New books deliver double dose of venomous animal facts

OUCH  Dasymutilla occidentalis, commonly known as the cow killer ant based on its painful sting, is actually a flightless wasp. The wasp and other venomous critters are the subjects of two new books.In the arms race of life, a number of animals use venom as a weapon to paralyze prey and jump-start digestion. Meanwhile, venom also helps a variety of other seemingly defenseless creatures improve their odds against larger, stronger or more aggressive foes.

In Venomous, molecular biologist Christie Wilcox surveys the animal kingdom’s wide array of biochemical warriors, from spiders and snakes to sea urchins and centipedes. InThe Sting of the Wild, entomologist Justin O. Schmidt takes a more focused approach, zooming in on stinging insects such as ants, wasps and bees. Both books recount the origins and effects of venom in wonderful detail, as well as relating the fascinating tales of the researchers who study these noxious and sometimes fatal cocktails.

Male platypuses have venomous spurs on their hind legs that they use in competition with other males during mating season and, when needed, for self-defense. But, Wilcox notes, this is a rare exception. Venoms generally fall into offensive or defensive categories. Venoms for offense tend to be fast-acting and fatal; defensive venoms usually just serve as a warning. The neurotoxins in these defensive venoms often cause great pain but typically aren’t lethal (unless the victim happens to be allergic to one or more of a venom’s many components).In the case of insects, venom has done much more than help protect individuals from harm, Schmidt points out: Venom actually helped set the stage for the evolution of ants, wasps, bees and other social insects. While a single insect might not be worth a large predator’s attention, an entire colony of defenseless insects — including their high-protein larvae — would be attractive indeed. Venom enables the members of a species to aggregate in large numbers, with many individuals contributing to the common defense.

As both books point out, researchers are still teasing out the secrets of venom. In addition to trying to develop better antivenoms for human victims, scientists are looking for individual components of venoms that could be used as painkillers, blood thinners or treatments for everything from epilepsy to erectile dysfunction.

Many of these scientists do their work in labs using test tubes, but Schmidt has gone above and beyond the call of duty. By letting more than 80 different types of stinging insects jab him, he has developed a “pain index” for each sting. Published in full for the first time in this book, Schmidt’s index ranges from 1 to 4 for all but a handful of species. His descriptions of the pain are wry and eloquent. While the sting of one bee species merits a mere 0.5 (“Did I just imagine that?”), the pain from a warrior wasp sting scores a 4 (“Torture. You are chained in the flow of an active volcano. Why did I start this list?”). 

See the Starship Enterprise, design virtual robots, and more

TO BOLDLY GO  The restoration of the Starship Enterprise studio model from the original Star Trek was completed in May for a National Air & Space Museum exhibit in Washington.

Boeing Milestones of Flight Hall

Now open

After two years of renovations, some of the museum’s most cherished artifacts — including the Spirit of St. Louis and an Apollo Lunar Module — are now on display alongside new objects, including a studio model of the Starship Enterprise.

National Air & Space Museum, Washington, D.C.

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Pterosaurs: Flight in the Age of Dinosaurs

Through October 2

Fossils, life-size models and a virtual flight lab transport visitors back to the time of these ancient fliers.

Natural History Museum of Los Angeles County

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At a DARPA exhibit in Chicago, visitors mix and match parts to create virtual robots.

J.B. SPECTOR/MUSEUM OF SCIENCE AND INDUSTRY, CHICAGO

DARPA: Redefining Possible

Through September 5

In this hands-on exhibit, see a humanlike robot, prosthetic arm, robotic exoskeleton and other high-tech innovations developed by the U.S. Defense Advanced Research Projects Agency over the last six decades. 

Museum of Science and Industry, Chicago

Ancient air bubbles could revise history of Earth’s oxygen

NOT-SO-FRESH AIR

Whiffs of ancient air trapped in rock salt for hundreds of millions of years are shaking up the history of oxygen and life on Earth.

By carefully crushing rock salt, researchers have measured the chemical makeup of air pockets embedded inside the rock. This new technique reveals that oxygen made up 10.9 percent of Earth’s atmosphere around 815 million years ago. Scientists have thought that oxygen levels would not be that high until 100 million to 200 million years later. The measurements place elevated oxygen levels well before the appearance of animals in the fossil record around 650 million years ago, the researchers report in the August issue of Geology.

“I think our results will take people by surprise,” says study coauthor Nigel Blamey, a geochemist at Brock University in St. Catharines, Canada. “We came out of left field, and I think some people are going to embrace it, and other people are going to be very skeptical. But the data is what the data is.”

Scientists have previously measured ancient Earth’s oxygen supply by looking for the fingerprints of chemical reactions that require oxygen to take place (SN: 11/29/14, p. 14). Such work has suggested that oxygen levels rose sharply around 600 million years ago, during the Neoproterozoic era.

That earlier work measured oxygen levels only indirectly, however, leading to uncertainty and mismatches between various studies of the Neoproterozoic oxygen rise. Blamey and colleagues instead went to the source: actual air left over from the time period.

Around 815 million years ago in what is now southwest Australia, rock salt formed on the surfaces of evaporating ponds. As the salt grew, microscopic air pockets formed. Hundreds of millions of years later, that air remains sequestered in the rock.

The researchers crushed match head–sized pieces of the salt in a vacuum, each piece releasing five to 12 puffs of gas. Oxygen levels in the newly liberated air were on average more than five times the 2 percent concentration predicted by previous studies, the researchers found. The team verified the technique by measuring oxygen in younger rock salts, including modern samples.

If the findings are correct, such an early appearance of abundant oxygen in Earth’s atmosphere adds a twist in a debate about whether limited oxygen stalled the evolution of animals (SN: 11/14/15, p. 18), says Nicholas Butterfield, a paleontologist at the University of Cambridge. Even with plenty of oxygen, animals still took a long time to evolve after the emergence of the first complex life, he argues. “The delayed evolutionary appearance of animals had nothing to do with limiting levels of atmospheric oxygen.”

Outside air may have tainted the new results, however, says Yale University geochemist Noah Planavsky. Over hundreds of millions of years, gases may have passed through the salt and boosted oxygen levels in the air pockets

The possibility of outside contamination seems especially likely given the surprisingly high oxygen levels recorded, says Timothy Lyons, a geochemist at the University of California, Riverside. A concentration of 10.9 percent “is really high,” he says. “There is nothing about the shifts you see in life or climate that demands an oxygen jump that high. That could be a worry. We have had so much oxygen over the last half a billion years, and this is a number like that.”

Website tests predictive powers of the hive mind

FUTURE FORECAST  The website Metaculus asks people to weigh in on questions about the future, such as whether 2016 will be the hottest year on record.  

As the saying goes, “It’s difficult to make predictions, especially about the future.” The website Metaculus.com aims to make this challenging task easier by harnessing collective wisdom.

Metaculus solicits answers to questions about the future — on topics spanning science, politics and economics — and combines these predictions to infer the likely outcomes. Will 2016 be the hottest year yet recorded? Will we find evidence for aliens soon? Will we hail self-driving taxis in the next few years? The hive mind might provide answers.

The website, created by physicists Anthony Aguirre and Gregory Laughlin of the University of California, Santa Cruz, along with former postdoc Max Wainwright, is an experiment to test whether our pooled instincts can produce reliable predictions. The site may also help scientists make informed decisions about which research to prioritize. Organizations funding research on pandemics, for instance, might want to know whether people are more concerned about bioterrorism, powerful germs escaping laboratories or naturally circulating diseases like the flu.

There’s a precedent for successful crowdsourcing of predictions. A U.S. government–funded geopolitical forecasting effort, the Good Judgment Project, has found that collective predictions can be remarkably accurate, and that prediction is a skill that can be honed.

After completing a free sign-up process, Metaculus users click through yes-or-no questions and make predictions, moving a slider from zero to 100 percent to indicate their level of certainty. The site provides relevant background information on each question, and additional research is encouraged. Prognosticators can hash things out in the comments section and share resources to help others make their predictions. Users rack up points — and bragging rights — when their predictions turn out to be correct.

The hive mind isn’t perfect — Metaculus users pegged the probability that the United Kingdom would vote to leave the European Union at just 32 percent. The United Kingdom did vote to leave, but that doesn’t mean the method is flawed. “The point of this is not to get a ‘yes’ or ‘no,’ ” Aguirre says, “but to get what is the probability.” Most events aren’t predictable with complete certainty, he says, but attaching a probability to such events can be useful in planning for the future.

So far, Metaculus has about 1,300 registered participants. In a review of more than 2,000 user predictions, the results were about as expected. When users predicted an event would happen with 80 percent certainty, they were correct about eight times out of 10. When many minds join forces, even nonexperts may collectively become capable guesstimators. 

To prevent cannibalism, bring chocolate

A GIFT FOR YOU  Male nursery web spiders (left) present nuptial gifts in the form of insect carcasses wrapped in silk.

Here’s another reason to show up with a box of chocolates: It doubles as a shield if she bites.

Edging slowly toward a female, male nursery web spiders clutch in front of their bodies their version of courtship candy: a big dead insect wrapped in white silk. “It’s pretty spectacular actually,” says Søren Toft of Denmark’s Aarhus University. It’s also prudent, he and colleague Maria Albo reported in the May Biology Letters. Sometimes femalePisaura mirabilis spiders just eat males that come calling. In a lab test, however, suitors bearing gifts were almost one-third as likely to be devoured as males that showed up empty-legged.

Males of diverse animal species go wooing with gifts of food or showy things. Biologists have long discussed the evolution of these nuptial gifts, including the possible benefits for male self-defense.

A different lab’s experiment with nursery web spiders had failed to find a defensive benefit because so few courtships in this species end in death. But Toft had been watching the spiders for years and had seen enough fatal flirtations to suspect the gifts, in part, function as shields. So he and Albo set up an experiment with enough mating opportunities to see lives lost — and saved. When a female pounced, “she actually hit the gift with her jaws,” he says. When that happened, the encounter turned from murder to mating.

BITE THIS, NOT ME New research suggests the gift can double as a shield.

WIKIMEDIA COMMONS (CC BY-SA 3.0)

Pouncing females are rare in this species. Typically, a female grabs the present and punches in her mouthparts to eat. The male then releases his grip and, while the female feeds, transfers sperm using organs near his mouth. The mating lasts, Toft says, “as long as it takes [her] to eat the fly.”

 In observations of nursery web spiders in the wild, “30 percent of males have a worthless gift,” reports Albo, now at Clemente Estable Institute of Biological Research in Montevideo, Uruguay. These sneaks have sucked the innards out of prey and packaged the inedible remains or some other debris into a silk-wrapped lump. Cheating doesn’t pay much: These matings last only as long as it takes the female to discover her pretty present is no gift.

Dolly the Sheep’s cloned sisters aging gracefully

CLONE CLUB  Dolly the Sheep’s nearly identical sisters — Debbie, Denise, Dianna and Daisy — were produced from the same mammary gland tissue as Dolly. The new clones are not aging prematurely as was feared for Dolly.

Clones don’t age prematurely, new research on Dolly the Sheep’s sisters suggests.

Researchers and animal welfare activists have been concerned that cloning, or somatic cell nuclear transfer, could cause health problems in cloned animals. Instead, a study of 13 cloned sheep found no signs of early aging or other health problems, researchers report July 26 inNature Communications.

“These animals were remarkably healthy and fall within the normal range that we’d expect in animals of this age,” said developmental biologist Kevin Sinclair of the University of Nottingham in Leicestershire, England. Sinclair spoke July 25 during a news conference at the EuroScience Open Forum in Manchester, England.

The cloning technique places the DNA-containing nucleus of an adult cell into an egg where the DNA is reprogrammed to an embryonic state. Dolly the Sheep, born in 1996, was the first mammal ever cloned. Since then, researchers have cloned a wide variety of animals. The technique doesn’t always work and many potential clones die before birth or shortly after. Surviving animals might have problems because of incomplete reprogramming of the DNA.

Dolly herself gave rise to the idea that clones age fast. Compared with other animals her age, Dolly had shorter telomeres, the caps that protect the ends of chromosomes from unraveling. Short telomeres have been associated with aging. Plus, Dolly had severe arthritis. She died at age 6, although not of old age. Dolly and other sheep in her flock were infected with a virus that killed them (SN: 3/1/03, p. 141).

Her untimely death, arthritis and short telomeres “were mushed together in people’s perception,” leading to the idea that clones age prematurely, said Katrin Hinrichs, a reproductive physiologist at Texas A&M University College of Veterinary Medicine and Biomedical Sciences in College Station. Hinrichs and other researchers not involved in the study hope the new report corrects the record on cloning and aging. “Now we have a reference to say what is and what is not a result of cloning,” she says.

How fast animals age varies, even among nonclones, says reproductive biologist Mark Westhusin, also of Texas A&M. Westhusin was on the team that produced cc (short for Carbon Copy), the first cloned cat (SN: 3/23/02, p. 189). She is now 15 and doing fine, says Westhusin. “This is a nice paper to confirm in a more formal scientific setting what most people involved with cloning have believed for a long time,” he says. Some studies have even hinted that clones may live longer than conventionally bred animals (SN: 4/29/00, p. 279).

In the study, Sinclair and colleagues examined 13 cloned sheep from 7 to 9 years old (roughly equivalent to people in their 50s to 70s). Four of the sheep — Debbie, Denise, Dianna and Daisy — were cloned in 2007 from the same mammary gland tissue that produced Dolly. “We had four almost identical sisters to Dolly and thought this would be a great chance to revisit this,” Sinclair said. He and colleagues compared the Dolly the Sheep sisters and nine clones of other sheep with 5- to 6-year-old sheep bred by traditional means.

Cloned sheep had normal blood sugar, insulin levels and blood pressure. A few had mild arthritis. One of Dolly’s sister clones had moderate arthritis. The researchers have not yet measured the clones’ telomeres.

Sheep in this study were cloned with modifications to the original technique that may have produced a better outcome. But Dolly’s problems didn’t necessarily stem from being a clone. She may have developed arthritis as a result of trauma to her joints. It’s also not clear whether her short telomeres were really an indicator of premature aging. Certainly her death had nothing to do with being a clone; noncloned animals in her flock also died, researchers say. Overall, Sinclair said, “perhaps Dolly was a little less lucky.”

Cloning today is done mostly in South America and Asia, and infrequently in the United States, says Hinrichs. Polo ponies and cattle are among the most-cloned animals. “Cloning is so costly and inefficient that your animal has to be very special for a cloning to be worth it,” she says. As a result, most cloned animals are prized breeding stock or performance animals. Some animals that are genetically resistant to diseases are also cloned for veterinary and medical research.

With additional reporting from Eva Emerson in Manchester, England.

Vaping’s toxic vapors come mainly from e-liquid solvents

VAPOR VIEW  The vapor from an e-cig can contain substantial amounts of toxic gases, a new study finds. And much of those toxicants trace to the solvent used to carry flavorings and any nicotine through the device.

Over the last three years, growing evidence has shown that electronic cigarettes are not the harmless alternative to smoking that many proponents have argued. Now, a new study traces a large share of e-cigs’ toxic gases to a heat-triggered breakdown of the liquids used to create the vapors. And the hotter an e-cig gets — and the more it’s used — the more toxic compounds it emits, the study shows.

“There is this image that e-cigarettes are a lot better than regular cigarettes, if not harmless,” says Hugo Destaillats, a chemist at Lawrence Berkeley National Laboratory in California. But after his team’s new analyses, published July 27 in Environmental Science & Technology, “we are now definitely convinced that they are far from harmless.”

Electronic cigarettes draw liquids over one or more hot metal coils to transform them into vapors. Those liquids — polyethylene glycol, glycerin or a mix of the two — are food-grade solvents laced with flavorings and usually nicotine.

The Berkeley team used two current models of e-cigs and three different commercially available e-liquids. The experimental setup mechanically drew air through the devices to create the vapors that a user would normally inhale.

Heating up

The higher an e-cigarette’s voltage, the more toxic aldehydes it produces in each puff of vapor. Once a certain threshold is hit, each voltage increase produces a disproportionate increase (see last bar) in acrolein, acetaldehyde and formaldehyde, three of the most harmful compounds in the vapor.

ADAPTED FROM M. SLEIMAN ET AL/ENVIRONMENTAL SCIENCE & TECHNOLOGY2016

Toxic aldehydes (such as formaldehyde, acetaldehyde and acrolein) were at negligible levels in the starting e-liquids, Destaillats notes. But the chemistry of the vapors varied as the e-cig device heated up: The first puffs contained somewhat less of the aldehydes than later puffs.

The new data show that “through the process of vaping, you are generating almost 1,000-fold higher emissions of those same compounds. And that is from the thermal degradation of the solvents,” Destaillats says.

Some devices can vary the voltage used to heat their coils. Higher voltages produced hotter conditions and more of the toxic aldehydes, which are probable or suspected carcinogens. Acrolein is also a potent irritant of the eyes and airways.

With a rise from 4.3 to 4.8 volts, the jump in emissions “goes exponential,” Destaillats adds, particularly “for the three aldehydes that are among the most harmful compounds present in the vapor.” Users could inhale up to 165 micrograms of these aldehydes per puff, the study found.

In their first tests, the chemists used a new e-cigarette for each puffing session. But in a second set of tests, they used one device over and over at its high-voltage setting. After the ninth 50-puff cycle, the toxic aldehyde emission rate had climbed by another 60 percent. This was consistent with a buildup on or near the heating element of what has come to be known colloquially as “coil gunk,” the researchers say. “Heating these residues would provide a secondary source of the volatile aldehydes.”

The data on changes in the vapor composition of “aged” e-cigarettes “is something new,” notes toxicologist Maciej Goniewicz of the Roswell Park Cancer Institute in Buffalo, N.Y. And using a better analytical technique than others have employed, he says, the Berkeley team turned up new toxicants — such as propylene oxide and glycidol — which neither his group nor others had detected in e-cig vapors. 

Newly discovered big-headed ants use spines for support

A STORM OF SPINES  A newly discovered ant species, named Pheidole drogon after a dragon in Game of Thrones, sports spines that resemble a dragon wing and claw. The ants can’t fly or breathe fire, but their spines are filled with muscles, which may lend support to their giant heads.The newest and thorniest members of a diverse ant family may have extra help holding their heads high.

Found in the rainforests of Papua New Guinea, Pheidole drogon and Pheidole viserion worker ants have spines protruding from their thoraxes. For many ant species, the spiky growths are a defense against birds and other predators. But Eli Sarnat and colleagues suggest the spines might instead be a muscular support for the ants’ oversized heads, which the insects use to crush seeds. The heads “are so big that it looks like it would be difficult to walk,” says Sarnat, an entomologist at the Okinawa Institute of Science & Technology Graduate University in Japan.

Micro‒CT scans of worker ants with larger heads revealed bundles of thoracic muscle fibers within spines just behind their heads. Worker ants with smaller heads did not have muscles in their spines, the researchers report online July 27 in PLOS One. More research is needed to establish the spines’ function and understand why they evolved, Sarnat says. While buff spines may support big heads, hollow spines probably keep predators at bay, the researchers suspect.    

HEAD TO HEAD The thorny outgrowths of P. drogon worker ants with large heads (left) contain muscle fibers which may support their massive heads. The spines of worker ants with smaller heads (right), on the other hand, are practically hollow.

GEORG FISCHER/OIST

Researchers named the ants after two fearsome dragons, Drogon and Viserion, in the popular book and TV series Game of Thrones. 

SPIDER shrinks telescopes with far-out design

BIG DREAMS FOR SMALL SCOPE  Lockheed Martin imagines a relatively small and light advanced SPIDER telescope with thousands of tiny lenses on one face of a surveillance orbiter.

In the space business, weight and size are what run up the bills. So imagine the appeal of a telescope that’s a tenth to as little as a hundredth as heavy, bulky and power hungry as the conventional instruments that NASA and other government agencies now send into space. Especially alluring is the notion of marrying the time-tested technology called interferometry, used in traditional observatories, with the new industrial field of photonics and its almost unimaginably tiny optical circuits.

Say hello to SPIDER, or Segmented Planar Imaging Detector for Electro-optical Reconnaissance.

Some doubt it will ever work.

But its inventors believe that, once demonstrated at full-scale, SPIDER will replace standard telescopes and long-range cameras in settings where room is scarce, such as on planetary probes and reconnaissance satellites.

Researchers at the Lockheed Martin Advanced Technology Center in Palo Alto, Calif., with partners in a photonics lab at the University of California, Davis, have described work on SPIDER for several years at specialty conferences. In January, they revealed their progress with a splash to the public in a press release and polished video.

Somewhat like a visible-light version of a vast field of radio telescopes, but at a radically smaller scale, a SPIDER scope’s surface would sparkle with hundreds to thousands of lenses about the size found on point-and-shoot cameras. The instrument might be a foot or two across and only as thick as a flat-screen TV.

Transit system for light

SPIDER probably won’t be equivalent to a large instrument such as the Hubble Space Telescope, but it could be a smaller, lighter alternative to modest telescopes and long-range cameras. Experts tend to rank telescopes by their aperture — the size of the bucket that catches light or other such radiation. The wider the bucket’s mouth, the higher the resolution. Ordinarily, behind the bucket’s maw is an extensive framework for massive lenses, mirrors and heating or cooling systems. Hubble’s aperture spans 2.4 meters; its power-generating solar panels enlarge it to the size and weight of a winged city bus. Even a compact telescope with a saucer-sized lens might have more than a kilogram of equipment stretched behind its face for a third of a meter or so.

Story continues below graphic

Shrink it

Compared with a conventional reflecting telescope (left), a prototype for a proposed telescope called SPIDER (middle) has a radial design, with spokes of multiple photonic chips. In a farther-out design (right), a single-disk photonic chip has the same diameter and focus as the regular scope, but is much thinner.

B. YOO/UC DAVIS

Alan Duncan, a senior fellow at Lockheed Martin’s Advanced Technology Center, has devoted much of his career to space and reconnaissance imaging. He often focuses on interferometry, a method astronomers have long used to combine electromagnetic waves — both radio and visible — from several different telescopes. The results, with the help of computers, are images more sharply focused than from any of the smaller telescopes or radio dishes. Yet even with the leverage of conventional interferometry, Duncan struggled to slash the SWaP: size, weight and power demand.

His ambitions leapt at the Photonics West 2010 meeting in San Francisco. He learned that IBM researchers had a supercomputer design that would need relatively little energy to cool its electronic innards. They proposed finely laced channels through which data-filled beams of light would travel to deliver the computer’s output data. The setup would require a fraction of the energy of standard, integrated electronic chips that use metal wiring.

A future setup

LOCKHEED MARTIN

A square model of a SPIDER sensor (top) is about the size of a coin. In an upclose view (bottom), an array of aligned lenses take in light from a distant scene and send it through a photonic integrated circuit of waveguides, filters and interferometers to compare the signals’ waveforms. The results are sent to a computer to construct an image.

Duncan stared at the skeins of optical channels and the millions of junctions portrayed on the screen during the IBM talk. He recalls seeing “about as many optical interconnects as a digital camera has pixels.” (A point-and-shoot camera’s pictures can have several megapixels, or millions of individual dots.) He imagined turning IBM’s tactic on its head. “They create photons in the chip, impose information on them and send them out to be decoded. What if you captured the light waves on the outside?” Duncan says. “The photons already have the [image] information you want.… You have to decode it inside the device. The decoder is the interferometer.”

The IBM people had not designed an interferometer, of course, but their optical circuitry seemed sophisticated enough to be adaptable to interferometry. Duncan figured that the fast-growing photonics industry already had or would soon invent fabrication solutions that his suddenly imagined telescope could use. Already, photonics companies were selling machines to create transparent channels or waveguides only a few millionths of a meter wide.

Considerably smaller than the fibers bundled into fiber-optic cables that carry data across continents and under oceans, photonic waveguides are made by finely focused, pulsating laser beams. As the beams scan along inside silicon-based photonic integrated circuits, or PICs, they leave behind close-packed strings in molten silicon that swiftly merge and cool. The resulting trails of transparency are superb transit systems for light, and they can be laser-incised in any pattern desired. Similar wizardry can shrink the scale of other optical gadgetry, such as filters to sort the signals by color, or the interferometry gadgetry to mix signals from different lenses in a SPIDER scope.

Decoding fringes

Interferometry does not produce pictures the way a conventional telescope does. Telescopes refract a scene’s incoming light through lenses or bounce it off of mirrors. The lenses or mirrors are shaped so that light beams, or photons, from a given part of a scene converge on a corresponding place on a photo-sensitive surface such as an image chip of a digital camera, similar to the retina of an eye.

Interferometry, instead, gathers signals from pairs of receivers — sometimes many pairs — all aimed at the same scene. It combines the signals to reveal the slight differences in the phases and strengths of the radio, light or other waves. The separate wave trains, or signals, are projected on a screen in an interferometry chamber as patterns of light and dark fringes where the signals from the paired receivers reinforce or counteract each other. The fringes, somewhat resembling checkout counter bar codes, carry a distinct, encoded hint of the difference in the viewed object as seen from the receivers’ offset positions in the aperture. With enough measurements of fringes from enough pairs of waves gathered by enough small receivers, a computer can deduce a picture that is as sharp as from a telescope with a lens as wide as the distance between the most widely spaced lenses, for example, on a SPIDER’s face.

MINI GUIDES A photonic waveguide map for just four lenses is connected to a digital chip that calculates the contribution to the ultimate image. Thousands of lenses and waveguides could be combined to make a SPIDER telescope.

B. YOO

Building a tiny version of this using photonics requires separate sets of waveguides for different colors or “spectral bins.” The more bins used, the more accurately an object can be portrayed. But each such layer of complexity aggravates the chore of fabrication.

So even a bare-bones SPIDER may need thousands of waveguides. Advanced SPIDERs may have millions of them. As far as Duncan knows, SPIDER would be the most complicated interferometer ever made.

Spycraft and space views

After his epiphany, Duncan began working with Lockheed colleagues, chiefly technology expert Richard L. Kendrick. Computed simulations convinced them that their mini-interferometer should work. In 2012, Lockheed Martin filed for a patent — granted in late 2014 — naming the two men as the inventors. Reflecting the company’s defense ties, the document provides a hypothetical application: SPIDER in a proposed, high-altitude Pentagon recon drone called Vulture, perhaps built into the curved bottom of a wing.

Initial simulations showed how SPIDER’s pictures of one satellite taken from another, or of buildings as seen from space, compare with pictures by standard long-range cameras. Interferometric images, due to the complex calculations using the equations of Fourier transforms, often have extra flares and streaks. Nonetheless, to a layman’s eye, the simulated SPIDER images look about the same as equivalent ones from standard lens or mirror telescopes.

If SPIDER pans out, its inventors imagine uses beyond spycraft. NASA is planning a mission to orbit Jupiter’s moon Europa (SN Online: 5/26/15). The SPIDER team calculates that, given the same space that has already been assigned to a conventional imager, SPIDER’s instrument could inspect 10 times the terrain at 17 times better resolution. SPIDER should be able to have a wider array of lenslets — or receivers — take pictures at points farther from Europa on the craft’s elliptical orbit and should have a wider field of view.

One proposed design for the first fully operable, but spartan, SPIDER is to have 37 radial blades, each backed by a single photonic chip with 14 lenslets along one edge. The whole model would be about the size of a dinner plate. Eventually, a SPIDER might be built on the face of a single chip of similar or larger size. This would allow more lenslets to be fitted, and permit waveguides to pair them up from anywhere in the aperture. Upshot: more “eyes” packed into the same space.

SPIDER designers compared an aerial photo (top) of Judiciary Square in Washington, D.C., with how their interferometer of similar aperture would do (bottom). SPIDER’s shot is blotchy, but sharp.

B. YOO

The Lockheed group has begun to fabricate test components in partnership with a photonics laboratory led by Ben Yoo, professor of electrical and computer engineering at UC Davis. DARPA, the Department of Defense’s agency for funding advanced research, granted about $2 million for prototype photonic integrated circuits and other gear to test the idea’s feasibility.

The technical challenges are extreme. Each tiny lenslet could need 200 or more separate waveguides leading from its focal area to the interferometers. For a fairly simple SPIDER scope, that would mean tens of thousands of waveguides coursing through the chips’ insides — perhaps fabricated many layers deep. So far, the researchers have built prototype components with only four lenslets, too few to get images.

Skeptics and a crusader

At least one top authority says the scheme is nonsense. Others are more amused than critical. Michael Shao, an MIT-trained astronomer and project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., has extensive experience with interferometry. He calls the concept of SPIDER “fundamentally sound,” but adds that it will require such extensive optical plumbing on a photonic scale that the sheer complexity “would scare a lot of folks away.” If the SPIDER team makes it work, great. “But it is a lot of work to save a little space.”

Peter Tuthill, an astronomer at the University of Sydney in Australia, leads one of the world’s busiest interferometry groups. His team has augmented such large conventional ground-based telescopes as the Keck Observatory in Hawaii with auxiliary interferometers. His group also designed an interferometer to be included on the James Webb Space Telescope, planned successor to the Hubble. After looking over the SPIDER proposal, he declared by e-mail, “I think the argument made that this can be somehow cheaper, simpler, lower mass and higher performance than conventional optics appears not to pass the laugh test.”

The extremely large number of waveguides in the SPIDER design, he added, would leave the signal strength per waveguide too feeble — hence vulnerable to swamping by noise in the system. “In short, I don’t think (the SPIDER team members) are waiting for technology to enable their platform. I think they are waiting for a miracle that defies physics.”

Duncan just smiles when he hears Tuthill’s opinion. Even if technical difficulties delay or quash this initial SPIDER project, he is confident somebody will step in and surmount any barriers. “It will happen,” he says.

Distinctions blur between wolf species

MIXED UP  Eastern wolves (second from left) and red wolves (second from right) might be better described as mixtures between gray wolves (far left) and coyotes (far right) rather than distinct species, a new genetic analysis suggests.

FROM LEFT  DENNIS MATHESON/FLICKR (GRAY WOLF); STEFFEN239/FLICKR (EASTERN WOLF); CHRISTINE MAJUL/FLICKR (RED WOLF); MAV/WIKIMEDIA Wolves are having something of an identity crisis. Gray wolves and coyotes might be the only pure wild canine species in North America, a new genetic analysis suggests. Other wolves — like red wolves and eastern wolves — appear to be blends of gray wolf and coyote ancestry instead of their own distinct lineages.

Red wolves contain about 75 percent coyote genes and 25 percent wolf genes, an international team of scientists reports online July 27 in Science Advances. Eastern wolves have about 25 to 50 percent coyote ancestry.

That finding adds another twist to the ongoing battle over wolf protection and regulation in the United States: how to protect a population that’s not its own species but carries valuable genetic information.

Gray wolves used to roam much of North America — until they were hunted to near-extinction. Protection under the Endangered Species Act has helped them to rebound, but their current range is still far smaller than it used to be. Red wolves, found in the southeastern United States, and eastern wolves, found in the Great Lakes region, look similar to gray wolves but are often treated as distinct species. The two groups occupy territory where gray wolves are now scarcer (in the Great Lakes area) or completely gone (in the southeast).

The new study examined the entire genetic makeup, or genome, of 23 wild canines from around North America. The researchers compared the mixed genomes to those from pure coyotes and Eurasian wolves to figure out what percent of each animal’s genetic material came from the wolf and what part came from the coyote.

Red and eastern wolves have historically mated with coyotes, the team found. But gray wolves have recent coyote ancestry too, and neither eastern wolves nor red wolves differ genetically from gray wolves any more than from other individuals of their species. That suggests that these different groups of wolves are more evolutionarily intertwined than previously believed, says Robert Wayne, a biologist at UCLA who coauthored the study

Red wolves and eastern wolves probably arose when gray wolf populations in the eastern United States were hunted by early settlers, says Doug Smith, a biologist who leads the Wolf Restoration Program in Yellowstone National Park. That created room for coyotes to move east, where the struggling wolves bred with them. Mixing genes with coyotes probably helped wolves survive in lean times.

While their coyote genes make red wolves and eastern wolves look slightly different from gray wolves, “we don’t find anything incredibly unique in the red wolf that you can’t find in other canines,” says Bridgett vonHoldt, a biologist at Princeton University who worked with Wayne and collaborators. But they’re still important to protect, because “the wolf part of their genome might actually represent the last of the southeastern gray wolf.” It’s a similar story for the eastern wolf.

Blended species like these are hard to label, Smith says, because traditional species definitions assume clear boundaries that prevent gene sharing.

“Nothing isolates a wolf,” says Smith. “They’re just so capable of moving around.”

Right now, wolves in the United States are managed through a patchwork of federal and state regulations. Red wolves are federally listed as endangered, and gray wolves are listed as endangered in the upper Midwest but not the rest of the country. Genetic mixing makes designing appropriate regulations even more challenging.

“These animals don’t walk around with little name tags on them in the field,” says vonHoldt. “So hybrids or admixed animals don’t always look very different from a pure coyote or pure wolf.”

The only way to ensure that wolf genes stick around in certain areas would be to prohibit killing of both wolves and coyotes, vonHoldt says. But such a restriction would be nearly impossible to implement.  

This study is an important step, but its conclusions aren’t definitive, says Paul Wilson, a biologist at Trent University in Ontario, Canada. His work still supports the idea that the eastern wolf is its own species. Comparison with DNA from ancient North American canids — before wolves and coyotes interbred at all — could help further clarify the debate, he says. 

50 years ago, humans could pick the oceans clean

ALL YOU CAN'T EAT BUFFET  Scientists warned 50 years ago that people could eat the oceans bare. Even with fishing limits, some food species such as pufferfish, remain in danger of overfishing. 

Seafood is exhaustible — Man is capable of using up the resources of the ocean … and if he is going to exploit them intelligently, he has a lot to learn…. The world’s annual fish catch went up from 23 million to 46 million tons between 1953 and 1963, and is now estimated at 50 million tons, but scientists do not expect it to double every decade indefinitely. — Science News, August 6, 1966.

UPDATE  

The fish catch hasn’t doubled every decade, but increasing catches still cause concern. The Fisheries and Aquaculture Department of the United Nations reported a worldwide catch of more than 89 million metric tons in 2010 and 93 million tons in 2014. These numbers may be an underestimate, ignoring small-scale fisheries, scientists reported in 2016. While governments set limits on fishing certain species, some critically endangered and threatened species — such as Chinese pufferfish and Pacific bluefin tuna — remain food favorites.

Nail-biting and thumb-sucking may not be all bad

Nail-biting and thumb-sucking bring germs into the mouth — and possibly fewer allergies, too.  

There are plenty of reasons to tell kids not to bite their nails or suck their thumbs. Raw fingernail areas pick up infection, and thumbs can eventually move teeth into the wrong place. Not to mention these habits slop spit everywhere. But these bad habits might actually good for something: Kids who sucked their thumbs or chewed their nails had lower rates of allergic reactions in lab tests, a new study finds.

The results come from a group of more than 1,000 children in New Zealand. When the kids were ages 5, 7, 9 and 11, their parents were asked if the kids sucked their thumbs or bit their nails. At age 13, the kids came into a clinic for an allergen skin prick test. That’s a procedure in which small drops of common allergens such as pet dander, wool, dust mites and fungus are put into a scratch on the skin to see if they elicit a reaction.

Kids whose parents said “certainly” to the question of thumb-sucking or nail-biting were less likely to react to allergens in the skin prick test, respiratory doctor Robert Hancox of the University of Otago in New Zealand and colleagues report July 11 in Pediatrics. And this benefit seemed to last. The childhood thumb-suckers and nail-biters still had fewer allergic reactions at age 32.

The results fit with other examples of the benefits of germs. Babies whose parents cleaned dirty pacifiersby popping them into their own mouths were more protected against allergies. And urban babies exposed to roaches, mice and cats had fewer allergies, too. These scenarios all get more germs in and on kids’ bodies. And that may be a good thing. An idea called the hygiene hypothesis holds that exposure to germs early in life can train the immune system to behave itself, preventing overreactions that may lead to allergies and asthma.

It might be the case that germy mouths bring benefits, but only when kids are young. Hancox and his colleagues don’t know when the kids in their study first started sucking thumbs or biting nails, but having spent time around little babies, I’m guessing it was pretty early.

So does this result mean that parents shouldn’t discourage — or even encourage — these habits? Hancox demurs. “We don’t have enough evidence to suggest that parents change what they do,” he says. Still, the results may offer some psychological soothing, he says. “Perhaps if children have habits that are difficult to break, there is some consolation for parents that there might be a reduced risk of developing allergy.”

Sea ice algae drive the Arctic food web

Even organisms that live in open waters of the Arctic, such as this Themisto libellula amphipod, get a lot of their carbon from algae that live in sea ice, a new study finds.

As happens every summer, sea ice in the Arctic is shrinking as temperatures warm. But this year is a particularly warm year, and there is less sea ice than there usually is. Scientists say Earth is on track to matchor perhaps even exceed the record low extent of summertime sea ice seen in September 2012.

The disappearing sea ice is a symptom of a warming planet, and it is also a problem for organisms associated with the ice, such as algae that live in the brine-filled channels within sea ice. “These algae are adapted to grow under very low light conditions,” says Doreen Kohlbach of the Alfred Wegener Institute in Bremerhaven, Germany. These algae, along with algal species that live in the open ocean, form the base of the Arctic food web. And they are an important food source even for species that don’t live under the ice, a new study shows.

This indicates that climate change will not only affect organisms with a close connection to the sea ice, Kohlbach says, but it will also subsequently affect the pelagic, or open-ocean, system.

In the new study, Kohlbach and her colleagues looked at the percentage of carbon that various species of zooplankton — one step up on the Arctic food web — get from sea ice algae during late summer. Some of the organisms live near the sea ice, while others are considered pelagic species. By using fatty acids as a marker, the researchers determined how much carbon in each species came from sea ice algae.

Animals that lived beneath the sea ice, not surprisingly, got a lot of their carbon from sea ice algae — from 60 to 90 percent, the researchers report July 8 in Limnology and Oceanography. But even pelagic species obtained 20 to 50 percent of their dietary carbon from algae embedded in sea ice. “Our results showed that not only the ice-associated animals were living mainly from ice algae–produced carbon, but that also the pelagic species showed a significant dependency on ice algae–produced carbon,” says Kohlbach.

Scientists have yet to test higher levels of the food web, so they can’t yet predict how the loss of sea ice algae might affect larger species, such as fish or seals or polar bears. But it will probably have some effect, Kohlbach says. “If alterations of the sea ice system affect the low members of the food chain, it will consequently affect all following members.”

There’s also a chance that species that currently feed on sea ice algae could switch to feeding on other species if their preferred food disappears. But the concern is for those species that depend entirely on sea ice algae. “We cannot say for sure what will happen to the organisms that depend highly on sea ice,” Kohlbach says. Some of them might adapt to the changes with a changing feeding behavior. To determine the consequences on a species-level, we need to do more research.”

Rosetta spacecraft has stopped listening for Philae lander

GOODBYE, PHILAE The European Space Agency’s Rosetta spacecraft (illustrated, upper left) will no longer listen for signals from the Philae lander, which has been silent since July 2015. 

It’s time for a final farewell to the comet lander Philae.

The European Space Agency announced that on July 27 it would shut off the equipment that the Rosetta spacecraft uses to listen in on communications from Philae. The lander, which touched down on comet 67P/Churyumov-Gerasimenko in November 2014, briefly transmitted data before entering a deep slumber.

Except for a brief awakening in June and July 2015, Philae has been silent ever since. Now, as the solar-powered Rosetta gets farther from the sun, scientists need to conserve power by shutting off nonessential equipment. So Rosetta will listen no more.

Rosetta will continue scientific operations around comet 67P for another two months before completing its mission, when it will join Philae, descending down onto the comet.