A study that looked at the most intimate of pests -- body lice -- suggests that humans started wearing clothes 70,000 years ago, scientists said.
The genetic study of lice strongly suggests they -- and clothing -- arose soon after modern Homo sapiens began moving out of Africa and into the cooler regions of Europe. Lice provide a unique insight into the development of clothing, according to the researchers, working in Germany. Only humans carry this particular species of louse, which lays its eggs in clothing.
"It seems fairly obvious that the body louse arose when humans made frequent use of clothing," a molecular anthropologist said.
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Staying power of smallpox shots: Those smallpox shots that millions of Americans received as children may still offer some protection, a new study suggests. But half of all Americans never received the vaccine, and many scientists believe protection wanes over time for those who did.
The vaccine has been assumed to offer its best protection for from three to five years. However, according to a new study, lab tests can detect immune response in 90 percent of vaccinated people for many years, some for up to 75 years.
But the presence of immune antibodies in the blood may not indicate protection from the disease, or how strong that antibody response may be. Two doctors not involved with the study agreed that the relationship between immune response and protection from disease is not well understood.
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Slaughtering hippos for meat: Burundi locals say hippopotamuses are being wiped out by soldiers who earn extra cash by selling the animals' meat to restaurants where middle-class gourmets pay highly to taste its flesh.
Experts fear the growing trade in bushmeat, which is fueled by poverty, is devastating much of Africa's wildlife. The animals' aquatic visits to lakeside bars are becoming more rare, and they have learned to avoid areas frequented by the army, during the country's 10-year-old civil war.
The army declines to comment on the allegations. But officers say privately that the killings are carried out by what they call uncontrolled elements in the army who are motivated by deepening poverty and exploit lawlessness caused by the war.
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Pumps translate to transplants: Doctors at the Texas Heart Institute hope the success they've had sending patients home after they received an experimental heart pump will result in a dependable alternative to transplants.
Physicians at the institute recently made their case for the benefits of the Jarvik 2000 heart pump with the help of 58-year-old man, who was stricken with congestive heart failure after developing a virus. He was one of the first heart pump patients in the country to be allowed to go home. The patient said he felt "just about as well as I did before I got really sick."
The heart pump, the size of a C-cell battery, is part of a federally approved study to evaluate it as a bridge to transplantation. But the chief of cardiopulmonary transplantation for the institute believes the device can be an alternative to transplants for patients whose health has not deteriorated too seriously. About 4,000 people are on the national patient waiting list and only about 2,300 donor hearts are available each year.
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The mental aspects of elder health: Doctors accustomed to diagnosing physical ailments too often miss symptoms of mental decline that may be early signs of dementia in the elderly, researchers said.
As a result, those patients do not benefit from early medical treatment or make legal and financial decisions while they are still able, a University of Chicago Medical School psychiatrist said.
The study of 2,150 people aged 65 and older, underway since 2000, found as many as 28 percent of participants showed symptoms of cognitive impairment. Yet their physicians noted the symptoms in the medical records of only 6 percent of patients, and only 2 percent were prescribed drugs.
In addition, doctors diagnosed only one-quarter of the 25 percent of participants with symptoms of depression.
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Compiled by Kari L. Dean. Reuters and AP contributed to this report.
