EVOLUTION AND SYSTEMATICS OF ANOPHELES - INSIGHTS FROM A MOLECULAR PHYLOGENY OF AUSTRALASIAN MOSQUITOS

Relationships among the genus Anopheles and its many sibling species-g roups are obscure despite the importance of anophelines as the vectors of human malaria. For the first time, the interrelationships and the origin of Australasian members of the subgenus Cellia are investigated by a cladistic analysis of sequence variation within the mitochondria l cytochrome oxidase subunit II gene. Estimated divergence times betwe en many Australasian and Oriental taxa predate the mid Miocene collisi on of Australasia and Southeast Asia. Phylogenetic analysis suggests t hat two-way exchanges with Oriental mosquitoes rather than only immigr ation may have been a characteristic of anopheline paleobiogeography i n Australasia. The Australasian fauna is mostly included in a large cl ade. The medically important Punctulatus Group is monophyletic and app ears derived from Oriental stock. Populations within this group hom as far apart as Australia and Vanuatu were in contact in the recent past (i.e., 0.35-2.44 mya), supporting dispersal rather than vicariance ex planations. Some support for the monophyly of the Myzomyia, Neomyzomyi a, and Pyretophorus Series was found. However, the subgenera Anopheles and Cellia and the Neocellia Series are paraphyletic, but branch supp ort at these taxonomic levels was poor. The COII gene shows promise fo r questions concerning alpha taxonomy but appears to be of Limited use for resolving deeper relationships within the Anopheles. (C) 1998 Aca demic Press.