Extreme high-altitude Asian and Andean pierid butterflies are not each others' closest relatives

Abstract

Some of the world's highest-altitude butterflies belong to the tribe Pierini of the family Pieridae. Two nominal species of Baltia occur in arid-semiarid oreal environments in Central Asia, the Himalaya, and Pamir to over 5500 m. At least 13 species currently placed in four genera (Phulia, Infraphulia, Pierphulia, Piercolias) occur in similar environments at similar altitudes in the high Andes. These genera all share numerous morphospecializations whose functional relation to the oreal environment is not understood. Their evolutionary and biogeographic relationships have been debated for over a century. We performed a phylogenetic analysis based on sequencing portions of the mitochondrial cytochrome oxidase subunit I and subunit II regions (COI and COII), incorporating all the genera but Piercolias and a variety of suspected relatives. The results from analyses of COI and COII were compared to relationships inferred from morphological and ecological characters. We conclude that Baltia is not the sister-group of the Andean genera, which are clearly nested within a Neotropical clade. The "Camelid scenario" deriving all the genera from a common ancestor no longer appears viable. © 2007 Regents of the University of Colorado.