Saturday, February 28, 2009
Thursday, February 26, 2009
The Diet of Giant Moas
A treasure trove of information about pre-human New Zealand has been found in faeces from giant extinct birds, buried beneath the floor of caves and rock shelters for thousands of years.Researchers have published their analyses of plant seeds, leaf fragments and DNA from the dried faeces (coprolites) to start building the first detailed picture of an ecosystem dominated by giant extinct species moa, which ranged up to 250 kg and 3 m in height. Some of the faeces recovered were up to 15 cm in length.
"Surprisingly for such large birds, over half the plants we detected in the faeces were under 30 centimetres in height," says Dr Wood. "This suggests that some moa grazed on tiny herbs, in contrast to the current view of them as mainly shrub and tree browsers. We also found many plant species that are currently threatened or rare, suggesting that the extinction of the moa has impacted their ability to reproduce or disperse." link
Ref.: Coprolite deposits reveal the diet and ecology of the extinct New Zealand megaherbivore moa (Aves, Dinornithiformes). 2009. J. Wood, et al. Quaternary Science Reviews 27: 2593-2602.
Tuesday, February 24, 2009
Father of The Robots Born Today
Jacques de Vaucanson (Feb. 24, 1709 - Nov. 21, 1782) was the French inventor of 'automata' - robot devices of later significance for modern industry. In 1737-38, he produced a transverse flute player, a pipe and tabor player, and a mechanical duck, which was especially noteworthy, not only imitating the motions of a live duck, but also the motions of drinking, eating, and "digesting." link
Sunday, February 22, 2009
How To Be King of The Giant Ants!
A European caterpillar can garner royal treatment from ants by mimicking the sound of their queen.Ants of the species Myrmica schencki can be fooled into carrying certain caterpillars into the colony nurseries where the fakers enjoy full care and five-star dining, and then turns into a Maculinea rebeli butterfly.
Chemical camouflage alone will let the caterpillars game their way into the ant colony. But, the rhythmic caterpillar purring has the effect of the queen ant’s noises.
M. rebeli caterpillars make a mini version of the brrrrrr of a woodcock or snipe, Thomas says. Recent work has suggested that caterpillar noises may come from repeated muscle spasms. And when caterpillars become enclosed pupae, they make noises by rubbing a scraper, or plectrum, on their abdomen against a patch of fine grooves called a file. “Actually they can wriggle their abdomen quite a bit,” Thomas says.
A caterpillar has fooled ants into feeding it during the final stages before it turns into a large blue butterfly. Photo: Jeremy ThomasAdvances in miniature electronics made the new study possible. When playing the caterpillar recordings to an ant colony, workers reacted as they do to queen scratchings. Most distinctive was what Thomas describes as on-guard attendance.
Clustering around the speaker, worker ants stay motionless in a hunched-over posture with antennae out and jaws slightly open. Like an honor guard around a human queen, worker ants will maintain that pose for hours.
Queen-mimicry could explain the VIP treatment caterpillars receive in the ant colony. “Quite often they’re treated as superior beings,” Thomas says. In a crisis, worker ants rescue caterpillars before a regular ant brood. And in famine, workers will kill their own brood and feed it to the caterpillar.
Ref.: Queen Ants Make Distinctive Sounds That Are Mimicked by a Butterfly Social Parasite. 2009. F. Barbero, et al. Science 323: 782–785.
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Superman’s Pal, Jimmy Olsen #54 (July), 1961 © DC Comics
Robert Bernstein: Script; Curt Swan: Pencils: Stan Kaye: Inks
Friday, February 13, 2009
Ancient Hot Springs of Mars May Hold Life
Data from the Mars Reconnaissance Orbiter (MRO) suggest the discovery of ancient springs in the Vernal Crater, sites where life forms may have evolved on Mars.Hot springs have great astrobiological significance, as the closest relatives of many of the most ancient organisms on Earth can thrive in and around hydrothermal springs. If life forms have ever been present on Mars, hot spring deposits would be ideal locations to search for physical or chemical evidence of these organisms and could be target areas for future exploratory missions.
Structures in Vernal Crater that appear to have arisen as part of a major area of ancient spring activity. The data suggest that the southern part of Vernal Crater has experienced episodes of water flow from underground to the surface and may be a site where martian life could have developed.
Such deposits on Earth preserve evidence of the fossilized remains of the microbial communities that inhabited the hot springs over a wide range of spatial scales. Hot spring fluids are typically laden with dissolved mineral ions that, when they precipitate out and create the hydrothermal deposit, enhance fossilization of all types of biosignatures.
Ref. “A Case for Ancient Springs in Arabia Terra, Mars. 2009. C. C. Allen and D.Z. Oehler. Astrobiology 8. 1093-1172.
Wednesday, February 11, 2009
Cave Carson: Adventures Inside Earth!
Cave Carson's first adventure!
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The Brave and the Bold #31 (August-September 1960). Cave Carson © DC Comics
Script: France Herron; Art by the great Bruno Premiani
Hey DC! Where’s my Cave Carson Archives?!