Molecular phylogenies and rooting the tree of life

• Grant number: 05/01244-4
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: October 01, 2005
• End date: September 30, 2008
• Field of knowledge: Biological Sciences - Zoology
• Principal Investigator: Dalton de Souza Amorim
• Grantee: Emanuelle Corbi Corrêa
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The living organisms have been divided into three domains: Bacteria, Archaea and Eukarya. The phylogenetic relationship among them have been discussed by a number of authors and most of them agree with ((Archaea + Eukarya) Bacteria). Some of these authors have used paralogue proteins to root the generated trees. The congruent results among the proposed hypothesis on this matter would indicate a high degree of robustness if it wasn´t for the lack of rigorous methodological protocols and treatment of these data. These papers suffer from problems of poor samplings and many times incomplete characters. This project aims to infer the phylogenetic relationship among the three domains under a philosophical and methodological consistent protocol, include new characters - emphasizing xylanases - together with a more complete and adequate sampling of taxa, to test not only the monopholy of the three domains, but also the relationship among them and among large groups within them. Based on the obtained results, we intend to alter the division of the living organisms. It is predicted an extrusion of knowledge on this area for high school, in which the division of life into five kingdoms - Bacteria being one of them - is still vastly spread. (AU)