Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Several projects aim at gathering together data concerning life around the world, in order to systematize them and produce a big, unified tree of life. Rather than a static single picture of the living world, this kind of tree: (i) is a result of a dynamic interaction among several models produced by biologists for describing life and expressing how life changes and evolves as time goes by, (ii) is not unique, since there are different competing perspectives describing life (morphology, behavior, ecology, genetics etc.) and different methods of reconstructing evolutionary trees. Our work addresses these problems by proposing a 'superimposed metamodel' mechanism, which acts as a modeling skeleton, supporting a unified view and articulation of models/ontologies involved in tasks that start at collecting data from the field towards producing descriptions and evolutionary trees. It enables to externalize specific knowledge as ontologies and to trace the entire rationale from one extreme of the process to the other one. This paper shows practical experiments in which we explore such characteristics as: guiding the expression of evolutionary hypotheses from observational data, going backwards on the provenance path, or evaluating changes of the tree in front of new evidences collected in the field.1 6572FAPESP; São Paulo Research FoundationFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Brazeau, M.D., Problematic character coding methods in morphology and their effects (2011) Biological Journal of the Linnean Society, 104 (3), p. 489498Dallwitz, M.J., A general system for coding taxonomic descriptions (1980) Taxon, p. 4146Hagedorn, G., (2007) Structuring Descriptive Data of Organisms Requirement Analysis and Information ModelsUng, V., Dubus, G., Zaragüeta-Bagils, R., Vignes-Lebbe, R., Xper2: Introducing e-taxonomy (2010) Bioinformatics, 26 (5), p. 703704Corvez, A., (2012) L'Origine de la Megaphylle Chez les Monilophytes, , muséum national d'Histoire naturelle ed., ParisHawkins, J.A., Hughes, C.E., Scotland, R.W., Primary homology assessment, characters and character states (1997) Cladistics, 13, pp. 275-283Lebbe, J., (1991) Représentation des Concepts en Biologie et Médecine, , introduction à l'analyse des connaissances et à l'identification assistée par ordinateur Ph. D. dissertation, Thèse de doctorat, spécialité Sciences de la vie. Université Pierre et Marie Curie-Paris 6, ParisPlatnick, N.I., Philosophy and the transformation of cladistics (1979) Systematic Zoology, 28 (4), pp. 537-546Nelson, G.J., Platnick, N.I., (1981) Systematics and Biogeography, Cladistics and Vicariance, , columbia university press ed. New York: Guildford, SurreyZaragüeta-Bagils, R., Bourdon, E., Three-item analysis: Hierarchical representation and treatment of missing and inapplicable data (2007) C. R. PalevolZaragüeta Bagils, R., Ung, V., Grand, A., Vignes-Lebbe, R., Cao, N., Ducasse, J., LisBeth: New cladistics for phylogenetics and biogeography (2012) Comptes Rendus Palevol, , AugSwofford, D.L., PAUP: Phylogenetic analysis using parsimony (1993) ChampaignHuelsenbeck, J.P., Ronquist, F., MRBAYES: Bayesian inference of phylogenetic trees (2001) Bioinformatics, 17 (8), pp. 754-755Goloboff, P.A., Farris, J.S., Nixon, K.C., TNT, a free program for phylogenetic analysis (2008) Cladistics, 24 (5), pp. 774-786. , OctProsdocimi, F., Chisham, B., Pontelli, E., Thompson, J.D., Stoltzfus, A., Initial implementation of a comparative data analysis ontology (2009) Evolutionary Bioinformatics Online, 5, p. 47Gkoutos, G.V., Green, E.C.J., Mallon, A.-M., Blake, A., Greenaway, S., Hancock, J.M., Davidson, D., Ontologies for the description of mouse phenotypes (2004) Comparative and Functional Genomics, 5 (6-7), pp. 545-551Washington, N.L., Haendel, M.A., Mungall, C.J., Ashburner, M., Westerfield, M., Lewis, S.E., Linking human diseases to animal models using ontology-based phenotype annotation (2009) PLoS Biology, 7 (11), p. e1000247. , NovBalhoff, J.P., Dahdul, W.M., Kothari, C.R., Lapp, H., Lundberg, J.G., Mabee, P., Midford, P.E., Vision, T.J., Phenex: Ontological annotation of phenotypic diversity (2010) PLoS ONE, 5 (5), p. e10500. , MayMungall, C.J., Gkoutos, G.V., Smith, C.L., Haendel, M.A., Lewis, S.E., Ashburner, M., Method integrating phenotype on tologies across multiple species (2010) Genome BiologyMabee, P.M., Arratia, G., Coburn, M., Haendel, M., Hilton, E.J., Lundberg, J.G., Mayden, R.L., Westerfield, M., Connecting evolutionary morphology to genomics using ontologies: A case study from cypriniformes including zebrafish (2007) Journal of Experimental Zoology Part B: Molecular and Developmental Evolution, 308 (5), pp. 655-668. , SepGasevic, D., Djuric, D., Devedzic, V., (2009) Model Driven Engineering and Ontology Development, , Springer Publishing Company, Incorporated