The lasting biological signature of Pliocene tectonics: Reviewing the re-routing of Australia's largest river drainage system

Abstract

Aim: Biological diversification can be substantially influenced by earth history. The links between biological and geological processes can be particularly tight for obligate freshwater biota. Here, we test for such links with respect to Pliocene shifts in drainage geometry of one of the Australia's largest river systems. Location: Major rivers of south-eastern Australia. Taxon: Freshwater-limited fishes and crayfish. Methods: We synthesize recently published geological and freshwater phylogeographic data to elucidate the evolutionary history of south-eastern Australia's major river drainages and their biotas. Results: Recent data demonstrate how a major Pliocene drainage rearrangement event in the lower Murray-Darling basin led to the evolution of a distinctive and “marooned” phylogeographic assemblage in the Glenelg and Wimmera drainages. Main conclusions: Biological data from southern Australia illuminate the region's geological history, and vice versa. Our study highlights the persisting evolutionary effects of a major Pliocene drainage rearrangement. The lasting geological and biological preservation of such an ancient tectonic event is apparently facilitated by Australia's uniquely stable geological setting.