| frequent mitochondrial gene introgression among high elevation tibetan megophryid frogs revealed by conflicting gene genealogies. | historical mitochondrial introgression causes differences between a species' mitochondrial gene genealogy and its nuclear gene genealogy, making tree-based species delineation ambiguous. using sequence data from one mitochondrial gene (cytochrome b) and three nuclear genes (introns), we examined the evolutionary history of four high elevation tibetan megophryid frog species, scutiger boulengeri, scutiger glandulatus, scutiger mammatus and scutiger tuberculatus. the three nuclear genes shared a s ... | 2009 | 19500253 |