Birds, molecules, and evolutionary patterns among Africa's islands in the sky

Combing results from phylogenetic and population level studies suggests that climatic cycling has had a profound influence on montane bird speciation in Africa. The results from this thesis suggest that there is deep genetic divergence between many clades (8-12%) of montane passerine birds in Africa, with some shallow divergence towards the tips (4-6%). For widespread species reciprocal monophyly has not been reached in some instances, but generally there is some support for the refuge idea that isolation (fragmentation) of montane forests has facilitated speciation. However, most speciation events happened well before the Pleistocene and therefore the Pleistocene Refugia Hypothesis is not appropriate as a model with which to explain patterns of montane bird diversification in Africa. Rather, both dispersal and vicariance have played important roles in shaping montane bird communities. Thus, a refugia type model does work, but only within the context of pulsed or cyclic expansion and contraction of montane forests, supported in thus study by the consistent recovery of spatially structured areas of endemism, despite varying temporal dynamics.

Grantor dc:publisher.institution

Department of Biological Sciences

Year dc:date.issued

2003

Author dc:creator

• Bowie, Rauri Charles Kerr

Advisor dc:contributor.advisor

• Crowe, Timothy M

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/6239

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/6239