Inside Science News Service

A collection of brief stories from the world of science

July 31, 2008
By Jim Dawson
Inside Science News Service


Chilean Chickens Step Up for Science

A study of the DNA of 41 Chilean chickens by an international team of researchers won't help answer one of the most controversial and long-standing questions about pre-historic contact between people living in South America and those from Polynesia.  Simply put, was it the post-Columbian Spanish in the 15th Century, or the pre-Columbian Polynesians, who first made contact with inhabitants of South America?  Evidence of the American sweet potatoes in ancient Polynesian sites has led some scientists to believe there was very early contact between the two cultures. Chickens became an issue when some researchers claimed in a paper published last year that there was a genetic link between ancient Polynesian and pre-Columbian chickens from Chile.  The new study, published in the Proceedings of the National Academy of Sciences, says that DNA testing shows that while ancient Polynesian and Chilean chickens both possessed what scientists call the "KFC gene," so too would have early Spanish chickens. "So while we can say the KFC chicken was popular amongst early Polynesian voyagers, we certainly can't use it as evidence for trade with South America," concluded Alan Cooper, of the University of Adelaide's Australian Centre for Ancient DNA.

Don't Bother the Flies, They're Sleeping

Fruit flies that don't get their full 12 hours of sleep each night aren't as physically coordinated as their well-rested mates, tend to have trouble sleeping when they do hit the sack, and only live about half as long as "normal" fruit flies. Researchers with the University of Pennsylvania School of Medicine, in a paper published in the journal Science, said they believe their fruit fly research has identified a gene that may control sleep.  Most people know the importance of sleep in both functioning and overall health, and that humans typically require between six and eight hours of sleep each night.  But scientists don't know what controls the biological need for sleep.  The fruit fly gene might be at least part of the answer. About 70 million people in the U.S. suffer from chronic sleep problems, the researchers note.  "In the long term, we hope that human equivalents of the gene will be isolated and will not only further our understanding of human sleep, but perhaps also serve as drug targets to promote sleep or treat insomnia," said neuroscientist Amita Sehgal, one of the lead researchers.

Titan's Lake Ontario Lacus – It Isn't Water, but It's Wet

 Scientists using an instrument on NASA's Cassini orbiter have confirmed the existence of the first known liquid lake that is not on Earth.  The 7,800 square mile lake is located in the south polar region of Titan, one of the Saturn's moons.  The lake, filled with the liquid hydrocarbon ethane, is 150 miles long and slightly larger than its earthly namesake, Lake Ontario, the smallest of the Great Lakes.  Titan is surrounded in a hydrocarbon haze that makes detailed study of its surface difficult, but images of Titan, both from Cassini and from a probe that parachuted into its atmosphere in 2005, revealed many large black regions that scientists thought could be liquid hydrocarbon lakes.  In a report in the journal Nature, University of Arizona researchers said that they confirmed the lake was truly wet by using an instrument on Cassini called a visual and infrared mapping spectrometer.  The lake is so dark that it only reflects about a tenth of one percent of the light that hits it.  "For it to be that dark, the surface has to be extremely quiescent, mirror smooth," said Robert Brown, of the university's lunar and planetary laboratory. "No naturally produced solid could be that smooth."  The observations indicated that the lake is surrounded by a dark beach.
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