Ecosystem collapse in Pleistocene Australia and a human role in megafaunal extinction.
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.
INSTAAR and Geological Sciences, University of Colorado, Boulder, CO 80309-0450 USA.
Gifford H
GH
Miller
Marilyn L
ML
Fogel
John W
JW
Magee
Michael K
MK
Gagan
Simon J
SJ
Clarke
Beverly J
BJ
Johnson
D000220:Adaptation, Biological; D000818:Animals; D000883:Anthropology; D001315:Australia; D018533:Biomass; D001717:Birds; D002119:Calcium Carbonate / Q000737:chemistry; D002247:Carbon Isotopes; D002980:Climate; D003743:Dental Enamel / Q000737:chemistry; D004032:Diet; D020312:Dromaiidae; D017886:Durapatite / Q000737:chemistry; D017753:Ecosystem; D004528:Egg Shell / Q000737:chemistry; D004777:Environment; D005390:Fires; D020387:Food Chain; D005843:Geography; D006801:Humans; D008322:Mammals; D008394:Marsupialia; D010944:Plants; D006109:Poaceae; D011157:Population Dynamics; D014197:Trees
D002247:Carbon Isotopes; D017886:Durapatite; D002119:Calcium Carbonate