Everest glaciers are melting
A warming climate is melting the glaciers of Mount Everest, shrinking the frozen cloak of Earth's highest peak by 13 percent in the last 50 years, researchers have found.
Rocks and natural debris previously covered by snow are appearing now as the snow line has retreated 590 feet, Sudeep Thakuri, a University of Milan scientist, said during a meeting of the American Geophysical Union in Cancun.
The team reconstructed the glacial history of the area using satellite imagery and topographic maps of Everest and the surrounding 713-square-mile Sagarmatha National Park. Their statistical analysis shows that the majority of the glaciers in the national park are retreating at an increasing rate, Thakuri said. Small glaciers of about a third of a square mile are vanishing fastest, registering a 43 percent decline in surface area since the 1960s.
The topic of glacial melt in the Himalayas has been controversial. Initial reports by the Intergovernmental Panel on Climate Change predicted glaciers in the region would disappear by 2035. Subsequent analysis by the Gravity Recovery and Climate Experiment satellite mission showed that the melt was one-tenth the reported rate, and that some areas were experiencing growth, particularly in the Tibetan plateau.
Research published last year, however, showed that glaciers have been retreating over a 30-year period on the plateau, which is of concern because it is the source of drinking and irrigation water for more than 1 billion people in Asia.
Typhoid Mary of the frog world?
Scientists believe they have discovered the Typhoid Mary of the frog world: a flat, feral creature that carried a deadly fungus from Africa to California's ponds and puddles through global trading.
Genetic analysis revealed that eight of 206 African clawed frogs-caught wild or preserved at the California Academy of Sciences-carried the fungal plague called chytridiomycosis, which leaves them unharmed but kills native frogs in catastrophic numbers. An infection was detected in a frog captured in Africa in 1934, supporting the theory that the fungus thrived there before spreading worldwide.
"It confirms our suspicions that this is one means of spread of the fungus into the environment, through frogs that were not native," said Sherril Green, professor and chairwoman of comparative medicine at Stanford University, who collaborated on the study with San Francisco State biologist Vance Vredenburg.
The frog was first brought to the United States for use as a pregnancy test in the early 20th century. The practice is now discontinued and the frogs likely were released into the environment by hospital workers, Green said.
a word in early human's ear
A team of scientists reports recovering the earliest known complete set of the three tiny middle ear bones — the malleus ("hammer"), incus ("anvil"), and stapes ("stirrup") — in a 2.0-million-year-old skull of Paranthropu dern humans, whereas the two other ear bones most closely resemble existing African and Asian great apes.
Since the malleus is attached directly to the eardrum, the researchers suggest that it might be an early sign of the high human sensitivity to middle-range acoustic frequencies critical to spoken language, but which apes and other primates are much less sensitive to.