Publication Date:
2005-07-09
Description:
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.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Miller, Gifford H -- Fogel, Marilyn L -- Magee, John W -- Gagan, Michael K -- Clarke, Simon J -- Johnson, Beverly J -- New York, N.Y. -- Science. 2005 Jul 8;309(5732):287-90.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉INSTAAR and Geological Sciences, University of Colorado, Boulder, CO 80309-0450 USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/16002615" target="_blank"〉PubMed〈/a〉
Keywords:
Adaptation, Biological
;
Animals
;
Anthropology
;
Australia
;
Biomass
;
*Birds
;
Calcium Carbonate/chemistry
;
Carbon Isotopes
;
Climate
;
Dental Enamel/chemistry
;
*Diet
;
Dromaiidae
;
Durapatite/chemistry
;
*Ecosystem
;
Egg Shell/chemistry
;
Environment
;
Fires
;
*Food Chain
;
Geography
;
Humans
;
*Mammals
;
Marsupialia
;
*Plants
;
Poaceae
;
Population Dynamics
;
Trees
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
