Science Briefing African genes vary more, study finds / Fungus prompts bat cave closures / NASA to cut 900 jobs in manufacturing / Some animals can 'dance' to music, scientists say / Roman bowl unearthed in London May 2, 2009

African gene variations

Africans have more genetic variation than anyone else on Earth, according to a new study that helps narrow the location where humans first evolved, probably near the South Africa-Namibia border.

"Given the fact that modern humans arose in Africa, they have had time to accumulate dramatic changes" in their genes, said University of Pennsylvania geneticist Sarah Tishkoff, whose study was published online Thursday in the journal Science. Clear differences were found in prevalence of diseases such as hypertension and prostate cancer across populations. The study also found that about 71% of African Americans can trace their ancestry to West Africa.

Fungus prompts bat cave closures

The U.S. Forest Service is preparing to close thousands of caves and former mines across the eastern United States to control a bat-killing fungus.

Forest Service biologist Becky Ewing said caves from New England to West Virginia were closed last week, and an order for Southeastern states will be issued soon.

The caves will be closed for a year as wildlife biologists try to get a handle on a fungus that has been linked to the deaths of 500,000 bats.

The decision to close the caves came after the fungus was reported near large populations of endangered bats.

NASA cuts jobs in manufacturing

NASA plans to eliminate 900 manufacturing jobs over the next five months as it prepares to retire its space shuttle fleet in 2010, officials at the space agency said.

The first 160 layoff notices went out Friday, primarily to contractors producing the space shuttle fuel tanks outside New Orleans and the shuttle solid rocket boosters in Utah.

The shuttle fleet is due to be retired after eight more flights to finish building and equipping the International Space Station and a final servicing call to the Hubble Space Telescope.

Some animals may feel the beat

Scientists say they've documented for the first time that some animals "dance" to a musical beat.

The researchers studied a few live birds and about 1,000 YouTube videos, looking for signs that animals feel the beat of music they hear.

Some parrots did, and maybe an occasional elephant, according to two studies published Thursday in Current Biology(09)00890-2.

But they found no evidence of such behavior in dogs and cats, despite long exposure to people and music, nor for chimps, our closest living relatives.

The truly boppin' animals shared with people some ability to mimic sounds they hear, which in people is considered a key component of learning to talk.

Roman bowl found in London

Archaeologists have unearthed a Roman glass bowl, a unique find in the Western Roman Empire, at an ancient cemetery beyond the walls of the old city of London.

The dish, believed to date from around the 2nd to 3rd century, is a mosaic of indented blue petals with white bordering. "It is unprecedented in the western Roman world," said Jenny Hall, curator of the Roman collection at the Museum of London. The artifact was found eight to 10 feet down at an ancient cemetery in Aldgate, east London, just beyond the old city walls. Romans were required by law to bury their dead outside the city gates.

Technique tracks disease carriers

A novel genetic technology will be used in Africa to track mosquitoes that can spread a disease disfiguring millions of people with often grotesque swellings, scientists said Wednesday.

"DNA barcoding," a technique that quickly obtains a unique genetic code, will help identify mosquitoes that spread elephantiasis, or lymphatic filariasis (LF). It results from microscopic, threadlike worms spread among humans by mosquito bites. The worm larvae can clog the lymph system and cause grotesque swellings. Mosquitoes have widely differing abilities to transmit LF, so identifying species can help refine use of insecticides.

Georgia installs food safety alert

In the wake of the salmonella outbreak, Georgia Gov. Sonny Perdue has signed a bill that would make the state the first to require food makers to swiftly alert state inspectors if their internal tests show products are tainted.

The proposed food safety regulations would require the food processors to report the results within 24 hours. Perdue says it will help "guard the safety and security of our food supply from bad actors." The proposal moved rapidly through the Georgia Legislature after the salmonella outbreak that was traced to a south Georgia peanut processing plant. The outbreak sickened about 700 people and may have caused nine deaths, officials say.

-- from times staff and wire reports