Our objective is to contribute to the teaching of Classical Darwinian Evolution by means of a study of analogies and metaphors. Throughout the history of knowledge about Evolution and in Science teaching, tree structures have been used an analogs to refer to Evolution, such as by Darwin in the Tree of Life passage contained in On The Origin of Species (1859). We analyze the analogies and metaphors found in the Darwinian text the Tree of Life and propose Comparative Structural Models of Similarities and Differences between the vehicle and target, considering the viability of their use in teaching Sciences. Our foundation is the Theory of Conceptual Metaphor by Lakoff and Johnson (1980) and the Methodology of Teaching with Analogies--MECA-by Nagem et al. (2001). The analogies and metaphors were classified and analyzed and the similarities and differences were highlighted. We found conceptual metaphors in the text. The analogies and metaphors in the Tree of Life are complex and appropriate for didactic use, but require an adequate methodological approach.

Os autores determinaram os hospedeiros reais para seis espécies de ectoparasitos na região de Caratinga, Minas Gerais, sendo quatro espécies de ácaros e duas de pulgas, utilizando-se do índice de infestação e do coeficiente de associação interespecífico hospedeiro/ parasito.

This work discusses the use of Darwin's 'Tree of Life' as a didactic analogy and metaphor in teaching evolution. It investigates whether biology teachers of pupils from 17 to 18 years old know Darwin's text 'Tree of Life'. In addition, it examines whether those teachers systematically employ either the analogies present in that text or other analogies between the tree and evolution, and whether they adopt a specific methodology for teaching with analogies and metaphors (A&M). The academic training of teachers regarding use of A&M is review briefly. A diagnostic study was carried out with biology teachers in a public school in the town of Contagem in the state of Minas Gerais in Brazil. The data were obtained through direct observation, questionnaires and a focus group. The teachers pointed out in the questionnaires that some details of Darwin's analogy are utilized as a resource. However, analysis of the data indicates that the 'Tree of Life' text is not known or utilized in class. At the same time, the teachers state that they use aspects of the tree as a didactic resource to teach evolution and that its use facilitates the learning of content. The teachers have little knowledge of specific methodologies of teaching with analogies and metaphors, revealing that their training is incomplete in this area.The affinities of all of the beings of the same class have sometimes been represented by a great tree. I believe this simile largely speaks the truth. (Darwin 1859, p. 129).

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Susceptibility levels for the adult bed-bug, Cimex lectularius, in Belo Horizonte, Minas Gerais-Brazil, to DDT, were determined during the period 1985 to 1986. The test results showed that a 4% dosage of DDT is not enough to kill 55% of the insects. The data are sufficient to show that there exists bed-bug resistance to DDT in Belo Horizonte.