Ecosystem collapse in Pleistocene Australia and a human role in megafaunal extinction.
Department or Program
Adaptation, Biological, Animals, Anthropology, Australia, Biomass, Birds, Calcium Carbonate, Carbon Isotopes, Climate, Dental Enamel, Diet, Dromaiidae, Durapatite, Ecosystem, Egg Shell, Environment, Fires, Food Chain, Geography, Humans, Mammals, Marsupialia, Plants, Poaceae, Population Dynamics, Trees
Most of Australia's largest mammals became extinct 50,000 to 45,000 years ago, shortly after humans colonized the continent. Without exceptional climate change at that time, a human cause is inferred, but a mechanism remains elusive. A 140,000-year record of dietary delta(13)C documents a permanent reduction in food sources available to the Australian emu, beginning about the time of human colonization; a change replicated at three widely separated sites and in the marsupial wombat. We speculate that human firing of landscapes rapidly converted a drought-adapted mosaic of trees, shrubs, and nutritious grasslands to the modern fire-adapted desert scrub. Animals that could adapt survived; those that could not, became extinct.
Miller, G.H., Fogel, M.L., Magee, J.W., Gagan, M.K., Clarke, S.J., and Johnson, B.J., 2005. Ecosystem collapse in Pleistocene Australia implies a human role in megafaunal extinction: Science, 309, 287-290.