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.