viernes, 29 de agosto de 2008
Largest Squid Ever Caught Is "Giant, Gelatinous Blob"Dave Hansford in Wellington, New Zealand
Armed with giant tentacles, swiveling hooks, and the world's largest eyes, the colossal squid is thought to be the biggest squid species and the source of centuries-old sea monster myths.
But the largest squid ever caught was "a giant, gelatinous blob," sluggish and highly vulnerable to predators, a squid expert who dissected the specimen said last week.
The dissection of the half-ton female at a New Zealand museum in April suggests she was an egg-producing machine, which—like most squid—would probably have given birth once before dying, said Steve O'Shea of New Zealand's Auckland University of Technology.
The 30-foot-long (10-meter) squid, snagged on a fishing line off Antarctica in 2007 (photos), carried some partially developed eggs. But when fully mature, he said, she would have had "many, many thousands of eggs" inside her mantle cavity, a chamber inside her tubular upper body.
That may explain why she had been scavenging from fishing lines, rather than actively hunting.
O'Shea stressed that much of his work was still theoretical.
"Life cycles, reproductive strategies, egg brooding, all the behavior of these things is basically unknown, so we've got to make do with the most closely related example for which we have more information."
That example, he said, is Teuthowenia pellucida, "a small-bodied colossal-squid equivalent in New Zealand waters," he said.
Though it grows to only about 8 inches (20 centimeters) long—versus the colossal squid's estimated 50 feet (15 meters)—Teuthowenia is "basically identical," O'Shea said.
Female Teuthowenia that have mated carry "very large eggs" in their mantle cavities.
"The male has an enormous, long penis—but it's incredibly narrow—with which he inserts packages of sperm directly into the female's mantle," he said. "The heads of those packages of sperm explode and individually fertilize the eggs within the mantle itself.
"That process is confirmed" in Teuthowenia, O'Shea said. "It's obvious that she's brooding those eggs within the mantle, and I don't think it's a big stretch to extrapolate that to the colossal squid."
Glowing Babies Blacked Out
O'Shea also speculates that, as the thousands of baby colossal squid grow inside their mother, they develop the light-emitting organs called photophores, which were confirmed during the April dissection. That could pose a risk in the dark depths where colossal squid live—as far down as 6,500 feet (1,980 meters).
"She's just a sitting duck down there," O'Shea said. "You don't want to be lit up like a giant crystal chandelier."
The squid's natural predator, the sperm whale, would relish a meal of "nutritious, egg-brooding colossal squid," he added.
But, in an apparent evolutionary defense, the colossal squid's mantle is lined with an opaque, deep-red membrane, which would block the light of her babies' photophores.
(See "Colossal Squid Has Glowing 'Cloaking Device,' Huge Eyes" [May 1, 2008].)
Previous research has proposed that colossal squid lay eggs. But O'Shea speculates that the giants give birth to live young.
"She's holding onto them until they're fully functional juveniles, then spitting them out at great depth. Then she is going to die," he said. Though the life cycles of deep-sea squid are not fully known, better-studied squid species are known to die shortly after birth.
Fresh from dissection, the colossal squid is now on display at the Museum of New Zealand in Wellington.
Chris Paulin is the natural environment projects officer at the Museum of New Zealand in Wellington, where the colossal squid is now on display. He said growth rings seen in another species, the giant squid, indicate that giant squid live for just a few years.
"It's quite likely that this colossal squid—assuming it has a similar life history to the giant squid—may have reached this size in three or four years."
"A Hell of a Lot of Squid"
Confirmation of the colossal squid's habits, though, will come only from "more specimens and building our knowledge base … ," Paulin said.
Given the recent boom in commercial fishing for toothfish (sold as "sea bass") in Antarctic seas, more colossal squid specimens should turn up in the next few years, he said—particularly if New Zealand mandates that all accidentally caught animals be brought back to port along with the intended catch. Colossal squid are thought to frequent the same deep Antarctic waters as toothfish, apparently a favorite colossal squid food.
Colossal squid could well be very numerous, Paulin said.
"Put it this way: A sperm whale has to eat about 2,200 pounds [1,000 kilograms] of food a day, and the colossal squid makes up about 75 percent of that.
"I don't know how many sperm whales there are in Antarctica, but that's a hell of a lot of squid."
jueves, 28 de agosto de 2008
Alexis Okeowo in México City
A labyrinth filled with stone temples and pyramids in 14 caves—some underwater—have been uncovered on Mexico's Yucatán Peninsula, archaeologists announced last week.
The discovery has experts wondering whether Maya legend inspired the construction of the underground complex—or vice versa.
Earliest Maya Writing Found in Guatemala, Researchers Say (January 5, 2006)
The Rise and Fall of the Maya in Geographic Magazine (August 2007)
Ancient Maya Tomb Yields "Amazing" Fabrics (April 25, 2008)
According to Maya myth, the souls of the dead had to follow a dog with night vision on a horrific and watery path and endure myriad challenges before they could rest in the afterlife.
In one of the recently found caves, researchers discovered a nearly 300-foot (90-meter) concrete road that ends at a column standing in front of a body of water.
"We have this pattern now of finding temples close to the water—or under the water, in this most recent case," said Guillermo de Anda, lead investigator at the research sites.
"These were probably made as part of a very elaborate ritual," de Anda said. "Everything is related to death, life, and human sacrifice."
Stretching south from southern Mexico, through Guatemala, and into northern Belize, the Maya culture had its heyday from about A.D. 250 to 900, when the civilization mysteriously collapsed.
(Read about the watery graves of the Maya in National Geographic magazine.)
Myth and Reality
Archaeologists excavating the temples and pyramids in the village of Tahtzibichen, in Mérida, the capital of Yucatán state, said the oldest item they found was a 1,900-year-old vessel. Other uncovered earthenware and sculptures dated to A.D. 750 to 850.
"There are stones, huge columns, and sculptures of priests in the caves," said de Anda, whose team has been working on the Yucatán Peninsula for six months.
"There are also human remains and ceramics," he said.
Researchers said the ancient legend—described in part in the sacred book Popul Vuh—tells of a tortuous journey through oozing blood, bats, and spiders, that souls had to make in order to reach Xibalba, the underworld.
"Caves are natural portals to other realms, which could have inspired the Mayan myth. They are related to darkness, to fright, and to monsters," de Anda said, adding that this does not contradict the theory that the myth inspired the temples.
William Saturno, a Maya expert at Boston University, believes the maze of temples was built after the story.
"I'm sure the myths came first, and the caves reaffirmed the broad time-and-space myths of the Mayans," he said.
Saturno said the discovery of the temples underwater indicates the significant effort the Maya put into creating these portals.
In addition to plunging deep into the forest to reach the cave openings, Maya builders would have had to hold their breath and dive underwater to build some of the shrines and pyramids.
Other Maya underworld entrances have been discovered in jungles and aboveground caves in northern Guatemala Belize.
"They believed in a reality with many layers," Saturno said of the Maya. "The portal between life and where the dead go was important to them
martes, 26 de agosto de 2008
Tutankhamun: His Tomb and the Treasures" is a new exhibition now in Zurich that has meticulously reconstructed the tomb complex and its treasures. Specially trained craftspeople in Cairo built more than 1,000 exact replicas under scientific supervision. The work took over five years. Here is a replica of the famous mask of King Tut, weighing 24 lbs, which was pressed over the head of the king's bandaged mummy. The idealized portrait of the young king echoes the style of the late Amarna period. The life-like eyes are formed by bright quartz, with obsidian inlays for the pupils.
Tutankhaten, means "Living Image of Aten", while Tutankhamun means "Living Image of Amun". Often the name Tutankhamun was written Amen-tut-ankh, meaning "living image of amun", due to scribal custom which most often placed the divine name at the beginning of the phrase in order to honor the divine being. He is possibly also the Nibhurrereya of the Amarna letters. He was likely the eighteenth dynasty king 'Rathotis', who according to Manetho, an ancient historian, had reigned for nine years - a figure which conforms exactly with Flavius Josephus' version of Manetho's EpitomeThe 1922 discovery by Howard Carter of Tutankhamun's intact tomb received worldwide press coverage and sparked a renewed public interest in ancient Egypt, for which Tutankhamun's burial mask remains the popular face
Tutankhamun was only eight or nine years old when he became pharaoh, and reigned for approximately ten years. In historical terms, Tutankhamun's significance stems from his rejection of the radical religious innovations introduced by his predecessor Akenhaten and that his tomb, uniquely, in the Valley of the Kings was discovered almost completely intact -- the most complete ancient Egyptian tomb ever found. As Tutankhamun began his reign at such an early age, his vizier and eventual successor Ay was probably making most of the important political decisions during
Tutankhamun's reign Parentage and lineage
Tutankhamun's parentage is uncertain. An inscription calls him a king's son, but it is not clear which king was meant.
He was originally thought to be a son of Amenhotep III and his Great Royal Wife Queen Tiye. Later, further research claimed that he may have been a son of Amenhotep III, although not by Queen Tiye, since Tiye would have been more than fifty years old at the time of Tutankhamun's birth.
At present, the most common hypothesis holds that Tutankhamun was the son of Akhenaten, also known as Amenhotep IV, and his minor wife Queen Kiya. Queen Kiya's title was "Greatly Beloved Wife of Akhenaten" so it is possible that she could have borne him an heir. Supporting this theory, images on the tomb wall in the tomb of Akhenaten show a royal fan bearer standing next to Kiya's death bed, fanning someone who is either a princess or more likely, a wet nurse holding a baby, considered to be the wet nurse and the boy, king-to-be.
Professor James Allen argues that Tutankhamun was more likely to be a son of the short-lived king Smenkhkare rather than Akhenaten. Allen argues that Akhenaten consciously chose a female co-regent named Neferneferuaten as his successor, rather than Tutankhamun, which would have been unlikely if the latter had been his son.
Another theory is that Tutankhamun was the son of Smenkhkare and Meritaten (one of the six daughters of Akhenaten and Nefertiti).Smenkhkare appears when Akhenaten entered year 14 of his reign and it is thought that during this time Meritaten married Smenkhkare. Smenkhkare, as the father of Tutankhamun, needed at least a three year reign to bring Tutankhamun to the right age to have inherited the throne. However, if there had been lengthy co-regency between Amenhotep III and Akhenaten, Amenhotep definitely could be Tutankhamun's father Tutankhamun was married to Ankhesenpaaten (possibly his half-sister, since Ankhesenpaaten is unequivocally recorded as another of the six daughters of Akhenaten and Nefertiti), and after the re-establishment of the traditional Egyptian religion the couple changed the –aten ending of their names to the –amun ending, becoming Ankhesenamun and Tutankhamun. It is assumed they had two children, both girls, whose mummies were discovered in Tutankhamun's tomb - they both died as babies, and medical evidence suggests they may have been stillborn. DNA testing has recently begun on the two fetuses to determine whether they were indeed his children or not.
Cartouches of his birth and throne names are displayed between rampant Sekhmet lioness warrior images (perhaps with his head) crushing enemies of several ethnicities, while Nekhbet flies protectively aboveDuring Tutankhamun's reign, Akhenaten's Amarna revolution (Atenism) was being reversed. Akhenaten had attempted to supplant the traditional priesthood and deities with a god who was until then considered minor, Aten. In Year 3 of Tutankhamnen's reign (1331), while he was still a boy, probably about 11, and under the influence of two older advisors (Akhenaten's vizier Ay and perhaps Nefertiti), the ban on the old pantheon of deities and their temples was lifted, the traditional privileges were restored to their priesthoods, and the capital was moved back to Thebes. The young pharaoh adopted the name Tutankhamun, changing it from his birth name Tutankhaten. Because of his age at the time responsibility for these decisions can be attributed to his advisors. King Tutankhamun restored all of the traditional deities, and restored order to the chaos created by his uncle Akhenaten. In addition, temples devoted to Amun-Ra were built during this period. Although, Tutankhamun's wooden box depicts him going to war against Hittites and Nubians, and he is shown wearing the blue war crown, it is doubtful that he ever went to war since scrutiny of the period's extensive written evidence does not yield records of him participating in any wars or battles
Events following Tutankhamun's death
A now-famous letter to the Hittite king Suppiluliuma I from a widowed queen of Egypt, asking for one of his sons as a husband, has been attributed to Ankhesenamun (among others). The royal lineage of Egypt was carried by its women. Marriage to a woman of the royal line was essential for a male pharaoh, even if he came from outside the lineage. Suspicious of this good fortune, Suppiluliumas I first sent a messenger to make inquiries about the truth of the young queen's story. After receiving reports that the situation was as related to Suppiluliuma I, he sent his son, Zannanza, accepting her offer. However, Zannanza got no further than the border before he was killed, according to the Hittite archives. If Ankhesenamun were the queen in question, and his death a strategic murder, it was probably at the orders of either Horemheb or Ay, who both had the opportunity and the motive to kill him
lunes, 25 de agosto de 2008
Mammals Have "Alarm Detectors" in NosesJames Owen
Mammals, including humans, have a built-in alarm detector in the tip of the nose for sniffing out danger, new research suggests.
The tiny sensor, discovered in mice, is used to pick up chemical warning signals sent by fellow animals in distress, scientists say.
Many plants and animals emit airborne molecules called alarm pheromones, which alert members of their species to dangers such as predators.
But how mammals detected these pheromones has been a mystery.
Now a team from the University of Lausanne in Switzerland says the answer lies in a microscopic ball of cells in the nose called the Grueneberg ganglion.
(Read: "Plant Networks Can Send Warnings, Spread Viruses" [October 1, 2007].)
The Grueneberg ganglion was first identified in 1973 in various types of mammals, including rodents, cats, apes, and humans.
These mammals probably all have a nose for danger, the study team said, although the discovery has only been made so far in mice.
The new discovery—to be reported tomorrow in the journal Science—was made during a study of the Grueneberg ganglion in mice using physiological techniques.
"The ganglion is the only [smell] sub-system that's completely functional at birth, so we were thinking it was important for nipple finding for the baby mouse," said study co-author Marie-Christine Broillet.
But after numerous tests for nipple finding and other possible functions, the team found that the ganglion played a role in danger communication
The researchers then compared how mice with and without their Grueneberg ganglia responded to alarm pheromones.
The contrast was very striking, Broillet said. "The normal mouse immediately gets scared and goes to the corner of the box and freezes," she said. But mice without the ganglia carried on as before, seemingly unaware of the danger signals.
Both groups were able to sniff out cookies hidden in their cages, however, suggesting the altered group's sense of smell was otherwise unaffected.
(Related: "Elephants Distinguish Human Friends From Foes by Smell" [October 18, 2007].)
The chemical sensor's nose-tip location is ideal for early detection of pheromones, Broillet added.
Stuart Firestein, professor of biology at Columbia University, New York, said that the new finding represents two important scientific advances.
"First of all, it extends a growing appreciation that the olfactory system is not a singular system but is really made up of several subsystems," he said.
Second, the study advances the understanding of how body cells and molecules function together within the nervous system.
The newfound mouse alarm detection system introduces "a new and likely powerful model" for such investigations, Firestein said.
The chemical makeup of alarm pheromones and where they are produced in the body remains unknown.
But the discovery of the pheromone sensor should finally enable researchers to identify the molecules involved, study co-author Broillet said.
Alarm pheromones, if they can be artificially produced, could have various uses, such as repelling pests or dispersing crowds, she added.
viernes, 22 de agosto de 2008
José Orozco in Caracas, Venezuela
The Bolivian river dolphin is a separate species from the Amazon river dolphin, scientists announced recently.
Thousands of years ago a powerful drought dried up Brazil's Madeira River, causing a "radical separation" as dolphin populations were caught on different sides of the newly created rapids, said researcher Manuel Ruiz-Garcia.
Dolphin Numbers Still Low Despite "Safe" Tuna Fishing, Experts Say (March 26, 2007)
The Madeira split into today's Beni and Mamoré rivers of northeastern Bolivia. "When they separated, [the dolphins] were never again able to return and reproduce," said Ruiz-Garcia, who heads the Molecular Genetics Lab at Javeriana University in Bogotá, Colombia.
"Thus isolated, the Bolivian river dolphin, Inia boliviensis, eventually developed," he said.
The announcement was made at a recent conservation workshop in Santa Cruz de la Sierra in Bolivia.
Ruiz-Garcia took DNA samples from 40 river dolphins from Bolivia and 56 from Colombia by extracting tissue from their tail muscles.
A limited comparison of the DNA revealed significant genetic differences between the two river-dolphin populations.
This led Ruiz-Garcia to initially estimate that the species separated five to six million years ago.
But after comparing 32 more genes from DNA in another 40 Bolivian dolphins and about 60 Colombian and Peruvian dolphins, he concluded that the separation happened much sooner—about 100,000 to 500,000 years ago.
"Bolivian dolphins are totally different molecularly from other dolphins," Ruiz-Garcia said. "After being split up, they accumulated mutations and formed a new species."
Bolivian river dolphins—especially females—also look different from their Amazon relatives.
In contrast to Amazon river dolphins, which are considered "pink," the members of this new species are a pale gray. They also have more teeth, smaller heads, and smaller bodies.
Ruiz-Garcia also considers the Bolivian species to be chubbier and rounder.
The latest genetic studies on the newly declared species allow "a very clear reconstruction of evolutionary history," said Fernando Trujillo, scientific director of Colombia's Fundación Omacha and the leader of South America's first river-dolphin census in 2007.
The River Dolphin Monitoring initiative for South America counted 3,188 river dolphins along 2,232 miles (3,593 kilometers) of the Amazon and Orinoco rivers and their tributaries. (See video of dolphins spotted during the survey.)
The Bolivian river dolphin population may include as many as 25,000 individuals, making the mammal "very abundant," Ruiz-Garcia said.
And unlike the havoc wrought on its relatives by fishers on Brazilian rivers, Bolivia's newfound dolphin can roam safely through pristine freshwater channels.
Yet the mammal still remains vulnerable to environmental disruptions, experts say.
"They're very vulnerable predators," said Paul Van Damme, a researcher for Faunagua, a Bolivian organization that monitors dolphins. "So if fish are affected, they're the first to feel the effects."
For example, if a river fills with mercury, dolphins that eat contaminated fish consume the accumulated metal.
"The dolphins are a reflection of the entire aquatic system," Van Damme said.
(Related: "Last River Porpoises Dying in Polluted Yangtze" [April 23, 2008].)
The animal's greatest threat comes from a Brazilian dam that could raise the water level, alter the river flow, or divert the migration of fish, experts say.
A water-level rise could allow dolphins from both sides of the rapids to move back and forth again for the first time in over a hundred thousand years, Ruiz-Garcia said.
But such a reunion would soon turn tragic, he added.
"The Amazon river dolphin could compete against the Bolivian river dolphin for food, and perhaps bring about its extinction."
A new regional network of 18 scientists have created a conservation plan, which includes economic activities such as dolphin-watching ecotours.
jueves, 21 de agosto de 2008
Archaeologists have unearthed a 1,900-year-old well-preserved chariot at an ancient Thracian tomb in southeastern Bulgaria, the head of the excavation said Thursday.
Daniela Agre said her team found the four-wheel chariot during excavations near the village of Borisovo, around 180 miles east of the capital, Sofia.
"This is the first time that we have found a completely preserved chariot in Bulgaria," said Agre, a senior archaeologist at the Bulgarian Academy of Sciences.
She said previous excavations had only unearthed single parts of chariots -- often because ancients sites had been looted.
At the funerary mound, the team also discovered table pottery, glass vessels and other gifts for the funeral of a wealthy Thracian aristocrat.
In a separate pit, they unearthed skeletons of two riding horses apparently sacrificed during the funeral of the nobleman, along with well preserved bronze and leather objects, some believed to horse harnesses.
The Culture Ministry confirmed the find and announced $3,900 in financial assistance for Agre's excavation.
Agre said an additional amount of $7,800 will be allocated by the Bulgarian Academy of Sciences for an initial restoration and conservation of the chariot and the other Thracian finds.
The Thracians were an ancient people that inhabited the lands of present day Bulgaria and parts of modern Greece, Turkey, Macedonia and Romania between 4,000 B.C. and the 6th century, when they were assimilated by the invading Slavs.
Some 10,000 Thracian mounds -- some of them covering monumental stone tombs -- are scattered across Bulgaria.
miércoles, 20 de agosto de 2008
If noisy chewing bothers you, never date a sea urchin.
New Zealand scientists say they have confirmed that the spiny sea creatures are responsible for a mysterious, twice-daily uproar heard underwater.
The 20- to 30-decibel noise is caused by the spiny sea creatures' teeth scraping on reefs as the hungry starfish relatives feed on algae and invertebrates.
Auckland University marine biologists Craig Radford and Andrew Jeffs solved the mystery during a study of ambient noise around northern New Zealand reefs.
The pair recorded two massive spikes in sound intensity each day: The first occurs just before dusk, the other before sunrise.
Radford said urchins had long been suspected of creating the din, but it took a series of experiments to confirm it.
"We put some urchins in a tank and got them feeding on algae, then we recorded them. The noise they were producing caused spikes at certain frequencies."
Those frequencies matched the sonic peaks the team had recorded at sea. The recorded frequencies also confirmed a series of earlier Australian experiments using Helmholtz resonance, the phenomenon of air resonating as it moves in and out of a cavity—as when you blow across a bottle opening to create a tone.
Radford said the nocturnal animals' hard shells produced just such a resonance as they fed with their five-toothed, calcium-carbonate mouths. An urchin's chewing apparatus is called an Aristotle's lantern, due to the ancient Greek philosopher's reference to the mouth's resemblance to a type of five-sided lamp.
"The noise they make is the sound of those teeth scraping on the rocks," Radford said. "A large urchin will have a low resonance frequency, while a small urchin will have a higher frequency.
"When they emerge from their crevices at dusk, they're probably really hungry, munching away quite rapidly," he said, adding that the din drops off as the night progresses.
"They have another big feed before they go to sleep" at dawn, the biologist said.
On heavily fished reefs—where depleted fish stocks have led to an increase in urchin numbers—the noise was much greater than in reserves where fishing was banned, the researchers found.
Coastal noise of similar frequency and bandwidth has been recorded near the Bahamas; San Diego, California; and Australia.
Chris Tindle, a physicist at the University of Auckland, said the urchins made more noise on dark nights around the new moon.
"It's a huge increase—20 to 30 decibels—which is an increase of a hundred to a thousand times the background level."
Biologists believe the noise of reefs—not just the munching of urchins, but also the pops of snapping shrimps and the grunts of fish—acts as a beacon. The sound may guide larval fish and crustaceans, which hatch in plankton swarms many miles out at sea, to suitable habitats.
"They have to find their way back somehow," study co-leader Radford said. "They've got really impressive swimming abilities—7.8 inches [20 centimeters] a second for a 0.2-inch-long [5-millimeter-long] animal. But they need some kind of cue to swim towards."
In a featureless blue world, he said, "there are no visual cues. So we reckon it's sound."
Tindle, the physicist and marine sound expert, noted that fish larvae have been attracted toward sound in laboratory experiments.
"Whether they are attracted by sound from way out at sea, we still don't know. But we think sea creatures use the sounds coming from different directions to find their way around, to navigate."
martes, 19 de agosto de 2008
Mati Milstein in Zippori National Park, Israel
Ruins of a pagan temple from the second century A.D. have been unearthed in the heart of a Jewish capital that existed during Israel's Roman period.
In its heyday, the temple sat within a walled courtyard abutting the most centrally-located homes in the ancient city of Zippori, about halfway between Lake Kinneret (Sea of Galilee) and the Mediterranean.
Archaeologists discovered the temple's foundations under the ruins of a Christian church that had been built on the site during the Byzantine period, which spanned the fifth and sixth centuries.
Although pagan artifacts have been found in Zippori before, the temple represents the first significant structural evidence of a pagan settlement in the capital.
"We have textual accounts from the second century indicating the presence of a pagan population in Zippori," said Zeev Weiss, lead archaeologist of the Noam Shudofsky Zippori Expedition at the Hebrew University of Jerusalem.
Based on the new find, "it is clear [the pagans] had the influence and the ability to erect this temple in the center of the city."
Zippori was a thriving multicultural center where tens of thousands of pagans, Jews, and Christians lived and worshipped, the researchers say.
Temple of the Gods
The newfound temple measures about 40-by-78 feet (12-by-24 meters). It was built just south of the decumanus, a colonnaded street running east to west that served as the main thoroughfare in most Roman cities.
The temple originally had a decorated façade, but its walls were plundered in ancient times and only the foundations have survived.
No archaeological evidence was found to indicate the nature of pagan rituals carried out in the temple. The structure was not built like a Jewish synagogue, and formal Christian churches did not exist until at least the third century A.D.
Coins minted in Zippori that date to the time of Antoninus Pius, who ruled Rome from A.D. 138 to 161, depict a temple to the Roman god Jupiter and goddess Fortuna.
"Roman religion of the time was complex and variegated and involved civic religions, mystery religions, personal religions. Romans could function in different religious contexts," said Ed Wright, director of the University of Arizona's Center for Judaic Studies.
Experts don't know exactly when the newly discovered structure ceased to function as a pagan temple.
But the large church built above its foundations indicates that the site maintained its sacred, religious character throughout the various periods of Zippori's history.
The temple "is a testament to the cosmopolitan nature of what was going on at that site," Wright added.
Beth Nakhai, also at the Arizona center, noted that significant tension existed between Jews and pagans in the period leading up to the second century A.D.
During the second and first centuries the Jewish Hasmoneans attempted forced conversions of pagans to Judaism.
"The problems between Romans and Jews culminated in the destruction of the Galilee [region] and of the first Jewish temple, and pagans often were at the vanguard and worked with the Romans," she said.
Under Roman command, pagan mercenary soldiers often led violent attacks on Jews.
"However, by the end of the second century the Jews understood they needed to live together with the Romans and pagans," said Weiss, the excavation leader.
In fact, the pagan population between the second and fourth centuries had a certain amount of influence on Jewish culture.
A fifth-century synagogue uncovered earlier in Zippori, for example, was found to include a mosaic with an image of Helios, the Greek sun god.
"Interpretation of the textual evidence," Weiss added, "indicated good ties between the Jews and the pagans."
lunes, 18 de agosto de 2008
Neanderthals and anatomically modern humans likely did not interbreed, according to a new DNA study.
The research further suggests that small population numbers helped do in our closest relatives.
Researchers sequenced the complete mitochondrial genome—genetic information passed down from mothers—of a 38,000-year-old Neanderthal thighbone found in a cave in Croatia. (Get the basics on genetics.)
The new sequence contains 16,565 DNA bases, or "letters," representing 13 genes, making it the longest stretch of Neanderthal DNA ever examined.
Mitochondrial DNA (mtDNA) is easier to isolate from ancient bones than conventional or "nuclear" DNA—which is contained in cell nuclei—because there are many mitochondria per cell.
"Also, the mtDNA genome is much smaller than the nuclear genome," said study author Richard Green of the Max Planck Institute for Evolutionary Biology in Germany.
"That's what let us finish this genome well before we finish the nuclear genome," he said.
The new findings are detailed in the August 8 issue of the journal Cell.
A Small Population
The new analysis suggests the last common ancestor of modern humans (Homo sapiens) and Neanderthals lived between 800,000 and 520,000 years ago. This is consistent with previous work on shorter stretches of Neanderthal DNA.
Contrasted with modern humans, Neanderthals exhibited a greater number of letter substitutions due to mutations in their mitochondrial DNA, although they seem to have undergone fewer evolutionary changes overall.
The fact that so many mutations—some of which may have been harmful—persisted in the Neanderthal genome could indicate the species suffered from a limited gene pool. This might be because the Neanderthal population was smaller than that of Homo sapiens living in Europe at the time.
A small population size can "diminish the power of natural selection to remove slightly deleterious evolutionary changes," Green said.
The researchers estimate the Neanderthal population living in Europe 38,000 years ago never reached more than 10,000 at any one time.
Homo neanderthalis first appeared in Europe about 300,000 years ago but mysteriously vanished about 35,000 years ago, shortly after the arrival of modern humans—Homo sapiens—in Europe.
"If there were only a few, small bands of Neanderthals, barely hanging on, then any change to their way of life could have been enough to drive them to extinction," Green said.
"One obvious change would have been the introduction of another large hominid—modern humans."
Stephen Schuster, a molecular biologist at Pennsylvania State University, said the new study should silence a lot of theories about interbreeding between Neanderthals and modern humans.
The study shows that "at least for the maternal lineage, there are no traceable genetic markers that suggest admixture of Neanderthals and modern humans," he said.
Schuster added that the researchers were exceptionally careful to isolate the Neanderthal DNA.
"Many more precautions were taken to ensure that no contamination with human DNA has flawed the analysis," he said, noting that researchers sequenced each letter about 35 times to be sure of their work.
"This was the weak point of previous reports," said Schuster, who was not involved with the study.
Thomas Gilbert, an ancient DNA expert at the University of Copenhagen in Denmark who also was not involved in the study, called the research a "step forward" and a taste of what might come when the Neanderthal nuclear DNA is finished.
The team's argument that the Neanderthal population was small 38,000 years ago is speculative, Green said, but "it's better than what we could have said before."
jueves, 14 de agosto de 2008
In a scene out of a Road Runner cartoon, a soaring sandstone arch has plummeted to the floor of the Utah desert, forever altering an iconic American landscape. But neither Wile E. Coyote nor the Acme Corporation is being fingered for this collapse in Arches National Park.
Erosion—the same force that largely formed the park's arches—and gravity are the most likely culprits for the destruction of Wall Arch sometime last week.
"They all let go after a while," Paul Henderson, the park's chief of interpretation, told the Associated Press.
Wall Arch—shown at top in an undated photo and below on August 5, 2008—was more than three stories tall and spanned 71 feet (22 meters).
Home of the famed Delicate Arch (see photo), the park boasts the world's greatest concentration of natural arches, each the product of millions of years of deposition and scouring.
miércoles, 13 de agosto de 2008
Maria Cristina Valsecchi in Rome
An ancient Greek ship recently raised off the coast of southern Sicily, Italy, is the biggest and best maintained vessel of its kind ever found, archaeologists say.
At a length of nearly 70 feet (21 meters) and a width of 21 feet (6.5 meters), the 2,500-year-old craft is the largest recovered ship built in a manner first depicted in Homer's Iliad, which is believed to date back several centuries earlier.
The ship's outer shell was built first, and the inner framework was added later. The wooden planks of the hull were sewn together with ropes, with pitch and resin used as sealant to keep out water.
Carlo Beltrame, professor of marine archaeology at the Università Ca' Foscari in Venice, said the boat, found near the town of Gela, is among the most important finds in the Mediterranean Sea.
"Greek sewn boats have been found in Italy, France, Spain, and Turkey. Gela's wreck is the most recent and the best preserved," Beltrame said.
After 25 Centuries
The Italian Coast Guard helped archaeologists pull the wreck to the surface last month.
A floating crane lifted the main segment, a 36-foot (11-meter) chunk, and dragged it to land. The remains were then plunged into a tank of fresh water to remove the salt from the wood.
"The vessel was a mercantile sailer, probably used to sail short stretches along the coast, docking frequently to load and unload," said Rosalba Panvini, head of the Cultural Heritage Department of Sicily, who directed the raising operations.
Recovered artifacts—including cups, two-handled jars called amphoras, oil lamps, pottery, and fragments of straw baskets—reveal details of the ship's journey before it sank, Panvini said.
"The vessel stopped in Athens, then in the Peloponnese Peninsula," Panvini said. "It sailed up the western coast of Greece, crossed the Otranto Channel, coasted along Italy, and pointed to Sicily."
The ship was headed for Gela, then a Greek colony. About a half mile (800 meters) off the coast, a storm probably tilted the ship. The ballast broke the hull, and the vessel went down, where it lay on the muddy seabed for 25 centuries.
In 1988 two scuba divers discovered the remains and informed the Sicilian Cultural Heritage Department.
It took 20 years to recover the whole vessel, which will now be sent to Portsmouth, U.K., to be restored before it returns to Gela. Officials hope to display the restored ship in a planned new sea museum.
A Sewn Boat
Beltrame, of the Università Ca' Foscari, said the ship—"part of a family of archaic Greek vessels"—is something of a missing link in the evolution of naval engineering.
"It shows a mix of sewing and mortise-and-tenon joints—a different technique that later prevailed in shipbuilding," Beltrame said, referring to joints in which a protrusion in one piece of wood inserts into a cavity in another.
Roberto Petriaggi of the Italian Central Institute for Restoration said Greeks were not the only people in the region to build ships using the sewing method.
"Technical knowledge spread easily around the Mediterranean Basin," he said. "We have finds proving that Egyptians and Phoenician-Punic people used that method, too."
martes, 12 de agosto de 2008
Victoria Jaggard in Baltimore, Maryland
What goes up must come down. Few on Earth would argue with the fundamental law of gravity.
But ten years ago this month the Astronomical Journal accepted a paper for publication that revealed there is a dark side of the force.
For decades physicists were convinced that gravity should be causing the expansion rate of the universe to slow.
"When I throw my keys up in the air, the gravity of the Earth makes them slow down and return to me," said Mario Livio, a theoretical physicist at the Space Telescope Science Institute (STScI) in Baltimore, Maryland.
But the study, along with an independent work released later the same year, showed that the expansion rate is actually speeding up.
This observation, Livio said, is as if "the keys suddenly went straight up toward the ceiling."
Scientists attribute the phenomenon to dark energy, a force that repels gravity. Even more surprising, measurements show that dark energy accounts for about 74 percent of the substance of the universe.
A decade later, a new suite of experiments may pin down the properties of dark energy and solve what some experts are calling "the most profound problem" in modern physics.
"This is game-changing science," Michael Turner, a cosmologist at the University of Chicago, told a packed auditorium during the Decade of Dark Energy Symposium held last week at STScI.
"We've gone from establishing the phenomenon to probing the underlying cause," he said. "We're not anywhere near the point where it's time to give dark energy a rest."
Energy in a Vacuum
So far, one of the biggest challenges for dark energy researchers is marrying observations to theory.
"We have two known, totally unsatisfactory explanations," Turner said.
One possibility is there is no dark energy, and gravity works differently than scientists think.
But "physicists are conservative. We don't want to throw away our theory of gravity when we might be able to patch it up," Adam Riess, an STScI cosmologist and lead author on one of the dark-energy discovery papers, told National Geographic News.
"Basically it all comes down to the fact that there's one relatively simple equation we work with to describe the universe," Riess said.
"Because we see this extra effect, we can either blame it on the left-hand side of the equation and say we don't understand gravity, or we can blame it on the right-hand side and say there's this extra stuff."
The extra stuff—and the leading contender for explaining dark energy—is quantum vacuum energy.
The idea is tied to quantum mechanics, which predicts that even in the vacuum of space, particles are constantly winking in and out of existence, generating energy.
The trick is that no one has been able to unify the math used in quantum mechanics, which describes the physics of the very small, with the equations in general relativity, which deal with large-scale interactions.
"The two theories use two different sets of rule books [and] we've always known that these two books are incompatible," Riess said. "Dark energy is one of the few cases in nature that really requires us to use both sets of rules."
Quantum calculations, however, predict that the amount of vacuum energy in the universe should be more than a hundred orders of magnitude greater than has been observed.
To help solve the riddle, NASA and the U.S. Department of Energy will soon announce the flagship of the Joint Dark Energy Mission (JDEM), the first program specifically designed to study dark energy.
A request for proposed probes will come out later this year and a decision will be made by 2009, Michael Salamon, program scientist for NASA's Physics of the Cosmos program, told National Geographic News.
Salamon also stressed that current NASA missions have already played a key role in measuring dark energy.
"For one, the Hubble Space Telescope has weighed in on dark energy by virtue of the measurements of supernovae," he said.
Researchers first observed accelerated expansion by studying Type Ia supernovae—the explosive deaths of white dwarf stars.
Astronomers know that each Type Ia explosion has about the same brightness.
As light from the most distant explosions travels toward Earth, it is stretched by the universe's expansion so that it appears red, a phenomenon known as redshift. The higher the redshift, the longer light has been traveling and the further back in time the supernova occurred.
Examining as many supernovae as possible can help researchers measure how fast galaxies are moving away from one another.
Supernovae studies have allowed scientists to see that dark energy has been impacting galaxies since as far back as nine billion years ago.
Other groups are looking for even earlier clues in the cosmic microwave background, the leftover radiation from the Big Bang about 13.7 billion years ago.
In 2003 NASA's Wilkinson Microwave Anisotropy Probe produced the first full map of the early microwave sky in unprecedented detail.
WMAP revealed tiny ripples in density that are the seeds of today's galaxies, Licia Verde, an astrophysicist at the Institute of Space Sciences in Bellaterra, Spain, said during the symposium.
"This is a cosmic symphony. You are really seeing sound, [and] the sound can help you understand how the instrument was made," Verde said. (Related: "Is This What the Big Bang Sounded Like?" [March 22, 2005].)
And in 2005 astronomers found that sound waves rippling through the primordial plasma 400,000 years after the Big Bang left imprints in modern nearby galaxies.
These so-called baryon acoustic oscillations offer another yardstick for measuring the expansion rate of the universe over time and putting limits on the value of dark energy.
Ultimately it will take data from a combination of methods to help unravel the mystery, the experts said.
"The name of the game is to take more measurements over the expansion history of the universe, make each of them more precise, and tighten the model for understanding how dark energy works," STScI's Riess said.
A key goal of experiments is to measure the ratio of energy density to pressure in the universe, denoted by the letter "w."
This value tells physicists "what kind of gravity a material has—whether it's repulsive or attractive—and how strong it is," Riess said.
"If [dark energy] is vacuum energy, then w will be -1 always and precisely," a find that would match quantum predictions with general relativity.
Otherwise, it might be time to re-write the rules.
Lawrence Krauss, a theoretical physicist at Case Western Reserve University, noted at the symposium that most observations currently show that the value for w is pretty close to -1.
For theorists, he quipped, "measuring w … is therefore not going to tell us anything we don't know already."
But "new windows show us new surprises. You have to do what you can do, because you don't know where the answer's going to come from."
A new color-coded image represents the first visual evidence of the existence of dark energy, a mysterious force that astronomers think is causing the expansion of the universe to speed up.
"This is the first time when we actually see the effect of dark energy in a picture," said study leader István Szapudi of the University of Hawaii. "This is the most direct evidence of dark energy."
The new image reveals the spectral fingerprints created by dark energy as it stretches huge supervoids and superclusters, structures that are roughly half a billion light-years across.
Superclusters are filled with dense clusters of galaxies, while supervoids are made up of mostly empty space.
According to the team, there is only a 1-in-200,000 chance that their detection of dark energy's fingerprints happened randomly.
Hot and Cold
Using mapping data gathered by the Sloan Digital Sky Survey, the team found evidence that dark energy alters ancient microwave radiation as it passes through superclusters and supervoids.
This diffuse radiation, called the cosmic microwave background, is the faint buzz of microwaves left over after the big bang.
Theory had predicted that as the universe expands at a constant rate, microwaves should gain energy as they enter a supercluster and lose an equal amount of energy as they leave.
The reverse should happen as microwaves travel through supervoids.
But if dark energy is causing the universe's expansion to accelerate, superclusters and supervoids should flatten out over time relative to the radiation.
Microwaves passing through superclusters would thus keep some of the gained energy as they leave, while microwaves passing through supervoids would lose energy.
The effect would create hot and cold regions in maps of the cosmic microwave background, a temperature difference that is visible in the new image as red and orange or blue areas.
Such an influence of dark energy on the microwave background has been observed before. But previous studies gave only a 1-in-20 chance that the effect was real and not the result of random temperature fluctuations.
Szapudi's team examined 50 superclusters and 50 supervoids and found with a high degree of precision that the amount of microwave heating and cooling is consistent with an accelerating universe.
"The most plausible explanation is dark energy," Szapudi said.
(Related: "Future Universe Will 'Stop Expanding,' Experts Suggest" [June 4, 2007].)
The research will be detailed in an upcoming issue of the Astrophysical Journal Letters.
Adam Riess is an astrophysicist at the Space Telescope Science Institute in Baltimore, Maryland. His team published one of the first papers on dark energy more than a decade ago.
Riess said that while the new study strengthens the case for dark energy's existence, it sheds little light on the nature of the mysterious force.
"All of the studies of this generation are good enough to just see the presence of dark energy, but usually not enough to nail down its properties to great precision," Riess said. "I think this study falls into that category."
Robert Kirshner, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, agreed.
"These measurements are too new for us to know if they will help determine the properties of dark energy," Kirshner said.
"But it is always good to have another route to show that dark energy is real."
lunes, 11 de agosto de 2008
(NaturalNews) The British government is developing a plan to track current and former prisoners by means of microchips implanted under the skin, drawing intense criticism from probation officers and civil rights groups.
As a way to reduce prison crowding, many British prisoners are currently released under electronic monitoring, carried out by means of an ankle bracelet that transmits signals like those used by mobile phones.
Now the Ministry of Justice is exploring the possibility of injecting prisoners in the back of the arm with a radio frequency identification (RFID) chip that contains information about their name, address and criminal record. Such chips, which contain a built-in antenna, could be scanned by special readers. The implantation of RFID chips in luggage, pets and livestock has become increasingly popular in recent years.
In addition to monitoring incarcerated prisoners, the ministry hopes to use the chips on those who are on probation or other conditional release. By including a satellite uplink system in the chip, police would be able to use global positioning system (GPS) technology to track subjects' exact locations at all times. According to advocates of such a measure, this could help keep sex offenders away from "forbidden" zones like schools.
Harry Fletcher, assistant general secretary of the National Association of Probation Officers, blasted the measure as degrading to the people chipped and of no benefit to probation officers.
"Knowing where offenders like pedophiles are does not mean you know what they are doing," Fletcher said. "Treating people like pieces of meat does not seem to represent an improvement in the system to me."
Shami Chakrabarti of the civil rights group Liberty had even stronger words:
"If the Home Office doesn't understand why implanting a chip in someone is worse than an ankle bracelet, they don't need a human-rights lawyer; they need a common-sense bypass."
A Rhode Island school district has announced a pilot program to monitor student movements by means of radio frequency identification (RFID) chips implanted in their schoolbags.
The Middletown School District, in partnership with MAP Information Technology Corp., has launched a pilot program to implant RFID chips into the schoolbags of 80 children at the Aquidneck School. Each chip would be programmed with a student identification number, and would be read by an external device installed in one of two school buses. The buses would also be fitted with global positioning system (GPS) devices.
Parents or school officials could log onto a school web site to see whether and when specific children had entered or exited which bus, and to look up the bus's current location as provided by the GPS device.
The American Civil Liberties Union (ACLU) has criticized the plan as an invasion of children's privacy and a potential risk to their safety.
"There's absolutely no need to be tagging children," said Stephen Brown, executive director of the ACLU's Rhode Island chapter. According to Brown, the school district should already know where its students are.
"[This program is] a solution in search of a problem," Brown said.
The school district says that its current plan is no different than other programs already in place for parents to monitor their children's school experience. For example, parents can already check on their children's attendance records and what they have for lunch, said district Superintendent Rosemary Kraeger.
Brown disputed this argument. The school is perfectly entitled to track its buses, he said, but "it's a quantitative leap to monitor children themselves." He raised the question of whether unauthorized individuals could use easily available RFID readers to find out students' private information and monitor their movements.
Because the pilot program is being provided to the school district at no cost, it did not require approval from the Rhode Island ethics commission.
viernes, 8 de agosto de 2008
Prehistoric humans consumed milk at least 8,500 years ago—up to 2,000 years earlier than previously thought—new discoveries of the the earliest known milk containers suggest.
The find shows that the culinary breakthrough of using animal milk was first developed by cow herders in northwest Turkey. The first milk users, though, are not thought to have been milk drinkers—but butter, yogurt, or cheese eaters.
"It's the earliest direct evidence for milk use anywhere," said lead study author Richard Evershed, professor of biogeochemistry at the University of Bristol, United Kingdom.
Evershed and his team analyzed more than 2,200 ceramic vessels from late Stone Age sites across Turkey, southeastern Europe, and the Middle East.
Evidence for milk fats—as opposed to meat fats—showed up clearly on unglazed pots dating back to 6500 B.C. from the Sea of Marmara region. Ancient animal bones at the site also revealed the dairy livestock used there were cattle, rather than goats or sheep.
"It's where you start to see milk really being used," Evershed said. "As you go to other locations, the cattle evidence is much weaker, and the milk residues also show up much more weakly."
The new findings will be reported tomorrow in the journal Nature.
Previously, experts argued that sheep and goats kick-started dairy production, Evershed said.
"This [study] shows that if you get into serious milk consumption, where you're using pottery and preparing your milk, it's really related to cattle suddenly coming onstream," he said.
Northwest Turkey probably provided the right environmental conditions for cattle herding, having "higher rainfall and greener grazing" than other regions where farming began, the study team wrote. The development of pottery and dairy products such as butter, yogurt, and cheese seem to go hand in hand, Evershed said.
"Pots become a very convenient medium for processing milk [into butter, yogurt, or cheese]," he said.
"They're definitely doing fairly intensive processing [for] that fat [to get] into the pot wall. It's showing up in a huge proportion of the pottery." Joachim Burger of the Institute of Archaeology at Johannes Gutenberg University Mainz, Germany, said the latest findings are highly significant.
While other recent research based on bone remains of slaughtered livestock suggests even earlier use of cows for dairy products, the new evidence is less open to doubt, he said.
"We can now spot the very probable origin of dairying in the most western part of Asia," Burger said.
Burger's own research indicates that raw milk wasn't part of the late Stone Age diet, since adults were uniformly lactose intolerant as recently as 7,000 years ago.
However an inability to drink milk wasn't necessarily a barrier to earlier dairy consumption, as lactose breaks down during processing, Burger said.
Even so, raw milk probably wasn't consumed until some 1,000 to 2,000 years later, he said.
By then dairy farming had spread into Europe, where it met a genetic mutation that allowed humans to digest lactose into adulthood, he added.
"There are some hunter-gatherers running around in central Europe not knowing they have this gene, and as soon as the dairy culture meets these people, it becomes the subject of natural selection and the whole thing explodes."
Lead study author Evershed said dairy production would have been a key driver in human civilization: It provided a reliable, year-round source of nourishment and allowed a key staple to be produced on a large scale.
In lactose-tolerant central and northern Europe, dairy farming became "the basis of our culture," according to Burger of Mainz. Dairy products gave lactose-tolerant people, he said, a major advantage over fellow Europeans.
"Without milk," he said, "everything would have been different. Thirty to 40 per cent of the middle to northern European gene pool would have been different, different people would have taken over the continent, and so on."
jueves, 7 de agosto de 2008
Invisible to the Naked Eye
The eighth planet from the sun, Neptune was the first planet located through mathematical predictions rather than through regular observations of the sky. (Galileo had recorded it as a fixed star during observations with his small telescope in 1612 and 1613.)
When Uranus didn't travel exactly as astronomers expected it to, a French mathematician, Urbain Joseph Le Verrier, proposed the position and mass of another as yet unknown planet that could cause the observed changes to Uranus's orbit. After being ignored by French astronomers, Le Verrier sent his predictions to Johann Gottfried Galle at the Berlin Observatory, who found Neptune on his first night of searching in 1846. Seventeen days later, its largest moon, Triton, was also discovered.
Nearly 2.8 billion miles (4.5 billion kilometers) from the sun, Neptune orbits the sun once every 165 years. It is invisible to the naked eye because of its extreme distance from Earth.
The main axis of Neptune's magnetic field is "tipped over" by about 47 degrees compared with the planet's rotation axis. Like Uranus, whose magnetic axis is tilted about 60 degrees from the axis of rotation, Neptune's magnetosphere undergoes wild variations during each rotation because of this misalignment. The magnetic field of Neptune is about 27 times more powerful than that of Earth.
Neptune's atmosphere extends to great depths, gradually merging into water and other "melted ices" over a heavier, approximately Earth-size solid core. Neptune's blue color is the result of methane in the atmosphere. Uranus's blue-green color is also the result of atmospheric methane, but Neptune is a more vivid, brighter blue, so there must be an unknown component that causes the more intense color that we see. The cause of Neptune's bluish tinge remains a mystery.
Despite its great distance from the sun and lower energy input, Neptune's winds are three times stronger than Jupiter's and nine times stronger than Earth's.
In 1989, Voyager 2 tracked a large, oval, dark storm in Neptune's southern hemisphere. This hurricane-like Great Dark Spot was observed to be large enough to contain the entire Earth. It spun counterclockwise and moved westward at almost 750 miles (1,200 kilometers) per hour. (Subsequent images from the Hubble Space Telescope showed no sign of the Great Dark Spot photographed by Voyager. A comparable spot appeared in 1994 in Neptune's northern hemisphere but had disappeared by 1997.) Voyager 2 also photographed clouds casting shadows on a lower cloud deck, enabling scientists to visually measure the altitude differences between the upper and lower cloud decks.
The planet has six rings of varying thicknesses, confirmed by Voyager 2's observations in 1989. Neptune's rings are believed to be relatively young and relatively short-lived.
Neptune has 13 known moons, six of which were discovered by Voyager 2. The largest, Triton, orbits Neptune in a direction opposite to the direction of the planet's rotation. Triton is the coldest body yet visited in our solar system—temperatures on its surface are about -391 degrees Fahrenheit (-235 degrees Celsius). Despite this deep freeze, Voyager 2 discovered geysers spewing icy material upward more than five miles (eight kilometers). Triton's thin atmosphere, also discovered by Voyager, has been seen from Earth several times since, and is growing warmer—although scientists do not yet know why.
miércoles, 6 de agosto de 2008
A threatened African treasure
By Virginia Morell
Photograph by Christian Ziegler
In the year 1551 a strange male animal was put on public display in Augsburg, Germany. He had humanlike fingers on his hands and feet, observers noted, and a "cheerful nature," although he also had a tendency to turn his backside to viewers. Based on an illustration of the creature, biologists think it was most likely a drill (Mandrillus leucophaeus), a baboonlike primate. Even today, more than 450 years later, drills are studied so infrequently in the wild that when a small team of biologists recently spotted a troop of them on Equatorial Guinea's Bioko Island, they collectively gasped, then sat down on the rain forest floor to watch.
The drills, the largest primates on Bioko, were climbing and feeding in a fig tree at the floor of the island's 7,000-foot-high Gran Caldera. Earlier that morning the scientists had spotted troops (each five to thirty strong) of chattering monkeys: red-eared, black colobus, and red colobus, the latter one of the most threatened of all primates.
Biologists regard Bioko Island as a living laboratory for studying how plants and animals evolve in isolation. It lies in the Gulf of Guinea, 20 miles off the west coast of Africa, one of four islands in an archipelago. The three others—São Tomé, Príncipe, and Annobón—are deepwater isles formed tens of millions of years ago and colonized by plants and animals from Africa that arrived on their shores by chance.
Bioko, however, was connected to the African mainland during each ice age, most recently about 12,000 years ago. Like an exclusive ark, the island shelters an isolated set of subspecies evolved separately from those on the mainland. There are seven species of monkeys, including the drills; four galagos (bush babies); two small antelopes (duikers); one species of porcupine; one species of tree hyrax; one species of pouched rat; and three species of scaly-tailed squirrels. There are catlike linsangs (but no lions or leopards). The roster once included forest buffalo, but they were hunted to extinction a century ago.
Add orchids, land snails, freshwater fish, amphibians, spiders, and insects—all evolving apart from their mainland relatives. In the island's interior, woodlands, grasslands, and rain forest remain much as they were when the first Portuguese explorers stepped ashore in the 15th century: largely untouched and beautiful.
It's as close to pristine as any place I've seen," said Gail Hearn, one of the researchers leading the expedition into the Gran Caldera—her 13th trip into its forested depths. A primatologist at Pennsylvania's Drexel University, Hearn made her first trip here in 1990, intending to start a long-term study of the Bioko Island drills. Instead, "I just fell in love with the whole place," she said. "We've done so much damage to this planet. Here it's undamaged and impossibly beautiful. It feels like a place where one person could make a difference."
Hearn organized the Bioko Biodiversity Protection Program (BBPP). Each January she brings together teams of scientists and American and Equatorial Guinean students for comprehensive biodiversity surveys. This year a team sponsored by National Geographic magazine, Conservation International, and the International League of Conservation Photographers joined her for a 12-day RAVE (Rapid Assessment Visual Expedition) to document as many monkeys as possible, along with the rest of Bioko's stunning variety of other species— a richness protected by the island's history but now threatened by rampant hunting.
Bioko's flora and fauna so impressed the first European visitor, 15th-century Portuguese explorer Fernão do Po, that he named the island Formosa, "beautiful." Europeans who followed wanted to plant their first African colony here.
The indigenous Bubi people, however, who had arrived from mainland Africa, refused to cooperate with the white-skinned arrivistes, scuttling every attempt at European settlement until 1827. That year Britain established a base at Malabo (now Equatorial Guinea's capital) to combat the West African slave trade. Spain, which later colonized the neighboring mainland region of Río Muni, ultimately gained control of both colonies. The two together, called Spanish Guinea, gained independence from Spain in 1968 and emerged as the Republic of Equatorial Guinea.
Settlers from the mainland belonging to the Fang ethnic group took control from the Bubi, and since the Spanish left, Bubi separatists have clashed often with government forces. Neither the Fang nor the Bubi locals, accustomed to hunting the island animals for food, share the scientists' appreciation of Bioko's unique biodiversity. Further thwarting conservation efforts is a burgeoning offshore oil industry. Vast stores of oil and natural gas were discovered in the last decades of the 1900s, and now American corporations are pumping some 400,000 barrels of oil and natural gas a day, bringing new wealth to the island. More and more people who love the taste of monkey meat have the cash to buy it.
Primatologist Tom Butynski, senior conservation biologist on the expedition, first visited Bioko in 1986 in response to an International Union for Conservation of Nature report that identified the island as an important place to survey for monkeys. At the time, no biologist had visited for more than two decades, and Butynski expected to find the monkeys hunted nearly to extinction.
Instead, he found them thriving. It turned out that to prevent Bubi uprisings the Fang government had confiscated the islanders' shotguns from 1974 to 1986, which had given the primates a reprieve. Further, large tracts of lowland rain forest that the Spanish had cleared for cocoa plantations were returning to forest after the plantations were abandoned. Monkeys were busy recolonizing the forests.
"We saw about two troops a kilometer in the Gran Caldera transect," Butynski said. The monkeys were abundant, and they were fearless. "I remember thinking how naive they were. We were able to get good, close-up looks."
But there were ominous signs as well. During the same ten-week survey, Butynski spotted 14 Fang hunters with shotguns and saw numerous traps set for duikers, monkeys, and smaller mammals. Around the same time, bush-meat sales increased in Malabo. As in much of West Africa, bush meat, from wild animals in the forest, particularly from monkeys, is prized as a delicacy, even though it costs much more than chicken in local markets.
The steady slaughter of monkeys has taken its toll. By the time of this year's BBPP survey, hunters had wiped out many of the monkeys at the northern end of the 780-square-mile island, including those in a national park. They had also started shooting the monkeys in the Gran Caldera and Southern Highlands Scientific Reserve at the south end of the island, where villagers aided by the BBPP monitor monkey numbers.
Over the past decade BBPP staff have recorded the number of monkeys in the meat markets, and the tally had reached more than 20,000 by the end of March 2008. Tens of thousands of other animals have ended up there too. It is clear that all seven monkey species are in danger of becoming extinct, and that the Equatorial Guineans could well eat their way through the island's fabled biodiversity.
Documenting the carnage has had some effect. In October 2007 the BBPP convinced Equatorial Guinea's president, Teodoro Obiang Nguema Mbasogo, to issue a ban against the hunting, selling, and consumption of primate meat. It had been in place for two months when the BBPP team arrived in January. How were the monkeys faring? And how would they react to humans who wanted to count rather than shoot them? It didn't take long for the biologists to find out.
It was dusk, a time when monkeys chatter as they settle in for the night, but the caldera forest was oddly quiet. Butynski had anticipated an especially lively chorus because all seven monkey species live in the caldera. But there was little to hear aside from the trilling hum of insects and frogs. Butynski kept to a trail, stopping every 50 feet or so to look and listen. "Well," he said at last, clearly baffled, "maybe the monkeys have moved to another part of the forest for the night."
No sooner had he finished speaking than two fur bombs the size of large dogs hurtled overhead. They splashed into the leafy crown of a nearby tree and then plunged into another, as if diving from one green pool to the next. Finally, having uttered not a single call, they disappeared over the edge of a river gorge and into the forested twilight.
Butynski, who has made dozens of primate surveys throughout Africa, pulled out his notebook to record the sighting. "That's a surprise—two drills," he said. "They must have been in the trees sleeping when they heard my voice."
The next morning Butynski set out into the caldera again. The instant he spotted a troop of red-eared monkeys, they began to give hack calls and chirps, eyes wide with terror. Mothers clutched babies to their breasts; branches bounced and limbs heaved as the monkeys scurried to get away.
Such fleeting glimpses were all the scientists came to expect. In the first three days of the survey, as the team hiked from the island's southern shore 2,000 feet up the caldera, all the monkeys they spotted gave alarm calls before vanishing into one of the steep river gorges that cut through the caldera.
On the fourth day, however, the monkeys were less afraid. After hiking up and down steep, muddy trails littered with rough lava cobbles, the team reached the caldera's northern end, its inner sanctum. Bioko receives more than 400 inches of rain a year, and although this was supposed to be the dry season, daily thunderstorms unleashed torrents. Between storms, the sun shone fierce and bright, and large beads of sweat rolled off everyone's foreheads and noses.
Despite increased hunting, the forest canopy in this distant part of the crater fairly exploded with monkeys. In their leafy shelter a dozen red-eared monkeys leaped in alarm, trailing their long copper-colored tails along the branches and shouting their nasal call of warning. Forty feet farther on, a smaller group of gnomelike black colobus interrupted their leaf breakfast to race away. Just beyond them, a single charcoal-colored Preuss's monkey jumped from a low bush where he'd been feeding into a towering mahogany tree, then leaped into a neighboring tree, his dark tail curled in a shepherd's crook over his back. In the distance troops of red colobus gave honk calls, and crowned monkeys made their throaty booms.
Occasionally, red Ogilby's and blue duikers crashed through the tangled undergrowth. Dozens of butterflies in brilliant hues and patterns to rival a Missoni gown flitted along the trail, while Jurassic Park–size earthworms and millipedes slithered into damp ravines, and pairs of gray parrots pirouetted in the sky.
Butynski jotted down each monkey troop and duiker, and stopped to inspect flowers, leaves, and fruits that monkeys had nibbled. Sometimes a strong, ammonia scent filled the air—the calling card of a troop of red colobus, one of the rarest of Bioko's monkeys. But it was the drills—even scared drills—that we all most wanted to see.
Finally we spotted a small troop of drills below us on the far side of a river feeding in a tree. The distance and rushing water extinguished the sounds and smells of our little clutch of humans, and the drills went about their business as if we weren't there. This was when we sat down to watch.
All had bushy, gray-brown pelts, and all but one were adult females or adolescents. The sole adult male was nearly twice as big as the others. He was simultaneously muscled and rotund, his Buddha belly at odds with his sharp-featured, obsidian black face. So sculpted were the angles of his cheeks, brows, and nose that he looked as if he wore a mask. White fur bristled around his face; his rump shone red, blue, and purple. Whenever he moved, the other drills got out of his way. At last, when they had eaten their fill, the troop clambered down the tree and vanished into the shadowy forest.
"Isn't it remarkable?" Butynski said after the last drill was gone. For nearly 30 minutes the biologists had been able to observe monkeys that weren't frightened of humans. "No one has studied the ecology and behavior of these animals in the wild," he said. "But that might be possible here now: Someone could habituate a troop of drills to humans and start a long-term study."
Even with the number of dead monkeys that the BBPP staff had counted in Malabo's market, the northern caldera survey revealed a substantial and healthy primate population. "They're certainly not naive anymore, and they're not as abundant as in 1986, but they're still in relatively good numbers," Butynski said. His calculations suggested that the caldera's forest shelters a little more than one monkey troop a kilometer. "It's a much lower rate of encounter than what we recorded in 1986," he noted. That year there were almost twice as many monkeys. Nevertheless, Butynski remains hopeful. "The forest is still intact, even in places where there aren't monkeys now," he said.
Intact habitat is key for Bioko's monkeys. Most species go extinct for one of two reasons: overhunting or loss of habitat. It's far easier to control the first problem, Butynski said, than to rectify the second. "Bioko is not like parts of East Africa, where people have cleared the forest to the mountaintops for agriculture. Even still, in East Africa people seldom hunt monkeys."
"I'm an optimist," he continued, taking a seat on a slope overlooking the caldera's rugged rim and vine-draped woods. Recent monsoon winds and rainstorms had left parts of the forest flattened like wilted salad. Above the rumpled greenery, red-brown African mahogany trees rose at random, their trunks tall and straight, their limbs sagging with the weight of orchids and ferns. "Just look at those mahoganies. Anywhere else, they would have been logged long ago. This place is just too remote and difficult for large numbers of hunters to get to. It's what keeps the monkeys relatively safe."
Hearn, who hiked into the caldera a few days later, is not so sure. "We used to think the monkeys were safe here, that it was just too far for the hunters to travel. But it isn't."
On a camp table she unrolled a topographical map of the Gran Caldera and surrounding area. "See this area? It's not that far from the northern edge of the crater."
Hearn thinks the hunters probably use some of the trails the BBPP has cut over the years. "They know it's a protected area, but there's no law enforcement, so they come right in and shoot monkeys and duikers," she said. "In the Malabo market they'll even tell you brazenly, 'It's a Gran Caldera monkey.' "
For the first two months after the ban on primate meat was announced, monkey carcasses vanished from the market. You could still buy all the duikers, pangolins, pythons, pouched rats, and porcupines necessary to make a fancy stew—but not monkeys.
Part of the presidential edict explains that monkey meat is unsafe because "primates are carriers of epidemics and other pathologies" that can infect people. (Indeed, epidemiologists have found several simian immunodeficiency viruses in western and central Africa primate species, among which the precursors of HIV-1 and HIV-2 have been identified.) Hearn thinks the health risk may have discouraged the trade. "No one is going to serve their family meat that could make them sick," she said.
Back in Malabo, Felix Elori, a former monkey hunter now employed in the oil industry, shook his head at Hearn's suggestion. "Monkey meat is something we've eaten since we were young; it has a good flavor and isn't bad for you," he said. "It's never made us sick."
Elori doesn't eat monkey meat himself, though. Two female drills he'd killed had had babies, a male and a female. He had nursed and raised them; now his sister keeps them in a cage. "I can't eat monkeys anymore. They look like people. And anyway, it's more economical to eat chicken."
Did we want to buy the two young drills? he wondered.
Elori thinks the whopping fine—as much as a thousand dollars—is the best reason to forgo hunting monkeys. But after the two-month lull, the trade in monkey meat may be resuming. The day after Hearn and Butynski returned with the expedition to Malabo, a drill and two red colobus went up for sale. They'd probably been killed near the caldera.
Hearn's face fell at the news. "It shows the ban alone is not enough. It's going to take law enforcement and armed forest patrols," she said. "At least they've taken the first step."
If the hunting can be stopped for good, monkeys may return to all of Bioko's forests. The caldera populations will serve as the source, Butynski says, and scientists, students, and the people of Bioko will have a rare chance to watch a natural experiment take place: monkeys reclaiming their ranges of old.
martes, 5 de agosto de 2008
Although they are sometimes called 'Salt Men,' it is not clear that all of the mummies found so far were men (at least one news account refers to one of the mummies as being a woman). News has been sketchy, and scientific studies were not begun until late 2006. Background of the accidental mummies From 1993 to December 2005, a series of salt mummies were found in the Chehrabad salt mine near Zanjan in northwestern Iran. Details of the discoveries are somewhat vague. In fact, until November 2006, information about the mummies indicated that four had been found. However, a news report in November 2006 announced that five had been discovered. Now a sixth has been discovered. According to this last account, here are the dates and details of the discovery: Salt mummy 1: This body was accidentally discovered by miners in 1993 (or perhaps 1994; different dates are given in news accounts) in the Chehrabad salt mine. According to the Tehran Times, the man was approximately 35 years old and he "lived over 1700 years ago.... He has long white hair and a beard and was discovered wearing leather boots and with some tools and a walnut in his possession." Since only the head and booted left leg were displayed, it may be that a good portion of his body was either not recovered or not well-preserved. A Wikipedia account gives a more complete list of the items found with the body: "three iron knives, a woolen half trouser, a silver needle, a sling, parts of a leather rope, a grind stone, a walnut, some pottery shares, some designed textile fragments, and finally a few broken bones." He was wearing at least one earring. Salt mummy 2: The second salt mummy, nicknamed the Twin Salt Man, was reported to have been found in November 2004 some 50 yards away from the site where the first salt mummy was discovered. The body seems to have become mostly a skeleton, though some preservation was noted: it still had hair and nails. According to mehrnews.ir, the remains of the second salt mummy's skeleton "are almost perfect, and they include parts of the skull, jaw, both arms, as well as the left and right legs and feet. Several pieces of wool cloth and a piece of a straw mat with a unique style of weaving were also discovered beside the second Salt Man." This description seems to indicate that the first salt mummy may not have been as complete. Salt mummy 3: In January 2005, the third salt mummy was discovered, buried under a two-ton rock that caused considerable damage to the body (and resulting skeleton). According to mehrnews.ir, the body was accompanied by "[s]everal items such as a leather sack full of salt, a clay tallow burner, two pairs of leather shoes, and two cow horns....[all] in excellent condition." The director of the excavation revealed that 'The...leather sack was full of crystals of salt and was completely tightened. This indicates that the owner was about to carry it out of the mine, but was suddenly crushed by the heavy rock, leaving him no chance to escape." Salt mummy 4: The fourth mummy was discovered in March 2005 and was the most preserved body to date. Researchers conducted X-ray and CT scans on the body and concluded that the mummy was a 15- or 16-year old male. Recent studies indicate that he died about 2,000 years ago. According to Iran's Cultural Heritage News Agency, excavators found a number of possessions with the young person: he wore two earrings and an iron dagger in a scabbard around his waist. Nearby were two pottery vessels (containing oil) that may have been used as lanterns. The teenager was wearing a knee-length quilted garment and thigh-high leggings (or gaiters). Controversy surrounding their discovery The first two salt mummies were discovered by miners in the Chehrabad salt mine. After the second discovery, mining operations were stopped in the areas of the mines considered useful to archaeologists. The company that owns the rights to the salt mines wishes to renew its permit with the Mines and Industries Ministry; the renewal would allow mining in even the most archaeologically sensitive areas of the mine. Archaeology and tourist groups are attempting to block this renewal, but no decision has been made as of May 2007. Where to see them The head and leg of the first salt man are displayed at the National Museum of Iran in Tehran. According to the latest report, the second, third, fourth, and fifth salt mummies are now on exhibit at Zanjan's Anthropology Museum (formerly the Zolfaqari House). The sixth remains in situ. Reports appear to indicate that Salt Mummy 4 is in the best and most complete condition, though descriptions of the six mummies are sketchy at best. Reports indicate that the bodies of the other salt mummies are no longer intact, except for Salt Mummy 4. Salt mummy 5: A report from Iran's Cultural Heritage News Agency indicates that a fifth salt mummy was discovered in December 2005, but no information about that mummy was given. When details are provided, this posting with will updated. Salt mummy 6: Reports from Iranian news agencies in early June, 2007, suggest that a sixth salt mummy has been found. No specific information about the mummy has been provided to date, however. Scientists will not excavate the mummy and remove it from the mine until better preservation techniques have been found. Archaeologists worry that the first five salt mummies are in danger of deteriorating unless better preservation techniques are found. In the meantime, the sixth salt mummy will be left under a pile of salt and dirt until excavators have found a better way to preserved him. A new report states that the sixth mummy dates from the Roman era and is the body of a person buried under rocks during an earthquake. Archaeologists in Iran have contacted scientists at the German Mining Museum in Bochum for help in studying the mummy, the Chehrabad Mine, and the plant life found there