Systematics Association Second Biennial

Pollen research has been carried out on 81 detarioid genera (253 species) to define informative characters for taxonomic studies and cladistic analysis. There is a huge variety of pollen morphological structures, although the presence of intermediate forms prevents some from being informative as characters. Ultrastructure does, however, provide an important source of taxonomic and systematic information. Three examples are given: 1) variation in the structure of the striae, 2) the presence or absence of a foot layer, and 3) the presence or absence of a layer of infratectal granules. These differences can be used to distinguish between taxa with similar surface patterns. ABSTRACT: In a phylogenetic analysis, it is difficult to use landmark coordinates, by means of classical methods of discretization, like gap-coding. For the purpose of talking into account these data for identification or phylogenetic reconstruction , it may be interesting to express them in symbolic terms, so as to make a biological explanation. In order to build a new representation of landmarks, we propose to define structured attributes by exploring a symbolic research space. This new symbolic representation describes the relative locations of the landmarks and not their absolute locations in a coordinate system. The principle lies in the extraction of qualitative features, using classical Pattern Recognition operators (distance ordinnation and other transformation operators which are invariant with affine transformations ...). We applied this generic approach on wings of Phlebotomine sandflies (Diptera Nematocera Phlebotominae), and discussed the interpretation of the phylogenetics tree in terms describing landmark moves.