Periodical cicadas, like the one pictured above, have missed a lot of news about insects since they last appeared. Photo via Wikimedia Commons

After 17 years underground, billions of cicadas are ready to emerge and see sunlight for the first time. They will blanket the East Coast until around mid-June, buzzing like jackhammers in harmony as they search for a mate. Since 1996, the periodical insects, which belong to a group called Brood II, have lived as nymphs two feet deep in the soil, feeding on nothing but the liquid they suck out of tree roots. Once they crawl up to the surface, they molt, mate, lay eggs and die within a month.

Scientists are still trying to determine how periodical cicadas know when to emerge. But in the last 17 years, researchers have made some other important discoveries about other insects, some of whom also enjoy swarming the United States. Here are 17 news items about the bugs’ brethren since 1996.

1. British researchers figured out how insects fly. In 1996, scientists at the University of Cambridge solved the mystery of how many winged insects can produce more lift than can be explained by aerodynamic properties. The team unleashed hawkmoths into a wind tunnel with smoke and then took high-speed photos of the insects in flight. By studying how the smoke moved around the moths’ wings, researchers were able to determine that flying insects create whirling spirals of air above the front edges of their wings, providing more lift.

2. Cuba claimed that the United States brought an insect infestation to the island. In 1997, Cuban authorities accused the U.S. of staging a biological attack the previous year by using a crop-duster to spread insects over the island. But what really happened? An American commercial airliner had flown over the country and released smoke to signal its location, an event that coincided with bug infestations on Cuba’s potato plantations.

3. A plague of crickets ravaged the Midwest. In 2001, hordes of crickets descended upon Utah, infesting more than 1.5 million acres in 18 of the state’s 29 counties. The damaged wreaked on the ironically named Beehive State’s crops totaled nearly $25 million. Michael O. Leavitt, Utah’s governor at the time, declared the infestation an emergency and sought help from the U.S. Department of Agriculture in combating the little critters.

4. Scientists uncovered an entire new order of insects. In 2002, entomologists discovered a group of inch-long wingless creatures that comprised a new order, a taxonomic rank used in the classification of organisms. The first to be identified in 88 years at that time, the order, dubbed Mantophasmatodea, consists of insects with features similar to praying mantises. The finding became the 31st known insect order.

5. A swarm of butterflies, thought to be one single species, turned out to be 10 of them. In 2004, researchers used DNA barcoding technology to study the Astraptes fulgerator butterfly, whose habitat ranges from Texas to northern Argentina. What they found was remarkable: an insect that was thought to be one species was actually 10 different species. The species’ habitats overlapped, but the butterflies never bred with its doppelganger neighbors.

6. Researchers pinpointed the world’s oldest known insect fossil. Until 2004, a 400 million-year-old set of tiny insect jaws—originally found in a block of chert along with a well-preserved and well-studied fossil springtail—lay untouched for almost a century in a drawer at the Natural History Museum in London. The rediscovery and subsequent study of the specimen meant that true insects appeared 10 million to 20 million years earlier than once thought. The researchers believe these ancient insects were capable of flight, which would mean the tiny creatures took to the skies 170 millions years ago, before flying dinosaurs.

7. Brood X invaded the East Coast. In 2004, another group of cicadas known as Brood X emerged after 17 years underground. The bugs’ motto? Strength in numbers. This class is the largest of the periodical insects, including three different species of cicada.

8. America’s bee population started to plummet. By spring of 2007, more than a quarter of the country’s 2.4 million honeybee colonies had mysteriously vanished. Something prevented the bees from returning to their hives, and scientists weren’t sure why, but they gave it a name: colony-collapse disorder. According to a recent report by the U.S. Department of Agriculture, the phenomenon continues to plague apiaries across the country, and no cause has been determined.

9. Gypsy moths destroyed thousands of trees in New Jersey. In 2007, gypsy moths ravaged more than 320,000 acres of forest in the Garden State. One of North America’s most devastating forest pests, the insect feeds on the leaves of trees, stripping branches bare. Agricultural officials said the infestation was the worst of its kind since 1990.

10. Scientists figured out how to extract DNA from preserved insect specimens. In 2009, researchers removed a barrier from the study of early insects, a practice that often left ancient specimens destroyed. In the past, too much tinkering around with tiny specimens meant that the samples often became contaminated or eventually deteriorated. The scientists soaked nearly 200-year-old preserved beetles in a special solution for 16 hours, a process that allowed them to then carefully extract DNA from the bugs without damaging them.

11. Hundreds of ancient insect species were found lodged in one chunk of amber. In 2010, a team of international researchers discovered 700 new species of prehistoric insects inside a block of 50-million-year-old amber in India. The finding signaled to scientists that the area was much more biologically diverse than previously thought.

12. The first truly amphibious insects were discovered. In 2011, a study reported that 11 species of caterpillar with the ability to live underwater indefinitely were found in freshwater streams in Hawaii. The twist? The same insects studied were land-dwellers too.

13. Scientists discovered a cockroach with more than just a spring in its step. In 2011, a new species of cockroach, for whom jumping and hopping accounts for 71 percent of movement, was found in South Africa. Saltoblattella montistabularis can cover a distance 50 times its body length with each hop. Dubbed the leaproach, the insect relies on its powerful hind legs, which are twice the length of its other limbs and make up 10 percent of its body weight, to propel it forward in high-speed bursts.

14. Japanese scientists documented radiation-induced mutations in butterflies. When a massive earthquake and tsunami severely damaged the Fukushima nuclear power plant in 2011, dangerous radioactive materials were spewed into the air and waterways. The following year, Japanese researchers said they observed dented eyes and stunted wings in local butterflies, mutations they believe were a result of radiation exposure.

15. The East Coast suffered a stink bug epidemic. In the summer of 2011, growing numbers of stink bugs prompted the Environmental Protection Agency to issue an emergency ruling that would allow farmers to use lethal insecticides. The insects had invaded crops of apples, cherries, pears and peaches from Virginia to New Jersey.

16. The world’s largest insect was discovered in New Zealand. Scientist Mark Moffett, known as Doctor Bugs, discovered the world’s largest insect, a surprisingly friendly female Weta bug, while traveling in New Zealand in 2011. The massive creature has a wingspan of seven inches and weighs three times as much as a mouse. Here’s a video of the bug eating a carrot out of Moffett’s hand.

17. A fly found in Thailand was determined to be the smallest in the world. Discovered in 2012, the fly, named Euryplatea nanaknihali, is 15 times smaller than a house fly and tinier than a grain of salt. But don’t let the miniature bugs fool you: they feed on tiny ants by burrowing into the larger insects’ head casings, eventually decapitating them.

What can’t a 3D printer build? The number of possible answers to this question has shrunk exponentially in recent years, as the high-tech machines continue to churn out solid object after object from computer designs.

The last few months alone saw countless new products and prototypes spanning an array of industries, from football cleats and pens to steel rocket parts and guns. Last month, the technology helped replace 75 percent of a person’s damaged skull, and this week it restored a man’s face after he lost half of it to cancer four years ago.

Today, a new study suggests 3D-printed material could one day mimic the behavior of cells in human tissue. Graduate student Gabriel Villar and his colleagues at the University of Oxford developed tiny solids that behave as biological tissue would. The delicate material physically resembles brain and fat tissue, and has the consistency of soft rubber.

To create this material, a specially designed 3D printing machine followed a computer programmed diagram and ejected tens of thousands of individual droplets according to a specified three-dimensional network. As seen in the video above, its nozzles moved in various angles to establish the position of each tiny bead. Each droplet weighs in at about one picoliter—that’s one trillionth of a liter—a unit used to measure the size of droplets of inkjet printers, whose nozzle technology works much the same way to consolidate tiny dots of liquid into complete images and words on paper.

The droplets of liquid contained biochemicals found in tissue cells. Coated in lipids—fats and oils—the tiny aqueous compartments stuck together, forming a cohesive and self-supporting shape, with each bead partitioned by a thin, single membrane similar to the lipid bilayers that protect our cells.

Several 3D-printed droplet networks. Image courtesy of Gabriel Villar, Alexander D. Graham and Hagan Bayley (University of Oxford)

The shapes that the printed droplets formed remained stable for several weeks. If researchers shook the material slightly, droplets could become displaced, but only temporarily. The engineered tissue quickly sprung back into its original shape, a level of elasticity the researchers say is comparable to soft tissue cells in humans. The intricate latticework of a network’s lipid bilayers appeared to hold the “cells” together.

In some of the droplet networks, the 3D printer built pores into the lipid membrane. The holes mimicked protein channels inside the barriers that protect real cells, filtering molecules important for cell function in and out. The researchers injected into the pores a type of molecule important for cell-to-cell communication, one that delivers signals to numerous cells so that they function together as a group. While the 3D-printed material couldn’t exactly replicate how cells propagate signals, researchers say the movement of the molecule through defined pathways resembled the electrical communication of neurons in brain tissue

Water readily permeated the network’s membranes, even when pores were not built into its structure. The droplets swelled and shrank by the process of osmosis, trying to establish equilibrium between the amount of water they contained and the amount surrounding them on the outside. The movement of water was enough to lift the droplets against gravity, pulling and folding them, imitating muscle-like activity in human tissue.

The researchers hope that these droplet networks could be programmed to release drugs following a physiological signal. Printed cells could someday also be integrated into damaged or failing tissue, providing extra scaffolding or even replacing malfunctioning cells, perhaps even supplanting some of the 1.5 million tissue transplants that take place in the United States each year. The potential seems greatest for brain tissue transplants, as medical engineers are currently trying to grow brain cells in the lab to treat progressive diseases like Huntington’s disease, which slowly destroys nerve cells.

Whether it’s growing human tissue or entire ears, 3D printing technology is in full swing in the field of medicine, and countless researchers will no doubt jump on the bandwagon in the coming years.

Roosters have an internal circadian rhythm, which keeps them crowing on schedule even when the lights are turned off. Image via Wikimedia Commons/Muhammad Mahdi Karim

Some scientists investigate the universe’s biggest mysteries, like the Higgs boson, the mysterious particle that endows all other subatomic particles with mass.

Other researchers look into questions that are, well, a bit humbler—like the age-old puzzle of whether roosters simply crow when they see light of any kind, or if they truly know to crow when the morning sun arrives.

Lofty or not, it’s the goal of science to answer all questions that arise from the natural world, from roosters to bosons and everything in between. And a new study by Japanese researchers published today in Current Biology resolves the rooster question once and for all: The birds truly do have an inner circadian rhythm that tells when to crow.

The research team, from Nagoya University, investigated via a fairly straightforward route: They put several groups of four roosters in a room for weeks at a time, turned the lights off, and let a video camera running. Although roosters can occasionally crow at any time of day, the majority of their crowing was like clockwork, peaking in frequency at time intervals roughly 24 hours apart—the time their bodies knew to be morning based on the sunlight they’d last seen before entering the experiment.

This consistency continued for about 2 weeks, then gradually began to die out. The roosters were left in the room for 4 weeks in total, and during the second half of the experiment, their crowing began occurring less regularly, at any time of day, suggesting that they do need to see the sun on a regular basis for their circadian rhythms to function properly.

In the experiment’s second part, the researchers also subjected the roosters to alternating periods of 12 hours of light and 12 hours of darkness, while using bright flashes of light and the recorded crowing of roosters (since crowing is known to be contagious) to induce crowing at different times of day. When they activated these stimuli near at or near the dawn of the roosters’ 12-hour day, crowing rates increased significantly. At other times of day, though, exposing them to sudden flashes of light or playing the sound of crowing had virtually no effect, showing that the underlying circadian cycle played a role in the birds’ response to the stimuli.

Of course, many people who live in close proximity to roosters note that they often crow in response to a random light source turning on, like a car’s headlights, no matter what time of day it is. While this may be true, the experiment shows that the odds of a rooster responding to a car’s headlights depend on how close the current time is to dawn—at some level, the rooster’s body knows whether it should be crowing or not, and responding to artificial stimuli based on this rhythm.

For the research team, all this is merely a prelude to their bigger, more complex questions: Why do roosters have a biological clock that controls crowing in the first place, and how does it work? They see the simple crowing patterns of the rooster as an entry point into better understanding the vocalizations of a range of animals. “We still do not know why a dog says ‘bow-wow’ and a cat says ‘meow,’” Takashi Yoshimura, one of the co-authors, said in a press statement. “We are interested in the mechanism of this genetically controlled behavior and believe that chickens provide an excellent model.”

One of the Cornell team’s prosthetic ears, created from living cartilage cells. Image via PLOS ONE/Reiffel et. al.

3D printing is big news: During his State of the Union speech, President Obama called for the launch of manufacturing hubs centered around 3D printing, while earlier this week, we saw the birth of one of the most playful applications of the technology yet, the 3D Doodler, which lets you draw solid plastic objects in 3 dimensions.

Yesterday, Cornell doctors and engineers presented a rather different use of the technology: a lifelike artificial ear made of living cells, built using 3D printing technology. Their product, described in a paper published in PLOS ONE, is designed to help children born with congenital defects that leave them with underdeveloped outer ears, such as microtia.

The prosthesis—which could replace previously used artificial materials with styrofoam-like textures, or the use of cartilage tissue harvested from a patient’s ribcage—is the result of a multistep process.

First, the researchers make a digital 3D representation of a patient’s ear. For their prototype, they scanned healthy pediatric ears, but theoretically, they might someday be able to scan an intact ear on the other side of a patient’s head—if their microtia has only affected one of their ears—and reverse the digital image, enabling them to create an exact replica of the healthy ear.

Next, they use a 3D printer to produce a solid plastic mold the exact shape of the ear and fill it with a high-density collagen gel, which they describe as having a consistency similar to Jell-O.

A 3D printer creates a plastic mold for the ear’s collagen scaffolding. Image via Lindsay France/Cornell University Photography

A collagen ear, to be seeded with living cartilage cells and implanted under skin. Image via Lindsay France/Cornell University Photography

After printing, the researchers introduce cartilage cells into the collagen matrix. For the prototype, they used cartilage samples harvested from cows, but they could presumably use cells from cartilage elsewhere on the patient’s own body in practice.

Over the course of a few days in a petri dish filled with nutrients, the cartilage cells reproduce and begin to replace the collagen. Afterward, the ear can be surgically attached to a human and covered with skin, where the the cartilage cells continue to replace the collagen.

So far, the team has only implanted the artificial ears underneath the skin on the backs of lab rats. After 3 months attached to the rats, the cartilage cells had replaced all the collagen and filled in the entire ear, and the prosthetic retained its original shape and size.

In a press statement, co-author Jason Spector said that using a patient’s own cells would greatly reduce the chance of the body rejecting the implant after surgery. Lawrence Bonassar, another co-author, noted that in addition to congenital defects, the prosthesis could also be valuable for those who lose their outer ear as a result of cancer or an accident. If used for a child with microtia, the ear won’t grow along with the head over time, so the researchers recommend waiting to implant one of their prostheses until the patient is 5 or 6 years old, when ears have normally grown to more than 80 percent of their adult size.

The biggest advantage of the new technology over existing methods is the fact that the production process is customizable, so it could someday produce remarkably realistic-looking ears for each patient on a rapid timescale. The researchers have actually sped up the process since conducting the experiments included in the study, developing the ability to directly print the ear using the collagen as an “ink” and skip making the mold.

There are still a few problems to tackle, though. Right now, they don’t have the means to harvest and cultivate enough of a pediatric patient’s own cartilage to build an ear, which is why they used samples from cows. Additionally, future tests are needed to prove that surgical implantation is safe for humans. The team says they plan to address these issues and could be working on the first implant of such an ear in a human as soon as 2016.

The Opte Project creates visualizations of the 14 billion pages that make up the network of the web. Image via Opte Project

Note: After publishing this article, it came to our attention that Barabási originally made this finding in 1999, and it was merely referenced in the recent publication. We regret the error.

No one knows for sure how many individual pages are on the web, but right now, it’s estimated that there are more than 14 billion. Recently, though, Hungarian physicist Albert-László  discovered something surprising about this massive number: Like actors in Hollywood connected by Kevin Bacon, from every single one of these pages you can navigate to any other in 19 clicks or less.

Barabási’s findings, published noted yesterday in Philosophical Transactions of the Royal Society (Correction: initially made way back in 1999), involved a simulated model of the web that he created to better understand its structure. He discovered that of the roughly 1 trillion web documents in existence—the aforementioned 14 billion-plus pages, along with every image, video or other file hosted on every single one of them—the vast majority are poorly connected, linked to perhaps just a few other pages or documents.

Distributed across the entire web, though, are a minority of pages—search engines, indexes and aggregators—that are very highly connected and can be used to move from area of the web to another. These nodes serve as the “Kevin Bacons” of the web, allowing users to navigate from most areas to most others in less than 19 clicks.

Barabási credits this “small world” of the web to human nature—the fact that we tend to group into communities, whether in real life or the virtual world. The pages of the web aren’t linked randomly, he says: They’re organized in an interconnected hierarchy of organizational themes, including region, country and subject area.

Interestingly, this means that no matter how large the web grows, the same interconnectedness will rule. Barabási analyzed the network looking at a variety of levels—examining anywhere from a tiny slice to the full 1 trillion documents—and found that regardless of scale, the same 19-click-or-less rule applied.

This arrangement, though, reveals cybersecurity risks. Barabási writes that knocking out a relatively small number of the crucial nodes that connect the web could isolate various pages and make it impossible to move from one to another. Of course, these vital nodes are among the most robustly protected parts of the web, but the findings still underline the significance of a few key pages.

To get an idea of what this interconnected massive network actually looks like, head over to the Opte Project, an endeavor started by Barrett Lyon in 2003 to create publicly available visualizations of the web. In the map above, for example, red lines represent links between web pages in Asia, green for Europe, the Middle East and Africa, blue for North America, yellow for Latin America and white for unknown IP addresses. Although the most recent visualization is several years old, Lyon reports that he’s currently working on a new version of the project that will be released soon.

You may have never seen a zebrafish in person. But take a look at the zebrafish in the short video above and you’ll get to see something previously unknown to science: a visual representation of a thought moving through a living creature’s brain.

A group of scientists from Japan’s National Institute of Genetics announced the mind-boggling achievement in a paper published today in Current Biology. By inserting a gene into a zebrafish larvae—often used in research because its entire body is transparent—and using probe that detects florescence, they were able to capture the fish’s mental reaction to a swimming paramecium in real time.

The key to the technology is a special gene known as GCaMP that reacts to the presence of calcium ions by increasing in florescence. Since neuron activity in the brain involves rapid increases in concentrations of calcium ions, insertion of the gene causes the particular areas in a zebrafish’s brain that are activated to glow brightly. By using a probe sensitive to florescence, the scientists were able to monitor the locations of the fish’s brain that were activated ay any given moment—and thus, capture the fish’s thought as it “swam” around the brain.

Zebrafish embryos and larvae are often used in research because they are largely translucent. Image via Wikimedia Commons/Adam Amsterdam

The particular thought captured in the video above occurred after a paramecium (a single-celled organism that the fish considers a food source) was released into the fish’s environment. The scientists know that the thought is the fish’s direct response to the moving paramecium because, as an initial part of the experiment, they identified the particular neurons in the fish’s brain that respond to movement and direction.

They mapped out the individual neurons responsible for this task by inducing the fish to visually follow a dot move across a screen and tracking which neurons were activated. Later, when they did the same for the fish as it watched the swimming paramecium, the same areas of the brain lit up, and the activity moved across these areas in the same way predicted by the mental maps as a result of the paramecium’s directional movement. For example, when the paramecium moved from right to left, the neuron activity moved from left to right, because of the way the brain’s visual map is reversed when compared to the field of vision.

This isn’t the first time that GCaMP has been inserted into a zebrafish for imaging purposes, but it is the first time that the images have been captured as a real-time video, rather than a static image after the fact. The researchers accomplished this by developing an improved version of GCaMP that is more sensitive to changes in calcium ion concentration and gives off greater levels of florescence.

The accomplishment is obviously a marvel in itself, but the scientists involved see it leading to a range of practical applications. If, for example, scientists had the ability to quickly map the parts of the brain affected by a chemical under consideration as a drug, new and effective psychiatric medications could be more easily developed.

They also envision it opening the door to a variety of even more amazing—and perhaps a bit troubling (who, after all, really wants their mind read?)—thought-detecting applications. “In the future, we can interpret an animal’s behavior, including learning and memory, fear, joy, or anger, based on the activity of particular combinations of neurons,” said Koichi Kawakami, one of the paper’s co-authors.

It’s clearly some time away, but this research shows that the concept of reading an animal’s thoughts by analyzing its mental activity might move beyond science fiction to enter the realm of real world science applications.

Image via Wikimedia Commons

Next time you’re reading about a scientific finding and feeling a bit skeptical, you may want to take a look at the study’s authors. One simple trick could give you a hint on whether the work is fraudulent or not: check whether those authors are male or female.

According to a study published yesterday in mBio, men are significantly more likely to commit scientific misconduct—whether fabrication, falsification or plagiarism—than women. Using data from the U.S. Office of Research Integrity, this study’s authors (a group that includes two men and one women but we’re still trusting, for now) found that out of 215 life science researchers who’ve been caught misbehaving since 1994, 65 percent were male, a fraction that outweighs their overall presence in the field.

“A variety of biological, social and cultural explanations have been proposed for these differences,” said lead author Ferric Fang of the University of Washington. “But we can’t really say which of these apply to the specific problem of research misconduct.”

Fang first became interested in the topic of misconduct in 2010, when he discovered that a single researcher had published six fraudulent studies in Infection and Immunity, the journal of which he is editor-in-chief. Afterward, he teamed up with Arturo Casadevall of the Albert Einstein College of Medicine to begin systematically studying the issue of fraud. They’ve since found that the majority of retracted papers are due to fraud and have argued that the intensely competitive nature of academic researcher engenders abuses.

For this study, they worked with Joan Bennett of Rutgers to break down fraud in terms of gender, as well as the time in a scientist’s career when fraud is most likely. They found that men are not only more likely to lie about their findings but are disproportionately more likely to lie (as compared to women) as they ascend from student to post-doctoral researcher to senior faculty.

While the percentage of those who engage in misconduct is disproportionately male at all levels, the trend is even more extreme at the senior faculty level. Image via Fang et. al.

Of the 215 scientists found guilty, 32 percent were in faculty positions, compared to just 16 percent who were students and 25 perecent who were post-doctoral fellows. It’s often assumed that young trainees are most likely to lie, given the difficulty of climbing the academic pyramid, but this idea doesn’t jive with the actual data.

“Those numbers are very lopsided when you look at faculty. You can imagine people would take these risks when people are going up the ladder,” said Casadevall, “but once they’ve made it to the rank of ‘faculty,’ presumably the incentive to get ahead would be outweighed by the risk of losing status and employment.”

Apparently, though, rising to the status of faculty only increases the pressure to produce useful research and the temptation to engage in fraud. Another (unwelcome) possibility is that those who commit fraud are more likely to reach senior faculty positions in the first place, and many of them just get exposed later on in their careers.

Whichever the explanation, it’s clear that men do commit fraud more often than women—a finding that shouldn’t really be so surprising, since men are more likely to indulge in all sorts of wrongdoing. This trend also makes the fact that women face a systemic bias in breaking into science all the more frustrating.

The gooseneck barnacle (with a relaxed penis at arrow) is capable of a method of sex previously unobserved in barnacles, upending 150 years of theory. Image via Barazandeh, et al. Proc. R. Soc. B.

Barnacles are renowned for the size of their penises. The strange-looking creatures, which live inside shells glued to rocks or boat hulls, have outsized members that are among the longest in the animal kingdom relative to their size—their penises can stretch up to eight times their body length. Barnacles can even change the size and shape of their penis depending on the amount of wave action in their ocean real estate.

Perhaps this is why the sex lives of barnacles have long been of interest to scientists—luminaries such as Darwin, among others, closely studied the subject. Until recently, though, scientists recognized just two methods of reproduction in the species, and both left unanswered questions.

Pseudo-copulation, in which the penis enters a neighboring barnacle’s shell and deposits sperm, has been observed, but this method restricts them to reproducing only with others in their vicinity. Scientists have also observed that individual barnacles with no neighbors can reproduce, and they assumed this was accomplished through self-fertilization, because most barnacles are hermaphrodites.

Gooseneck barnacles (Pollicipes polymerus) taken at Limekiln Point on San Juan Island. Photo: Biriwilg, Wikimedia Commons

Now, though, researchers at the University of Alberta, Edmonton and Bamfield Marine Sciences Centre in British Columbia seem to have discovered a new reproduction method while studying the gooseneck barnacle (Pollicipes polymerus), upending more than 150 years of theory. Previously, the researchers had noticed that in other studies of the gooseneck barnacle, self-fertilization was never observed. They also saw sperm leaking from the barnacles in the field, which made them consider the possibility that barnacles could pick up sperm from the water.

In the study, the scientists collected gooseneck barnacles—both isolated and in pairs—along with their fertilized eggs from Barkley Sound in British Columbia to take back to the lab so they could genetically analyze the paternal combinations. The DNA of the fertilized eggs revealed that none of the isolated barnacles had produced embryos through self-fertilization—so one hundred percent of these eggs must have been fertilized by capturing sperm from the water.

Surprisingly, though, even some of the barnacles that resided in pairs had embryos that had been fertilized with sperm from a non-neighbor. This left one possibility: that the barnacles release their sperm into the ocean and let the water carry it to distant neighbors. This type of fertilization has been observed in other marine animals that can’t or don’t move, but it was always assumed that barnacles can’t reproduce in this way.

The authors point out that this mode of reproduction may be unusually common in this particular barnacle species because of the small size of their penis—but the fact that this phenomenon occurs at all opens the door to re-thinking the biology of these creatures. Other barnacle species might also have more mating options, with fathers coming from farther afield than previously thought.

 Learn more about the ocean from the Smithsonian’s Ocean Portal. 

A new DNA analysis method reveals how ancient skeletons would have looked in the flesh. Image via Jolanta Draus-Barini, Susan Walsh, Ewelina Pospiech, Tomasz Kupiec, Henryk Glab, Wojciech Branicki and Manfred Kayser

For years, when museums, textbooks or other outlets attempted to illustrate what a particular ancient human skeleton would have looked like in the flesh, their method was admittedly unscientific—they basically had to make an educated guess.

Now, though, a group of researchers from Poland and the Netherlands has provided a remarkable new option, described in an article they published in the journal Investigative Genetics on Sunday. By adapting DNA analysis methods originally developed for forensic investigations, they’ve been able to determine the hair and eye color of humans who lived as long as 800 years ago.

The team’s method examines 24 locations in the human genome that vary between individuals and play a role in determining hair and eye color. Although this DNA degrades over time, the system is sensitive enough to generate this information from genetic samples—taken either from teeth or bones—that are several centuries old (although the most degraded samples can provide information for eye color only).

As a proof of concept, the team performed the analysis for a number of people whose eye and hair color we already know. Among others, they tested the DNA of Władysław Sikorski, a former Prime Minister of Poland who died in a 1943 plane crash, and determined that Sikorski had blue eyes and blonde hair, which correctly matches color photographs.

But the more useful application of the new method is providing new information. “This system can be used to solve historical controversies where colour photographs or other records are missing,” co-author Manfred Kayser, of Erasmus University in Rotterdam, said in a statement.

For example, in the paper, the researchers analyzed the hair and eye color for a female skeleton buried in the crypt of a Benedictine Abbey near Kraków, Poland, sometime between the 12th and 14th centuries. The skeleton had been of interest to archaeologists for some time, since male monks were typically the only people buried in the crypt. The team’s analysis showed that she had brown eyes and dark blond or brown hair.

The team is not sure yet just how old a skeleton has to be for its DNA to be degraded beyond use—the woman buried in the crypt was the oldest one tested—so it‘s conceivable that it might even work for individuals who’ve been in the ground for more than a millenium. The researchers suggest this sort of analysis could soon become part of a standard anthropological toolkit for evaluating human remains.

Last summer, a study found that long-term cannabis use reduced cognitive skills. A new study seems to say the opposite. Image via Wikimedia Commons/Bokske

Last summer, a study published in the Proceedings of the National Academy of Sciences sparked a new round of worries about the dangers of smoking pot—especially for those who start smoking at younger ages. The study found that consistent marijuana use gradually eroded cognitive functioning and IQ, and with the legalization of recreational marijuana in Colorado and Washington, it’s made an appearance in a number of articles arguing that legalized pot poses a serious health hazard. Today, though, a new study published in the very same journal—and using the very same data set—suggests that the case against marijuana is a little less cut-and-dry.

Ole Røgeberg, a researcher at the Frisch Centre for Economic Research in Norway, analyzed the same survey results and found that the declines in cognitive abilities could be entirely attributed to socioeconomic factors. As a result, “the true effect” of marijuana use, he argues, “could be zero.”

Røgeberg is careful to note that his reinterpretation of the data doesn’t entirely discredit the original study, but he does write that its “methodology is flawed and the causal inference drawn from the results premature.”

Both the new and old studies draw upon a data set of 1,037 individuals from Dunedin, New Zealand, who were followed from their birth (either in 1972 or 1973) until they turned 38. At the ages of 18, 21, 26, 32 and 38, each of them were interviewed and scored for marijuana use. The original study found that IQ decline increased proportionately with cannabis dependence—especially for those who started smoking earlier on—and the authors concluded that using the drug was the cause of the decline.

Røgeberg, though, dug a little deeper into the data. He found those who started using marijuana during adolescence were disproportionately likely to have poor self-control and conduct problems in school—both factors that are themselves correlated with low socioeconomic status. In particular, members of the study with these traits were more likely to come from a Maori background, a group indigenous to New Zealand that has much higher unemployment, poverty and incarceration rates than the country’s population as a whole.

Numerous other studies have shown that low socioeconomic status adolescents are more likely to experience steeper IQ declines during adulthood. (Researchers hypothesize this is a result of being exposed to less intellectually stimulating environments.) As a result, Røgeberg wondered, could socioeconomic factors explain the IQ declines originally attributed to marijuana?

In his simulation, he tested whether socioeconomic environmental factors (dropping out of school, being exposed to less stimulating environments, and so on) could conceivably drive the same IQ declines reported in the group without turning to marijuana as an explanation. His statistical analysis found that these other factors could indeed completely account for the cognitive declines observed.

For support, he also points to a 2002 Canadian study that also asked whether long-term marijuana use impacted IQ, but with data entirely from middle-class survey participants. That paper found that IQ only decreased for current cannabis users, and when even heavy users stopped smoking, their IQ rebounded. Since that study largely excluded socioeconomic factors and did not find a permanent trend, he feels that it supports his argument that such factors play a major role.

Researchers have developed a breath-based test for bacterial infections, using the same concepts employed in a breathalyzer (above). Image via Wikimedia Commons

We’re all familiar with the concept of a breathalyzer—a device that indicates someone’s blood alcohol content by precisely analyzing his or her breath. Because the breakdown of alcohol produces predictable quantities of various gases, these machines are reliable enough to be used by law enforcement to declare a driver, say, as legally intoxicated.

Recently, a group of researchers from the University of Vermont saw this idea and had another: What if a device could be designed to detect a chemical signature that indicates a bacterial infection in someone’s lungs? Their result, revealed yesterday in the Journal of Breath Research, is a quick and simple breath test—so far used only with mice—that can diagnose infections such as tuberculosis.

In their study, they focused on analyzing volatile organic compounds (VOCs) in mouse breath to distinguish between different strains of bacteria that were infecting the animals’ lungs. They hypothesized that these bacteria produce VOCs not normally present in the lungs, thus allowing their test to differentiate between a healthy animal and a sick one.

Initially, a number of the mice were infected with either Pseudomonas aeruginosa or Staphylococcus aureus—both common types of bacteria in either acute and chronic lung infections—and their breath was tested 24 hours later. The researchers used a technique called “secondary electrospray ionization mass spectrometry” (a name that, admittedly, requires quite a mouthful of expelled air), which can detect VOC quantities of as little as a few parts per trillion.

Their test was a success: There was a significant difference between the chemical signatures of healthy and infected mouse breath, and their test was even able to indicate which type of bacteria were the source of the infection.

Although the concept has only been used on mice so far, the researchers think that you could someday be blowing into a bacterial breathalyzer as part of your routine medical exam. Their prediction stems from the fact that the approach offers several advantages over conventional ways of detecting bacterial infections in the lungs.

“Traditional methods employed to diagnose bacterial infections of the lung require the collection of a sample that is then used to grow bacteria,” said Jane Hill, one of the paper’s co-authors, in a statement. “The isolated colony of bacteria is then biochemically tested to classify it and to see how resistant it is to antibiotics.”

This process can take days and sometimes even weeks just to identify the type of bacteria. By contrast, she said, “Breath analysis would reduce the time-to-diagnosis to just minutes.”

This type of test would also be less invasive than current methods. Thus, for patients suffering from bacterial infections…a breath of fresh air.

Another one of the products of science that seem too amazing to be true: Researchers at MIT have invented the technological equivalent of Mexican jumping beans. As seen in the video above, they’ve created polymer films that act like artificial fast-twitch muscles, spontaneously curling up and dancing around in an eerily life-like way.

The polymer sheets are specially designed to rapidly expand when they come into contact with water, and contract when they expel it. Thus, by placing the sheets on a slightly moist surface, Mingming Ma and colleagues were able to make them dance around completely on their own. They published the details of their invention today in a paper in Science.

Although the polymers are simply pretty cool to watch, the researchers had a practical application in mind when they developed them: producing electricity. When they covered the sheets with a piezoelectric polymer that generates electricity from pressure and stress (30 seconds into the video), and wired it to a capacitor, they were able to store minute amounts of energy expelled by all that folding and flipping.

They say the sheets produced bursts of electricity peaking at about 1 volt. Since the polymer can also be stimulated by the mere presence of water vapor in the air—and not just water on a table—they speculate that these types of thin water-powered sheets could someday be harnessed to provide electricity for small ubiquitous objects, like environmental sensors.

“With a sensor powered by a battery, you have to replace it periodically,” lead author Ma said in a statement. “If you have this device, you can harvest energy from the environment so you don’t have to replace it very often.”

It’s even possible, they suggest, that this type of material could be sewn into clothing, in order to harvest electricity from the sweat that evaporates off your body. ”You could be running or exercising and generating power,” said Liang Guo, a co-author.

The sheets are made from a pair of polymers: one called polypyrrole, which serves as a rigid supporting matrix, and another called polyol-borate, a flexible gel substance woven throughout that does the expanding and contracting when in contact with water. The researchers were inspired by the configuration of animal muscles (including our own), which are made from a rigid network of collagen fibers woven with elastic microfibrils.

In the video above, when the superthin film comes in contact with minute amounts of moisture, the bottom layer absorbs water and quickly curls upward. Then, once the bottom is lifted off the table and comes into contact with the air, the moisture evaporates off of it, and it flattens back out.

The team even tested the strength of this fascinating polymer construction, using clamps and heavy objects, to see just how much weight the polymer sheets could lift when stimulated. They found that a 25-milligram piece of film could lift a stack of glass slides 380 times heavier than itself and produce up to 27 megapascals of pressure—80 times more than the amount of pressure generated by typical mammalian muscle. Pretty amazing for a paper-thin sheet of film.

Small red boring sponges embedded in star coral, killing the coral polyps immediately surrounding them. Image via Sean Nash, Flickr

Whenever anyone talks about ocean acidification, they discuss vanishing corals and other shelled organisms. But these aren’t the only organisms affected—the organisms that interact with these vulnerable species will also change along with them.

These changes won’t necessarily be for the good of the shell and skeleton builders. New research published in Marine Biology shows that boring sponges eroded scallop shells twice as fast under the more acidic conditions projected for the year 2100. This makes bad news for the scallops even worse: not only will they have to cope with weakened shells from acidification alone, but their shells will crumble even more quickly after their cohabiters move in.

Boring sponges aren’t named thus because they’re mundane; rather, they make their homes by boring holes into the calcium carbonate shells and skeletons of animals like scallops, oysters and corals. Using chemicals, they etch into the shell and then mechanically wash away the tiny shell chips, slowly spreading holes within the skeleton or shell and sometimes across its surface. Eventually, these holes and tunnels can kill their host, but the sponge will continue to live there until the entire shell has eroded away.

Alan Duckworth of the Australian Institute of Marine Science and Bradley Peterson of Stony Brook University in New York brought boring sponges (Cliona celata) and scallops (Argopecten irradians) into the lab to examine the effects of temperature and acidity (measured through pH) on drilling behavior. They set up a series of saltwater tanks to compare how much damage sponges did to scallops under current temperature and ocean conditions (26°C and pH 8.1), projected conditions for 2100 (31°C and pH 7.8), and each 2100 treatment alone (31°C or pH 7.8).

Cliona celata (yellow), the boring sponge species used in the study, is commonly found on oysters and scallops and lives throughout the Atlantic and Mediterranean. Here, numerous sponges have drilled into coral. Image via Bernard Picton, National Museums Northern Ireland

Under higher acidity (lower pH), boring sponges drilled into scallop shells twice as fast, boring twice as many holes and removing twice as much shell over the course of the 133-day study. The lower pH alone weakened the shells, but after the boring sponges did their work, the scallop shells were an additional 28% weaker, making them more vulnerable to predation and collapse from the sponges’ structural damage.

The sponges weren’t entirely thrilled by the water’s higher acidity, which killed 20% of the them (although the researchers aren’t sure why). Despite this loss, 80% of the sponges doing twice as much drilling meant more damage to shelled organisms in total. Temperature did not affect sponge behavior at all.

This study illustrates a classic positive feedback loop, where weakness in the shells leads to more weakness. And not through the sponge-drilled holes alone: the addition of sponge-drilled holes creates more surface area for acidification to further erode the shells, hastening each scallop’s inevitable collapse. It’s tempting to speculate out to the rest of the system—that the sponges are destroying their own habitat more quickly than scallops can produce it—but we don’t really know whether in the long run this is also bad news for the sponges.

Though a small and specific example, this study illustrates how a seemingly small change—more acid and weaker shells—can ripple out and affect other organisms and the rest of the ecosystem.

  Learn more about coral reefs from the Smithsonian’s Ocean Portal.

Coral from the Northern Line Islands reveals a link between climate change and El Niño. Photo by Forest Rohwe

El Niño, the climate pattern that increases Pacific Ocean surface temperatures every three to seven years, has long been known to pummel the Sierra Nevada with snow, limit Peruvian anchovy fishermen’s harvest and bless the Hawaiian Islands with dry, beach-friendly weather. The question of whether the effects of El Niño have become more extreme in recent decades, as climate change has intensified, hasn’t accrued a consensus among scientists. But now, new research released last week, sponsored by the National Science Foundation and published in Science, strengthens the link between El Niño activity and climate change.

During an El Niño season (the next one has been delayed, but is expected to begin later this year) the force of trade winds in the western and central Pacific diminishes or even reverses, causing a spike in surface water temperatures. As the slackened winds allow–or the reversed winds slowly push–the warmer water east across the ocean, rainfall follows it.

El Niño and its cold-water counterpart La Niña, which occurs between El Niño episodes when the regular trade winds intensify their westward push, have global ramifications. Wildfires in Australia and famines in India have been associated with the climate pattern. The cycle of El Niño and La Niña also appears to have intensified in recent years. Searching for reasons why, scientists debated a link with climate change as long ago as 1997, when researchers at the National Center for Atmospheric Research published a study titled “El Niño and Climate Change.” They couldn’t identify a clear connection, but they believed there was an unidentified force at work–one that required further investigation. “[A]t least part of what is happening… can not be accounted for solely by natural variability,” they wrote.

A year later, experts at the Nevada-based Western Regional Climate Center, which disseminates climate data and conducts research, also contemplated whether global warming was goosing El Niño. They were more overtly suspicious of a linkage, but again, lacked specific evidence. In a post on the center’s website, they noted:

It is plausible that a warmer earth would produce more and stronger El Niños. There is some evidence that the earth has warmed over the past two decades, and there is no doubt that El Niño has been much more frequent in that time. If the evidence of a warming earth is taken at face value (not universally accepted), there still remains a wide spectrum of opinions on whether we are seeing a manifestation of human modification of global climate, or whether the natural climate system would be exhibiting this behavior anyway.

In the new study, conducted by the Georgia Institute of Technology and the Scripps Institute of Oceanography, scientists traveled to the central tropical Pacific, where the variations in El Niño-driven temperature and precipitation patterns are most acute. Studying the region’s coral gave them a window into the historical effects of El Niño.

They extracted core samples from large coral rocks that had been pushed by storm activity onto Christmas (Kiritimati) and Fanning Islands, tiny spits of land within Kiribati’s Northern Line Islands. Using radioactive dating, they ascertained the ages of 17 samples, each of which spanned 20 to 80 years in time, allowing them to create a patchwork timeline covering 7,000 years.

Then they looked at the ratio of oxygen isotopes within the coral skeletons as a way of measuring variations in weather patterns. Since temperature and rainfall affect isotope ratios, they were able to glean the environmental conditions present during each phase of the corals’ lifespans. Dips and surges in rain and sea surface temperatures left an imprint in the coral samples, and in their analysis, scientists found significantly more intense and variable El Niño activity in the 20th century than most other periods represented.

“The level of [El Niño] variability we see in the 20th century is not unprecedented,” said the study’s lead author, Georgia Institute of Technology’s Kim Cobb in a statement, noting a similarly severe period in the 17th century. “But the 20th century does stand out, statistically, as being higher than the fossil coral baseline.”

The researchers reluctantly went a step further to connect the increase in El Niño activity to climate change: “We kind of answered the question, is El Niño changing with respect to recent natural variability?” said Cobb. “The answer is yes, tentatively so.” Yet despite the bounty of new data, researchers say they would need to go back even further in time to make a more definitive linkage between climate change and El Niño activity.

They were less ambiguous about the impact of the study on future climate change research. The new data will help other scientists investigate past climate change events in both paleoclimate records and model simulations, Cobb said. “Prior to this publication, we had a smattering of coral records from this period of interest,” she explained. “We now have tripled the amount of fossil coral data available to investigate these important questions.”

A new study shows that when our fingers get wrinkly, they’re better at gripping wet objects. Image via Wikimedia Commons/Fir0002/Flagstaffotos

Standing in the shower or sitting in the tub, many of us have looked at our wrinkled fingertips and had occasion to wonder: Why do they get so pruney when wet?

Over the years, people have pointed to a number of explanations, most commonly the idea that the wrinkles are simply a reflection of the skin absorbing water. Now, according to a study published yesterday in the journal Biology Letters by researchers from Newcastle University in the UK, we have a definitive (and more interesting) explanation: Pruney fingers are better at gripping wet objects.

The idea was first suggested in a 2011 paper, which showed that the wrinkles that form on our fingers exhibit consistent patterns that allow water to sluice away—indicating that their role is to improve traction, like the tread on a tire. For this paper, an unrelated group of researchers put the theory to the test, letting twenty volunteers soak their fingers in warm water for 30 minutes to get them good and pruney, then testing exactly how long it took them to move wet glass marbles and fishing weights from one container to another.

On average, pruney-fingered participants moved wet marbles 12 percent more quickly than when they were tested unwrinkled fingers. When the same test was performed with dry marbles, the times were roughly the same. Thus, it seems, the hypothesis was proved: pruney fingers do help us grip better.

Other research has shown that the wrinkles form as a result of blood vessels beneath the skin constricting, as directed by the autonomic nervous system. Because this is an active process—rather than merely a byproduct of the skin absorbing water, as previously assumed—scientists began looking for the underlying reason why this might be the case.

The gripping hypothesis makes sense from an evolutionary standpoint, too. “Going back in time, this wrinkling of our fingers in wet conditions could have helped with gathering food from wet vegetation or streams,” study coauthor and behavioral researcher Tom Smulders said in a press statement. “And as we see the effect in our toes too, this may have been an advantage as it may have meant our ancestors were able to get a better footing in the rain.”

If pruney fingers are better at gripping wet objects and don’t slow us down with dry ones, though, the theory prompts a question: Why aren’t our fingers permanently wrinkled? The study’s authors acknowledge this query and admit they don’t have a ready answer, but speculate that permanent pruniness could limit our fingers’ sensitivity or even make them more likely to be cut by sharp objects.