This Science in Developing Countries award will support travel to Chile and Paraguay, per diem, and materials associated with the dissertation research of R. Eduardo Palma, a Chilean doctoral student working under Donald Duszynski at the University of New Mexico. The project aims to evaluate phylogenetic relationships within the marsupial genus Thylamys, using molecular analytical methods of allozyme variation and mtDNA. The molecular data are expected to elucidate evolutionary relationships within the genus, since most studies have been limited to morphologic and chromosomic analyses. The research also will likely provide results needed to develop conservation strategies in the Neotropics, a region in which research in systematic mammalogy is critical. Both the U.S. and Chilean sides will benefit from new advances in South American biogeography. The Chilean side will benefit from dissertation research support, which will enhance collaborative ties between the U.S. and South America, the region's scientific infrastructure, and its capacity for basic biological research.