Contributions of molecular studies to the phylogeny and systematics of African birds

Abstract

Helbig, A.J. 2000. Contributions of molecular studies to the phylogeny and systematics of African birds. Ostrich 71 (1 & 2): 40. Recent advances in DNA technology allow us to study the phylogenetic relationships of birds from a completely new perspective and to base avian systematics on a more solid foundation. In the present paper, relationships of selected groups of birds (birds of prey, Sylviid warblers) will be analysed based on extensive nucleotide sequences of the mitochondrial cytochrome b gene. DNA was isolated from blood, amplified via polymerase chain reaction (PCR) and sequenced directly. Main findings include the following: (1) Old World vultures are polyphyletic with Neophron and Gypaetus being more primitive than the other species. (2) The primitive position of Pandion is confirmed. (3) Aquila rapax and, A. nipalensis are differentiated at species level. (4) Genetic differentiation is substantial in the kestrel complex (Falco tinnunculus, rupicoloides, naumanni), but only slight in the peregrine group (E p. peregrinus, brookei, minor, pelegrinoides). Sylviidae: (5) The genus Sylvia is paraphyletic relative to Parisoma, the latter is in itself not a monophylum and should be merged with Sylvia. (6) Acrocephalus griseldis is genetically a highly distinctive species; A. baeticatus is very similar to A. scirpaceus. Large and small-bodied species groups of reed warblers are each monophyletic. (7) Eastern and western forms of Hippolaispallida are strongly differentiated, probably demanding species status for each. (8) African “Seicercus” are members of the Phylloscopus radiation and probably derive from Asian rather than West Palearctic ancestors. (9) Cisticola and Prinia appear to be sister genera, Camaroptera is closer to these than to Palearctic genera. DNA studies are revolutionising avian systematics by providing easily comparable and highly reproducible information at all taxonomic levels: from within-species differentiation to higher level phylogeny. Mitochondrial DNA is also a suitable marker to study gene flow in hybrid zones and thus establish or refute biological species status of taxa in secondary contact.