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Establishing a perimeter position: speciation around the Indian Ocean Basin
1Department of Biology, University of Memphis, Memphis, TN 38152, USA. gvoelker@memphis.edu
Journal of Evolutionary Biology
|August 12, 2008
Summary
Continental vicariance, not ocean dispersal, likely explains avian genus distribution around the Indian Ocean Basin. This study suggests habitat changes, not island hopping, drove ancient bird movements between Africa and Asia.
Area of Science:
- Evolutionary Biology
- Biogeography
- Ornithology
Background:
- Understanding historical biological interactions on Indian Ocean Basin (IOB) peripheries is limited.
- Previous studies debated Gondwanan vicariance versus trans-IOB dispersal for lineage distributions.
Purpose of the Study:
- To investigate the roles of continental vicariance and trans-IOB dispersal in the distribution of an avian genus across the IOB periphery.
Main Methods:
- Molecular phylogeny construction
- Molecular clock dating
- Ancestral area analyses
- Paleoclimatic reconstructions
Main Results:
- Phylogeny indicated potential trans-IOB dispersal between Africa and Sri Lanka.
- Evidence suggests vicariance linked to tropical forest dynamics facilitated African-Asian interchange.
- Dispersal events were inferred from Asia to Sri Lanka and islands east of the Sunda Shelf.
Conclusions:
- Circum-IOB distributions likely resulted from continent-based vicariance, especially habitat alterations, post-Gondwanan breakup.
- Trans-IOB dispersal is less probable for the studied avian genus distribution.
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