Trees Make Ants Chemically Dependent, Turn Them Into Indentured Servants

Trees Make Ants Chemically Dependent, Turn Them Into Indentured Servants

November 12, 2013 | by Lisa Winter
IFL Science

Ants on Acacia Tree

Ants on Acacia Tree (Photo credit: Ryan Somma)

There are all kinds of mutually beneficial relationships that exist in nature in which two seemingly unconnected species live in harmony and provide vital services for one another. This does not always result in both parties benefiting equally – but as long as it still works, it keeps on going. A recent study has shown that certain Central American ants live on and defend a particular tree not because they want to, but because enzymes in the tree’s nectar have made it impossible for them to get food anywhere else. The research team was led by Martin Heil of Cinvestav Unidad Irapuato in Mexico and was published in Ecology Letters.

The acacia tree is covered in pods that can be taken by insects. Colonies of Pseudomyrmex ferrugineus patrol the tree, protecting the pods. Some species of acacia tree even have thorns large enough for the ants to move into. In turn for their defense against predators like termites, the tree produces nectar for the ants. The nectar is rich in sucrose, a type of sugar. Using an enzyme called invertase, the ants break up the large sucrose molecules into smaller bits which can then be used to generate energy. About eight years ago, Heil’s previous research showed that the adult ants don’t even make invertase, but it is produced by the tree and can be found in the nectar. It is a classic textbook example of mutualism, or so we all thought. The truth, as it seems, is a bit more complicated.

Five years ago, Heil found out that young ants do produce invertase, but that ability is lost at some point during life. In recent years, he has searched for the answer which, he would find out, almost seems like one of the biggest betrayals in mutualism history: the tree stops the ants from producing their own digestive enzymes. Included in the sucrose and invertase is chitinase: an enzyme that blocks invertase production.

While it is true that the ants protect the tree in exchange for food, they do so because they have no other options. They are completely unable to eat from any other source, because they rely on the invertase from the acacia’s nectar. So, the tree gives them exactly what they need to live, but only because it made them invertase-deficient in the first place. The tree makes out like a bandit by having armies of ants to protect it, who will never be able to leave.

This methodology has vague (and highly anthropomorphized) connotations to Münchausen syndrome by proxy (MSbP) in which someone believes they are sick and have a dedicated caretaker, but it turns out that the caretaker was the one making them sick in the first place. In the case of the acacia tree, it is damning the ants to an eternity of servitude on top of blocking the invertase production to ensure it is the ants’ only food source.

On a very basic level, however, this is astoundingly impressive. Solely through genetic mutations over countless generations, the acacia tree has adapted a way to protect itself from predators and the ants won’t be able to leave, leaving the tree vulnerable. It just happened to evolve this way, which is absolutely amazing. You win this one, acacia tree.

Chemists show life on Earth was not a fluke

24 October 2013, 6.16am BST

In them, began life. University of Utah

How life came about from inanimate sets of chemicals is still a mystery. While we may never be certain which chemicals existed on prebiotic Earth, we can study the biomolecules we have today to give us clues about what happened three billion years ago.

Now scientists have used a set of these biomolecules to show one way in which life might have started. They found that these molecular machines, which exist in living cells today, don’t do much on their own. But as soon as they add fatty chemicals, which form a primitive version of a cell membrane, it got the chemicals close enough to react in a highly specific manner.

This form of self-organisation is remarkable, and figuring out how it happens may hold the key to understanding life on earth formed and perhaps how it might form on other planets.

The 1987 Nobel Prize in Chemistry was given to chemists for showing how complex molecules can perform very precise functions. One of the behaviours of these molecules is called self-organisation, where different chemicals come together because of the many forces acting on them and become a molecular machine capable of even more complex tasks. Each living cell is full of these molecular machines.

Pasquale Stano at the University of Roma Tre and his colleagues were interested in using this knowledge to probe the origins of life. To make things simple, they chose an assembly that produces proteins. This assembly consists of 83 different molecules including DNA, which was programmed to produce a special green fluorescent protein (GFP) that could be observed under a confocal microscope.

The assembly can only produce proteins when its molecules are close enough together to react with each other. When the assembly is diluted with water, they can no longer react. This is one reason that the insides of living cells are very crowded, concentrated places: to allow the chemistry of life to work.

In order to recreate this molecular crowding, Stano added a chemical called POPC to the dilute solution. Fatty molecules such as POPC do not mix with water, and when placed into water they automatically form liposomes. These have a very similar structure to the membranes of living cells and are widely used to study the evolution of cells.

Stano reports in the journal Angewandte Chemie that many of these liposomes trapped some molecules of the assembly. But remarkably, five in every 1,000 such liposomes had all 83 of the molecules needed to produce a protein. These liposomes produced large amount of GFP and glowed green under a microscope.

Computer calculations reveal that even by chance, five liposomes in 1,000 could not have trapped all 83 molecules of the assembly. Their calculated probability for even one such liposome to form is essentially zero. The fact that any such liposomes formed and that GFP was produced means something quite unique is happening.

Stano and his colleagues do not yet understand why this happened. It may yet be a random process that a better statistical model will explain. It may be that these particular molecules are suited to this kind of self-organisation because they are already highly evolved. An important next step is to see if similar, but less complex, molecules are also capable of this feat.

Regardless of the limitations, Stano’s experiment has shown for the first time that self-assembly of molecular machines into simple cells may be an inevitable physical process. Finding out how exactly this self-assembly happens will mean taking a big step towards understanding how life was formed.

What Created This Mysterious “Picket Fence” in the Amazon?

It’s probably the only picket fence in the Amazon, but scientists have no idea what made it or what its purpose might be.

Georgia Tech doctoral student Troy Alexander stumbled upon these two-centimeter-long white structures growing on trees in Peru on June 7.

The picket fence of the Amazon. Photograph courtesy Troy S. Alexander, Tambopata Research Center

Since then, the intricate handiwork has baffled scientists. Although most agree it was likely built by an insect, no one can identify the species that built it, or what the fence might be protecting.

“I thought anything this distinctive would have been discovered already,” Alexander said.

“I’ve talked to researchers worldwide and haven’t found an answer, so I don’t feel crazy saying that I’ve found a new species, or at the very least, a new behavior,” he said.

“What Is That?”

Alexander made the discovery when he was volunteering at the Tambopata Research Center as part of the Tambopata Macaw Project. He noticed something unusual on one of the blue tarps the group was working under for shade. (Read more about a new species of decoy spider that was discovered at Tambopata.)

“I looked up and thought, ‘What is that?’” Alexander said. “At the time, I thought a Urodid moth had started building a cocoon and then just got distracted and didn’t finish or got eaten.”

Alexander in the Peruvian Amazon. Photograph courtesy Troy S. Alexander, Tambopata Research Center

Intrigued, Alexander snapped a few photos to show an entomologist back at the center. But the expert had never seen anything like it. Neither had anyone on Reddit’s What’s This Bug group, where Alexander also posted the photo.

Soon after, he saw several more of these structures, which consist of a tall, white conical post in the middle, surrounded by what can only be described as a small, circular white picket fence.

Having spotted several, Alexander knew that this wasn’t just the efforts of a distracted moth. He posted these new photos on Reddit and got a few suggestions, but nothing conclusive. Alexander’s leading hypothesis—one proposed by a Reddit reader—is that the structure was spun and built by a spider instead of a standard web. (Also see “Photos: World’s Biggest, Strongest Spider Webs Found.”)

Instead of spinnerets, or silk-spinning organs, some spiders have what’s called a cribellum, which, instead of spinning silk fibers, pushes the molecules through a fine mesh.

“Looking more closely at the photos, I thought, yeah, that does make sense. It does look like the silk was just pushed through a mesh,” Alexander said.

Unveiling the Mystery Builder

Alexander, who’s working on his Ph.D. in natural drug discovery, said he intends to stick with his chosen field, even with the glut of attention he has received from his Amazonian discovery.

The mystery object is less than an inch long. Photograph courtesy Troy S. Alexander, Tambopata Research Center

He added he’d like to go back to Tambopata, although he doesn’t have plans to return in the immediate future. Luckily though, an entomologist will be traveling to the research center this winter to try to identify what’s building the forest fences.

When asked what he would name his find if it proved to be a new species, Alexander said he would need to learn some Latin so he could incorporate the word for “fence” in the name.

The Bestial Virus: The Infectious Origins of Werewolves, Zombies & Vampires – Body Horrors |

By Rebecca Kreston | July 11, 2013 12:45 pm

Rabies is one of mankind’s long-feared diseases. And rightfully so: for centuries, a bite from a crazed, slavering animal was almost always a guarantee of a slow warping of the mind and a pained, gruesome demise. A death sentence.

I just recently finished reading about our long and tragic relationship with rabies in Rabid: A Cultural History Of The World’s Most Diabolical Virus by Bill Wasik and Monica Murphy, easily one of the finest non-fiction narratives on infectious diseases. The husband-and-wife duo have synergistically joined forces as a journalist and public health veterinarian to write a witty and thorough telling of the history and cultural mythology of the virus and the animals that it infects, us included.

The book charts the earliest mentions of rabies treatment in ancient Greek and medieval Islamic medicine, and follows its manifestations in folklore, literature and cinema, and to its eventual taming in the development of Pasteur’s hard-won vaccine. It’s a delightful read spanning the stories of Odysseus and American frontiersmen, of the Brontë sisters and Stephen King, and of Christian saints and vampires.

A canine suspected of being rabid that had been exhibiting symptoms of rabies, including restlessness and overall uncharacteristic aggressive behavior. Image: CDC.

Upon finishing the book, I felt that there appeared to be no aspect of our culture that this virus hasn’t played a role in infecting and transfiguring. But the most intriguing aspect of the book is its brief sojourn into the development of some of our most historically endurable monsters: vampires, werewolves and zombies. The authors write,

Between the fifteenth and the eighteenth centuries, Europe gestated two enduring legends whose part-human, part-animal villains bite their victims, thereby passing along their own degraded conditions.

Rabies is a scourge as old as human civilization, and the terror of its manifestation is a fundamental human fear, because it challenges the boundary of humanity itself. That is, it troubles the line where man ends and animal begins – for the rabid bite is the visible symbol of the animal infecting the human, of an illness in a creature metamorphosing demonstrably into that same illness in a person.

A hospitalized man is shown in restraints as he suffers from the final stages of the rabies infection, 1959. Image: CDC

Doesn’t this sound familiar? It’s the de-evolution of man into something not quite human but subhuman. An unrecognizable family member demonically possessed by some unfathomable but instantly recognizable animal instinct. The frothing at the mouth, the lucid madness, the lost humanity: it’s all here and stems from our ancient, tragic history with rabies and canines. To be human is a sacred and inviolable thing; rabies infection breaches that principal. The animal bite and the transmission of disease represent a moment of transgressive contact between animal mouth and human flesh, the possibility of losing one’s humanity and regressing to an animal state. Our horror stories capitalize on this lurid fear.

Our horror stories and long-constructed mythology of vampires, werewolves and the zombies that now reside in the modern vernacular are the long-lasting symptomatology of man plagued by an insensate virus. Though humans do not spread rabies – not only do we lack the sharp teeth, but the virus doesn’t prompt the infected to bite and is not shed copiously in the saliva – the potential of disease transference and the psychological horror of infection is still a marvelously rich goldmine to be pilfered and rehashed for an eager public. We’re only halfway through 2013 and already have been exposed to cinematic gems such as World War Z, Warm Bodies and Go Goa Gone, all films relying on the biologically transformed, slavering human. And there’s many, many more to come and, of course, the collective trauma of the Twilight series to be dealt with.

Rabies is of the world’s most interesting zoonotic diseases, the one that “has always shaded into something more supernatural: into bestial metamorphoses, into monstrous hybridities.” It is this concept of transmogrification, of irrevocable and deadly change that haunts our movie theatres, campfire stories and imaginations to this day even as the rabies virus’s grip on mankind’s health has diminished and faded.

Eyes in the Sky Look Back in Time

Charles Q. Choi is a science journalist who has also written for Scientific American, The New York Times, Wired, Science, and Nature. In his spare time, he has ventured to all seven continents.

The Fertile Crescent in the Near East was long known as “the cradle of civilization,” and at its heart lies Mesopotamia, home to the earliest known cities, such as Ur. Now satellite images are helping uncover the history of human settlements in this storied area between the Tigris and Euphrates rivers, the latest example of how two very modern technologies—sophisticated computing and images of Earth taken from space—are helping shed light on long-extinct species and the earliest complex human societies.

In a study published this week in PNAS, the fortuitously named Harvard archaeologist Jason Ur worked with Bjoern Menze at MIT to develop a computer algorithm that could detect types of soil known as anthrosols from satellite images. Anthrosols are created by long-term human activity, and are finer, lighter-colored and richer in organic material than surrounding soil. The algorithm was trained on what anthrosols from known sites look like based on the patterns of light they reflect, giving the software the chance to spot anthrosols in as-yet unknown sites.

This map shows Ur and Menze’s analysis of anthrosol probability for part of Mesopotamia.

Armed with this method to detect ancient human habitation from space, researchers analyzed a 23,000-square-kilometer area of northeastern Syria and mapped more than 14,000 sites spanning 8,000 years. To find out more about how the sites were used, Ur and Menze compared the satellite images with data on the elevation and volume of these sites previously gathered by the Space Shuttle. The ancient settlements the scientists analyzed were built atop the remains of their mostly mud-brick predecessors, so measuring the height and volume of sites could give an idea of the long-term attractiveness of each locale. Ur and Menze identified more than 9,500 elevated sites that cover 157 square kilometers and contain 700 million cubic meters of collapsed architecture and other settlement debris, more than 250 times the volume of concrete making up Hoover Dam.

“I could do this on the ground, but it would probably take me the rest of my life to survey an area this size,” Ur said. Indeed, field scientists that normally prospect for sites in an educated-guess, trial-by-error manner are increasingly leveraging satellite imagery to their advantage.

For instance, paleoanthropologist Lee Berger at the University of Witwatersrand in South Africa and his colleagues discovered Australopithecus sediba, a 1.98-million-year-old relative of humans, with the aid of Google Earth. The 3-D capabilities of the program—originally developed by a CIA-funded company that Google acquired—helped the scientists identify nearly 500 new caves for study from satellite images, which further research revealed had more than 25 fossil sites previously unknown to science. (Berger’s 9-year-old son was the one who actually uncovered the first fossils when they reached the site, by literally stumbling over the bones.)

Paleontologists are also developing an artificial intelligence network to scan satellite images for new fossil sites in the Wyoming desert. The computer program is a neural network that imitates the working of the human brain, and is scanning maps and satellite imagery that include known fossil sites to learn what they look like, relying on factors like color. It then uses this experience to point out areas that might hold hitherto unknown fossil sites in the Great Divide Basin, a large stretch of rocky desert in Wyoming.

Archaeology and paleontology have long been shovel- and pickaxe-dependent sciences, and will almost certainly stay so for the foreseeable future: Despite the occasional use of a backhoe or ground-penetrating radar, most digs simply lack the funding to bring anything they cannot carry in a bucket or the back of a pickup truck. But given the chance to use what once was classified military satellite imagery for free, it makes sense that researchers are leaping at the chance to prospect for sites using Google instead of boots on the ground.

So what might such a trend suggest for the future? Archaeologists and paleontologists are already working to bring the extraordinary power of publicly available satellite and other mapping technologies to bear on the unexplored wilds of the world. But there may be a more interesting development in aerial archaeology: Dilettantes and hobbyists could use the technology to make their own discoveries from afar. After all, amateur astronomers make monumental finds all the time in space, such as alien solar systems, and on Earth, mysterious mammoth structures spotted in China have drawn both amateur and professionally trained analysts to publicly speculate over their nature.

But as more amateurs swarm onto archaeological and paleontological sites, they may also be a risk that looters will come in with them. Hopefully the curious and careful will be more numerous than the greedy and grasping. As Indiana Jones said about such historical treasures, “That belongs in a museum!”

17 Best Places for a Geek to Go This Summer

by Emily Elert

A man was working on a plot of private land in Arkansas last fall when he uncovered a set of huge, fossilized dinosaur tracks. Also last year, interested amateurs photographed tides on low-lying stretches of the California coast to help predict the effects of climate change; they also checked up on local patches of milkweed, prime real estate for monarch butterflies, to keep tabs on the insects’ migration patterns.

Scientific wonders are accessible to anyone with the curiosity to seek them out, and summer is the perfect time to get exploring. In that spirit, we’ve brainstormed a whole season’s worth of places to go, sights to see, and things to do. There are destinations across the country, so whether you’re in Albany or Albuquerque, you should be able to find something nearby.

The adventurous among you may find yourselves strapping on an undersea helmet and strolling through a submarine kelp forest or wielding a Geiger counter in a field strewn with remnants of the atomic era, while those traveling with the family can swing by the bayou for a relaxed but rewarding swamp-by-boat tour. And plan to watch the sunset on June 5—there won’t be another like it for 105 years.


 The most exotic geological hot spots in the country

Grand Prismatic Spring Yellowstone 
National Park, Wyoming
The plume of molten rock that rises from more than 400 miles inside Earth beneath Yellowstone National Park powers the 10,000 springs, geysers, and other thermal features located where magma-heated water and steam come simmering to the surface. Yellowstone’s biggest hot spring, Grand Prismatic, also hosts some of the planet’s strangest, hardiest life.

“Yellowstone’s known for its bison and bald eagles,” says John Spear, an environmental microbiologist at the Colorado School of Mines, in Golden, “but it’s really a microbial wonderland.”

Brilliant green, yellow, brown, and orange bacterial mats encircle the spring. In each mat a small population of photosynthetic bacteria gather energy for the rest of the community, while the spring’s hot, mineral-rich water, flowing from the ground at 560 gallons a minute, provides the bacteria with other essential resources.

Spear says the best view of Grand Prismatic is from above: An offshoot of the Fairy Falls trail leads up a hill on the spring’s west side. For the full rainbow effect, summer afternoons are ideal. Spear also recommends going early or late in the day, “when all the steam rising out of it reflects the colors,” glowing turquoise, peach, and lime green. Hiking Yellowstone’s backcountry (permit required) yields a more intimate look at the park’s springs, but—chastened by a painful dip at a surprisingly acidic spring in Russia—Spear warns that it’s best to resist the temptation to go in.

Arches National Park

Sandstone Sojourns 
 Arches National Park, Utah
Famed environmental advocate and essayist Edward Abbey lived and worked in Utah’s Arches National Park as a ranger in the 1950s. Today you can follow in his footsteps through the park’s sandstone landscape, viewing features such as the Fiery Furnace, a labyrinth of dramatic red rock formations. Abbey wandered the park’s backcountry on his own, but times have changed: Due to the Fiery Furnace’s fragile soils and rare plants, access is limited to guided tours. Reserve tickets online up to six months in advance.

Fluorescent Minerals 
 Franklin and Ogdensburg, New Jersey
These neighboring towns share the title of fluorescent mineral capital of the world. Their two zinc mines have yielded more than 90 types of rare minerals that glow under ultraviolet light, due to trace amounts of manganese trapped when the crystals formed. Visitors to Sterling Hill Mining Museum in Ogdensburg, where UV lights expose glowing red calcite and green willemite in the mine’s walls, can take a chunk of the stuff home with them.

Subterranean Winery 
 Napa, California
Wine making is an art, but fickle fermenting grapes pose hefty technical challenges as well. Jarvis Winery built a 45,000-square-foot cave into the side of the Vacas Mountains to age their drink at high humidity and constant temperature. Tours of the cave include a visit to its underground chamber for aging wine—the world’s largest—and a formal tasting. (Non-oenophiles will appreciate the wine cave’s uncanny resemblance to the Star Wars rebel base on Hoth.)



Transit of Venus 
 All of the U.S. (and most of the world)

In 1716 the astronomer Edmond Halley, of comet fame, had a brilliant idea: Observations of the transit of Venus, a rare event in which our sister planet crosses between Earth and the sun, could be used to calculate the distance between us and our star. That epic experiment, conducted during the next two transits half a century later, sent dozens of observers to far-flung corners of the world. Their remarkable stories include that of French astronomer Guillaume le Gentil, who was driven to the brink of insanity after being foiled—twice—in his attempts to witness the event in India.

If you want to try observing the famous transit yourself, clear your calendar for June 5: Your next chance won’t come around until 2117. In the continental U.S., anyone with a clear, cloudless view of the horizon should be able to see the black dot of Venus late in the day as it begins to move over the solar disk.

The in-progress transit will make for a spectacular sunset, but to view the entire event, you’ll need to head farther west. The full transit will be visible from just east of Hawaii to just west of Hong Kong. Several travel companies are running educational island trips and cruises in Hawaii and the South Pacific. Our sister Kalmbach publication, Astronomy, is offering a tour to see the transit from Hawaii’s Big Island.

True transit die-hards may want to follow Louisiana State University astronomer Brad Schaefer’s lead and set out for the 
Australian outback, where the risk of inclement weather is slim. Of course, wherever you are, never stare directly into the sun. Bring viewing equipment, like a sheet of number 14 welder’s glass, or project an image with a telescope.

Volcanic Eruption 
 Montserrat, Lesser Antilles

The eruption of Mount Vesuvius in A.D. 79 buried the city of Pompeii in a single day. By comparison, the Soufrière Hills volcano on Montserrat, a 60-square-mile island in the Caribbean, has been erupting sporadically since 1995, slowly entombing the lower two-thirds of the island in ash. Visitors can look down on the destroyed capital city of Plymouth from the Montserrat Volcano Observatory, where scientists monitor the volcano’s rumblings and issue hazard warnings to the island’s depleted population. Ferries from nearby Antigua can take you to the island or around it, depending on your appetite for risk.

Swamp Tours 
 Near New Orleans, Louisiana
The delicate Mississippi River delta ecosystems have been taking a beating from pollution, stream diversion, and other human activities upstream. But there is, for now, still some intact marsh to see, including the 35,000 protected acres of the Honey Island Swamp, 30 miles northeast of New Orleans. To admire the moss-hung Seussian cypress trees and deceptively lethargic alligators from a dry, safe distance, sign up for one of the flat-bottomed boat tours in the area. Tours run year-round, but local guide Paul Wagner says that spring, which brings a wealth of wildflowers and migratory birds to the swamp, is particularly magical. No word on which season is best for spotting the Honey Island Swamp Monster, a hairy, Bigfoot-like creature fabled to live in the wetland.

Ice-capped peaks encircle Lake McDonald in Glacier National Park

Retreating Ice 
Glacier National Park, Montana
Most of the ice that carved Glacier National Park’s ridges and valleys melted more than 10,000 years ago, but by the time fur trappers ventured into the area in the 1800s, new glaciers had formed. Now those, too, are disappearing, and researchers say the handful of holdouts could be gone within a decade. So go now to see these glacial remnants in the hollows at the heads of valleys or under mountain peaks—or to take a dip in the lakes that collect downslope in summer.

Side Trip Science Museum of Minnesota St. Paul, Minnesota 

When the Museum of Questionable Medical Devices in Minneapolis closed in 2002, curator Bob McCoy donated his incredible collection of quackery to the science museum. The devices on display include a vibratory chair, which supposedly cured constipation and headaches through shaking so violent that patients had to hold tight to its handles, and a fluoroscope, once casually used in shoe stores to X-ray customers’ feet. Other exhibits include a miniature golf course that teaches visitors about both landscape evolution and biodiversity.


SWIM WITH THE FISHES Intimate looks at underwater life

Spearhunting Cozumel, Mexico
On the surface, the island of Cozumel—a 30-minute ferry ride from Playa del Carmen on Mexico’s Yucatán peninsula—is a peaceful tropical paradise. But off the island’s shore, it is under siege from the beautiful, exotic lionfish, which is encroaching on the world’s second-largest coral reef.
Invulnerable to virtually all predators due to poisonous spines that cover its body, the lionfish has spread from the North Atlantic—where it was accidentally introduced by the aquarium trade in the 1980s—to the Caribbean and across the Gulf of Mexico. When it reached the Cozumel reefs in 2009, its voracious appetite for more than 50 fish species made it a threat to the local ecosystem.
Scuba instructor Gabriel Santana Perez is one of many local divers fighting the invasion. He leads awestruck tourists around the reefs, most of the time as a conventional tour guide—navigating narrow swim-throughs in the coral and spotting sharks, eels, rays, and other exciting sea life. But he is always on the hunt for lionfish.
 When he spies a group of the interlopers lurking under the coral, the dive master darts toward them, readying the spear he carries on every dive. He impales the fish one after another, snips off their poisonous spines, and feeds them to other fish, including groupers that circle suspiciously before swallowing their meal whole.
Visitors can sign up to accompany Santana Perez at Del Mar Aquatics or take spear-hunting classes at several local dive shops. For those who prefer to keep a safe distance from the fray, some area restaurants cook up and serve the lionfish.

Marine Safari Catalina Island, California

Visitors here, an hour out to sea from Los Angeles, can decide just how close they want to get to the rich marine life thriving in the area’s kelp forests and coral reefs. Glass-bottomed boat tours provide a glimpse down into a marine conservation area called Lover’s Cove. To get an even closer look, clamber into a semisubmersible vessel and view the ocean from a few feet below the surface, or strap on an undersea helmet (complete with speakers and an air-supply hose) and stroll on the seafloor with a biologist guide.

Salmon Spotting 
 Warm Springs Reservation, Oregon
A wild run of spring chinook salmon make their annual 300-mile journey from the Pacific Ocean to the Warm Springs National Fish Hatchery in central Oregon, arriving each spring and summer. Visitors can walk the grounds, watch salmon climb the fish ladders, and tour the facilities. Nearby, guided tours in inflatable kayaks travel the last leg of the salmon’s route along the river.

Side Trip US Space and Rocket Center Huntsville, Alabama

You’re never too old for space camp, and the U.S. Space and Rocket Center knows it. Adults can register for a weekend filled with model rocket building, spaceflight history classes, and, upon special request, underwater astronaut training. Students also pilot a flight simulator and climb into the camp’s centrifuge to experience the 3g force astro­nauts feel during launch. For a less intense NASA experience, the center also features an extensive collection of rocketry, including the Apollo 16 capsule and a full-size replica of the Apollo 11 Saturn V, the largest rocket ever launched.


DIG IN AND GET DIRTY Adventures for the hands-on type

Trinity test explosion, 1945; Los Alamos National Laboratories

Atomic Artifacts Bayo Canyon, New Mexico 

Three miles east of Los Alamos, this canyon lies between two volcanic mesas. There, the U.S. military perfected the implosion mechanism used in the Fat Man bomb detonated over Nagasaki, Japan, in 1945.
These days, a hiker passing through the canyon might not notice anything unusual, other than a few posted signs instructing visitors not to collect firewood in the area. Closer inspection of the ground will reveal bits of “interesting-looking metal,” says Carl Willis, a nuclear engineer at Qynergy Corporation in Albuquerque. These bits include sockets for photomultiplier tubes from the radiation detectors, and coaxial cables used for signals and timing purposes. The detritus is fair game for anyone who wants to take home a piece of the Manhattan Project (Native American artifacts at the site are strictly off-limits, however). Most of the items aren’t radioactive, Willis says, “but there is hot stuff for people who get down on their knees with a Geiger counter and sort through all that rubble.”
Several other hot spots dot the surrounding mesas and valleys. A two-hour drive south from Los Alamos lands visitors at the National Museum of Nuclear Science and History in Albuquerque. For those willing to venture even farther, Willis says, there is a remarkable site just south of town, a half mile west of the government-run Sandia National Lab, where in 1957 a bomber accidentally dropped a mammoth Mark-17 hydrogen bomb. “There’s a huge swath of debris, and anyone can go out there and look for stuff,” Willis says. Ever-so-slightly radioactive bits of white plastic, chunks of lead, and green-painted pieces of the bomb’s casing are among the most common finds.

Cooking with Science 
 Brooklyn, New York, and other cities

Spanish chef Ferran Adrià made complex chemistry a star in the kitchen when he started molecular gastronomy, a culinary movement that uses sophisticated science to create imaginative dishes, such as foams made from solids like mushrooms and “spheres” of liquid that hold their shape. Cooking classes inspired by his ideas are now cropping up in major cities.

Devonian Fossils 
 Petoskey, Michigan

Some 350 million years ago, Michigan lay under a shallow ocean in which coral, trilobites, and other marine life thrived. Today fossilized coral makes its way into Lake Michigan from Little Traverse Bay, near the northern tip of the state’s Lower Peninsula, where the ancient rock layer is exposed. Polished and smoothed by eons of roiling water and sand, these fossils—called Petoskey stones—are strewn along Lake Michigan’s shore. Collectors will have the most luck spotting the stones after summer windstorms, which reveal the long-buried 
treasures littering the shore.

 All across the United States

The American Association of Zoos and Aquariums’ FrogWatch program enlists amphibian fans from coast to coast to track local frog and toad species by identifying the animals’ mating calls. To distinguish the ribbits and croaks, 
volunteers take a short training course at one of 43 participating nature organizations across the country. Then they check in at 
designated posts at least twice a 
week during the breeding season to listen for the amphibians’ calls. Researchers use the data they submit to develop conservation strategies for the animals.

Superfreak of Evolution: The Lizard With a Humanlike Placenta

by Ed Yong

Trachylepis ivensi nurtures its fetus much like humans do.
Courtesy: Dr. Philipp Wagner

In central Africa, an unassuming little lizard has evolved a spectacular and oddly human feature of gestation: a complex placenta. It is the first time that scientists have observed such an advanced version of this organ connecting the fetus to the womb in nonmammals.

Biologist Alexander Flemming made the anatomical find, announced late last year, while sorting through specimens at the Port Elizabeth natural history museum in South Africa. Flemming and his collaborator, Daniel Blackburn, knew that about 20 percent of lizards give birth to live young, but finding the placenta came as a shock.

Whereas virtually all cold-blooded reptiles supply embryos with nutrients from a large egg yolk, five-inch-long Trachylepis ivensi females ovulate small, yolk-poor eggs that implant in the uterus. As the fetus develops, its tissues become intimately entangled with the blood vessels of its mother, providing ready access to nutrients and oxygen in the mother’s blood. Sound familiar? “The fetal tissues actually invade the uterine ones, much like in humans,” Blackburn says. “It’s totally unexpected.”

Blackburn wants to reconstruct the evolution of this complex organ from simpler versions in other lizards. Doing so might even tell us about how the human placenta evolved. “It goes to show,” he says, “that you never know what diversity may be out there until you look.”

Plants Repel Bacteria’s Assaults by Spying on Their Chatter

Researchers discover an impressive ability never seen in plants before.
by Veronique Greenwood

Some rice plants have evolved a leg up on their microbial adversaries by
breaking the chemical code bacteria use to communicate.

Bacteria are quite the talkers. Lying low inside their hosts, they scheme up attacks through coded biochemical messages that are largely imperceptible to the immune systems of plants and animals. But in December researchers published the first evidence that some plants have broken the code, allowing them to listen in on chatter and thwart infection.

Evidence for this reconnaissance emerged in 2009, when University of California, Davis, plant pathologist Pamela Ronald discovered a bacterial protein called Ax21 in some strains of rice. Whenever Ax21 was present, the plants flooded their tissues with antibacterial chemicals. The mere presence of an immunity-inducing protein like Ax21 was not that unusual—the immune systems of most organisms identify a microbial intruder through proteins protruding from its outer membrane. But last year Ronald discovered that Ax21 is not part of the bacterial cells themselves. Instead, it is a secreted chemical rallying cry. When Ax21 chatter reaches a certain level, the microbes pack into a thin layer called a biofilm that protects them from immune defenses and many antibiotics. These rice plants are the only known organisms able to intercept the messages and act before the bacteria can form their biological bunker.

Ronald’s discovery may spark similar finds. University of North Carolina plant immunologist Jeff Dangl says plants have many immune receptors with unknown functions: “There may be a vast listening apparatus just waiting to be discovered.”

NASA Telescope Confirms Alien Planet in Habitable Zone

By Mike Wall, Senior Writer

MOUNTAIN VIEW, Calif. — NASA’s planet-hunting Kepler spacecraft has confirmed the discovery of its first alien world in its host star’s habitable zone — that just-right range of distances that could allow liquid water to exist — and found more than 1,000 new explanet candidates, researchers announced today (Dec. 5).

The new finds bring the Kepler space telescope’s total haul to 2,326 potential planets in its first 16 months of operation.These discoveries, if confirmed, would quadruple the current tally of worlds known to exist beyond our solar system, which recently topped 700.

The potentially habitable alien world, a first for Kepler, orbits a star very much like our own sun. The discovery brings scientists one step closer to finding a planet like our own — one which could conceivably harbor life, scientists said.

“We’re getting closer and closer to discovering the so-called ‘Goldilocks planet,'” Pete Worden, director of NASA’s Ames Research Center in Moffett Field, Calif., said during a press conference today. The newfound planet in the habitable zone is called Kepler-22b. It is located about 600 light-years away, orbiting a sun-like star.

Kepler-22b’s radius is 2.4 times that of Earth, and the two planets have roughly similar temperatures. If the greenhouse effect operates there similarly to how it does on Earth, the average surface temperature on Kepler-22b would be 72 degrees Fahrenheit (22 degrees Celsius).

Hunting down alien planets
The $600 million Kepler observatory launched in March 2009 to hunt for Earth-size alien planets in the habitable zone of their parent stars, where liquid water, and perhaps even life, might be able to exist.

Kepler detects alien planets using what’s called the “transit method.” It searches for tiny, telltale dips in a star’s brightness caused when a planet transits — or crosses in front of — the star from Earth’s perspective, blocking a fraction of the star’s light.

The finds graduate from “candidates” to full-fledged planets after follow-up observations confirm that they’re not false alarms. This process, which is usually done with large, ground-based telescopes, can take about a year.

The Kepler team released data from its first 13 months of operation back in February, announcing that the instrument had detected 1,235 planet candidates, including 54 in the habitable zone and 68 that are roughly Earth-size.

Of the total 2,326 candidate planets that Kepler has found to date, 207 are approximately Earth-size. More of them, 680, are a bit larger than our planet, falling into the “super-Earth” category. The total number of candidate planets in the habitable zones of their stars is now 48.

To date, just over two dozen of these potential exoplanets have been confirmed, but Kepler scientists have estimated that at least 80 percent of the instrument’s discoveries should end up being the real deal.

More discoveries to come
The newfound 1,094 planet candidates are the fruit of Kepler’s labors during its first 16 months of science work, from May 2009 to September 2010. And they won’t be the last of the prolific instrument’s discoveries.

“This is a major milestone on the road to finding Earth’s twin,” Douglas Hudgins, Kepler program scientist at NASA headquarters in Washington, D.C., said in a statement.

Mission scientists still need to analyze data from the last two years and on into the future. Kepler will be making observations for a while yet to come; its nominal mission is set to end in November 2012, but the Kepler team is preparing a proposal to extend the instrument’s operations for another year or more.

Kepler’s finds should only get more exciting as time goes on, researchers say.

“We’re pushing down to smaller planets and longer orbital periods,” said Natalie Batalha, Kepler deputy science team lead at Ames.

To flag a potential planet, the instrument generally needs to witness three transits. Planets that make three transits in just a few months must be pretty close to their parent stars; as a result, many of the alien worlds Kepler spotted early on have been blisteringly hot places that aren’t great candidates for harboring life as we know it.

Given more time, however, a wealth of more distantly orbiting — and perhaps more Earth-like — exoplanets should open up to Kepler. If intelligent aliens were studying our solar system with their own version of Kepler, after all, it would take them three years to detect our home planet.

“We are getting very close,” Batalha said. “We are homing in on the truly Earth-size, habitable planets.”

You can follow senior writer Mike Wall on Twitter: @michaeldwall. Follow for the latest in space science and exploration news on Twitter @Spacedotcomand on Facebook.