Geological processes are hypothesised to strongly affect species distributions. In particular, a combination of geological and biological data has suggested that tectonic processes can drive vicariant isolation and speciation in freshwater-limited taxa. Here we synthesise geological and biological evidence to demonstrate a composite geological and biological history for New Zealand's 290-km long Taieri River. Specifically, we assess evidence from structural geology and petrology, combined with phylogenetic and biogeographic analysis of galaxiid fishes, to show that the modern Taieri River was formed via capture of the ancestral Kye Burn during the mid-late Quaternary. Molecular dating analyses support a late-Quaternary timeframe for the geologically-mediated divergence between formerly-connected sister taxa Galaxias depressiceps and G. ‘teviot’. Fish biogeography lends further support to the geological hypothesis, as there is a substantial biogeographic disjunction between the lower- (ancestral) and upper (captured) portions of the Taieri River. Geological and biological data are assessed independently yet yield consilient patterns and timeframes for the evolutionary events inferred. Broadly, this study highlights the interplay between physical and biological processes in a geologically dynamic setting.

Item Type:	Refereed Article
Keywords:	biogeography, dating, evolution, river capture, tectonics, vicariance
Research Division:	Biological Sciences
Research Group:	Evolutionary Biology
Research Field:	Biogeography and Phylogeography
Objective Division:	Expanding Knowledge
Objective Group:	Expanding Knowledge
Objective Field:	Expanding Knowledge in the Biological Sciences
UTAS Author:	Burridge, CP (Associate Professor Christopher Burridge)
ID Code:	100521
Year Published:	2015
Web of Science® Times Cited:	9
Deposited By:	Zoology
Deposited On:	2015-05-19
Last Modified:	2017-11-01
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