Weevils in the Beetle Tree of Life: Exploring the phylogeny of Curculionoidea using morphology and molecules.

MARVALDI, A. E.; MCKENNA, D. M.; FARRELL, B. D.

San Miguel de Tucumán, Tucumán

Congreso; XXVII Meeting of The Willi Hennig Society and VIII Reunión Argentina de Cladística y Biogeografía; 2008

The Willi Hennig Society

Exploration of meaningful markers of genealogical descent is fundamental for making progress in the phylogenetic systematics of weevils, and this approach is essential towards having a better understanding of their evolution. Results of recent phylogenetic studies based on evidence from DNA sequences are presented along with an updated phylogenetic hypothesis for Curculionoiodea based on morphology. Approximately 130 morphological characters (35 % and 65 % from larvae and adults, respectively) are so far described and coded for weevil species representative of all families and subfamilies. A cladogram resulting from analysis of these data recovers seven major lineages or families and the relationships among them, with the relevant nodes defined by both larval and adult synapomorphies. This study sets the stage for ongoing exploration of subfamily relationships. Results from a recent higher level molecular phylogenetic study  including rDNA sequences from more than 100 species of weevils and several closely related outgroups (in Cucujiformia) are also presented. This study incorporates an annotated alignment based on secondary structural information, which in turn, provides improved rRNA structure models useful for phylogenetic reconstruction in beetles. The resulting cladogram indicates that Chrysomeloidea are the closest relatives of weevils. Interestingly, the curculionoid phylogeny recovered from the aligned 18S and 28S segments, which is independent of morphological data, is in agreement with recent hypotheses based on morphological evidence, particularly with respect to families. The next step is to perform a combined analysis using the morphological and molecular data sets. The value of incorporating structure information in the process of alignment is highlighted. Results from these studies indicate two data sets as informative phylogenetic markers for weevils: larval morphology and nuclear rDNA sequences.