Neanderthals Ate Dolphins, Seals, Cave Remains Suggest

Neanderthals living in a pair of caves on the Mediterranean Sea regularly feasted on mussels, fish, and other types of marine life, according to a new study. The finding suggests that Neanderthals actively foraged for seafood just like early modern humans, according to Clive Finlayson, an anthropologist at the Gibraltar Museum. Neanderthals and modern humans are distinct species that split from a common ancestor several hundred thousand years ago. Why modern humans thrived and Neanderthals ultimately failed has long been a topic of scientific intrigue, and previous research had suggested that the ability to exploit marine resources was one of the defining characteristics for the success of modern humans. But the new research may eliminate sophisticated foraging skills from the list of potential advantages unique to humans. "I don't think that the success of one or the other had to do with subsistence, with the way they hunted or fed," Finlayson said. "There may be other factors coming into this, or it may just have been a question of luck."

Seafood Feasts

The new theory is based on excavations of two caves on the western edge of Gibraltar, a British territory at the southern tip of Spain. Previous studies showed Neanderthals periodically occupied the caves as recently as 28,000 years ago. Inside the caves Finlayson and his colleagues found mussel shells and the bones of seals, dolphins, and fish mixed in with the remains of deer and other land mammals. Many of the bones show signs of being cooked over a fire, and some have marks left by stone tools used to cleave off chunks of flesh. Seafood remains are found throughout various layers in the caves, indicating that Neanderthals regularly exploited marine resources for tens of thousands of years. "It seems to suggest that this wasn't a one-off, but that these guys were doing it on a regular basis," Finlayson said.He and colleagues describe the findings online today in the journal Proceedings of the National Academy of Sciences.

Systematic Foraging?

Curtis Marean is an anthropologist at Arizona State University in Tempe who has found evidence that prehistoric humans were feasting on seafood in South Africa 165,000 years ago. Marean said the new study clearly shows that Neanderthals occasionally ate seafood. But he is not convinced their exploitation of seafood was on par with that of early modern humans in Africa. "I don't think there's enough evidence here to indicate that they are systematically being a coastal forager in the sense that we think of coastal foragers," he said. In South Africa, Marean noted, scientists have found waste piles called shell middens that date back nearly a hundred thousand years. These piles contain several thousand pieces of shellfish discarded by humans. By contrast, the Gibraltar caves yielded just 149 pieces of shellfish. Those pieces could be from a handful of mussels, Marean noted. The differences in abundance could stem from different availabilities of seafood at the two sites, or in the abilities of the two species to actively forage for ocean food, he added. To resolve the issue, Marean recommends a systematic comparison of Neanderthal and human seafood collection at sites with similar availability. "Were Neanderthals like we expect they would if they were modern? And if they weren't, then the question is: Why?" he said. "We could be getting into something interesting there, for sure."

"Jet Man" to Cross English Channel Like a Human Rocket

After two weather-related delays, Swiss pilot Yves Rossy, aka the Jet Man, is slated to attempt to rocket into the history books Friday by becoming the first person to fly across the English Channel using a single, jet-propelled wing attached to his back.

On live television, Rossy will jump from a plane about 10,000 feet (3,048 meters) above Calais, France, unfold his wing, fire up the jets, and attempt to cross the 20 miles (32 kilometers) over water to Dover, England. The machine should propel him at about 118 miles (190 kilometers) an hour, making it a 12- to 15-minute trip. Failure is not an option, as the Channel is one of the world's busiest shipping lanes, and Rossy's jet pack is not designed for landing on water. "He will be wearing a fireproof flight suit [and] 120 pounds [54 kilograms] of wings, fuel, engines, and parachutes, so staying afloat for any length of time could be difficult," said Tom Benson, an aeronautical engineer at the NASA Glenn Research Center in Cleveland, Ohio. Rossy's support team is confident that he can carry out his Channel-hopping feat—but that likely won't stop them from biting their fingernails when he sets off. "The first five seconds will probably define whether he is going to make it or not," said Markus Zipperer, an engineer with the German company JetCat, which helped build the machine. "The biggest challenge for him is to get into a stable flying configuration once he has left the plane."

Fly Like a Bird

Like many other aviation enthusiasts before him, Rossy wanted to find a way for people to get as close as possible to flying like birds. He started working on the project about 15 years ago, building prototypes in his garage. He first created an inflatable wing that enabled him to glide, but Rossy was really after powered flight. With the help of JetCat and Swiss firm ACT Composites, Rossy built a prototype and began improving upon his jet-wing design. A few weeks ago he carried out his longest flight yet, covering 22 miles (35 kilometers) in 12 minutes, but Friday's scheduled event will be the first time he will try to cross a major body of water. The 49-year-old Swiss pilot will be following the route taken by Louis Blériot 99 years ago, when he became the first person to fly an airplane across the English Channel. Although Blériot's route is the shortest, Rossy could be hampered by winds blowing from England toward France. "With a trailing wind, he can fly farther across the surface than with no wind using the same amount of fuel," said NASA's Benson, who is not involved in the attempt. "With a headwind, he will fly a shorter distance across the surface before exhausting his fuel. With a crosswind, he could be pushed off course, again making the crossing distance longer." Already the weather has forced Rossy to delay his flight twice—the original date was Wednesday. The team has an additional two-day window of opportunity if unfavorable conditions persist "The best conditions are likely to be a calm, cold day when the air density is high. This will assist the wing and the jets to produce more thrust," said Glenn Martin, a jet-pack inventor from Christchurch, New Zealand. When the attempt happens, it will air live on the National Geographic Channel Web site. (The National Geographic Channel is part owned by the National Geographic Society, which owns National Geographic News.)

Composite Craft

In the version of the craft Rossy will use for the Channel crossing, the wing has four jet engines linked by digital processing equipment. "If one engine fails, the digital signal ensures that its opposite pair is shut down in half a millisecond," said JetCat's Zipperer. "Otherwise his wing would go into a flat spin." At 5 inches (12.7 centimeters) across, his turbines are much smaller than conventional jet engines, although they use the same type of fuel. "We use very fast motors and have developed special parts to ensure that the jet fuel is vaporized and burned completely," Zipperer said. The craft is constructed from three main materials: carbon fiber to provide a lightweight but strong wing, glass fiber to mold it into an aerodynamic shape, and Kevlar to protect Rossy should an engine explode. "The turbines run at a very high revolution per minute. If there was a fracture, there is a danger that metal parts would leave the engine and hit Rossy," Zipperer said. "The Kevlar encases the engines and acts like a bulletproof vest." In flight, Rossy uses his shoulders, head, and arms to steer the wing. To land, he has to deploy a series of parachutes while at a height of at least 1,800 feet (550 meters). The first parachute is a small one that reduces his speed. The next is a large one that stops him going forward and enables him and his wing to float safely to the ground. This dual parachute system prevents a sudden halt. "On one of the previous prototypes Rossy used only one parachute," noted Alain Ray of ACT Composites. "Afterward he said, Never again." In addition to good winds, Rossy needs ground visibility from 10,000 feet (3,048 meters) for the flight to be cleared. He and his team are keeping a careful eye on the weather, and the flight will only go ahead if the winds and visibility requirements are suitable.

Sun's Power Hits New Low, May Endanger Earth?

Even the sun appears headed for a recession.

The Ulysses space probe has detected fewer sunspots, decreased solar winds, and a weakening magnetic field—the lowest solar activity observed in 50 years, NASA scientists said yesterday.

That translates into a shrinking of the heliosphere, the invisible "bubble" of solar wind that extends beyond Pluto and guards the planets—ours included—from bombardment by cosmic rays. Speaking yesterday at a NASA teleconference, scientists refused to draw conclusions from their observations, especially with respect to whether the changes are influencing Earth's climate. "That area of science is in the realm of speculation at this point," said Nancy Crooker, a researcher at Boston University. But David J. McComas of the Southwest Research Institute, who leads one of the experiments onboard Ulysses, called the changes "significant." "This is a whole-sun phenomenon. The entire sun is blowing significantly less hard than it was 10 to 15 years ago," he said. "Over the entire record of sun observations, this is the longest prolonged low pressure that we've observed."

Variable Star

Some variance in solar activity is normal for the sun, which has a 22-year magnetic cycle and an 11-year sunspot cycle. But McComas said in a statement that researchers have been "surprised to find that the solar wind is much less powerful than it had been in the previous solar minimum." Despite its name, solar wind is actually a stream of charged particles that expands out from the sun. Scientists noted that while solar activity is low compared to the past 50 years of data, the sun's output has dipped before. In the early 1600s Galileo and other astronomers observed only about 50 sunspots over a 30-year period. Normally, the early scientists would have witnessed closer to 50,000. Scientists have also speculated for centuries about an intuitive link between the sun's intensity and Earth's climate. There is evidence of the sun causing short-term impacts on Earth's weather. The so-called Maunder Minimum, a time of low solar activity, lasted from about 1645 to 1715. During this time, access to Greenland was largely cut off by ice, and canals in Holland routinely froze solid, according to NASA. Glaciers advanced in the Alps, and sea ice increased so much that no open water flowed around Iceland in the year 1695. The latest observations show that the sun is even more mercurial than previous research could have found. "The sun is a variable star after all," Crooker said. Less protection from the sun's heliosphere may also make space exploration more dangerous, according to Crooker. Astronauts could encounter more lethal cosmic rays without the sun's protection, for example. Most of the effects of a shrinking heliosphere, however, will be felt billions of miles beyond Pluto, at the edges of the sun's influence. If the solar wind stays weak, NASA's Voyager 1—launched in 1977 and now headed beyond our solar system—should reach the edge of the heliosphere earlier than expected, becoming the first craft to enter interstellar space.

Mission Sunset

Launched in 1990, the joint NASA and European Space Agency Ulysses mission has lasted four times longer than expected. The probe, which is slowly freezing to death and is expected to shut down within months, observed a dramatic slowdown in solar activity during its third and final orbit around the sun last year. While the demise of Ulysses is imminent, NASA will soon develop the Solar Probe mission, which will fly close to the sun to determine what heats its corona—the outer layer—and accelerates solar wind.

Oldest Ice in North America Hints at Hardy Tundra

The oldest ice ever found in North America shows that ancient permafrost withstood periods of warming, a new study says. Scientists fear that modern permafrost—soil that remains frozen in the polar regions—may melt and release potentially huge reservoirs of carbon that would speed global warming, scientists say.
But the new study suggests that such a thaw could take much longer than previously believed, according to study leader Duane Froese, a geology professor at the University of Alberta in Edmonton, Canada. Estimated to be at least 740,000 years old, the wedges of Canadian ice illustrate the longevity and resiliency of deeper permafrost during warmer climates of the past, they say. The findings counter previously held theories that permafrost in Alaska and in Canada's central Yukon Territory thawed about 120,000 years ago, during a period warmer than today.

The study appears in the journal Science.

Ash and Ice

Ice wedges are formed in frigid dry areas when temperatures get so cold that the ground cracks open. Water runoff from spring thaws fills the vertical cracks in the earth and then freezes, creating a vein of ice that builds outward with each passing year. The ancient ice wedge studied by Froese and his team was found buried under layers of volcanic ash and sediment in a mining area in Canada's central Yukon Territory. When gold miners exposed the ancient ice vein, they also uncovered a layer of volcanic ash immediately covering the ice wedge, the researcher explained. "What was unique about this situation is we had volcanic ash we could date," Froese said. Volcanic ash can help scientists determine the age of ice that is older than the range of radiocarbon dating, which spans about 50,000 years, Froese explained. It's a strategy often used in volcanic regions, such as New Zealand, Alaska, and Iceland, he added. The team recovered 740,000-year-old ash from the 4-inch (10-centimeter) thick layer covering the ice wedge over a 160-foot (50-meter) area. The layer of ash was made up of small glass grains that the team then dated used a radiometric technique. "We cannot directly determine the age of the ground ice, but we can determine the age of the overlying volcanic ash, providing a minimum age for the ground ice," said John Westgate, a geologist at the University of Toronto and co-author of the study. Froese said this means the permafrost under the ash has not disappeared since at least that time. "What it tells us is that the deeper part of permafrost has been stable for a long time," he said. It's not surprising that permafrost dating back more than 700,000 years has been found, said Larry Hinzman, director of the International Arctic Research Center at the University of Alaska in Fairbanks. "It has been assumed there was very old, ancient permafrost. This is the first evidence," Hinzman said.

Deep Freeze

Ice-rich permafrost holds together Arctic ground that would turn to "soup" if thawed. That melting threatens basic infrastructure in inhabited polar regions, such as pipelines, roads, and airport runways. Lead study author Froese emphasized that the study's findings do not suggest permafrost melting is not occurring. But the thaw may take much longer than in other areas of the Arctic that are rapidly crumbling, such as glaciers and sea ice. Although deep permafrost may thaw slowly, shallow layers is "where the action will take place" by melting faster and releasing large stores of carbon trapped in the ice, Froese said.

Red Glowing Fish Discovered

Enneapterygius pusillus has found a creative way to communicate with other fish in a world dominated by blues and greens: The fish literally glows red. At least 32 species of reef fish that live at depths below 33 feet (10 meters) possess this unique method of signaling, researchers said in a September 2008 study. Because the color red has a longer wavelength and fish are better attuned to seeing colors with shorter wavelengths (such as green and blue), scientists had thought red was irrelevant to fish. "Marine fish are generally assumed not to see or use red light, with the exception of some deep-sea fish," lead researcher Nico Michiels of the University of Tuebingen in Germany said in an email. "Our discovery shows that there is a lot of red fluorescence that is very indicative of an active role of red in fish communication."


The study appeared recently in the journal BMC Ecology.

--Kimberly Johnson
—Photographs by Michiels et al./BMC Ecology 2008