The aim of this thesis is to analyse offered meaning, that is, what and how subject content is communicated to the recipients. In this case the subject content is biological diversity and the communicative artefacts are biology books for the latter grades in the Swedish compulsory school. The four papers cover aspects of biodiversity in biology books (I), connections between biology books and the world outside school (II), the definition of the species concept and the use of the concept species in textbooks and in pupils' assertions (III), and finally how instances of modes are connected in a multimodal text and how the design of texts may affect the possibilities of meaning making (IV). The biology books used for data collection are multimodal texts with different types of written text and a rich amount of illustrations. The collected data was primarily used for content analysis but also to explore the design of the books. In paper III and IV data was also obtained by two questionnaires to students. Data is analysed and the results are discussed on the basis of a social semiotic theory of communication and meaning making. The books contain many facts about biological diversity, but the concept is not defined explicitly in several of them. In relation to human beings and human activities are beneficial aspects of biological diversity given precedence over ethical, aesthetic and economic aspects. The results also show that the books contain inaccuracies and questionable formulations regarding biodiversity, as well as simplifications and colloquial expressions rather than scientifically accurate terminology. Direct address, anthropomorphism, analogies and connections to life outside school are also found in the books. To recognize themselves in many of the connections to everyday life, pupils need to have visited many habitats in different seasons. The use of concepts is an area where there is a great potential for change. The species concept can be seen as an example of how a concept is introduced early and that understanding is taken for granted in the remaining text. Responses from the questionnaires suggest that more time needs to be given to basic biological concepts and that a big amount of instances of modes may impede meaning making. Textbooks are compromise products created to suit a diverse audience. There is a risk that the offered meaning of the books is not consistent with the perceived meaning of the students. The results of the thesis may contribute to reduce the gap between offered and perceived meaning. If awareness is raised about the problems pupils may face when using textbooks, the teachers' and the authors' ability to support meaning making may increase. / <p>Akademisk avhandling för filosofie doktorsexamen i Naturvetenskap, inriktning utbildningsvetenskap, som med tillstånd från Naturvetenskapliga fakulteten kommer att offentligt försvaras fredag den 7 november, 2014 kl. 10.00 i Föreläsningssalen, Institutionen för biologi och miljövetenskap, Medicinaregatan 18, Göteborg.</p><p>I. Ferlin, M. (2011). Biologisk mångfald i svenska läroböcker för skolår 6–9. NorDiNa, 7(1), 71–84</p><p>II. Ferlin, M. (2013). Vardagsanknytning i biologiböcker. Paideia 5, 52–61</p><p>III. Ferlin, M. &amp; Sundberg, P. (Accepterat manuskript). Grundskoleelevers uppfattningar om begreppet art relaterade till formuleringar i läroböcker i biologi. Publiceras i NorDiNa våren 2015.</p><p>IV. Ferlin, M. (Manuskript). Connections between instances of modes in multimodal texts.</p>

The present thesis surveys topic of taxonomic diversity and phylogeny of bears (Mammalia, Ursidae) and aspects of its contextual setting under effects of changing conceptual and methodological viewpoints. This problem is studied from several perspectives. The historical perspective is represented by a critical overview of the history of specific and infraspecific classification of bears with special respect to mutual influences of this classification and theoretical concepts of species accepted in particular periods. The perspective of material approach is exemplified by a material-based study of taxonomical and phyletic status of selected Pliocene to Middle Pleistocene ursine taxa. Along with deconstruction of some traditional hypotheses this produced a model explaining species diversification in ursine bears and its discussion in terms of factual relevance of included background concepts. In the pre-evolutionary period the bear species were usually understood broadly, as incipient immanent entities, yet exhibiting obvious certain infraspecific variability. This was established using definitions of varieties (mostly not identifiable with present subspecies or infraspecific taxa) considered as unstable modes of particular species. Although, in the post-Darwinian period, the concept and taxonomic...

Les chênes sessiles et pédonculés sont deux espèces sympatriques interfertiles occupant des places distinctes dans la succession écologique. Elles constituent pour cela un bon modèle pour l’étude de la spéciation écologique. Malgré leur écologie contrastée, les deux espèces de chênes coexistent naturellement dans de nombreuses forêts, rendant possible l’étude de leur système de reproduction intra- et interspécifique. Des travaux précédents ont suggéré que l’hybridation entre ces deux espèces serait fréquence-dépendante. Elle dépendrait de la proportion de pollen allospécifique (c'est-à-dire de pollen de l’autre espèce) que reçoit l’arbre mère étudié. Ce phénomène d’hybridation fréquence-dépendante est appelé effet Hubbs, du nom d’un ichtyologue qui découvrit ce mécanisme en 1955. Mon travail a consisté à étudier, dans une parcelle mixte de chênes, les barrières à l’hybridation qui permettent la coexistence de ces deux espèces. Pour cela, j’ai effectué une étude de paternité de grande ampleur (près de 3500 individus typés sur 12 marqueurs microsatellites). Tout d’abord, je me suis intéressée à la délimitation des deux espèces en appliquant pour la première fois in situ le critère d’interfertilité. Je me suis ensuite concentrée sur les facteurs qui influencent l’hybridation au travers d’une modélisation des croisements à l’échelle de l’individu. Les résultats montrent que le maintien de ces deux espèces est régi par deux composantes environnementales importantes : la fréquence de chaque espèce et leur distribution, qui influencent la quantité de pollen reçue. Grâce à cette étude empirique et à l’approche de modélisation de ces croisements, nous avons désormais une bien meilleure vision de l’effet de l’environnement sur l’hybridation. J’ai par la suite comparé les caractéristiques du système de reproduction de chaque espèce (dispersion du pollen et fécondité mâle) en cherchant si un lien existait avec leur stratégie écologique. Les résultats suggèrent que les différences de dynamique écologique pourraient être à l’origine de la spéciation du fait de l’existence de compromis différents en termes d’allocation de ressources mais qu’à plus court terme la stabilité de l’environnement est essentielle au maintien des espèces. / Quercus petraea and Q. robur are two interfertile sympatric species. They occupy distinct stages during forest succession and constitute therefore good models for ecological speciation studies. Despite their differences, they often grow together in mixed stands, allowing the study of their intra- and interspecific reproductive system. Hybridization between these two oak species has been suggested to be frequency-dependent. The effect of the relative species abundance on hybridization is known as the “Hubbs’ effect”, from the name of an ichthyologist who described this mechanism in 1955. My work was to study the processes that limit hybridization between these two species, thereby allowing their coexistence. I conducted an extensive paternity analysis (almost 3500 individuals genotyped at 12 microsatellite markers). First, I tried to delimitate the two oak species by applying for the first time in situ the interfertility criterion. Then, I focused on interspecific crosses by studying those factors influencing hybridization. Results showed that the maintenance of these two species depends on the frequency of each species and their distribution, as both factors influence the quantity of pollen received by female flowers. Thanks to this empirical study and to this modeling approach, we have now a much better view of environmental effects on hybridization. I then compared the characteristics of the reproductive system of each species (pollen dispersal and male fertility) in relation with their ecological strategies. The results suggest that differences in species ecological dynamics are at the origin of the speciation process but that at a finer scale the stability of the environment is crucial for species’ maintenance.

Since the human inclination to estimate and trace natural diversity, usable species definitions as well as taxonomical systems are required. As a consequence, the first proposed classification schemes assigned the filamentous and parenchymatous taxa to the green algal order Chaetophorales sensu Wille. The introduction of ultrastructural and molecular methods provided novel insight into algal evolution and generated taxonomic revisions based on phylogenetic inference. However, until now, the number of molecular phylogenetic studies focusing on the Chaetophorales s.s. is surprisingly low. To enhance knowledge about phylogenetic relationships among taxa within the order, the nuclear?encoded SSU rDNA sequences from 30 strains covering all three chaetophoralean families have been investigated. All revealed monophyletic groupings were further screened for molecular non-homoplasious synapomorphies within the Viridiplantae. To address the question of the correspondence between morphological characters traditionally used for taxonomical delimitation of the Chaetophorales and the tree topology favored by molecular data, the list of morphological/ ultrastructural/ecological characters was elaborated and further analyzed. In addition, to obtain a close-up view into the evolution of Compensatory Base Changes (CBCs) of the second internal transcribed spacer (ITS2) which is currently often used to delimit putative biological species, 86 newly obtained/published sequences of ITS2 for five families of the order Ulvales were analyzed. Furthermore, a detailed comparative study of all ITS2 substitutions has been done. Subsequently all revealed CBCs and hemi- CBCs have been mapped upon the ITS2 phylogenetic tree topology. Finally, CBCs/hCBCs taxonomic inference in the Ulvales has been discussed.

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