Oaks (Quercus) are a very important group of plants that consists of approximately 500 species. Despite this large diversity, the phylogenetic relationships among the major oak groups remain uncertain. One of the questions to be answered concerns the phylogenetic relationships among the oak sections in subgenus Quercus. Although a few molecular and morphological studies have been carried out, no consensus has been reached on the evolutionary relationships of these groups. To address this problem, I am applying the Amplified Fragment Length Polymorphism (AFLP) method to obtain DNA fingerprints of a sample of species. The results will be analyzed using phylogenetic methods based on maximum parsimony.  Further studies in this area will include the design of polymerase chain reaction (PCR) primers to assess the phylogenetic utility of several nuclear genes. Additional sources of data will be obtained from morphological vegetative and reproductive characters.  A clear understanding of the phylogenetic relationships in oaks will provide relevant information of character evolution, and at the same time it will facilitate the interpretation of biogeographical studies.  Furthermore, the results of this research could provide a framework for studies in other areas of biology such as ecology, entomology, and phytochemistry.