The Natufians got their protein from hunting, especially gazelles.
The Natufians buried their dead together in cemeteries, sometimes with flowers and leaves. Some were buried with dogs, the first domesticated animals. Some were buried under the floors of their houses. The Haifa researchers also found evidence of feasts around the graves.
Some Natufian cemeteries became the final resting place of as many as 100 people of all ages. Their mortuary practices indicated a cohesive, organized society that mourned and honored their dead.
What intrigued the researchers were large round boulders that had been dragged to the burial sites. A lot of Natufian art involved carved stones, but these stones were special, and archaeologists have debated their purpose. They seemed to be only placed near grave sites.
The boulders were rough and seemingly designed to be functional. Unlike the other carved Natufian stones, no effort went into making them beautiful. The mortars have not been dated, but probably came late in the Natufians' history.
They are irregular in shape, weighing between 85 and 220 pounds, some two feet across, and three feet high buried as much as two feet deep. They had shafts carved into them, and were made of limestone or dolomite.
Nadel, and his coauthor, Danny Rosenberg, also of the Zinman Institute, suggested in their article in Current Anthropology that most of the boulders were mortars used for grinding grain. The larger ones, however, were most likely "used in the social realm, for example during burials or memorial events. It is also possible that during these events they were used as musical instruments," Nadel said.
We see them as implements essential for the successes of the ritual. And most probably, important for the "future of the deceased or the living community and as implements bearing significant symbolic meanings pertaining to the production of food and the transformation of substances from one state to another," Nadel and Rosenberg wrote.
Nadel emphasizes that this is all mostly speculation.
"Like many things in archaeology, we don't have a smoking gun; it is mostly circumstantial evidence," he said.
"Likely, the sounds of actual pounding accompanying these ceremonies may have been used to signal members of the relevant group that such events were taking place and together with the material processed, designated either to the living and/or the dead," the Haifa researchers wrote.
"Sounds possible," said David Lubman, an acoustical consultant in Westminster, California who has done research in acoustics in ancient societies. The people might pound in synchrony, and it might even be hypnotic to the pounders. The sound would carry some distance, he said.
The only danger, Lubman said, was that the noise might also alert enemies.
Natufian society eventually disappeared but there is no evidence anything dramatic happened to them. Rather, their culture and innovations probably were absorbed by others around them, Nadel said, and they eventually faded into the surrounding population. The climate eventually cooled down, which might have contributed to their disappearance. No DNA has been discovered so no one knows for sure.
This paper is the first to demonstrate this finger-to-the-wind ability in any migrating animal, but it likely won't be the last. Nilsson points out that any flying or swimming animal must determine how much and in which direction the current displaces them. Zooplankton, juvenile sea turtles and other marine animals have been hypothesized to sense currents directly.
The researchers still don't know how the moths do this, however, or how they distinguish atmospheric turbulence from their own wakes, which they create by beating their wings. Insects are known to use their antennae to sense flows, and related organs called Johnston's organ and Bohm's bristles are also sensitive to tiny forces, said Tom Daniel, a biologist at the University of Washington who studies insect flight. But the mechanisms involved in turbulence sensing are still unknown.
Chapman said the true test would be to replicate the experiment in the Southern Hemisphere to see whether migrating animals veer to the left, once again using the Ekman spiral as proof.
Her team has already seen two promising signs: several inquiries about the research from clinicians and medical companies and a high overall level of interest from scientists who have read the paper that describes the work.
The disease starts with a parasite carried by female Anopheles mosquitoes, from a group of protozoa called Plasmodium. The bite of the mosquito introduces protozoa into a victim’s bloodstream. The parasites travel to the liver and reproduce there. Two weeks later, symptoms appear: raging fever, vomiting, headaches, and possibly coma and death. If not treated, the parasites continue for generations and the victim has recurring bouts of malaria for years.
Traditionally, doctors used quinine and chloroquine to treat malaria. British colonials learned to put quinine in their gin to act against malaria -- the origin of the gin and tonic, although there was not enough quinine to make much difference. The disease sickle-cell anemia, which mostly affects people of African origin, is believed to be an evolutionary defense against malaria. Defective hemoglobin genes make it impossible for Plasmodium to reproduce, so people with sickle cell are more likely to survive a malaria infection.
But the parasites evolved to be resistant to the drugs, and the mosquitoes became resistant to insecticides. In some places in Asia, resistant mosquitoes and resistant parasites have combined to produce the worst of all possible outcomes, according to Matthew B. Laurens, associate professor of pediatrics at the University of Maryland School of Medicine in Baltimore, who has worked on the disease in Asia.
Malaria now kills almost a half a million people a year, mostly children.