Researchers Discover Greek Temple In Albania Dating Back To 6th Century B.C.

A fragment of a tablet recovered from the Albanian site. (Image courtesy of University of Cincinnati)

Researchers from the University of Cincinnati’s Classics faculty are preparing to make their first public presentation of details surrounding their find of one of the earliest Greek temples in the Adriatic region north of Greece.
The UC researchers, along with colleagues from the International Centre for Albanian Archaeology and the Institute of Archaeology, Tirana, will be presenting on their new work on Friday, Jan. 6, 2006, in Montreal at the annual meeting of the Archaeological Institute of America.

"This is a case where a hunch about the potential of a site is paying off in the discovery of a temple that has extraordinary and singular importance to Albanian archaeology and to the history of Greek colonization in the Adriatic Sea region," says Jack L. Davis, the Carl W. Blegen Professor of Greek Archaeology at the University of Cincinnati and co-director of the international research team working at the site. "We are gaining the tools for an understanding of religious life in the 6th and 5th centuries B.C., a part of the early history of Apollonia of which little is known."

Presenting with Davis will be UC colleagues Sharon R. Stocker, Kathleen Lynch and Evi Gorogianni, along with Albanian researchers Iris Pojani and Vangjel Dimo.

The temple they have discovered, located in coastal Albania, is only the fifth known stone temple in Albania. It stands out both because of its age and its size.

The site is just outside of the ancient Greek city-state of Apollonia, and dates back to the late 6th century B.C. That would put its use in the Archaic and Classical periods, a time from which little has been recovered from inside the acropolis of Apollonia.

So far, in addition to remains of sacrificial meals and broken fineware pottery, substantial numbers of Classical and Hellenistic figurines have been found, although the principal deity of the sanctuary remains undetermined at this point.

"It now seems likely that the life of the sanctuary began not long after the founding of the Apollonia colony," Davis says. "What we discover here will contribute much to our understanding of religious life in the 6th and 5th centuries B.C., a period that is hardly known from previous excavations inside the borders of Apollonia itself."

The researchers suspected the temple was large, but only recently determined its approximate proportions: 14 meters by 40 meters.

The history of excavations on the site, located on a farm known by the family name of Bonjaket, dates back more than 40 years ago, when a farmer’s tractor uncovered terracotta figurines outside the walls of Apollonia. The site appeared to include remains of a sanctuary. An Albanian-Russian archeological team explored it, finding traces of brick walls and dating hundreds of the figurines to the 4th-2nd century B.C. Their work went unnoticed, however: the rupture in Soviet-Albanian relations in 1960 kept the team from publishing much about their work

In 2002, Albanian archeologists, working collaboratively with Davis and other UC colleagues, conducted a surface survey. Measuring off a grid in the low-lying land between the ancient walls of Apollonia and the Adriatic Sea, team members walked, painstakingly searching for artifacts hidden in the dirt and vegetation.

They found more figurines, the foot of a statue, a late Greek inscription, a small stone altar – and pottery from a much earlier date.

The combination of figurines, "which often point to ancient places of worship," and the older pottery led the team to believe the site was older than they first thought, Davis said.

"It seemed to us that the sanctuary was already being used in the Archaic period," some 100-350 years earlier than the 1960 team had believed, he said.

Then came the kicker: a family who owns a section of the land told Albanian team leader Lorenc Bejko that they had uncovered a foundation made of large, regular blocks as they were building a new house back in 1997.

Now, the UC-Albanian team needed to dig. Evidence was mounting that a large temple, not just a sanctuary, had occupied the site. The archeologists wanted to "trace lines of (the) massive ashlar blocks" that had been disturbed during the building of the family’s house, Davis said.

After careful negotiations with the Bonjaket family, major work began in 2004 to unearth the true scope of the apparent temple. After two seasons spent at the site, momentum continues to build that many details about the religious history of the temple and the Apollonia colony are about to be determined.

Can the science of biogeography find Osama bin Laden?

Osama bin Laden, the FBI's most wanted terrorist, has proved an extremely elusive quarry. Could biology and geography help crack the case—and net the man with a $25-million bounty on his head for plotting numerous terrorist strikes?

Two geography professors and five of their undergraduate students at the University of California, Los Angeles (U.C.L.A.), recently published an analysis (pdf) in MIT International Review proposing that biogeographic theories, in conjunction with readily available mapping data, could help pinpoint the al-Qaeda leader's whereabouts, assuming he's still alive. Their "musing" over this possibility, the researchers wrote, led them to three buildings in Parachinar in Pakistan, where they believe bin Laden may be holed up.

They fingered the spots based on two theories on the distribution of biological species. One of them, the so-called distance-decay theory, states that the similarity and correlation between species at two locations decreases as the distance between them increases. As such, the geographers figure bin Laden can't have gone far—he is believed to have fled Afghanistan's Tora Bora region at the end of 2001—if he wished to remain on similar terrain in a familiar cultural environment.

Island biogeography, the other tool in the team's theoretical analysis, posits that large, closely spaced pockets of life (islands) support more species and are less ravaged by extinction than small, isolated islands. With cities standing in for islands, the researchers speculate that bin Laden would most likely hide out in a large town with minimal isolation, because even though there's more risk of being spotted he would also have access to resources needed to stay alive as well as under cover.

These theories, they say, point to Parachinar in Pakistan's Federally Administered Tribal Areas. Within the town, whose relative populousness was determined by its nighttime glow, the U.C.L.A. group identified three structures that best fit a list of characteristics that might be necessary for bin Laden, based on his height (believed to be 6'4" to 6'6"), his requirements for security and privacy, and his possible need for dialysis (to filter waste from blood, a process normally done by kidneys, but bin Laden's are rumored to be damaged), which would require electrification. At the very least, the study's authors write, U.S. intelligence agencies should closely monitor Parachinar and the three suspect buildings to disprove their hypotheses, perhaps refining the predictions in the process.

A geographic information systems (GIS) scientist we contacted, who asked to remain anonymous at the request of his employer, says that in theory, "spatial models of some sort could be used with the latest technology to predict" bin Laden's whereabouts. But he added quickly that "whether or not the predictions of such models are valid is another matter."

Distance-decay and island biogeography theories, the GIS scientist adds, "were developed for purposes of understanding the distribution of species, not the movements of individuals." Another problem with the U.C.L.A. team's approach is that it is untested, he says: "Why didn't the authors use historical information on bin Laden's whereabouts to both train and test the models?"

In a rebuttal to the U.C.L.A. paper published on the MIT International Review Web site, Murtaza Haider, a retail management professor at Ryerson University in Toronto, said the authors omitted several key details from their analysis, most notably pertinent political or historical context.

"Since I am from the Northwest Frontier Province," Haider wrote, "I find it a little odd that Osama may be hiding in the only Shiite majority town in the entire tribal region of Pakistan"—al-Qaeda is an extremist Sunni group.

The study's authors "may have used spatial analysis to determine the probable hideout of Osama," he said, but "they certainly overlooked history and anthropology, which would have explained the gory sectarian rivalries between the Shiites of Parachinar and the Sunni supporters of Osama bin Laden."

By the way, if bin Laden was hiding out in any of those places, chances are he isn't anymore: the researchers put out a press release on their findings for all—including bin Laden's Web-savvy supporters—to read. The researchers did share their paper with the FBI before submitting it for publication, and an FBI spokesperson told the Los Angeles Times that the information had been passed on to people working the case.

The Future of Man--How Will Evolution Change Humans?

Contrary to popular belief, humans continue to evolve. Our bodies and brains are not the same as our ancestors' were—or as our descendants' will be

* People commonly assume that our species has evolved very little since prehistoric times. Yet new studies using genetic information from populations around the globe suggest that the pace of human evolution increased with the advent of agriculture and cities.
* If we are still evolving, what might our species look like in a millennium should we survive whatever environ­mental and social surprises are in store for us? Specu­la­tion ranges from the hopeful to the dystopian.

When you ask for opinions about what future humans might look like, you typically get one of two answers. Some people trot out the old science-fiction vision of a big-brained human with a high forehead and higher intellect. Others say humans are no longer evolving physically—that technology has put an end to the brutal logic of natural selection and that evolution is now purely cultural.

The big-brain vision has no real scientific basis. The fossil record of skull sizes over the past several thousand generations shows that our days of rapid increase in brain size are long over. Accordingly, most scientists a few years ago would have taken the view that human physical evolution has ceased. But DNA techniques, which probe genomes both present and past, have unleashed a revolution in studying evolution; they tell a different story. Not only has Homo sapiens been doing some major genetic reshuffling since our species formed, but the rate of human evolution may, if anything, have increased. In common with other organisms, we underwent the most dramatic changes to our body shape when our species first appeared, but we continue to show genetically induced changes to our physiology and perhaps to our behavior as well. Until fairly recently in our history, human races in various parts of the world were becoming more rather than less distinct. Even today the conditions of modern life could be driving changes to genes for certain behavioral traits.

If giant brains are not in store for us, then what is? Will we become larger or smaller, smarter or dumber? How will the emergence of new diseases and the rise in global temperature shape us? Will a new human species arise one day? Or does the future evolution of humanity lie not within our genes but within our technology, as we augment our brains and bodies with silicon and steel? Are we but the builders of the next dominant intelligence on the earth—the machines?


The Far and Recent Past

Tracking human evolution used to be the province solely of paleontologists, those of us who study fossil bones from the ancient past. The human family, called the Hominidae, goes back at least seven million years to the appearance of a small proto-human called Sahelanthropus tchadensis.Since then, our family has had a still disputed, but rather diverse, number of new species in it—as many as nine that we know of and others surely still hidden in the notoriously poor hominid fossil record. Because early human skeletons rarely made it into sedimentary rocks before they were scavenged, this estimate changes from year to year as new discoveries and new interpretations of past bones make their way into print [see “Once We Were Not Alone,” by Ian Tattersall; Scientific American, January 2000, and “An Ancestor to Call Our Own,” by Kate Wong; Scientific American, January 2003].

Each new species evolved when a small group of hominids somehow became separated from the larger population for many generations and then found itself in novel environmental conditions favoring a different set of adaptations. Cut off from kin, the small population went its own genetic route and eventually its members could no longer successfully reproduce with the parent population.

The fossil record tells us that the oldest member of our own species lived 195,000 years ago in what is now Ethiopia. From there it spread out across the globe. By 10,000 years ago modern humans had successfully colonized each of the continents save Antarctica, and adaptations to these many locales (among other evolutionary forces) led to what we loosely call races. Groups living in different places evidently retained just enough connections with one another to avoid evolving into separate species. With the globe fairly well covered, one might expect that the time for evolving was pretty much finished.But that turns out not to be the case. In a study published a year ago Henry C. Harpending of the University of Utah, John Hawks of the University of Wisconsin–Madison and their colleagues analyzed data from the international haplotype map of the human genome [see “Traces of a Distant Past,” by Gary Stix; Scientific American, July 2008]. They focused on genetic markers in 270 people from four groups: Han Chinese, Japanese, Yoruba and northern Europeans. They found that at least 7 percent of human genes underwent evolution as recently as 5,000 years ago. Much of the change involved adaptations to particular environments, both natural and human-shaped. For example, few people in China and Africa can digest fresh milk into adulthood, whereas almost everyone in Sweden and Denmark can. This ability presumably arose as an adaptation to dairy farming.

Another study by Pardis C. Sabeti of Harvard University and her colleagues used huge data sets of genetic variation to look for signs of natural selection across the human genome. More than 300 regions on the genome showed evidence of recent changes that improved people’s chance of surviving and reproducing. Examples included resistance to one of Africa’s great scourges, the virus causing Lassa fever; partial resistance to other diseases, such as malaria, among some African populations; changes in skin pigmentation and development of hair follicles among Asians; and the evolution of lighter skin and blue eyes in northern Europe.

Harpending and Hawks’s team estimated that over the past 10,000 years humans have evolved as much as 100 times faster than at any other time since the split of the earliest hominid from the ancestors of modern chimpanzees. The team attributed the quickening pace to the variety of environments humans moved into and the changes in living conditions brought about by agriculture and cities. It was not farming per se or the changes in the landscape that conversion of wild habitat to tamed fields brought about but the often lethal combination of poor sanitation, novel diet and emerging diseases (from other humans as well as domesticated animals). Although some researchers have expressed reservations about these estimates, the basic point seems clear: humans are first-class evolvers.

Unnatural Selection
During the past century, our species’ circumstances have again changed. The geographic isolation of different groups has been broached by the ease of transportation and the dismantling of social barriers that once kept racial groups apart. Never before has the human gene pool had such widespread mixing of what were heretofore entirely separated local populations of our species. In fact, the mobility of humanity might be bringing about the homogenization of our species. At the same time, natural selection in our species is being thwarted by our technology and our medicines. In most parts of the globe, babies no longer die in large numbers. People with genetic damage that was once fatal now live and have children. Natural predators no longer affect the rules of survival.

Steve Jones of University College London has argued that human evolution has essentially ceased. At a Royal Society of Edinburgh debate in 2002 entitled “Is Evolution Over?” he said: “Things have simply stopped getting better, or worse, for our species. If you want to know what Utopia is like, just look around—this is it.” Jones suggested that, at least in the developed world, almost everyone has the opportunity to reach reproductive age, and the poor and rich have an equal chance of having children. Inherited disease resistance—say, to HIV—may still confer a survival advantage, but culture, rather than genetic inheritance, is now the deciding factor in whether people live or die. In short, evolution may now be memetic—involving ideas—rather than genetic [see “The Power of Memes,” by Susan Blackmore; Scientific American, October 2000].Another point of view is that genetic evolution continues to occur even today, but in reverse. Certain characteristics of modern life may drive evolutionary change that does not make us fitter for survival—or that even makes us less fit. Innumerable college students have noticed one potential way that such “inadaptive” evolution could happen: they put off reproduction while many of their high school classmates who did not make the grade started having babies right away. If less intelligent parents have more kids, then intelligence is a Darwinian liability in today’s world, and average intelligence might evolve downward.

Such arguments have a long and contentious history. One of the many counterarguments is that human intelligence is made up of many different abilities encoded by a large number of genes. It thus has a low degree of heritability, the rate at which one generation passes the trait to the next. Natural selection acts only on heritable traits. Researchers actively debate just how heritable intelligence is [see “The Search for Intelligence,” by Carl Zimmer; Scientific American, October 2008], but they have found no sign that average intelligence is in fact decreasing.

Even if intelligence is not at risk, some scientists speculate that other, more heritable traits could be accumulating in the human species and that these traits are anything but good for us. For instance, behavior disorders such as Tourette’s syndrome and attention-deficit hyperactivity disorder (ADHD) may, unlike intelligence, be encoded by but a few genes, in which case their heritability could be very high. If these disorders increase one’s chance of having children, they could become ever more prevalent with each generation. David Comings, a specialist in these two diseases, has argued in scientific papers and a 1996 book that these conditions are more common than they used to be and that evolution might be one reason: women with these syndromes are less likely to attend college and thus tend to have more children than those who do not. But other researchers have brought forward serious concerns about Comings’s methodology. It is not clear whether the incidence of Tourette’s and ADHD is, in fact, increasing at all. Research into these areas is also made more difficult because of the perceived social stigma that many of these afflictions attach to their carriers.

Although these particular examples do not pass scientific muster, the basic line of reasoning is plausible. We tend to think of evolution as something involving structural modification, yet it can and does affect things invisible from the outside—behavior. Many people carry the genes making them susceptible to alcoholism, drug addiction and other problems. Most do not succumb, because genes are not destiny; their effect depends on our environment. But others do succumb, and their problems may affect whether they survive and how many children they have. These changes in fertility are enough for natural selection to act on. Much of humanity’s future evolution may involve new sets of behaviors that spread in response to changing social and environmental conditions. Of course, humans differ from other species in that we do not have to accept this Darwinian logic passively.

Directed Evolution
We have directed the evolution of so many animal and plant species. Why not direct our own? Why wait for natural selection to do the job when we can do it faster and in ways beneficial to ourselves? In the area of human behavior, for example, geneticists are tracking down the genetic components not just of problems and disorders but also of overall disposition and various aspects of sexuality and competitiveness, many of which may be at least partially heritable. Over time, elaborate screening for genetic makeup may become commonplace, and people will be offered drugs based on the results.The next step will be to actually change people’s genes. That could conceivably be done in two ways: by changing genes in the relevant organ only (gene therapy) or by altering the entire genome of an individual (what is known as germ-line therapy). Researchers are still struggling with the limited goal of gene therapy to cure disease. But if they can ever pull off germ-line therapy, it will help not only the individual in question but also his or her children. The major obstacle to genetic engineering in humans will be the sheer complexity of the genome. Genes usually perform more than one function; conversely, functions are usually encoded by more than one gene. Because of this property, known as pleiotropy, tinkering with one gene can have unintended consequences.

Why try at all, then? The pressure to change genes will probably come from parents wanting to guarantee their child is a boy or a girl; to endow their children with beauty, intelligence, musical talent or a sweet nature; or to try to ensure that they are not helplessly disposed to become mean-spirited, depressed, hyperactive or even criminal. The motives are there, and they are very strong. Just as the push by parents to genetically enhance their children could be socially irresistible, so, too, would be an assault on human aging. Many recent studies suggest that aging is not so much a simple wearing down of body parts as it is a programmed decay, much of it genetically controlled. If so, the next century of genetic research could unlock numerous genes controlling many aspects of aging. Those genes could be manipulated.

Assuming that it does become practical to change our genes, how will that affect the future evolution of humanity? Probably a great deal. Suppose parents alter their unborn children to enhance their intelligence, looks and longevity. If the kids are as smart as they are long-lived—an IQ of 150 and a lifespan of 150 years—they could have more children and accumulate more wealth than the rest of us. Socially they will probably be drawn to others of their kind. With some kind of self-imposed geographic or social segregation, their genes might drift and eventually differentiate as a new species. One day, then, we will have it in our power to bring a new human species into this world. Whether we choose to follow such a path is for our descendants to decide.

The Borg Route
Even less predictable than our use of genetic manipulation is our manipulation of machines—or they of us. Is the ultimate evolution of our species one of symbiosis with machines, a human-machine synthesis? Many writers have predicted that we might link our bodies with robots or upload our minds into computers. In fact, we are already dependent on machines. As much as we build them to meet human needs, we have structured our own lives and behavior to meet theirs. As machines become ever more complex and interconnected, we will be forced to try to accommodate them. This view was starkly enunciated by George Dyson in his 1998 book Darwin among the Machines: “Everything that human beings are doing to make it easier to operate computer networks is at the same time, but for different reasons, making it easier for computer networks to operate human beings.... Darwinian evolution, in one of those paradoxes with which life abounds, may be a victim of its own success, unable to keep up with non-Darwinian processes that it has spawned.”

Our technological prowess threatens to swamp the old ways that evolution works. Consider two different views of the future taken from an essay in 2004 by evolutionary philosopher Nick Bostrom of the University of Oxford. On the optimistic side, he wrote: “The big picture shows an overarching trend towards increasing levels of complexity, knowledge, consciousness, and coordinated goal-directed organization, a trend which, not to put too fine a point on it, we may label ‘progress.’ What we shall call the Panglossian view maintains that this past record of success gives us good grounds for thinking that evolution (whether biological, memetic or technological) will continue to lead in desirable directions.”Although the reference to “progress” surely causes the late evolutionary biologist Steven Jay Gould to spin in his grave, the point can be made. As Gould argued, fossils, including those from our own ancestors, tell us that evolutionary change is not a continuous thing; rather it occurs in fits and starts, and it is certainly not “progressive” or directional. Organisms get smaller as well as larger. But evolution has indeed shown at least one vector: toward increasing complexity. Perhaps that is the fate of future human evolution: greater complexity through some combination of anatomy, physiology or behavior. If we continue to adapt (and undertake some deft planetary engineering), there is no genetic or evolutionary reason that we could not still be around to watch the sun die. Unlike aging, extinction does not appear to be genetically programmed into any species.

The darker side is all too familiar. Bostrom (who must be a very unsettled man) offered a vision of how uploading our brains into computers could spell our doom. Advanced artificial intelligence could encapsulate the various components of human cognition and reassemble those components into something that is no longer human—and that would render us obsolete. Bostrom predicted the following course of events: “Some human individuals upload and make many copies of themselves. Meanwhile, there is gradual progress in neuroscience and artificial intelligence, and eventually it becomes possible to isolate individual cognitive modules and connect them up to modules from other uploaded minds.... Modules that conform to a common standard would be better able to communicate and cooperate with other modules and would therefore be economically more productive, creating a pressure for standardization.... There might be no niche for mental architectures of a human kind.”

As if technological obsolescence were not disturbing enough, Bostrom concluded with an even more dreary possibility: if machine efficiency became the new measure of evolutionary fitness, much of what we regard as quintessentially human would be weeded out of our lineage. He wrote: “The extravagancies and fun that arguably give human life much of its meaning—humor, love, game-playing, art, sex, dancing, social conversation, philosophy, literature, scientific discovery, food and drink, friendship, parenting, sport—we have preferences and capabilities that make us engage in such activities, and these predispositions were adaptive in our species’ evolutionary past; but what ground do we have for being confident that these or similar activities will continue to be adaptive in the future? Perhaps what will maximize fitness in the future will be nothing but nonstop high-intensity drudgery, work of a drab and repetitive nature, aimed at improving the eighth decimal of some economic output measure.”

In short, humanity’s future could take one of several routes, assuming we do not go extinct:

Stasis. We largely stay as we are now, with minor tweaks, mainly as races merge.

Speciation. A new human species evolves on either this planet or another.

Symbiosis with machines. Integration of machines and human brains produces a collective intelligence that may or may not retain the qualities we now recognize as human.

Quo vadis Homo futuris?

Google Earth to Plato buffs: Lost continent of Atlantis still waiting to be found

Google Earth can do many things: gaze into the cosmos, track the flu, and even stalk your friends. What it doesn’t do—or hasn’t yet, anyway—is discover the mythical lost continent of Atlantis.

A British tabloid, The Sun, claimed Friday that an image captured by users of Google Ocean “could show” Atlantis, a gigantic island described by Plato as a utopian society that “was swallowed up by the sea and vanished” after a great war with Athens. Plato was vague about the island’s location (and whether it was merely a parable or an actual place is hotly debated online), but the Sun claimed that a “host of crisscrossing lines, looking like a map of a vast metropolis” 620 miles off of Africa’s western coast, near the Canary Islands, “seem too vast and organized to be caused naturally.”

Alas, Google had to go and spoil all the fun. In a statement, the company explained that the software had actually spotted “an artifact of the data collection process.”

“Bathymetric (or seafloor terrain) data is often collected from boats using sonar to take measurements of the sea floor," the statement said. "The lines reflect the path of the boat as it gathers the data. The fact there are blank spots between each of these lines is a sign of how little we really know about the world's oceans."

This is hardly the first time Atlantis has been “discovered.” Explorers have previously claimed to have located it in the Canary Islands, as well as off the Spanish coast, in the Mediterranean Sea, the Azores, the Caribbean, Tunisia, Sweden, Iceland and South America, we noted in this 2004 piece in Scientific American.

Thawing Martian Ice Age Left Telltale Water Tracks

Signs of repeated ice and snow melt in a mid-latitude gully may point to the most recent water activity on the Red Planet's surface

A new analysis of puzzling gullylike features on Mars offers further evidence that water flowed on the Red Planet's surface, perhaps as recently as several hundred thousand years ago. The findings bolster the case that melting snow from a departed Martian ice age carved these gullies, rather than shifting sands or other "dry" phenomena.

The paper, published today in the journal Geology, examines one of the many gullies on crater and valley walls visible in satellite images of the Martian surface. The cause and age of these channels are the subject of debate.

To help settle the matter, the paper's authors relied on a bit of geologic good luck to date one of the features. Images snapped by the HiRISE (High Resolution Imaging Science Experiment) camera onboard the Mars Reconnaissance Orbiter showed a typical gully system about 0.62 mile (one kilometer) long with a deltalike fan at its bottom—similar to features on Antarctic Dry Valleys and on dry mountains after rain in the U.S. Southwest.

The researchers noticed an array of craters dotting the delta's western portion [lower left in the photograph] and suspected that a large meteorite impact had peppered the area with ejected rocks to form these so-called secondary craters. Sure enough, the pattern of pockmarks led like a trail of bread crumbs to a large impact crater some 62 miles (100 kilometers) southwest. Infrared imaging assisted in matching the impact events.

"We had hoped to find the source of these secondary craters, and voilà, we found a link to this big crater," says lead study author Samuel Schon, a graduate student at Brown University's Planetary Geosciences Group.

To estimate the age of planetary surfaces, geologists look to craters. Earth, with its active tectonics and dynamic weather, has few impact craters on its relatively young surface; Earth's weatherless, geologically dead moon, however, is heavily cratered and has very old surfaces (except where ancient lava flows formed large, flat, dark areas called maria, or "seas"). Because much of the rest of the studied Martian gully system is craterless [at right in the photograph], those areas are believed to be geologically younger than the cratered portions, Schon says.

By dating the primary Martian crater that sprayed the gully to 1.25 million years old—which qualifies as very young in Mars's 4.6-billion-year history—Schon and his colleagues demonstrated that an estimated three subsequent outflows in the gully system must be younger than the first, which was bombarded by ejecta.

"Dating these gullies has been a big problem," says Michael Meyer, lead scientist for NASA's Mars Exploration Program. "But because these guys dated the nearby crater, you have proof that the water activity is recent."

Today, virtually all water on Mars is believed to be trapped underground or frozen near the poles, where the Phoenix lander found ice mere inches under the soil this past summer. Unresolved research, though, has hinted at very recent water activity on Mars—within the past decade. A tantalizing ribbon of light-colored material mimicking water flow appeared in satellite images of a crater wall sometime between 1999 and 2005. But materials scientists have shown that avalanching sands can also create this effect, and later studies cast doubt on water as the culprit.For this newly studied gully system, the evidence of multiple outflows discredits drifting sands, and the classic alluvial pattern of the delta does not fit with sedimentary shifts, Schon says. Jack Holt, a geophysicist at the University of Texas at Austin, agrees "melting an ice deposit caused by an ice age seems like a more feasible scenario."

Mars has an axial tilt (similar to Earth's) that causes seasons, but the Red Planet wobbles more on its axis than Earth does because it lacks the gravitational stabilization that our relatively large moon provides. Coupled with a more elliptical orbit than Earth, Mars likely has major swings in climate and temperature over short spans of geologic time. Other recent discoveries, including massive Martian glaciers still present under blankets of crustal debris in the mid-latitudes, support theories of past ice ages on the Red Planet.

"This new study is yet more strong evidence for widespread deposition of ice during a different climatic regime," says Holt, who led the glacier work.

Due to frigid surface temperatures and low atmospheric pressure, liquid water could not persist for long on Mars's surface nowadays. But scientists continue to hunt for signs of liquid water in the recent and distant past—not least for the clues they may provide about the possible development of extraterrestrial life when Mars's climate was more hospitable.

"We think the heyday for water on Mars was over three billion years ago," Schon says. "With this gully system, we're talking about a relative trickle compared to then, but nonetheless, this happened, and now we know when."

Dolphin-Inspired Man-Made Fin Works Swimmingly

Lunocet swimmers have already hit about eight miles per hour, almost twice the speed of Michael Phelps at his fastest

The human body does many things well, but swimming isn't one of them. We're embarrassingly inefficient in the water, able to convert just 3 or 4 percent of our energy into forward motion. (Even with swim fins, we're only 10 to 15 percent more efficient.) But a new, dolphin-inspired fin promises to fuel the biggest change in human-powered swimming in decades, putting beyond-Olympian speeds within reach of just about anyone.

Culminating decades of research, engineer and inventor Ted Ciamillo, an inventor and engineer in Athens, Ga., who made his name (and fortune) building high-performance bicycle brakes, created what he has dubbed the Lunocet, a 2.5-pound (1.1-kilogram) monofin made of carbon fiber and fiberglass that attaches to an aluminum foot plate at a precise 30-degree angle. With almost three times the surface area of conventional swim fins, the semiflexible Lunocet provides plenty of propulsion. The key to the 42-inch- (one-meter-) wide fin's speed: its shape and angle, both of which are modeled with scientific precision on a dolphin's tail.

These sprinters of the sea can swim up to 33 miles (53 kilometers) per hour and turn up to 80 percent of their energy into thrust.

"The mechanism functions like a wing to generate a lift force," which is directed forward and turned into thrust, says Frank Fish, a marine biologist at West Chester University of Pennsylvania. "This propulsive mechanism is extremely efficient compared to conventional rigid marine propellers." Fish, a specialist in the swimming morphology of marine mammals, provided Ciamillo with data from CAT scans of dolphins' tails that he used to design his fins, which went on the market last year for $1,800 each.

Lunocet users have already hit about eight miles (13 kilometers) per hour, nearly twice as fast as Olympic Gold Medal swimmer Michael Phelps at his speediest.

Using the Lunocet, some swimmers are close to being able to breach completely out of the water, like whales. Ciamillo envisions a new high-speed, free-diving community of swimmers united around "hydrotouring": long-distance swimming expeditions using Lunocets to cover dozens of miles a day, with participants carrying streamlined, waterproof packs containing only a global positioning system (GPS), satellite phone, and enough food and water for a few nights on shore.The fin could also have a "profound effect" on the sport of free diving (where divers compete to see who can go the deepest while holding their breath), says Grant Graves, president of the U.S. Apnea Association, the country's leading competitive free diving organization. Its efficiency could let those who dive by holding their breath set depth records by going deeper more quickly. Still, speed isn't everything underwater. "The faster you go, the harder you have to work," since drag increases as the square of velocity, he says. "There's a sweet spot between friction, speed, oxygen consumption and distance."

Another attempt to balance that equation is taking shape in the labs of inventor and entrepreneur Dean Kamen's company, DEKA Research and Development Corp. [www.dekaresearch.com] in Manchester, N.H. The creators of the Segway two-wheel, one-person electric vehicle are working with the Defense Sciences Office of the U.S. military's Defense Advanced Research Projects Agency (DARPA), the research arm of the U.S. Defense Department, to develop the PowerSwim, a high-efficiency, human-powered propulsion system for combat and reconnaissance swimmers. A fiberglass spar (pole) clamped between the calves holds two oscillating foils of carbon fiber, a wide one at the hips and a narrower one at the feet. A shallow squatting motion makes the foils undulate, creating vortices that push forward against the trailing edge and provide thrust.

This design uses the largest leg muscles instead of just the calves and ankles, says DARPA Defense Sciences PowerSwim Program Manager Lt. Col. John Lowell. Top speed is about 2.5 miles (four kilometers) per hour, which still works with scuba gear, but more important, the PowerSwim is 70 to 75 percent efficient at translating effort into propulsion. "We're getting to the point where its getting harder to imagine getting much better than that," Lowell says. DARPA hopes to have working prototypes ready for military divers to test by the end of the year.

Ciamillo is also planning a demo the Lunocet for the Marine Corps's amphibious unit, and is continually refining the fin's pitch control mechanism, which dictates the angle between fin and feet, in an attempt to improve efficiency and speed. He notes that he won't be patenting the Lunocet's design. "If you're taking ideas from nature," he says, "how can you then go to the patent office and say these are mine?"

Ancient Mass Graves of Soldiers, Babies Found in Italy

Archeologists have uncovered thousands of graves holding the remains of fifth-century BC soldiers near the ancient Greek colony of Himera, in Italy.Also included in the burials were arrowheads, amphorae, and infants with baby bottles-like vessels. Researchers think the adult skeletons are from soldiers who died fighting the Carthaginians in a famous 480 BC battle described by Greek historian Herodotus of Halicarnassus.

More than 10,000 graves containing ancient amphorae, "baby bottles," and the bodies of soldiers who fought the Carthaginians were found near the ancient Greek colony of Himera, in Italy, archaeologists announced recently. (See photos.)

"It's probably the largest Greek necropolis in Sicily," said Stefano Vassallo, the lead archaeologist of the team that made the discoveries, in September.

The ancient burial ground was uncovered during the construction of a railway extension.

"The remains of Himera's buildings had been known and studied for a long time, and we knew there should be some graves. We didn't expect so many graves", said Vassallo, who works for the Italian province of Palermo's government.

"Each [mass grave] contains from 15 to 25 skeletons. They were all young healthy men and they all died a violent death. Some of the skeletons have broken skulls and in some cases we found the tips of the arrows that killed them," Vassallo said.

He thinks the human remains are from soldiers who died fighting the Carthaginians in a famous 480 B.C. battle described by Greek historian Herodotus of Halicarnassus.

He adds that they still don't know the extent of the necropolis or how many graves it contains.

A Rich Town and Two Bloody Battles

Founded in 648 B.C. by Greek settlers, Himera was a rich seaport trading colony. The city was situated on the northern coast of Sicily, a few miles from the Phoenician outpost of Solunto.

"Himera had a privileged role in commercial exchanges between Phoenicians, Greeks, and Etruscans," said Clemente Marconi, professor of Greek art and archaeology at the Institute of Fine Arts at New York University.

In 480 B.C. Carthage, or present-day Tunisia, sent an army against Himera. "Greeks and Carthaginians fought a bloody battle in the plain under the town walls, right on the burial ground," Vassallo said. "People from Himera won."

In 409 B.C., Carthage waged a new war against Himera, conquered, and razed the town. "All the people were slaughtered or deported and the colony never rose again," Vassallo said.

Remains of Adults and Babies

Archaeologists at Himera also unearthed the skeletons of many newborn babies in some of the mass graves.

"Infant mortality was very high at the times," Vassallo said. "We found the tiny skeletons placed inside funerary amphorae, like in a womb, alongside small terracotta vases called guttus, with spouts like present-day feeding bottles."

Researchers will examine the skeletons in an effort to gather information about the population's health, lifestyle, and eating habits.

"People from Himera were very tall, about 175 centimeters [69 inches]," Vassallo said. "Unusual for the times."

New York University's Marconi said he thinks the discovery is extremely important.

"Thanks to the big number of burials, we will gather precious information about funerary rituals in Himera: the way they took care of the bodies, preserved the remains, and perpetuated the memory of the dead. Such rituals reflect social structure," Marconi said.

Finds will be restored and put on display in a new museum to be built in the nearby town of Termini Imerese. The Palermo government is working out a plan to create a national archaeological park to protect the area, Vassallo said.

Ancient Camels Butchered in Colorado, Stone Tools Show?

In May 2008 a landscaping crew accidentally happened upon a stash of 83 stone tools (above), including well-crafted knives, small blades, and axes.About 13,000 years ago, humans in the Clovis culture may have used the tools to butcher American camels in what is now the city of Boulder, a February 2009 analysis of blood residue suggests.

Humans may have hunted down Ice Age camels 13,000 years ago on what are now the streets of Boulder, Colorado, a new analysis of ancient tools suggests.

Blood residue on stone blades found recently in a Boulder resident's backyard could be the first evidence that the implements were used to butcher horses and American camels.

The extinct camel species had almost no hump and was slightly taller than a modern camel, with a shoulder height of seven feet (about two meters).

The tools are thought to be products of the Clovis people, early Americans known for their distinctive spearheads.

"The really amazing thing about this kind of find is [that] it represents an instant in time," said research leader Douglas Bamforth, an anthropologist at the University of Colorado, Boulder.

More than likely, one or two humans buried the artifacts on the banks of an ancient stream with the intention of coming back later to collect them.

Shared Craftsmanship

The stash, found accidentally in May 2008 by a landscaping crew, contained 83 stone tools ranging from well-crafted knives to small blades and axes.

Only a handful of such caches have ever been found, and the discovery may give researchers clues as to how the mysterious Clovis people lived.

For instance, close similarities between one two-sided tool found in the Boulder site and another from Wyoming suggests that craftmanship was shared between groups.

It also suggests that the Clovis journeyed vast distances, forging relationships along the way, said Bamforth, who presented his unpublished research at a recent meeting.

A "reasonable guess" is that the Clovis carried supplies of high-quality stone through game-rich but stone-poor regions where the material would be needed to make new tools, said Bruce Huckell, senior research coordinator at the University of New Mexico's Maxwell Museum of Anthropology.

The American camel, which went extinct at the end of the last ice age, roamed alongside many giant beasts—including woolly mammoths, dire wolves, sabertooths, and giant ground sloths.

But when asked about the tools' use in butchering camels, Huckell said blood residue tests can be controversial.

"Certainly it's exciting to see reports that indicate that a part-stone tool was used to butcher a particular animal in the remote past," Huckell said.

"[But it's] not a method that has met with universal acceptance among archaeologists."

Curious Octopus Floods Aquarium

A dexterous octopus (center) disassembled part of its tank in February 2009 at California's Santa Monica Pier Aquarium—high jinks typical of the intelligent creatures, experts say.

For one dexterous octopus, an attempt at a great escape turned into a great flood Thursday at the Santa Monica Pier Aquarium in California.

The female California two-spotted octopus swam to the top of her tank, disassembled a valve with her powerful arm, and released at least 200 gallons (757 liters) of seawater into nearby exhibits and offices.
The foot-long (0.3-meter) creature remained in her tank and survived her ordeal. But the aquarium's brand-new floors weren't so lucky.

Such high jinks are typical of the invertebrates' still unexplained smarts, experts say.

"Octopuses have a wonderful combination of intelligence, tremendous manipulative ability, curiosity, and strength," said Jennifer Mather, a psychology professor at Canada's University of Lethbridge who has studied cognition in octopuses.

"So the result is that everybody who has ever kept octopuses has a string of stories about how octopuses can go where they want in aquariums."

Unbelievably Brainy?

Many octopuses show behavior that suggests curiosity, consciousness, and even a sense of humor, said Eugene Linden, author of the 2002 book The Octopus and the Orangutan: More True Tales of Animal Intrigue, Intelligence, and Ingenuity.

In one instance, an octopus given a slightly spoiled shrimp stuffed it down the drain while maintaining eye contact with its keeper, Linden said.

Wild octopuses have also been found to maintain "homes" and can remember where they've been in their neighborhood, pointing to a sort of self-awareness, Lethbridge's Mather said.

But it's hard to directly prove that octopuses are intelligent.

A smart animal that has the lowly clam for a cousin already "flies in the face of conventional wisdom of where you look for intelligence," Linden said. Also, many scientists believe that intelligent beings are social, learn from others, and need a long lifespan to accrue brainpower.

Octopuses live only about a year and are solitary animals.

curious octopus

"It's enjoyable to speculate that nature doesn't always follow our rules [when] it decides to create an intelligent being," Linden said.

Fast Decisions

The University of Lethbridge's Mather suggests octopuses may have evolved braininess to cope with a highly complex environment—usually coral reefs—where they must make lightning-fast, life-or-death decisions.

For example, the animals are extremely flexible, able to fit their boneless bodies through tiny cracks. Some species can change color in a thirtieth of a second.

As for the crafty cephalopod in Santa Monica, aquarium staffers have rigged her tank with clamps and tape to thwart future getaways, the Los Angeles Times reported.

But, as Mather pointed out, there "isn't an awful lot [that will] stop them."

Black hole constant makes unexpected appearance

A constant akin to one that emerges when an object, such as a small black hole, orbits a massive rotating black hole (shown in an artist's rendition) shows up in a simple Newtonian system.

If you were orbiting a rotating black hole, you might be in for a wild ride of dizzying and seemingly unpredictable gyrations. Yet more than 40 years ago, a physicist found a mathematical constant that revealed regularity in that ride. Now a similar constant has been discovered in a mild-mannered Newtonian system, reports a paper in the Feb. 13 Physical Review Letters.

The findings could be mere coincidence, nothing more than a mathematical curiosity, comments astrophysicist Saul Teukolsky of Cornell University. But, he says, they could shed light on the mysterious conditions of rotating black holes, which are predicted to exist by Einstein’s general relativity equations.

Rotating black holes are thought to be the end point in the evolution of massive stars that collapse under their own gravity when their nuclear fuel is exhausted. For black holes with no electrical charge, the gravitational field depends on only mass and spin (hence the saying that “black holes have no hair”). Strangely, this simplicity holds true even though a rotating black hole doesn’t have perfect symmetry. Like any rotating object, a black hole becomes slightly flattened because of centrifugal forces (like Earth, which bulges at the equator).

That loss of symmetry in a massive rotating black hole should suggest that anything orbiting it, such as a neutron star, would behave erratically. Such orbits do appear chaotic, says physicist Clifford Will of Washington University in St. Louis, author of the new paper.

“The orbits go wild — they gyrate and spin, they’re incredibly complex. It’s fantastic,” Will says.

But in 1968, physicist Brandon Carter discovered a mathematical constant that showed the orbits are predictable.

“Black holes have this extra constant that restores the regularity of the orbits,” Teukolsky says. “It’s a mystery. Every other situation where we have these extra constants, we have symmetry. But there’s no symmetry for an orbiting black hole — that’s why it is regarded as a miracle.”

There’s no obvious reason why the Carter constant should emerge in the general-relativity description of spinning black holes, says Teukolsky. By looking for it in other places, scientists might learn more of the specialness of the conditions surrounding such black holes.

Now Will has found a Carter-like constant in a Newtonian system. The equations describing a third body orbiting two masses that are arranged just right yield a similar constant.

“I still don’t completely understand what it is telling us,” says Will, who says he was amazed at the appearance of the constant.

Other physicists also aren’t sure what specialness leads to the constant in both systems.

“I have no idea — to me this is a mystery,” says Teukolsky, who worked on similar questions as part of his Ph.D. thesis in the 1970s. “I’m still baffled.”

Will is still pushing the pencil, adding higher-order terms to the equations. He says that the constant disappears when he adds the mathematical terms for frame-dragging, the ability of a rotating body to drag spacetime around it, akin to the swirling exhibited around a spoon stirring a bowl of molasses. However, adding the next order of terms brings the constant back, Will says.

“It’s mathematically intriguing,” says E. Sterl Phinney of the California Institute of Technology in Pasadena. Similar work was published in 2003 by English astrophysicist Donald Lynden-Bell, Phinney says. “I don’t know what it means, or that it has deep meaning.”

Hubble Resolves Puzzle About Loner Starburst Galaxy

This image taken by NASA's Hubble Space Telescope showcases the brilliant core of one of the most active galaxies in our local neighborhood. The entire core is 5,000 light-years wide. (Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA), and A. Aloisi (STScI/ESA))

Astronomers have long puzzled over why a small, nearby, isolated galaxy is pumping out new stars faster than any galaxy in our local neighborhood.
Now NASA's Hubble Space Telescope has helped astronomers solve the mystery of the loner starburst galaxy, called NGC 1569, by showing that it is one and a half times farther away than astronomers thought.

The extra distance places the galaxy in the middle of a group of about 10 galaxies centered on the spiral galaxy IC 342. Gravitational interactions among the group's galaxies may be compressing gas in NGC 1569 and igniting the star-birthing frenzy.

"Now the starburst activity seen in NGC 1569 makes sense, because the galaxy is probably interacting with other galaxies in the group," said the study's leader, Alessandra Aloisi of the Space Telescope Science Institute in Baltimore, Md., and the European Space Agency. "Those interactions are probably fueling the star birth."

The farther distance not only means that the galaxy is intrinsically brighter, but also that it is producing stars two times faster than first thought. The galaxy is forming stars at a rate more than 100 times higher than the rate in the Milky Way. This high star-formation rate has been almost continuous for the past 100 million years.

Discovered by William Herschel in 1788, NGC 1569 is home to three of the most massive star clusters ever discovered in the local universe. Each cluster contains more than a million stars.

"This is a prime example of the type of massive starbursts that drive the evolution of galaxies in the distant and young universe," said team member Roeland van der Marel of the Space Telescope Science Institute. "Starburst galaxies can only be studied in detail in the nearby universe, where they are much rarer. Hubble observations of our galactic neighborhood, including this study, are helping astronomers put together a complete picture of the galaxies in our local universe. Put the puzzle pieces in the right place, as for NGC 1569, and the picture makes much more sense."

Aloisi and her team actually discovered the new distance by accident. They were using Hubble's Advanced Camera for Surveys to hunt in NGC 1569 for the kind of red giant stars (stars near the ends of their lives) that shine because of fusion of helium nuclei in their cores. These stars are dimmer than bright red giants without helium burning, but when detected, they can be used to estimate the galaxy's age.

"When we found no obvious trace of them, we suspected that the galaxy was farther away than originally believed," said Aaron Grocholski of the Space Telescope Science Institute and the lead author on a paper describing the results. "We could only see the brightest red giant stars, but we were able to use these stars to recalibrate the galaxy's distance." Bright red giants are reliable "standard candles" for measuring distance because they all shine at the same brightness. Once astronomers know a star's true brightness, they can calculate its distance from Earth.

Previous estimates of the galaxy's distance made with ground-based telescopes were unreliable because they looked at the galaxy's crowded core and were unable to resolve individual red giant stars.

The Hubble study observed both the galaxy's cluttered core and its sparsely populated outer fringes. The sharpness of Hubble's Advanced Camera pinpointed individual red giants, which led to a precise distance to the galaxy. Astronomers measured the galaxy's distance at nearly 11 million light-years away, about 4 million light-years farther than the old distance.

"This was a serendipitous discovery," Aloisi said. "Hubble didn't go deep enough to see the faintest red giant stars we were hunting for because the galaxy is farther away than we thought. However, by capturing the entire population of the brightest red giant stars, we were able to calculate a precise distance to NGC 1569 and resolve the puzzle about the galaxy's extreme starburst activity."

The results were published in the Oct. 20 issue of the Astrophysical Journal Letters.

The science team for the NGC 1569 observations consists of Alessandra Aloisi and Marco Sirianni (STScI/ESA), Aaron Grocholski, Jennifer Mack, and Roeland van der Marel (STScI), Luca Angeretti, Donatella Romano, and Monica Tosi (INAF-OAB), and Francesca Annibali, Laura Greggio, and Enrico Held (INAF-OAP).

Origin of Life On Earth: Scientists Unlock Mystery Of Molecular Machine

The amino acid (green) slithers into the chemical reaction center, moving through an evolutionarily ancient corridor of the ribosome (purple). The amino acid is delivered to the reaction core by the transfer RNA molecule (yellow). (Image courtesy of Los Alamos National Laboratory)

ScienceDaily (Mar. 1, 2009) — A major mystery about the origins of life has been resolved. According to a study published in the journal Nature, two Université de Montréal scientists have proposed a new theory for how a universal molecular machine, the ribosome, managed to self-assemble as a critical step in the genesis of all life on Earth.
"While the ribosome is a complex structure it features a clear hierarchy that emerged based on basic chemical principles," says Sergey Steinberg, a Université de Montréal biochemistry professor who made his discovery with student Konstantin Bokov. "In the absence of such explanations, some people could imagine unseen forces at work when such complex structures emerge in nature."

What is a ribosome?

The ribosome is an enormous molecule responsible for translating the messages carried in the genetic code of all organisms into the workhorse molecules of the cell – proteins – that carry out all functions, including replicating the genome itself. As the world celebrates the bicentennial anniversary of the Father of Evolution, Charles Darwin, Prof. Steinberg's theory brings the scientific community even deeper into the study of the origins of life.

By examining the molecular self-organizing processes that preceded the living cell, the point where time begins for biologists, Prof. Steinberg goes further than Darwin and the many evolutionary biologists who followed could have imagined

By the standards of biological molecules, ribosomes are immense. Though visible only through lenses of the most powerful microscopes, comparing most other biological molecules to this behemoth is like comparing a tricycle to a jumbo jet. Having spent years gazing at the detailed structure of the ribosome, Prof. Steinberg pondered how such an immense and complex structure could have assembled itself from smaller building blocks that existed on the early Earth.

From the simple to the complex

The key breakthrough came when he realized that the ribosome is organized by a set of simple structural rules and that it had to be assembled from basic building blocks in a very specific order; otherwise it would have fallen apart. He then showed with mathematical rigor that the construction of the ribosome likely followed an ordered series of steps to form the structure found in the first living cell. To this day, that structure exists almost unchanged in our own cells.

Chemists have been able to observe many examples of self-organizing behavior with simple molecules, yet explaining the complex self-assembly of biomolecules had not been so obvious.

"Thanks to the research of Sergey Steinberg and Konstantin Bokov, scientists now have a glimpse of one key event that emerged spontaneously out of the primordial chemical soup of the early Earth," explains Stephen Michnick, a Université de Montréal biochemistry professor and Canada Research Chair in Integrative Genomics. "Perhaps in the near future we may look forward to more discoveries that will take us beyond the world of Darwin into an understanding of the basic chemical principles that drove the emergence of life on our planet and perhaps beyond."

Professor Steinberg's research is supported by Canadian Institutes of Health Research and by the National Science and Engineering Research Council.

Voyager Squashes View Of Solar System

NASAs Voyager 2 spacecraft as it studies the outer limits of the heliosphere - a magnetic 'bubble' around the solar system that is created by the solar wind. Scientists observed the magnetic bubble is not spherical, but pressed inward in the southern hemisphere, according to recent data published as part of a series of papers in this week's (July 3, 2008) Nature. These findings help build up a picture of how the sun interacts with the surrounding interstellar medium. (Credit: Image courtesy of NASA/Jet Propulsion Laboratory)

Scientists using data from NASA's Voyager 2 spacecraft have observed the bubble of solar wind surrounding the solar system is not round, but has a squashed shape, according to recent data published as part of a series of papers in Nature the week of July 3.
The beginning of the transition zone between the heliosphere (the solar wind bubble) and the rest of interstellar space is known as the 'termination shock'. Scientists report that Voyager 2 crossed this boundary closer to the sun than expected, suggesting that the heliosphere in this region is pushed inward, closer to the sun, by an interstellar magnetic field. These findings help build up a picture of how the sun interacts with the surrounding interstellar medium.

Launched in 1977, two Voyager spacecraft were originally sent to fly by and observe Jupiter and Saturn. Voyager 1's flight path at Saturn bent it up and away from the ecliptic, the plane in which most planets orbit the sun. Voyager 2's trajectory continued in the ecliptic, allowing the spacecraft two more planetary encounters, the distant planets Uranus and then Neptune. The Voyager spacecraft are the most distant human-made objects in space -- with Voyager 1 more distant than Voyager 2.

The current mission of Voyager 2, and its sister Voyager 1, is to reach the edge of interstellar space.

Poison-Arrow Killings Surge in Africa Elephant Poaching

Five elephants, including this one, have been found killed for their ivory in Kenya's Tsavo National Park region in early 2009—some by poison and some by bullets.

Elephant poachers are increasingly using poison arrows and spears in southern Kenya, a February 2009 report says. The methods are harder to trace and draw less immediate attention than gunshots.

Poachers on the hunt for ivory have stepped up their use of poison arrows and spears to kill elephants in southern Kenya, according to conservationists who say the techniques are harder to trace than gun attacks.

The surge is part of a nationwide increase in attacks on the animals, according to a report issued earlier this month by the Amboseli Trust for Elephants.

Since the start of 2008, 19 elephants have been killed and another 25 wounded by spears, arrows, and bullets in the Amboseli region near Mount Kilimanjaro, the report says.

Of those killed, ten animals had had their tusks removed—the first time in many years that ivory has been taken from Amboseli elephants, the group said.

In the last six weeks, poachers have also killed five elephants in the nearby Tsavo National Park region. Some were felled by gunfire, others by poisoned arrows.

Conservation groups fear that the rise in poaching is a result of a UN decision to allow the first ivory auction in a decade in 2008, an event that yielded more than a million U.S. dollars from Chinese and Japanese bidders.

"Since the one-off ivory sales from southern Africa countries late last year, we have noted an unprecedented rise of elephant poaching incidents in Tsavo," Jonathan Kirui, Tsavo National Park's assistant director, said in a statement released Monday.

"Our security team is on full alert and is going full force to ensure that the poachers are deterred."

"Soft" Killing

Officials with the Amboseli trust think poachers are using a poison made from acocanthera shrubs, which are common in Kenya.

"The toxin is frighteningly effective and there is no antidote," the report says.

Poisoning elephants attracts far less attention than shooting them with a gun, wildlife officials note. "When you shoot an elephant—that loud bang—people will hear it," said Patrick Omondi, head of species conservation at the Kenya Wildlife Service.

"You shoot this elephant with a poisoned arrow, then they follow the elephant until it dies, and then they pluck out the ivory," Omondi said. "It's a soft way of killing."

In 2008 the Kenya Wildlife Service reported 98 elephants killed for their ivory, double the 2007 figure, Omondi said.

Conservationists from the Amboseli Trust and Kenya Wildlife Service link the rise in attacks to demand from Chinese workers constructing a road near Amboseli National Park and to lucrative trade across the border into Tanzania.

The wildlife service has launched an investigation into the trade and is collecting evidence in hopes of arresting those involved, Omondi said.

In a recent interview with a local East African newspaper, Chinese embassy spokesperson Liu Bo denied that Chinese in Kenya are smuggling ivory.

Threatened But Healthy

Officials estimate that 1,600 elephants currently live in the Amboseli region. While the attacks are disturbing, the local population remains healthy, conservationists say.

"The threat is there—the indication is that there is a high demand for ivory," Omondi said.

"But it has not hit the elephants in a way that we are going to lose our Amboseli elephants."

Oldest Human Footprints With Modern Anatomy Found

About 1.5 million years ago, human ancestors walked upright with a spring in their steps just as modern humans do today, suggests an analysis of ancient footprints found in northern Kenya.

The prints are the oldest known to show modern foot anatomy. The discovery also helps round out the picture of a cooling and drying episode in Africa that compelled tree-dwelling human ancestors to venture into the open landscape for food, said John Harris, a paleoanthropologist at Rutgers University in New Brunswick, New Jersey.

The ancient footprints indicate a rounded heel, pronounced arch, and a big toe parallel to the other toes just as modern humans have, Harris noted. The big toes of chimpanzees, by contrast, splay outward, which is useful for grasping branches.

"We've lost that, but what we've created is a platform from which we can step up on and balance ourselves on and push off on in bipedal locomotion," said Harris, who is a co-author of a paper describing the footprints in tomorrow's issue of the journal Science.

Embedded in Mud

The rare prints were found embedded in what was once muddy soil among tracks of ancient birds, lions, antelopes, and other critters. Harris said the print makers were likely walking to or from a watering hole.

The size and spacing of the footprints indicate they were made by people with bodies similar to modern humans. Given their age, the prints were most likely made by Homo erectus, the first human ancestor to sport long legs and short arms, Harris said.

At the time H. erectus emerged, about 1.5 to 1.7 million years ago, global climate was cooling and the African landscape was changing from tropical forest to open savanna. Food sources—nuts, fruits, vegetables, and animals—were becoming more dispersed.

"There was selection for creatures, including ourselves, that could walk over longer distances on the landscape between the patches of more productive food," Harris said.

Adapted for Running?

Daniel Lieberman is an anthropologist at Harvard University in Cambridge, Massachusetts, and an expert on the evolution of human locomotion. In an email exchange, he said the "prints unambiguously indicate that by 1.5 million years ago H. erectus had a human-like foot."

Other human ancestors such as the australopithecines may have also been efficient walkers, he said. But a more modern foot anatomy with spring-like arches and short toes is important for running, which may have contributed to the success of H. erectus.

"I would be surprised if this were not the case," Lieberman said. "Because how could H. erectus have hunted more than a million years before the invention of tipped spears—as we know it did—without the ability to run well?"