Mitochondrial phylogeny of extant Hawaiian tree snails (Achatinellinae)

Hawaiian tree snails in the endemic subfamily Achatinellinae display a stag gering variety of shell colors and banding patterns. Despite numerous attem pts to classify this morphological variation, a conclusive phylogeny has no t been proposed, To improve conservation efforts, we sought to better under stand the species identities and phylogenetic relationships among the extan t species of Achatinella and Partulina using partial mitochondrial 16S ribo somal DNA sequences. The reconstructed phylogeny showed a high degree of su pport for more recent branches, but gave little support to deeper nodes. Th e most confident branches challenge previous systematic arrangements of the se snails, grouping species that previously had been placed into different subgenera, High levels of sequence divergence within some species may refle ct the long-term isolation of subpopulations. Rapid rates of sequence diver gence may have saturated base substitutions and contributed to the lack of resolution of higher-order relationships. We did not find support for the m onophyly of the Achatinella species, nor thus for a single colonization of O'ahu from Maul Nui, (C) 2000 Academic Press.