques. Les Ionoscopiformes sont placés dans le clade des Halecomorphi qui comptent trois ordres (Amiiformes, Parasemionontiformes et Ionoscopiformes) et plusieurs espèces incertae sedis (e.g., Heterolepidotus, Osteorachis, and Neorhombolepis). Les Halecomorphi sont considérés plus proches des Ginglymodi que des Teleostei, et avec ces premiers ils forment le clade Holostei. Certaines des espèces halécomorphes incertae sedis ont été précédemment associées aux Ionoscopiformes, notamment à la famille des Ophiopsidae. Plusieurs questions sur la composition des Ophiopsidae et la position des taxa associés ont récemment été rapportées dans la littérature, comme par exemple la position des genres Placidichthys, Heterolepidotus et Furo. On a suggéré pour le genre Heterolepidotus un placement dans la famille Ophiopsidae, notamment avec une position basale dans la famille, mais aussi comme appartenant à la famille Caturidae. Placidichthys a été récemment placé au sein des Macrosemiiformes et Furo muensteri dans la famille des Ophiopsidae. Considérant le besoin flagrant d'améliorer nos connaissances sur les espèces d'Ionoscopiformes et des taxons incertae sedis associés, ce présent travail expose une revue anatomique de ces taxons et des hypothèses quant à leur position phylogénétique au sein des Neopterygii. Sur cette base, plusieurs suggestions taxonomiques sont formulées. Les genres Ionoscopus, Ophiopsis et Heterolepidotus sont redéfinis, la définition des espèces nominales est revue et leur diagnose émendée. Quatre espèces du genre Ionoscopus sont considérées valides (I. pietraroiea, I. desori, I. cyprinoides, and I. elongatus), ainsi que six espèces d'Ophiopsis (O. procera, O. breviceps, O. dorsalis, O. lepersonnei, O. montsechensis, et O. lepturus), et seulement deux d'Heterolepidotus (H. rhombifer et H. serrulatus). Des cas de synonymie, de réversion, de nomen nudumet de nomen dubium ont aussi été relevés. L'hypothèse phylogénétique retenue ne retrouve pas les Ionoscopiformes comme un taxon monophylétique. Néanmoins, les familles Ionoscopidae et Ophiopsidae sont retrouvées au sein des Halecomorphi; on trouve aussi une relation étroite entre les Ionoscopidae et les Amiiformes, tandis que les Ophiopsidae sont plus proches de Furo et Heterolepidotus. Les relations internes au sein des Ionoscopidae et des Ophiopsidae restent non résolues, mais Placidichthys est retrouvé au sein des Ophiopsidae. La non-monophylie des Ionoscopiformes et les incertitudes sur la position des espèces proches des Ophiopsidae montre la nécessité de la révision d'autres taxons halécomorphes, tels que les Caturidae, ainsi que le besoin d'identifier de nouveaux caractères, tels ceux de l'histologie, afin d'améliorer la résolution et la robustesse des hypothèses sur les relations phylogénétiques de ces clades. / Ionoscopiformes is an actinopterigian fossil fish order with wide temporal and geographic distribution, known from the Middle Triassic to the Upper Cretaceous, in Europe, Africa, Asia, and North and South America. Ionoscopiformes is composed of two families, Ophiopsidae and Ionoscopidae, which present various species, some of them with a poorly known anatomy. Although Ionoscopiformres is considered a monophyletic group, the species of Ophiopsidae and Ionoscopidae differ on various characters, including the type of scales and the pattern of ornamentation on the dermic bones. Ionoscopiformes is placed into the clade Halecomorphi, which is represented by three orders (Amiiformes, Parasemionontiformes, and Ionoscopiformes) and several incertae sedis taxa (e.g., Heterolepidotus, Osteorachis, and Neorhombolepis). Halecomorphi is considered to be closer to Ginglymodi than to Teleostei, forming with the former the clade Holostei. Some of these incertae sedis taxa were previously related to Ionoscopiformes, especially to the family Ophiopsidae. Several questions concerning the composition of Ophiopsidae and related taxa have been recently reported in literature, such as, the position of the genera Placidichthys, Heterolepidotus, and Furo. The genus Heterolepidotus was previously suggested as Ophiopsidae and as a taxa with a basal position to this family, but also as belonging to the family Caturidae. Placidichthys was recently proposed as a Macrosemiiformes and Furo muensteri as an Ophiopsidae. Given the need for greater knowledge on the species of Ionoscopiformes and related incertae sedis taxa, the present work presents an anatomical review of these taxa and phylogenetic hypotheses on the position of them within Neopterygii. Considering the anatomical and phylogenetic review, herein are proposed several taxonomical suggestions. The genera Ionoscopus, Ophiopsis, and Heterolepidotus were redefined and its nominal species were diagnosed. Were suggested as valid: four species of the genus Ionoscopus (I. pietraroiea, I. desori, I. cyprinoides, and I. elongatus), six of Ophiopsis (O. procera, O. breviceps, O. dorsalis, O. lepersonnei, O. montsechensis, and O. lepturus), and only two of Heterolepidotus (H. rhombifer and H. serrulatus). Were also suggested some cases of synonymy, reversals, nomen nudum, and nomen dubium. The phylogenetic hypotheses presented here did not recovered Ionoscopiformes as a monophyletic clade. However, the families Ionoscopidae and Ophiopsidae were confirmed as Halecomorphi and it was also suggested a closer relationship between Ionocopidae and Amiiformes, while Ophiopsidae appears to be more closely related to Furo and Heterolepidotus. The internal relationships of both Ionoscopidae and Ophiopsidae were not resolved; however Placidichthys was recovered within the family Ophiopsidae. The non monophyletism of Ionoscopiformes and the absence of resolution concerning the taxa closely related to Ophiopsidae, reinforce the need of reviewing other Halecomorphy taxa, such as Caturidae, and also the necessity of searching for new characters, such as those from histology, in order to improve the data matrix to achieve better supported phylogenetic analyses of these clades. / Ionoscopiformes é um ordem de peixes fósseis actinopterígios de ampla distribuição espaço-temporal, conhecido do Triássico Médio ao Cretáceo Superior, na Europa, África, Ásia, Américas do Norte e do Sul. Ionoscopiformes é composta por duas famílias, Ophiopsidae e Ionoscopidae, as quais apresentam várias espécies, algumas, pouco conhecidas anatomicamente. Embora, atualmente, a ordem Ionoscopiformes seja considerada monofilética, os representantes de Ophiopsidae e Ionoscopidae diferem entre si em diversas características anatômicas, inclusive quanto ao tipo de escama e ao padrão de ornamentação dérmica dos ossos. Ionoscopiformes está posicionada no clado Halecomorphi, o qual é representado por três ordens (Amiiformes, Parasemionontiformes e Ionoscopiformes) e diversos táxons incertae sedis (e.g., Heterolepidotus, Osteorachis e Neorhombolepis), estando mais próximo de Ginglymodi do que de Teleostei, formando com o primeiro o clado Holostei. Alguns desses táxons incertae sedis já foram relacionados à Ionoscopiformes, principalmente à família Ophiopsidae. Vários pontos relativos à composição de Ophiopsidae e táxons relacionados veem sendo recentemente abordados na literatura, como por exemplo, o posicionamento dos gêneros Placidichthys, Heterolepidotus e Furo. O gênero Heterolepidotus já foi sugerido como Ophiopsidae, como táxon basal à esta família, mas também como pertencente à família Caturidae. Placidichthys foi recentemente sugerido como Macrosemiiformes e Furo muensteri como Ophiopsidae. Visto a necessidade de maior conhecimento acerca de espécies de Ionoscopiformes e de táxons incertae sedis a ela relacionados, o presente trabalho apresenta uma revisão anatômica dos mesmos, além da investigação do posicionamento desta ordem e destes táxons incertae sedis no interior de Neopterygii. A partir das revisões anatômicas e filogenéticas realizadas, diversas sugestões taxonômicas foram apresentadas. Os gêneros Ionoscopus, Ophiopsis e Heterolepidotus foram redefinidos e suas espécies nominais foram diagnosticadas. Foram sugeridas como válidas: quatro espécies nominais para Ionoscopus (I. pietraroiea, I. desori, I. cyprinoides e I. elongatus), seis para Ophiopsis (O. procera, O. breviceps, O. dorsalis, O. lepersonnei, O. montsechensis e O. lepturus) e somente duas para Heterolepidotus (H. rhombifer e H. serrulatus). Para estes gêneros ainda foram sugeridas algumas sinonímias, reversões, nomen nudum e nomen dubium. As hipóteses filogenéticas apresentadas, não indicaram o clado Ionoscopiformes como monofilético. Todavia, as famílias Ionoscopidae e Ophiopsidae foram confirmadas como Halecomorphi, sendo sugerido um posicionamento mais próximo entre Amiiformes e a família Ionocopidae, enquanto Ophiopsidae estaria mais intimamente relacionada à Furo e à Heterolepidotus. As relações internas tanto de Ionoscopidae quanto de Ophiopsidae não se mostraram resolvidas, contudo foi recuperado o posicionamento de Placidichthys no interior de Ophiopsidae. Indicação do não monofiletismo de Ionoscopiformes e a não resolução das relações dos grupos próximos à Ophiopsidae, reforçam a necessidade de revisões de outros táxons de Halecomorphi, como por exemplo, a família Caturidae e ainda a necessidade da busca de novos caracteres, como por exemplo, os histológicos, para aprimorar a matriz de caracteres visando alcançar relações filogenéticas mais bem suportadas.

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<p>Att slippa diskriminering är en mänsklig rättighet. För den som utsätts, finns väl dokumente-rade psykiska och fysiska hälsorisker. Därför måste varje form av negativ särbehandling i samhället bekämpas. Ett aktivt arbete för en ökad förståelse människor emellan har sedan länge varit en av förskolans främsta uppgifter. Hur förskolor förhåller sig till de olika diskri-mineringsgrunderna i sitt likabehandlingsarbete är dock ett tidigare outforskat ämne.</p><p>I denna studie görs en text- och innehållsanalys av 14 likabehandlingsplaner från sju försko-lor, för att utröna hur planeringen för respektive diskrimineringsgrund är upplagd. Undersök-ningen syftar även till att studera om denna planering förändrats sedan lagen om förbud mot diskriminering och annan kränkande behandling av barn och elever (SFS 2006:67) ersattes med diskrimineringslagen (SFS 2008:567) den 1 januari 2009. Ytterligare en aspekt av stu-dien är att granska i vilken mån diskriminering och annan kränkande behandling erhåller samma uppmärksamhet i planeringen för likabehandlingsarbetet.</p><p>Resultaten visar en tendens till en något ökande medvetenhet om diskrimineringsgrunderna i likabehandlingsplanerna. Planeringen kring dessa är dock fortfarande mycket bristfällig. Kön är den diskrimineringsgrund som behandlas mest utförligt planerna. Problembeskrivning, målsättningar och åtgärdsförslag ligger på en högre konkretiseringsnivå än planeringen för andra diskrimineringsgrunder. Åtgärderna involverar dessutom oftare både barn, pedagoger, föräldrar och själva verksamheten. En diskussion förs kring huruvida genusdebatten i förskola och skola bidragit till att pedagogers medvetenhet ökat om hur könsdiskriminering och trakas-serier yttrar sig.</p><p>Religion eller annan trosuppfattning får den minst utförliga planeringen i likabehandlingspla-nerna. Pedagogerna för inte fram några egentliga behov, och målsättningar och åtgärdsförslag är vaga. Religiös diskriminering är ett minimaliserat ämne i samhällsdebatten. Förskolan ska vara en icke konfessionell miljö, och pedagogernas vana att hantera ämnet är sannolikt liten.</p><p>Annan kränkande behandling diskuteras ungefär dubbelt så ofta i likabehandlingsplanernas text som de fem diskrimineringsgrunderna tillsammans. Dessutom är behandlingen av ämnet påtagligt mer konkret än diskriminering. Detta förklaras i diskussionen med en större kompe-tens kring mobbning och andra kränkningar än diskriminering hos pedagogerna.</p><p>En påtaglig brist på konkreta exempel av diskriminering från förskolans vardag, i nuvärdes-analys, mål och åtgärdsförslag, antyder att pedagogerna saknar insikt i hur diskriminering och trakasserier yttrar sig i verksamheten. Pedagogerna tycks ha behov av stödmaterial, och lika-behandlingsplanerna ger uttryck för ett upplevt utbildningsbehov kring de enskilda diskrimi-neringsgrunderna.</p>