The concept of gene in the twenty-first century: What are the open avenues?

ABSTRACTThe view of the gene as a structural and functional unit has been increasingly challenged by findings mostly resulting from eukaryote research. We can classify these challenges in three kinds: (i) one-to-many correspondences between DNA segments and RNAs/polypeptides (as, for instance, in alternative splicing); (ii) many-to-one correspondences between DNA segments and RNAs/polypeptides (as in genomic rearrangements, say, those involved in the generation of diversity in lymphocyte antigen receptors); (iii) lack of correspondence between DNA segments and RNAs/polypeptides (as, for example, in mRNA editing). However, even if a single definition of a gene may not be a realistic (or even helpful) goal, being able to have different definitions connected to each other –operationally and theoretically– is of central importance.KEYWORDSGENE CONCEPT, DEFINITION, DNARESUMENLa idea según la cual el gen es una unidad estructural y funcional se ha visto cada vez más cuestionada a causa de descubrimientos realizados en investigaciones con eucariotas. Podemos clasificar los desafíos planteados a dicha idea en tres tipos: (i) correspondencias uno-a-muchos entre segmentos de ADN y ARN/polipéptidos (como, por ejemplo, en el empalme alternativo); (ii) correspondencias muchos-a-uno entre segmentos de ADN y ARN/polipéptidos (como en las reorganizaciones genómicas, tales como las implicadas en la generación de diversidad en los receptores de antígenos de los linfocitos); (iii) falta de correspondencia entre segmentos del ADN y ARN/polipéptidos (como, por ejemplo, en la edición del ARNm). Sin embargo, incluso si, por estas razones, no sería realista (o incluso útil) buscar una definición única de gen, es de capital importancia que seamos capaces de formular diferentes definiciones conectadas entre sí teórica y operacionalmente.PALABRAS CLAVECONCEPTO DE GEN, DEFINICIÓN, AD

beyond the divide between indigenous and academic knowledge: Causal and mechanistic explanations in a Brazilian fishing community

Transdisciplinary research challenges the divide between Indigenous and academic knowledge by bringing together epistemic resources of heterogeneous stakeholders. The aim of this article is to explore causal explanations in a traditional fishing community in Brazil that provide resources for transdisciplinary collaboration, without neglecting differences between Indigenous and academic experts. Semi-structured interviews were carried out in a fishing village in the North shore of Bahia and our findings show that community members often rely on causal explanations for local ecological phenomena with different degrees of complexity. While these results demonstrate the ecological expertise of local community members, we also argue that recognition of local expertise needs to reflect on differences between epistemic communities by developing a culturally sensitive model of transdisciplinary knowledge negotiation

A abordagem do tema Ambiente e a formação do cidadão socioambientalmente responsável

Este artigo de posicionamento apresenta uma reflexão sobre a abordagem do tema ambiente no contexto escolar do ensino de ciências e sua contribuição para a formação de um cidadão socioambientalmente responsável. Inicialmente, discutimos como a disseminação do saber ambiental nas escolas tem sido caracterizada por um predomínio de práticas vinculadas a um modelo de educação focado no indivíduo e pouco afeito ao tratamento de dimensões sociopolíticas. Essas práticas dão ênfase a ações pontuais, desarticuladas e descontextualizadas. A compreensão da questão ambiental é usualmente restringida, além disso, à dimensão ecológica. Desse modo, em geral não se contribui, na educação ambiental comumente propiciada no contexto escolar, para a construção de uma compreensão sociopolítica e integrada dos problemas ambientais, que não podem ser pensados separadamente de uma reflexão sobre a constituição do Estado moderno, do sistema capitalista de produção e consumo, e das relações entre ciência, tecnologia e sociedade (CTS). O processo educativo no ensino de ciências tem um papel preponderante na construção de uma compreensão da relação entre seres humanos, ambiente, cultura e tecnologia, podendo promover debates acerca da precaução no uso dos recursos naturais na sociedade contemporânea, entre outros aspectos relativos à crise socioambiental. Coloca-se a necessidade da formação de cidadãos politicamente atuantes, conscientes dos problemas ambientais que envolvem o indivíduo e a coletividade no contexto socioambiental. Torna-se relevante compreender quais são os valores, as atitudes e as crenças centrais que constituem tal cidadão e como ele deverá operar em consonância com uma orientação sociopolítica para expressar seu ponto de vista, considerando os aspectos individuais e coletivos no contexto histórico, social e cultural. Sendo assim, defendemos uma proposta de educação ambiental no ensino de ciências pautada na formação de um sujeito capaz de ler seu contexto sociopolítico, interpretar as relações, os conflitos e os problemas aí presentes, e tomar decisões voltadas para a ação socialmente responsável

Conceptual Profiles: Theoretical-methodological Grounds and Empirical Studies

AbstractIn this paper, we briefly address the theoretical and methodological grounds of the conceptual profile theory and discuss two empirical studies aiming at constructing conceptual profile models and using them to analyze classroom discourse in different sciences, chemistry (entropy and spontaneity) and biology (adaptation). The basic idea is to illustrate how these models were built, considering differences and similarities between the methods used for this purpose. Conceptual profiles are models of different modes of seeing and conceptualizing the world used by individuals to signify their experience. They are built for a given concept and are constituted by several zones, each representing a particular mode of thinking about that concept, related to a particular way of speaking. Each zone is individuated by ontological, epistemological, and axiological commitments underlying discourse. We will show how different concepts, situated in sciences with different levels of conceptual polysemy, demand different methodologies to deal with the variation found in meaning making in the sociocultural, ontogenetic, and microgenetic domains

Dimensões dos conteúdos mobilizados por estudantes de biologia na argumentação sobre antibióticos e saúde

Na literatura, têm sido apontadas muitas vantagens do ensino baseado em questões sociocientíficas (QSC). Contudo, reconhecer e avaliar conteúdos mobilizados pelos estudantes é um desafio no contexto da educação Ciência-Tecnologia-Sociedade-Ambiente (CTSA), pois ainda há poucos estudos acerca dos modos de avaliação de aprendizagem condizentes com os objetivos da perspectiva de educação CTSA. Neste trabalho empírico e qualitativo, temos como objetivo analisar a presença de dimensões conceituais, procedimentais e atitudinais dos conteúdos mobilizados por estudantes de um curso de Licenciatura em Biologia, a partir de uma atividade envolvendo a análise de um caso que expôs uma QSC acerca da resistência bacteriana a antibióticos. Os dados foram coletados a partir dos argumentos produzidos por equipes de estudantes, utilizando o modelo de argumentação de Toulmin. Os estudantes conseguiram mobilizar alguns dos conteúdos previstos no planejamento do ensino usando a QSC, sobretudo conhecimentos científicos. Aspectos sociais, éticos e políticos não foram suficientemente mobilizados, o que aponta para a necessidade de maior ênfase sobre eles na educação em ciências. Nesse sentido, sugerimos orientações para a pesquisa e a prática da educação em ciências a partir do conceito de letramento científico crítico, que considera a relevância da compreensão das relações entre ciência, tecnologia, sociedade e ambiente envolvidas na QSC, conduzindo ao alcance de ações sociopolíticas.In the literature, many advantages of a socioscientific issues (SSI)-based teaching have been highlighted. However, the recognition and evaluation of the contents mobilized by the students have been a challenge in the context of STSE education, with few studies focusing on the evaluation of learning consistent to principles of STSE education. In this empirical article whose approach is qualitative, we will discuss conceptual, procedural and attitudinal dimensions of the contents mobilized by students of a preservice biology teacher education course, based on an activity involving SSI on bacterial resistance to antibiotics. We collected data from the arguments produced by students’ groups, using Toulmin’s Argumentation Pattern. The students were able to mobilize some of the expected contents, based on the planning of the teaching sequence using SSI, mainly scientific knowledge. Social, ethical, and political aspects, however, were not sufficiently mobilized, which points to the need of a deeper emphasis on them in Science Education. Therefore, we suggest some perspectives to guide research and practice on Science Education based on the concept of critical scientific literacy, which considers the relevance of understanding the relationships between science, technology, society and environment encompassed by the SSI, leading to sociopolitical actions

Cultural consensus and intracultural diversity in ethnotaxonomy: lessons from a fishing community in Northeast Brazil

Background: Traditional fishing communities are strongholds of ethnobiological knowledge but establishing to what degree they harbor cultural consensus about different aspects of this knowledge has been a challenge in many ethnobiological studies. Methods: We conducted an ethnobiological study in an artisanal fishing community in northeast Brazil, where we interviewed 91 community members (49 men and 42 women) with different type of activities (fishers and non-fishers), in order to obtain free lists and salience indices of the fish they know. To establish whether there is cultural consensus in their traditional knowledge on fish, we engaged a smaller subset of 45 participants in triad tasks where they chose the most different fish out of 30 triads. We used the similarity matrices generated from the task results to detect if there is cultural consensus in the way fish were classified by them. Results: The findings show how large is the community’s knowledge of fish, with 197 ethnospecies registered, of which 33 species were detected as salient or important to the community. In general, men cited more fish than women. We also found that there was no cultural consensus in the ways fish were classified. Conclusions: Both free-listing and triad task methods revealed little cultural consensus in the way knowledge is structured and how fish were classified by community members. Our results suggest that it is prudent not to make assumptions that a given local community has a single cultural consensus model in classifying the organisms in their environment

Aprendizagem Baseada em Problemas (ABP) na Educação Científica como Estratégia para Formação do Cidadão Socioambientalmente Responsável

A partir do pressuposto de que o ensino tradicional, na educação científica, é insuficiente para uma aprendizagem integrada de conteúdos relevantes em direção a uma adequada ação social cidadã, defendemos que estratégias pedagógicas com base na Aprendizagem Baseada em Problemas (ABP) podem contribuir para a formação de cidadãos responsáveis no âmbito social e ambiental, ao fornecer um ambiente amplo de aprendizagem e ao promover o desenvolvimento de conteúdos conceituais, procedimentais e atitudinais. Neste artigo, discutimos características de duas estratégias da ABP (resolução de caso e sessões tutoriais) como meio de aproximar a aprendizagem de diferentes conteúdos dos desafios da realidade cotidiana da sociedade contemporânea e favorecer tomadas de decisão que sejam socialmente responsáveis. Apontamos, também, algumas limitações e desafios para o uso dessas estratégias na educação científica

Modeling a Virtual World for the Educational Game Calangos

Ecology plays a central role in biology and deserves special attention in scientific education. Nonetheless, the teaching and learning of ecology face a number of difficulties. In order to tackle these difficulties, electronic games have recently been used to mediate ecology learning. This paper presents an electronic game that fulfills these gaps in order to make the students’ work with ecological concepts more concrete, active, and systematic. The paper presents the computational model of the ecological system included in the game, based on a real ecological case, a sand dune ecosystem located in the semiarid Caatinga biome, namely, the sand dunes of the middle São Francisco River, in the state of Bahia, Brazil. It includes various ecological relationships between endemic lizards and the physical environment, preys, predators, cospecifics, and plants. The engine of the game simulates the physical conditions of the ecosystem (dune topography and climate conditions with their circadian and circannual cycles), its biota (plant species and animal species), and ecological relationships (predator-prey encounters, cospecific relationships). We also present results from one classroom study of a teaching sequence structured around Calangos, which showed positive outcomes regarding high school students’ understanding of thermal regulation in ectothermic animals

Detecting Network Communities: An Application to Phylogenetic Analysis

This paper proposes a new method to identify communities in generally weighted complex networks and apply it to phylogenetic analysis. In this case, weights correspond to the similarity indexes among protein sequences, which can be used for network construction so that the network structure can be analyzed to recover phylogenetically useful information from its properties. The analyses discussed here are mainly based on the modular character of protein similarity networks, explored through the Newman-Girvan algorithm, with the help of the neighborhood matrix . The most relevant networks are found when the network topology changes abruptly revealing distinct modules related to the sets of organisms to which the proteins belong. Sound biological information can be retrieved by the computational routines used in the network approach, without using biological assumptions other than those incorporated by BLAST. Usually, all the main bacterial phyla and, in some cases, also some bacterial classes corresponded totally (100%) or to a great extent (>70%) to the modules. We checked for internal consistency in the obtained results, and we scored close to 84% of matches for community pertinence when comparisons between the results were performed. To illustrate how to use the network-based method, we employed data for enzymes involved in the chitin metabolic pathway that are present in more than 100 organisms from an original data set containing 1,695 organisms, downloaded from GenBank on May 19, 2007. A preliminary comparison between the outcomes of the network-based method and the results of methods based on Bayesian, distance, likelihood, and parsimony criteria suggests that the former is as reliable as these commonly used methods. We conclude that the network-based method can be used as a powerful tool for retrieving modularity information from weighted networks, which is useful for phylogenetic analysis