A shifting diet of two flightless birds inhabiting Australia tens of thousands of years ago is the best evidence yet that early humans may have altered the continents interior with fire, changing it from a mosaic of trees, shrubs and grasses to the desert scrub evident today, according to a University of Colorado at Boulder-led team.
Nearly intact eggshell of the extinct giant bird Genyornis newtoni, discovered near Port Augusta, South Australia in 2002. Note puncture hole from predator in upper left. The egg has been dated by both Optically Stimulated Luminescence (OSL) and Amino Acid Racemization (AAR) at 60,000 years, about 10,000 years before megafaunal extinction. Photo by G H Miller
7 Plant ecosystems in monsoonal Australia burn frequently through natural ignition by lightning strikes during the build up to the wet season, when dry lightning storms are common. But burning is also promoted by human ignition, from both traditional burning practices of Aboriginal Australians and governmental land managers. In Kakadu, a World Heritage Area east of Darwin, ecosystems have adapted to millennia of Aboriginal burning. Consequently, land managers strive to maintain the "natural" vegetation through prescribed burns in consultation with Aboriginal advisors. Land managers deliberately set this fire, 100 km south of Darwin. Photograph by Gifford H. Miller, Sept. 1998.
The unprecedented ecosystem disruption is now thought to have led to the extinction of Australias large terrestrial mammals, which disappeared shortly after humans colonized the continent about 50,000 years ago, said Professor Gifford Miller of CU-Boulders Institute of Arctic and Alpine Research. Scientists have shown there were no significant swings in the continents climate during that period, leading most to believe that humans had a hand in the extinctions through over-hunting, spreading disease or by altering the vegetation of the vast interior through systematic burning.
Using isotopic studies of fossil eggshells from both indigenous emus and the extinct, ostrich-sized Genyornis, a new study by Miller and colleagues publishing in the July 8 issue of Science magazine shows that the ecosystems flora changed swiftly and dramatically after humans arrived.
Gifford Miller | EurekAlert!
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Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
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