上海后花园1314

In recent months, the Philippines has frequently provoked China in the waters surrounding Ren'ai Reef and Huangyan Island, attracting extensive international attention. Will the Philippines take the risk of relying on the support of the US to forcefully transport construction materials and personnel to the illegally "grounded" warship in Ren'ai Reef, thereby triggering an armed conflict between China and the Philippines? Although it has not been ruled out that the Philippines may take such extreme measures to further exacerbate the situation in the South China Sea and the China-Philippines relationship under the misjudgment of the situation, the probability of them taking such extreme actions is still relatively low.

Successive Philippine governments have shown periodic swings in dealing with relations with China. These swings can even occur within the same presidential term. The predecessor of former President Rodrigo Duterte,in the first four years of his presidency, distanced the Philippines from the US, reduced provocations in the South China Sea and actively participated in the Belt and Road Initiative. However, over the last two years in his presidency, the situation in the South China Sea had been tense. And he restored the Philippines' key military agreement with the US.

Since President Ferdinand Marcos Jr entered office in 2022, this trend in foreign policy is still evident. He not only became the first Philippine president to visit the White House in 10 years but also granted the US military access to four military sites. The Philippines under his leadership frequently clashed with China over the South China Sea issue. However, he also visited China in early 2023 and made a guarantee that the military bases accessible to the US would not be used in any offensive action, expressing a certain degree of goodwill toward China. Therefore, it is premature to say the Philippines will continue to antagonize China in the future based solely on its current "tough policy" in the South China Sea.

Furthermore, some domestic factions in the Philippines believe that the US would provide substantial support to the Philippines in the event of a military conflict with China. This is a serious strategic misjudgment influenced by two misleading signals. Firstly, in February 2023, the US and the Philippines expanded the Enhanced Defense Cooperation Agreement (EDCA). The Philippines agreed to allow US military presence in four new military bases, believing that the US would reciprocate and provide strong support to the Philippines in the event of a military conflict with China. Additionally, the US has expressed its intention to invite the Philippines to join its "Indo-Pacific" multilateral security cooperation mechanism, creating a new "Quadrilateral Security Mechanism" including the US, Japan, Australia and the Philippines to address potential conflicts in the South China Sea. However, the US has never publicly committed to militarily assisting or supporting the Philippines in the event of a military conflict with China. The Philippine government should abandon such illusion.

The current policy of provoking China by the Philippines is not well-received within the ASEAN. ASEAN member states hope that, amid the backdrop of the US and its allies using the Indo-Pacific Strategy to confront China, China can exercise maximum restraint, and they do not want their own countries to be used by the US as "pawns" in its efforts to contain China. Currently, the escalating provocations by the Philippines in the South China Sea do not align with the overall interests of ASEAN countries in pursuing "peace, security and stability." It is clear that the ASEAN countries will not take sides with the Philippines and will not allow the situation to escalate further. 

Relevant Philippine authorities should not underestimate China's determination and capability to maintain stability in the South China Sea. Currently, Philippine authorities and Western media have been continuously engaging in attention-seeking, live-streaming provocations. Besides exposing their attempts to wage a "public opinion war" to discredit China, it further demonstrates the lack of strategic thinking by the Marcos Jr government on critical issues related to regional peace and stability, putting the Philippines' national image and national security in a perilous situation. Philippine authorities should promptly cease such meaningless sensationalism and return to the path of resolving South China Sea disputes through negotiations and dialogue with China, and by reaching the Code of Conduct in the South China Sea as soon as possible.

Many cities in China, including Beijing, Central China’s Henan Province and North China's Inner Mongolia Autonomous Region, are experimenting with the nucleic acid self-testing, with the sampling done by individuals, with health officials responsible for guidance and sample collection.

“It's very convenient to complete nucleic acid tests at home without having to wait in line,” said several residents of Fengtai district in Beijing, describing their previous experience. Some neighborhoods in Beijing’s Fengtai have already launched at home self-testing.

The city of Ordos in Inner Mongolia and Xinxiang in Henan Province have also trialed self-testing in different forms. Residents can test at home through the collection swabs issued by neighborhood officials, or they can collect themselves at the nucleic acid testing stations located in and around residential compounds.

A resident from Inner Mongolia told the media that local residents can obtain cotton swabs at nucleic acid testing stations, and that health officials will help place the swabs into the sample tube after the residents complete their own sampling.

“There are workers on site to guide sampling which is fast and convenient, and it also avoids time wasting and risk of cross-infection,” said a resident who had used the service.

Several neighborhoods in Beijing’s Fengtai began distributing testing reagents to residents early in the morning. “We started distributing sampling tubes at 9:30 am, and collect completed samples at 15:00 pm in the afternoon,” a community worker said.

“The implementation of self-sampling is mainly in consideration of groups who have limited mobility,” a community worker told the media. “The service is focused on providing convenience to children and seniors.”

In addition, more than 300 new nucleic acid sampling machines appeared on the streets of Henan Province’s Xinxiang mainlyin shopping malls, supermarkets, schools and other public places.

These units can carry out testing using a cotton swab to wipe the back of the throat, after the device issued a "test passed" prompt, individuals place the cotton swabs into a waiting test tube.

This kind of machine only needs people to open their mouths at the unit following disinfection and temperature measurement, with a cotton swab to wipe their throats. “This type of test is more suitable for younger people,” a Xinxiang resident noted.

However, some experts also have doubts about whether this measure could be effective. “Nucleic acid testing has a series of collection procedures and specifications, and even some professionally trained medical staff cannot meet the full standards,” a Guangzhou-based medical expert told the Global Times on Sunday.

It is debatable whether requiring these residents to take a self-sampling of nucleic acid without any symptoms would be effective in detecting infections, Yang Zhanqiu, a professor of the pathogen biology department at Wuhan University, told the Global Times.

A total of 145 children from border regions and areas that receive aid met at the Three Gorges Dam in Central China's Hubei Province over the weekend during a themed summer camp to learn about the great achievement of the project.

The event aims to inspire students' sense of national pride, confidence, and the spirit of progress. As well as a field trip to the Three Gorges Dam in Yichang, Hubei, there are various activities such as visiting the Three Gorges Power Station, Three Gorges Project Museum, and the Yangtze River Rare Fish Breeding Center.

The majority of the participating students are from ethnic minority regions such as North China's Inner Mongolia Autonomous Region, Northwest China's Xinjiang Uygur Autonomous Region, and Southwest China's Xizang Autonomous Region. These areas are also designated areas for aid and support from the Three Gorges Group.

"I flew on a plane for the first time, and it was my first time on a ship. I'm so happy!" said Zubaiyier Maimaitijiang from Xinjiang's Bayingolin Mongolian Autonomous Prefecture. "The scenery of the Three Gorges is beautiful, and the Three Gorges Dam is magnificent!"

"This is the first time I have left my hometown to participate in an educational activity, and I've gained a lot. Seeing the majestic Three Gorges Dam makes me very happy," said Luobu Cuomu, from Dingqing county, Xizang.

Since 2006, nearly 10,000 outstanding students from primary and secondary schools in areas targeted for aid, as well as ethnic minority regions, have participated in this activity organized by the China Three Gorges Corporation, which can also contribute to the development of educational endeavors in these regions.

Ice removal may soon become a lot easier. Researchers have developed a new method for making ice-phobic surfaces by altering the density and slipperiness of spray-on polymer coatings.

The process, reported online March 11 in Science Advances, could lead to a wide range of long-lasting ice-repellent products including windshields, airplane wings, power cables and frozen food packaging, researchers say.

Scientists know that ice easily detaches from softer, less dense materials. Further adjusting the density of rubber polymers used to make the coatings and adding silicone or other lubricants such as vegetable oil, cod-liver oil and safflower oil amplifies the effect, Anish Tuteja, a materials science engineer at the University of Michigan in Ann Arbor, and colleagues found.
In multiple laboratory and field tests, ice slid off treated surfaces under its own weight or when it was pushed by mild wind. The researchers further tested the coatings’ durability on various surfaces such as metal license plates and glass panes. The coatings performed well through two Michigan winters and retained their ice-repelling properties after controlled exposure to icing and heat cycles, corrosive substances such as hydrochloric acid, and wear and tear.

The process has already yielded more than 100 different coatings tailored for specific surfaces, including metal, glass, wood, plastic and cardboard. Tuteja says his team is working on licensing the materials for commercial use.

Scientists may have found the cosmic birthplace of an ultra-high energy neutrino. They point the finger at a blazar — a brilliantly luminous galaxy that shoots a jet of radiation in the direction of Earth — 9 billion light years away.

If the link between the blazar and neutrino is real, scientists would be closer to long-sought answers about where such power-packing particles come from. Violent astronomical accelerators boost some neutrinos to high energies, but scientists have never been able to convincingly identify their sources.
Neutrinos are aloof elementary particles that rarely interact with other matter — they can sail straight through the Earth, and trillions of them zip through your body every second without a trace. On December 4, 2012, the neutrino in question (which scientists have affectionately nicknamed Big Bird) slammed into the Antarctic ice with an energy of around 2 million billion electron volts. The neutrino observatory IceCube glimpsed the aftermath of the collision and measured its energy with sensitive detectors embedded deep in the ice (SN Online: 04/07/14), leaving scientists hustling to pinpoint its source.

The blazar flared up at just the right time and place to be a prime suspect, researchers report in a paper accepted for publication in a peer-reviewed journal. The result, now available online at arXiv.org, strengthens the case that blazars are the source of such high-energy neutrinos, but it is no smoking gun.

After the neutrino was detected, a team of astrophysicists scoured the heavens for energetic galaxies with TANAMI, short for Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry, a network of telescopes peering into space at a variety of wavelengths. That team reported one likely candidate blazar.

But the candidate is not a surefire match, says IceCube leader Francis Halzen of the University of Wisconsin–Madison, who was not involved with the analysis. IceCube could determine the neutrino’s direction within only about 15 degrees on the sky, and the blazar flare-up continued for several months. The probability of such a chance concurrence between an unrelated neutrino and blazar is about 5 percent, the researchers say — too big to rule out chance. “It’s a very intriguing result,” says Halzen “but it’s not a proof.”

The matchup between the blazar and neutrino is noteworthy, even though the researchers can’t fully rule out the possibility that the match is a fluke, says astrophysicist Xiang-Yu Wang of Nanjing University in China, who was not involved with the research. “Given that the two events are very unique … I think it’s convincing.” Wang and colleagues have expanded on the result: In a paper accepted for publication in Physical Review Letters, they use the difference in arrival time between the neutrino and light from the blazar’s outburst — assuming the two are related — to test Einstein’s special and general theories of relativity. Certain theories of quantum gravity predict a delay in the arrival of a neutrino. (Einstein came out unscathed.)
The authors of the blazar study declined to comment on the result, citing the embargo policy of the journal where the paper will be published.

To convincingly identify a blazar as the source of a neutrino, Halzen says, scientists will need a better measurement of the neutrino’s direction, connected to a short-lived blazar outburst. In the future, Halzen says, IceCube will send out “astronomical telegrams” when it detects a neutrino, directing telescopes to take a look, perhaps catching a blazar in the act.

Herbivores beware: Take a bite out of bittersweet nightshade (Solanum dulcamara), and you might have an ant problem on your hands. The plants produce a sugary goo that serves as an indirect defense, attracting ants that eat herbivores, Tobias Lortzing of Berlin’s Free University and colleagues write April 25 in Nature Plants.

Observations of wild nightshade plants in Germany suggest that plants that ooze goo attract more ants (mostly European fire ants, or Myrmica rubra) than undamaged plants. In greenhouse experiments, those ants fed on both the goo and roving slugs and flea beetle larvae, substantially reducing leaf damage. Leaf-munching adult flea beetles and, to a lesser degree, slugs prompted the goo production. The ants didn’t attack the beetles but did protect the plant from slugs and beetle larvae.

Plenty of other plants produce defensive nectars via organs called nectaries, and nightshades’ bleeding may be a unique, primitive version of that protective strategy, the scientists report.

Labrador retrievers tend to be more overweight and keen to scarf down their kibble than other dog breeds. Eleanor Raffan of the University of Cambridge and her colleagues chalk this trend up — least in part — to a suspect gene.

The team found that, among a small group of assistance dogs, a form of a gene called POMC that was missing a chunk of DNA was more common in obese Labs than in lean ones. This held true on a larger scale, too: Out of 411 Labs in the United Kingdom and United States, 22 percent carried the deletion mutation. Looking across other breeds, only Labradors and flat coat retrievers, a close relative, carried the gene variant, which also correlated with greater weight and food begging tendencies, the team reports May 3 in Cell Metabolism.

POMC plays a role in a metabolism pathway, and the deletion may inhibit the production of proteins that regulate hunger, the researchers suspect. (That might explain why the variant turned up in about 75 percent of assistance dogs, which are trained using food motivation.)

There’s nothing like having kids to open your eyes to the world’s dangers. With two little rascals in tow, grocery stores, dentists’ offices and even grandparents’ homes morph into death traps full of sharp, poisonous and heavy things. Short of keeping a tight grip on little hands, there’s not much you can do to childproof absolutely everything when you’re out and about. At home, it’s easier to make rooms safe for kids: Cover electrical outlets, keep drugs and potentially poisonous stuff out of reach, bolt dressers to the wall, and so on.

But every so often, I come across a study that points out an unexpectedly dangerous object. Clearly, none of these things rise to Bag O’Glass danger levels. But in the spirit of The More You Know, here are five objects that carry hidden risks to children:

Laundry pods
These cute, candy-colored packets can be irresistible to children — and toxic when eaten. Since 2012, when single-load pods for laundry detergent became popular, poison control centers have been fielding calls about toddlers who got ahold of pods. From 2013 to 2014, over 22,000 U.S. children under age 6 were exposed to these pods, mostly by eating them, data from the National Poison Data System show. And in just that two-year period, cases of laundry pod exposure rose 17 percent, scientists reported in the May Pediatrics.

Those numbers are particularly worrisome because laundry pods appeared to be more dangerous than regular laundry detergent (liquid or powder) and dishwasher detergent in any form (pod, liquid or powder). In a small number of kids, eating laundry pods caused serious trouble, including coma, respiratory arrest and cardiac arrest. Two children died, scientists wrote in the Pediatrics paper.

Tiny turtles
Oh, they’re adorable, but turtles can carry salmonella, bacteria that come with diarrhea, fever and cramps. Kids are particularly susceptible, and infections can be severe for them. Recognizing this risk, the FDA banned the sale of small turtles (shell less than 4 inches long) in 1975.
Yet in recent years, small turtles have slowly crawled back into children’s grubby little hands, carrying salmonella with them, scientists reported in January in Pediatrics. From 2011 to 2013, turtles were implicated in eight multistate Salmonella outbreaks, hitting hard in children younger than 5. Of the 473 people affected by the outbreaks, the median age was 4.

Big TVs
I’m not talking about the dangers of screen time here. I mean the television itself. Today’s flat screen TVs are more wobbly than the older, heavier tube-based TVs. Every 30 minutes, a kid is treated in the emergency room for a TV-related injury — that’s more than 17,000 children in the United States per year and increasing. And little heads and necks are the most frequently injured body parts.

Liquid nicotine
Along with the rise of e-cigarettes come refill cartridges, most of which contain concentrated liquid nicotine in flavors such as cherry crush, vanilla and mint. These appealing flavors mask nicotine that can be dangerous to kids. In 2015, poison control centers reported over 3,000 incidents of unintentional nicotine exposure, many of them in children. In comparison, just 271 exposures were reported in 2011.

That worrisome increase prompted the Child Nicotine Poisoning Prevention Act of 2015, signed into law by President Obama on January 28, requiring nicotine cartridges to be packaged in child-proof containers — a no-brainer.

Trampolines
Maniacal bouncing is clearly exhilarating for children, but also risky. I say this as a childhood-double-bounce survivor, so I understand the appeal. But just a note of caution: These springy injury machines come with a constellation of scary medical stats. Concussions, broken bones, sprains and neck injuries are signature trampoline troubles. A survey of a national injury database showed that broken bones accounted for 29 percent of all trampoline injuries reported to emergency departments, scientists reported in 2014 in the Journal of Pediatrics Orthopedics. The vast majority (93 percent) of those fractures belonged to children 16 and under.

Attempts to make trampolines safer — by putting a net around the perimeter, for instance — don’t seem to lower injury rates, an Australian study found. That’s why the American Academy of Pediatrics, the Canadian Paediatric Society, the American Academy of Orthopaedic Surgeons and other groups all urge caution, or an outright ban.

WASHINGTON — There’s a long-standing joke that NASA is always 20 years from putting astronauts on Mars. Mission details shared at a recent summit shows that the space agency is right on schedule. A to-do list from 2015 looks remarkably similar to one compiled in 1990. One difference: NASA is now building a rocket and test-driving technologies needed to get a crew to Mars. But the specifics for the longest road trip in history — and what astronauts will do once they arrive — remain an open question.

“Are we going to just send them there to explore and do things that we could do robotically though slower, or can we raise the bar?” asked planetary scientist Jim Bell during the Humans to Mars summit. “We need to make sure that what these folks are being asked to do is worthy of the risk to their lives,” said Bell, of Arizona State University in Tempe.
The three-day symposium, which ended May 19, was organized by Explore Mars Inc., a nonprofit dedicated to putting astronauts on Mars by the 2030s.

While the summit didn’t break new scientific ground, it did bring together planetary scientists , space enthusiasts and representatives from both NASA and the aerospace industry to talk about the challenges facing a crewed mission to Mars and rough ideas for how to get there.

Part of the appeal in sending humans is the pace of discovery. Drilling just one hole with the Curiosity rover, which has been exploring Gale Crater on Mars since August 2012 (SN: 5/2/2015, p. 24), currently takes about a week. “It’s a laborious, frustrating, wonderful — frustrating — multiday process,” said Bell.

Humans also can react to novel situations, make quick decisions and see things in a way robotic eyes cannot. “A robot explorer is nowhere near as good as what a human geologist can do,” says Ramses Ramirez, a planetary scientist at Cornell University. “There’s just a lot more freedom.”

Researchers saw the human advantage firsthand in 1997 when they sent a rover called Nomad on a 45-day trek across the Atacama Desert in Chile. Nomad was controlled by operators in the United States to simulate operating a robot on another planet. Humans at the rover site provided a reality check on the data Nomad sent back. “There was a qualitative difference,” says Edwin Kite, a planetary scientist at the University of Chicago. And it wasn’t just that the geologists could do things faster. “The robots were driving past evidence of life that humans were finding very obvious.”
To get astronauts ready to explore Mars, the Apollo program is a good template, said Jim Head, a geologist at Brown University who helped train the Apollo astronauts. “Our strategy was called t-cubed: train them, trust them and turn them loose.” While each of the moon expeditions had a plan, the astronauts were trusted to use their judgment. Apollo 15 astronaut David Scott, for example, came across a chunk of deep lunar crust that researchers hoped to find although it wasn’t at a planned stop. “He spotted it three meters away,” said Head. “He saw it shining and recognized it immediately. That’s exploration.”

Despite a lack of clear goals for a jaunt to Mars, NASA is forging ahead. The Orion crew capsule has already been to space once; a 2014 launch atop a Delta IV Heavy rocket sent an uncrewed Orion 5,800 kilometers into space before it splashed down in the Pacific Ocean (SN Online: 12/5/2014). And construction of the Space Launch System, a rocket intended to hurl humans at the moon and Mars, is under way. The first test flight, scheduled for October 2018, will send Orion on a multiday uncrewed trip around the moon. NASA hopes to put astronauts onboard for a lunar orbit in 2021.

Meanwhile, the crew aboard the International Space Station is testing technologies that will keep humans healthy and happy during an interplanetary cruise. Astronaut Scott Kelly recently completed a nearly yearlong visit to the station intended to reveal the effects of long-duration space travel on the human body (SN Online: 2/29/2016). And on April 10, a prototype inflatable habitat — the Bigelow Expandable Activity Module — arrived at the station and was attached to a docking port six days later. The station crew will inflate the module for the first time on May 26. No one will live in it, but over the next two years, astronauts will collect data on how well the habitat handles radiation, temperature extremes and run-ins with space debris.
Beyond that, the plans get fuzzy. The general idea is to construct an outpost in orbit around the moon as a testing and staging ground starting in the late 2020s. The first crew to Mars might land on the planet — or might not. One idea is to set up camp in Mars orbit; from there, astronauts could operate robots on the surface without long communication delays. Another idea has humans touching down on one of Mars’ two moons, Phobos or Deimos. When crews do land on the Martian surface, NASA envisions establishing a base from which astronauts could plan expeditions.

With so few details, it’s difficult for the space agency to identify specific technologies to invest in. “There have been lots of studies — we get a lot of grief that it’s nothing but studies,” said Bret Drake, an engineer at the Aerospace Corp. in El Segundo, Calif. “But out of the studies, there are a lot of common things that come to the top no matter what path you take.”

Any mission to Mars has to support astronauts for roughly 500 to 1,000 days. The mission has to deal with round-trip communication delays of up to 42 minutes. It will need the ability to land roughly 40-ton payloads on the surface of Mars (current robotic missions drop about a ton). Living off the land is also key, making use of local water and minerals. And astronauts need the ability to not just survive, but drive around and explore. “We want to land in a safe place, which is going to be geologically boring, but we want to go to exciting locations,” said Drake.

The technical and logistical challenges might be the easiest part. “We do know enough to pull this off,” Ramirez says. “The biggest problem is political will.” Congress has yet to sign off on funding this adventure (nor has NASA presented a budget — expected to be in the hundreds of billions of dollars), and future administrations could decide to kill it.

Multiple summit speakers stressed the importance of using technology that is proven or under development — no exotic engines or rotating artificial gravity habitats for now. And a series of small missions —baby steps to the moon and an asteroid before committing to Mars — could show progress that might help keep momentum (and public interest) alive.

“We thought going to the moon was impossible, but we got there,” says Ramirez. “If we dedicate ourselves as a nation to do something crazy, we’ll do it. I have no doubt.”

Peppered moths and copycat butterflies owe their wing color-changing abilities to a single gene, two independent studies suggest.

A genetic tweak in a portion of the cortex gene that doesn’t make protein painted the speckled gray wings of peppered moths black, researchers report online June 1 in Nature. Genetic variants in DNA interspersed with and surrounding the cortex gene also help some tasty species of Heliconius butterflies mimic unpalatable species and avoid getting eaten by predators, a second team of scientists reports, also June 1 in Nature.
In the often-told evolutionary tale, the color shift in moths began as factories in Britain started to darken the skies with coal smoke during the Industrial Revolution in the 1800s. Victorian naturalists took note as a newly discovered, all-black carbonaria form of peppered moths (Biston betularia) blended into soot-covered backgrounds; the light-colored typica moths, which lacked the mutation, were easily picked off by birds. By 1970, nearly 99 percent of peppered moths were black in some localities. As air pollution decreased in the late 20th century, black moths became more visible to birds. As a result, carbonaria moths are now rare.

“This begins to unravel exactly what the original mutation was that produced the black … moths that were favored by natural selection” during much of the last century, says evolutionary biologist Paul Brakefield of the University of Cambridge in England. “It adds a new and exciting element to the story.”

Wing pattern changes in butterflies and peppered moths are textbook examples of natural selection, but the molecular details behind the adaptation have eluded scientists for decades. In 2011, researchers tracked the traits to a region of a chromosome all the species have in common (SN: 5/7/11, p. 11; SN: 9/24/11, p. 16). Which of the many genes in that region might be responsible remained a mystery.
In peppered moths, the region of interest stretches over about 400,000 DNA bases and contains 13 genes and two microRNAs. “There aren’t really any genes that scream out to you, ‘I’m involved in wing patterning,’” says evolutionary geneticist Ilik Saccheri at the University of Liverpool in England.
Saccheri and colleagues compared that region in one black moth and three typical moths. The researchers found 87 places where the black moth differed from the light-colored moths. Most of the differences were changes in single DNA bases — the information-carrying chemicals in DNA. Such genetic variants are known as SNPs for single nucleotide polymorphisms. One difference was the insertion of a 21,925-base-long stretch of DNA into the region. This big chunk of DNA contained multiple copies of a transposable element, or jumping gene. Transposable elements are viruslike pieces of DNA that copy and insert themselves into a host’s DNA.

By examining the DNA of hundreds more typica moths and ruling out mutations one by one, the team ended up with one candidate: the large transposable element that had landed in the cortex gene. But the jumping gene didn’t land in the DNA that encodes the protein. Instead it landed in an intron — a stretch of DNA that gets chopped out after the gene is copied into RNA and before a protein is made.

The jumping gene first landed in the cortex intron in about 1819, the researchers calculated from historical measurements of how common the trait was throughout history. That timing gave the mutation about 20 to 30 moth generations to spread through the population before people first reported sightings of the black moths in 1848. Saccheri and colleagues found the transposable element in 105 of 110 wild-caught carbonaria moths and none of the 283 typica moths tested. The remaining five moths are black because of another, unknown, genetic variation.

Similarly, Nicola Nadeau, an evolutionary geneticist at the University of Sheffield in England, and colleagues combed through more than 1 million DNA bases in each of five species of Heliconius butterflies. The researchers were looking for genetic variants associated with the presence or absence of yellow bands on the wings.

Nadeau’s team found 108 SNPs in all H. erato favorinus butterflies that have a yellow band on their hind wings. Most of those SNPs were in introns of the cortex gene or outside of the gene. Butterflies that lack the yellow band don’t have those SNPs.

Other DNA changes were found to draw yellow bars on the wings of different species of Heliconius butterflies, suggesting that evolution acted multiple times on the cortex gene with similar results.

The finding that the same gene influences wing patterns in butterflies and moths supports an idea that some genes are hot spots of natural selection, says Robert Reed, an evolutionary biologist at Cornell University.

None of the genetic differences in the butterflies or peppered moths change the cortex gene itself. That leaves open the possibility that the transposable element and SNPs aren’t doing anything to cortex, but may be regulating a different gene. But the evidence that cortex really is the gene upon which natural selection has acted is strong, says Reed. “I’d be surprised if they were wrong.”

Still, it’s not obvious how cortex changes wing patterns, says Saccheri. “We’re both equally puzzled about how it is doing what it appears to be doing.” The teams have evidence that cortex helps determine when certain wing scales grow. In butterflies and moths, the timing of wing scale development affects the color of the wings, says Reed. “You see colors popping up almost like a paint-by-numbers.”

Yellow, white and red scales develop first. Black scales come later. Cortex is known to be involved in cell growth. So varying levels of the protein may speed up development of wing scales, causing them to become colored, or slow their growth, allowing them to turn black, the researchers speculate.