Toads and the evolution of life-histories during range shift.

 17^th September
The Royal Society room, South Australian Museum

Abstract

The process of range expansion can have important ecological and evolutionary outcomes. During continuous range expansion, for example, populations on the expanding front experience novel evolutionary pressures because frontal populations are assorted by dispersal ability and have a lower density of conspecifics than do core populations. These conditions favour the evolution of traits that increase rates of dispersal and reproduction. Additionally, lowered density on the expanding front eventually frees populations on the expanding edge from specialist, co-evolved enemies, permitting higher investment into traits associated with dispersal and reproduction rather than defence against pathogens. Traits evolving on the expanding edge are smeared across the landscape as the front moves through, leaving an ephemeral signature of range expansion in the life-history traits of an organism across its newly-colonised range. I will demonstrate these processes with data from everyone's favourite invasive species: the cane toad.

Biography

Ben Phillips completed his PhD on evolution in response to invasive species in 2004 (at University of Sydney). He then headed north, taking up a field-based postdoc in the NT, and arrived at his study site about twelve months before toads. The initial plan was to work on the impact of toads on snakes, but this slowly morphed into work purely on toads, which ultimately became the subject of an Australian Postdoctoral Fellowship. Ben then headed west, for a short stint as the Regional Ecologist (northwestern Australia) for the Australian Wildlife Conservancy, before heading east to take up a QEII fellowship at JCU in Townsville working on the evolution of dispersal on stable range edges. His car is getting tired.