A/Prof Damien Fordham1, Dr Stuart Brown1, A/Prof David Nogues-Bravo2
1The Environment Institute and School of Biological Sciences, The University of Adelaide, Adelaide, Australia, 2Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
Disentangling climate from non-climate impacts on species’ range shifts has proved difficult using correlative approaches, because extinction threats rarely occur in isolation. Consequently, the principal drivers of megafauna extinctions during the late Pleistocene and early Holocene are still strongly polarized between proponents of the human-impact or climate-change perspective. Demographic-based simulation models provide a method for quantifying the relative strength of megafauna extinctions and for testing the potential importance of interacting factors. However, to date, these approaches have rarely been used to model the structure and dynamics of geographic ranges during the late Quaternary. We put the ‘dead to work’, by integrating fossil records and molecular ‘log books’ with mechanistic ecological simulation models, to continuously reconstruct the range dynamics of the woolly mammoth in response to human exploitation and climate variation since the Last Glacial Maximum. We use Approximate Bayesian Computation and machine learning approaches to determine the synergy of threatening processes that drove the range collapse and extinction of woolly mammoths; and to develop a stronger understanding of how changes in climate and exploitation (and their interactions) influence the rate, strength and outcome of ecological processes of range movement. More generally, we show how research emerging at the frontiers between paleoecology, paleogenomics, paleoclimatology and global ecology is unlocking the ecological mechanisms that drive geographical ranges to contract, improving conservation in changing climates.
Damien Fordham is an Associate Professor in global ecology at the University of Adelaide. His research blends theoretical and empirical approaches. It uses the latest developments in quantitative ecology, climatology, paleoecology and evolutionary biogeography to improve the way in which ecological-model projections are generated, interpreted, and used to protect natural systems for long-term resource sustainability.