Warning colouration paved the way for louder, more complex calls in certain species of poisonous frogs
Frogs are well-known for being among the loudest amphibians, but new research indicates that the development of this trait followed another: bright colouration. Scientists have found that the tell-tale colours of some poisonous frog species established them as an unappetizing option for would-be predators before the frogs evolved their elaborate songs. As a result, these initial warning signals allowed different species to diversify their calls over time.
Zoologists at the National Evolutionary Synthesis Centre (NESCent), the University of British Columbia, and other research universities assembled an acoustic database to analyse more than 16,000 calls from 172 species within the poison frog family, Dendrobatidae. The paper, which will appear in the December issue of the Proceedings of the Royal Society B, is now available online.
The study included both frogs that display bright colours and others that rely on camouflage for protection. Each call was examined in terms of pitch and duration, and researchers also factored in the size of the frogs and their visibility to predators. They found that because warning colouration protected them from predators, they were better able to attract a mate with low-pitch, pulsing vocalizations in plain sight than their quieter, darker-hued relatives.
“This allows the frog to have a unique type of call—a noisy call,” said lead author Juan C. Santos, formerly of NESCent and now at the University of British Columbia. “These noisy kinds of calls, in general, are what the females really like.”
Scientists already understood that predators shied away from brightly coloured frogs because of visual cues, but Santos and his colleagues hypothesized that some species evolved to include audio signals, as well. Such a warning system is not unprecedented: Tiger moths emit ultrasonic chirps to communicate their unsavoury taste to bats. Without a similar ability, frogs navigate a precarious dilemma in which they must either risk detection by predators or forgo possible courtship.
Initially the researchers expected that audio warnings pre-dated colouration but the results indicate the opposite. Using molecular data and statistical analyses, they were able to infer a phylogenetic tree and pinpoint which trait came first. Their findings indicate that visual traits established the frogs as poisonous and cleared the way for louder, more elaborate calls.
Species relying on camouflage for defence will not invite attention with boisterous calls, while their protected relatives—including non-poisonous frogs that mimic the appearance of their toxic counterparts— can be loud and more nuanced.
“The type of colour they have is in the range of the noisy ones,” Santos said. “When you’re mimicking somebody that’s already protected, you have some freedom to be found by potential mates.”
These calls require high energy expenditures, but the boon of attracting females without predatory threats makes it a rewarding behaviour males. Less is known about the reasons females are attracted to the noisier males and how they appraise the various calls. Santos explained that if the females are being especially picky, it will drive male diversity by pushing them to create even more complex songs.
“What can the females get from this information? Maybe females— by being very picky— increase male diversity,” Santos said. A more diverse pool of potential mates increases the likelihood that their offspring will have more advantageous genes over time.
This work was supported by the National Science Foundation (DEB: 0949899), the National Evolutionary Synthesis Center (NSF EF-0905606 and EF-0423641), and the University of Texas and the Amphibian Tree of Life project (NSF EF-0334952).
Santos, Juan C. et al. (2014). “Aposematism increases acoustic diversification and speciation in poison frogs” Proceedings of the Royal Society B.http://rspb.royalsocietypublishing.org/content/281/1796/20141761.abstract
The National Evolutionary Synthesis Center (NESCent) is a nonprofit science center dedicated to cross-disciplinary research in evolution. Funded by the National Science Foundation, NESCent is jointly operated by Duke University, The University of North Carolina at Chapel Hill, and North Carolina State University. For more information about research and training opportunities at NESCent, visit http://www.nescent.org.
For about a decade, Chinese consumers weren’t getting what they paid for when they purchased Wuchang, a special brand of gourmet rice that has a peculiar scent. The quality was being diluted when less expensive rice was aromatized, added to the packages of the high-quality rice, and sold at the premium price. Researchers at the University of Illinois studied how the tampering scandal affected the public’s perception of risk and their subsequent behavior.
Because public anxiety over the fake rice issue was more pronounced in urban districts, the researchers focused on residents of Xi’an, ultimately analyzing interviews and survey responses of 225 people.
“Over half of the people we interviewed were aware of the product tampering, but only very vaguely,” said U of I agricultural communications professor Lulu Rodriguez. “They rely much more on interpersonal communication with friends and family members for information.”
The study also showed that although people didn’t understand the details or potential health risks that the tainted rice may cause, the public’s perception of risk was considered to be high.
“In this case, their trust of society, such as the government, food-safety regulations, and the mass media was eroded,” Rodriguez said. “This incident came in the wake of other food-safety scandals in China. We hear people say in the interviews, ‘we are left to fend for ourselves.’ They seemed to feel like they need to make use of whatever information sources they have and make do because the government cannot be trusted. And the government tried to place the blame on local agencies.”
Rodriguez explained that rice retailers knew the product tampering was taking place. “Production was not jiving with what was being sold,” she said. About 800,000 tons of Wuchang rice were produced but up to 10 million tons were being sold. Adding 1 pound of fragrance to ten tons of rice allowed the lower-quality rice to pass as the more expensive Wuchang brand rice. The Chinese Central TV finally broke the story, saying that the government was doing its best to punish the culprits and that they would be dealt with accordingly, but that wasn’t good enough to calm the public’s anxiety.
“Fortunately, there wasn’t any real health risk, but that didn’t stop people from thinking about health-related concerns,” Rodriquez said. “It is food, after all, and the public didn’t know exactly what was being added to the rice. It shows that if you have the public perception as a communicator, you have a problem even if the accusations are not correct.”
Although their knowledge level was low, the uncertainty of what was perceived of as involuntary risk was high—high enough that their behavior shifted to not buying the rice.
“More openness is needed,” Rodriguez said. “This incident reminded me of the horrible way that the SARS epidemic was handled, in which the Chinese government delayed notifying the World Health Organization of the outbreak for three months. Keeping quiet just makes people more nervous.”
Rodriguez said that the problem was compounded because no one took ownership of the scandal. “They seemed to think that all they had to do was to assure the public that they were doing their best. But what exactly were they doing? It created high anxiety, particularly in urban districts where rice outlets are concentrated,” she said. “We also noted that although people seemed to know about the incident, they were very reluctant to speak out about it, fearing possible repercussions.”
As an agricultural communications educator, Rodriguez views this incident as a teachable moment.
“There is a window of opportunity for us,” she said. “There are Chinese students who come to the University of Illinois for undergraduate and graduate studies. These younger communicators will have a broader perspective to report on incidents like this. We hope that there can be mechanisms developed that can reestablish trust. Trust is very difficult to build and very easy to destroy.”
“Social trust and risk knowledge, perception and behaviours resulting from a rice tampering scandal” was published in an issue of International Journal of Food Safety, Nutrition and Public Health and written by Lulu Rodriguez, Jing Li, and Sela Sar.
Over the last thousand years Christianity has adopted many things from other religions, but it also took from science too.
A Spherical Harmony
The earliest ancient civilizations all shared the same fundamental view of the universe; that our earth lay at the centre. The characteristically inventive Sumerians of what we now call Iraq; the Amorite dynasty that founded the Babylonians; and also the North East African civilisation of the ancient Egyptians; all these ancient civilizations had the Sun, Moon, stars, and planets revolving around us. The specific explanations varied from society to society, but the viewpoint that came to dominate the minds of Europeans was established by successive generations of the ancient Greek philosophers. Though I say “ancient greeks” they were in reality learned philosophers who lived across many centuries with their theories of the cosmos being somewhat refined over a time period scanning more than six hundred years.
Te first known idea of the stars being fixed to a sphere, or hemisphere, rotating around the earth is attributed to Anaximenes of Miletus, who lived in the 6th century BC. Like his predecessors, Anaximenes was preoccupied with cosmology, searching for the world’s origin in which he is most known for his assertion that air is the most basic and originary material and the source of all things. While empirical evidence was essential in Anaximenes’ work, the less evidentiary notions of the divine remained apparent as well. Perhaps in line with early Greek literature that rendered air as the soul, as in the ‘breath of life,’ Anaximenes relates air with god and the divine, according to the accounts of Aetius. The qualities of air, that has similar attributes as the qualities of Anaximander’s aperion, are those of the divine and the eternal. It is posited, by Aetius and later by Cicero, that there is a strong correlation between the notion of air as an originary principle element and the notion of air and breath as the divine and eternal substance of the soul and of god.
In the 6th century, Anaximenes of Miletus, saw the Earth as a kind of flat disc, or a flat-topped cylinder that floated like a cork in the air. Pythagoras of Samos – the same Pythagoras whose theory we use today to calculate the area of a triangle – changed the disc to a globe then placing it at the centre of concentric spheres, one for the Sun, the Moon and each of the planets, with the other stars ‘fixed’ at the furthest distance. For Pythagoras, the physical distances separating the spheres was of great importance, even seeing the seven planetary spheres (Moon and Sun included) and the shpere of the stars being separated in the same seven ratios as those of the musical scale. It was this particular notion that gave us the concept of the “harmony of the spheres” that was to resonate for two milennia.
The model that later became fixed stemmed from a proposition laid down by the philospher and methematician Plato circa. 400 BC. For Plato, the circle was the perfect form and he was totally convinced that the Sun and the Moon revolved around a spherical Earth in circular orbits. Plato’s students were left with the challenge of creating a model that explained his philosophy. Eudoxus of Cnidus offered an ingenious solution of multiple concentric spheres. The orbit of our Moon illustrates this idea; to explain its apparent movement through the heavens the Moon needed three spheres; one rotating every day in order to explain the rising and setting; a second rotating every month in order to explain the movement through the zodiac (movement against the stars); and a third rotating monthly on a slightly different axis in order to explain its variation in latitude. To see Eudoxus solution click here.
The problem that was obvious to the ancient astronomers was that planets behaved in a strange fashion, sometimes they were closer, sometimes farther away from Earth, sometimes speeding up and sometimes slowing down or even appearing to travel backwards. The word “planet” comes from the Ancient Greek word for “wonder”. Our friend Eudoxus required 27 concentric spheres to explain the movements in the heavens, but that was later refined by his contemporary, the great philosopher Aristotle, in to a model of greater perfection. In an attempt to make sense of what was observed, he placed 55 concentric spheres around the Earth, each responsible for a specific movement of the heavenly bodies, always though in the perfect eternal motion of a circle, as they passed through the substance out there that he called the “aether”. At the furthest extremities he placed the “Unmoved Mover”, or the force that centuries later came to represent the all-powerful Christian God.
All this could have, and should have, been rendered irrelevant had the ideas of Aristarchus, also of Samos, caught on some 200 years later! Essentially he had it all worked out. He placed the Sun at the centre of the cosmos, with the Earth and other planets circling it, in the same order as we know them today.
But his theories did not stand up to the withering logic of the time. He was unpicking the established teachings of the great Aristotle and Plato. Yet it didn’t gain kudos because it seemed so self-evidently wrong. If indeed the Earth were moving through space, why would an object thrown upwards come straight back down? Surely it would land at a distance away as the ground the individual were standing on moved through space. So, the common sense of the time indicated that Aristotle had it right.
Scientists at Chicago’s Field Museum and international collaborators have reconstructed the phylogeny and biological history for the Yellow-shouldered bats in the New World tropics, the region of the Earth surrounding the equator. In-depth analysis of mitochondrial and nuclear DNA sequences uncovered three species new to science, each having previously been confused with another species. Since 1960, when modern studies on this group began, Sturnira has grown from eight species to 22. The newest additions were described in a new study, published online in ZooKeys.
The New World tropics have long been recognized as a region teeming with some of the richest biodiversity on Earth. It is home to a group of small, fruit-eating bats ranging from half-an-ounce to three ounces in size. The bats belong to the genus Sturnira, commonly named yellow-shouldered bats, which are found from northern Mexico to northern Argentina. One species in particular, Sturnira lilium, has figured among the most widespread and locally abundant bats of the New World topics.
“A curator’s job is to bring order out of chaos,” said Bruce Patterson, PhD, MacArthur Curator of Mammals at The Field Museum. “This group of bats offered an excellent opportunity study the process of species formation across the entire New World tropics.”
Paúl Velazco, PhD, who formerly worked at The Field Museum and now is with the American Museum of Natural History in New York, is the lead author on the new study. Velazco and Patterson began their endeavor by collecting 38 samples of six species from three countries. They also borrowed 94 samples from 24 countries from museums around the world in order to complete the project, highlighting the importance of museum collections for the growing body of scientific knowledge.
The researchers isolated DNA from a small portion of liver or muscle samples that had been frozen or preserved from each specimen. They then amplified and sequenced two nuclear and three mitochondrial genes from each tissue, amounting to nearly 5,000 base pairs of DNA, from over 120 individuals.
“We chose these genes because they have proven useful for classification of related groups of bats,” said Velazco. “Mitochondrial sequences tend to be fast-evolving and informative about very recent evolutionary splits, while nuclear genes tend to be slow-evolving and shed light on more ancient divergence events.”
By sequencing both classes of DNA, the researchers could recover the group’s entire history, which stretches back about 8 million years.
Every museum specimen that was sequenced already had both a name and a geographic distribution. However, the sequence analysis led the investigators to believe that some of the branch labels were incorrect. Indeed, after re-examining the museum specimens associated with each sample, they found that nearly 20 percent of the specimens had been incorrectly labeled!
How could so many individual animals have been misidentified? The answer lies within technology.
“The differences between species are often subtle, and difficult to describe in writing. The historic literature lacked access to the visual documentation that we rely on today, such as color photography and digital libraries,” said Patterson. “For this reason, small and imprecisely described morphological differences were often overlooked during the original identification of the specimens. This type of error pervades all biological collections.”
Their results identified three species entirely new to science, and provided evidence for the elevation of three subspecies to the species level. Two of the new species are described in the ZooKeys article.
In the process, Velazco and Patterson were able to revise the supposed geographic range of Sturnira lilium. Instead of extending from Mexico to Argentina, the real Sturnira lilium is limited to Bolivia, Brazil, Paraguay, Uruguay, and northern Argentina. The rest of its presumed range is occupied by six other close relatives that replace one another in jigsaw-like fashion across the Neotropics.
The distribution of Sturnira species across most of the New World tropics and its diversification throughout its eight-million-year existence make it informative for other sorts of biological reconstructions, such as the seed plants upon which it feeds.
In addition to its scientific usefulness, this study demonstrates the need for the ongoing revision of the Earth’s biological history, and highlights the immense value of museum collections in uncovering new knowledge.
“For this particular group of mammals, we are much closer that we were in framing their diversity, although there may be additional Sturnira out there,” said Patterson. “Over the years, I’ve learned that no one has the last word in science.”
By tracking brain activity when an animal stops to look around its environment, neuroscientists at the Johns Hopkins University believe they can mark the birth of a memory.
Using lab rats on a circular track, James Knierim, professor of neuroscience in the Zanvyl Krieger Mind/Brain Institute at Johns Hopkins, and a team of brain scientists noticed that the rats frequently paused to inspect their environment with head movements as they ran. The scientists found that this behavior activated a place cell in their brain, which helps the animal construct a cognitive map, a pattern of activity in the brain that reflects the animal’s internal representation of its environment.
In a paper recently published in the journal Nature Neuroscience, the researchers state that when the rodents passed that same area of the track seconds later, place cells fired again, a neural acknowledgement that the moment has imprinted itself in the brain’s cognitive map in the hippocampus.
The hippocampus is the brain’s warehouse for long- and short-term processing of episodic memories, such as memories of a specific experience like a trip to Maine or a recent dinner. What no one knew was what happens in the hippocampus the moment an experience imprints itself as a memory.
“This is like seeing the brain form memory traces in real time,” said Knierim, senior author of the research. “Seeing for the first time the brain creating a spatial firing field tied to a specific behavioral experience suggests that the map can be updated rapidly and robustly to lay down a memory of that experience.”
A place cell is a type of neuron within the hippocampus that becomes active when an animal or human enters a particular place in its environment. The activation of the cells helps create a spatial framework much like a map, that allows humans and animals to know where they are in any given location. Place cells can also act like neural flags that “mark” an experience on the map, like a pin that you drop on Google maps to mark the location of a restaurant.
“We believe that the spatial coordinates of the map are delivered to the hippocampus by one brain pathway, and the information about the things that populate the map, like the restaurant, are delivered by a separate pathway,” Knierim said. “When you experience a new item in the environment, the hippocampus combines these inputs to create a new spatial marker of that experience.”
In the experiments, researchers placed tiny wires in the brains of the rats to monitor when and where brain activity increased as they moved along the track in search of chocolate rewards. About every seven seconds, the rats stopped moving forward and turned their heads to the perimeter of the room as they investigated the different landmarks, behavior called “head-scanning.”
“We found that many cells that were previously silent would suddenly start firing during a specific head-scanning event,” Knierim said. “On the very next lap around the track, many of these cells had a brand new place field at that exact same location and this place field remained usually for the rest of the laps. We believe that this new place field marks the site of the head scan and allows the brain to form a memory of what it was that the rat experienced during the head scan.”
Knierim said the formation and stability of place fields and the newly activated place cells requires further study. The research is primarily intended to understand how memories are formed and retrieved under normal circumstances, but it could be applicable to learning more about people with brain trauma or hippocampal damage due to aging or Alzheimer’s.
“There are strong indications that humans and rats share the same spatial mapping functions of the hippocampus, and that these maps are intimately related to how we organize and store our memories of prior life events,” Knierim said. “Since the hippocampus and surrounding brain areas are the first parts of the brain affected in Alzheimer’s, we think that these studies may lend some insight into the severe memory loss that characterizes the early stages of this disease.”
Stand next to the entrance ramp of a busy freeway at rush hour or walk into an American Eagle clothing store and the first thing you’ll notice is the noise. The din can seem deafening, and it’s tempting to imagine channeling that sound energy into a way to power streetlights and electric cars—or at least to charge your smartphone.
“There is definitely energy contained in that sound,” says David Cohen-Tanugi, vice president of the MIT Energy Club and a John S. Hennessy Fellow in MIT’s Materials Science and Engineering department . “But the density of the energy is very low, and there is no way to capture it all. You’d have to have obscenely loud, continuous noise for harvesting to be worthwhile.”
What the human ear perceives as clanging cacophony—the roar of a train engine or the whine of a pneumatic drill—only translates to about a hundredth of a watt per square meter. In contrast, the amount of sunlight hitting a given spot on the earth is about 680 watts per meter squared. “That’s many orders of magnitude more,” explains Cohen-Tanugi. “That’s why it’s more efficient to collect and store sunlight using solar panels than to harvest energy from sound. And the energy density in oil and gas is orders and orders of magnitude higher, making generating power from those sources even more cost effective.”
That’s not to say researchers aren’t examining ways to transfer environmental noise into electrical energy. Passing trains and subways aren’t only loud, but their surroundings rattle and vibrate as they pass, and part of the thrill of a rock concert is feeling the whole auditorium shake. “There’s a strong interplay between vibrations through the medium that you hear through—air or water—and the physical objects around you,” says Cohen-Tanugi. “It’s perfectly conceivable to absorb that movement and glean useable energy. You’re not going to power a city with it, but you can power small devices.”
He cites the work of London-based Facility: Innovate, an architectural research firm investigating ways to convert environmental vibrations into electricity. As crowds walk through malls, sports arenas, and other high-traffic areas, small hydraulic generators beneath the company’s floor tiles capture the vibrations of their steps –and generate enough electricity to power nearby phone-charging stations and illuminate electronic signage and advertising.
Though still in the research phase, such technology could mean a new era in energy generation and conservation. “Harvesting acoustic noise is more about mechanical vibrations than sound itself,” says Cohen-Tanugi. “The idea is definitely there, and it’s quite promising.”
Exposing leafy vegetables grown during spaceflight to a few bright pulses of light daily could increase the amount of eye-protecting nutrients produced by the plants, according to a new study by researchers at the University of Colorado Boulder.
One of the concerns for astronauts during future extended spaceflights will be the onslaught of eye-damaging radiation they’ll be exposed to. But astronauts should be able to mitigate radiation-induced harm to their eyes by eating plants that contain carotenoids, especially zeaxanthin, which is known to promote eye health.
Zeaxanthin could be ingested as a supplement, but there is evidence that human bodies are better at absorbing carotenoids from whole foods, such as green leafy vegetables.
Already, NASA has been studying ways to grow fresh produce during deep space missions to maintain crew morale and improve overall nutrition. Current research into space gardening tends to focus on getting the plants to grow as large as possible as quickly as possible by providing optimal light, water and fertilizer. But the conditions that are ideal for producing biomass are not necessarily ideal for the production of many nutrients, including zeaxanthin.
“There is a trade-off,” said Barbara Demmig-Adams, professor of distinction in the Department of Ecology and Evolutionary Biology and a co-author of the study published in the journal Acta Astronautica. “When we pamper plants in the field, they produce a lot of biomass but they aren’t very nutritious. If they have to fend for themselves—if they have to defend themselves against pathogens or if there’s a little bit of physical stress in the environment—plants make defense compounds that help them survive. And those are the antioxidants that we need.”
Plants produce zeaxanthin when their leaves are absorbing more sunlight than they can use, which tends to happen when the plants are stressed. For example, a lack of water might limit the plant’s ability to use all the sunlight it’s getting for photosynthesis. To keep the excess sunlight from damaging the plant’s biochemical pathways, it produces zeaxanthin, a compound that helps safely remove excess light.
Zeaxanthin, which the human body cannot produce on its own, plays a similar protective role in our eyes.
“Our eyes are like a leaf—they are both about collecting light,” Demmig-Adams said. “We need the same protection to keep us safe from intense light.”
The CU-Boulder research team—which also included undergraduate researcher Elizabeth Lombardi, postdoctoral researcher Christopher Cohu and ecology and evolutionary biology Professor William Adams—set out to determine if they could find a way to “have the cake and eat it too” by simultaneously maximizing plant growth and zeaxanthin production.
Using the model plant species Arabidopsis, the team demonstrated that a few pulses of bright light on a daily basis spurred the plants to begin making zeaxanthin in preparation for an expected excess of sunlight. The pulses were short enough that they didn’t interfere with the otherwise optimal growing conditions, but long enough to cause accumulation of zeaxanthin.
“When they get poked a little bit with light that’s really not a problem, they get the biomechanical machine ready, and I imagine them saying, ‘Tomorrow there may be a huge blast and we don’t want to be unprepared,’ ” Demmig-Adams said.
Arabidopsis is not a crop, but past research has shown that its behavior is a good indicator of what many edible plant species will do under similar circumstances.
The idea for the study came from Lombardi, who began thinking about the challenges of growing plants during long spaceflights while working with CU-Boulder’s Exploration Habitat graduate projects team in the Department of Aerospace Engineering Sciences, which built a robotic gardening system that could be used in space.
While the study is published in an astronautics journal, Lombardi says the findings are applicable on Earth as well and could be especially relevant for future research into plant-based human nutrition and urban food production, which must maximize plant growth in small areas. The findings also highlight the potential for investigating how to prod plants to express traits that are already written in their genetic codes either more fully or less fully.
“Learning more about what plants already ‘know’ how to do and trying to manipulate them through changing their environment rather than their genes could possibly be a really fruitful area of research,” Lombardi said.
A new publication from researchers at the University of Southampton and the National Oceanography Centre, Southampton highlights the importance of nutrients for coral reef survival.
Despite the comparably small footprint they take on the ocean floor, tropical coral reefs are home to a substantial part of all marine life forms. Coral reefs also provide numerous benefits for human populations, providing food for millions and protecting coastal areas from erosion. Moreover, they are a treasure chest of potential pharmaceuticals and coral reef tourism provides recreation and income for many.
Unfortunately, coral reefs are declining at an alarming rate. To promote management activities that can help coral reef survival, an international group of world renowned scientists have summarised the present knowledge about the challenges that coral reefs are facing now and in the future in a special issue of the journal Current Opinion in Environmental Sustainability.
The contribution of scientists from the University of Southampton to this special issue, which highlights the crucial role of nutrients for the functioning of coral reefs, can be freely downloaded from;
The University of Southampton researchers who are based at the Coral Reef Laboratory in the National Oceanography Centre, Southampton, explain that “too many” nutrients can be as bad for corals as “not enough”.
Professor Jörg Wiedenmann, Professor of Biological Oceanography at the University of Southampton and Head of the Coral Reef Laboratory, says: “The nutrient biology of coral reefs is immensely complex. It is important to distinguish between the different direct and indirect effects that a disturbance of the natural nutrient environment can have on a coral reef ecosystem.”
Since corals live in a symbiotic relationship with microscopically small plant cells, they require certain amounts of nutrients as “fertiliser”. In fact, the experimental addition of nutrients can promote coral growth. “One should not conclude from such findings, however, that nutrient enrichment is beneficial for coral reefs – usually the opposite is true,” explains Dr Cecilia D’Angelo, Senior Research Fellow in the Coral Reef Laboratory and co-author on the article.
Professor Wiedenmann, whose research on coral reef nutrient biology is supported by one of the prestigious Starting Grants from the European Research Commission, adds: “Too many nutrients harm corals in many different ways, easily outweighing the positive effects that they can undoubtedly have for the coral–alga association. Paradoxically, the initial addition of nutrients to the water column might result in nutrient starvation of the corals at a later stage. In this publication, we conceptualise the important role that the competition for nutrients by phytoplankton, the free-living relatives of the corals’ symbiotic algae, may have in this context.”
“Nutrient pollution will continue to increase in many coral reefs. Therefore, an important prerequisite to develop efficient management strategies is a profound understanding of the different mechanisms by which corals suffer from nutrient stress.”
Scoffing at or cutting funds for basic biological research on unusual animal adaptations from Gila monster venom to snail sex, though politically appealing to some, is short-sighted and only makes it more likely that important economic and social benefits will be missed in the long run, say a group of evolutionary biologists at the University of Massachusetts Amherst.
Writing in a recent issue of BioScience, researchers Patricia Brennan, Duncan Irschick, Norman Johnson and Craig Albertson argue that “innovations often arise from unlikely sources” and “reducing our ability to creatively examine unique biological phenomena will ultimately harm not only education and health but also the ability to innovate, a major driver of the global economy.”
First author Patricia Brennan, known for her duck genitalia studies that could eventually aid human medical science points out, “Basic science has increasingly come under attack, and there is a growing perception that studying ‘odd’ science ideas with no clear societal benefits should be stopped. But we feel that these are the precise sorts of investigations that may lead to major innovations in biomedicine, technology and military applications.”
She and colleagues point to several specific examples where advances in understanding basic biological evolutionary adaptations led to successful technological applications, sometimes decades after the original work. Without basic work first published in 1967 on the enzyme Taq polymerase, for example, science wouldn’t have the immensely powerful DNA replication technique known as polymerase chain reaction, PCR, now providing “vast benefits” in medicine, agriculture and criminal justice.
A recent invention from UMass Amherst underscores the value of basic science, the authors add. After more than 50 years of basic research on gecko ecology and the remarkable anatomy that allows these lizards to walk up smooth walls and across the ceiling, a UMass Amherst research team invented Geckskin, an adhesive that can attach a 700-lb. weight to a smooth surface on an index-card-sized pad.
Functional morphologist Duncan Irschick, a member of that team, says, “Gecko adhesion stands as a classic example where long-term research on a seemingly frivolous topic has led to a major innovation with enormous potential for making an economic contribution.” He and colleagues say experts have identified more than 2,000 instances of technology inspired by evolutionary innovations, including highly efficient solar panels, insulated glass and body armor inspired by mantis shrimp appendages.
The public is already interested in “oddball science” and related success stories, the authors add, and “the abundance of organismal biology science stories in the news shows that [such] studies have mass appeal. This suggests they can play a role in education,” particularly in a nation where only 40 percent of the public acknowledges evolution.
Evolutionary developmental biologist Craig Albertson notes, “It’s easy to assume that innovation happens from well-planned research, but the history of innovation does not tell that story.” Norman Johnson adds, “We are not suggesting that applied science is unimportant, far from it. We are merely pointing out the long-term value and innovations that arise from what is commonly viewed as wasteful spending.”
Temperature, not snowfall, has been driving the fluctuating size of Peru’s Quelccaya Ice Cap, whose dramatic shrinkage in recent decades has made it a symbol for global climate change, a Dartmouth-led study shows.
The findings support many scientists’ suspicions that tropical glaciers are rapidly shrinking because of a warming climate, and will help scientists to better understand the natural variability of past and modern climate and to refine models that predict tropical glaciers’ response to future climate change.
The study appears in the journal Geology.
Dartmouth glacial geomorphologist Meredith Kelly and her lab team used field mapping combined with the beryllium-10 surface exposure dating method and ice cores obtained by Ohio State University paleoclimatologist Lonnie Thompson to examine how the Quelccaya Ice Cap has expanded and retreated over the past millennium. It is the first time that a record of past glacial extents has been compared directly with an annually dated ice core record from the same ice mass.
During the last millennium, a significant cooling event known as the Little Ice Age occurred, but scientists don’t know what caused the cooling or its geographic extent. The Dartmouth-led team determined beryllium-10 ages of moraines – or glacier sediments — that mark the past positions of Qori Kalis, an outlet glacier that has been monitored by Thompson since he first visited Quelccaya in the early 1960s. The Quelccaya Ice Cap, the largest ice mass in the tropics, sits 18,000 feet above sea level in the Peruvian Andes.
The results show that Qori Kalis advanced to its late Holocene maximum position prior to 520 years ago and subsequently retreated with only minor re-advances since that time. The comparison of the moraine record with the ice core record suggests that temperature was the driving force of glacial expansion and retreat, says Justin Stroup, lead author and a PhD candidate in Dartmouth’s Department of Earth Sciences.
“This is an important result since there has been debate about the causes of recent tropical glacial recession – for example, whether it is due to temperature, precipitation, humidity, solar irradiance or other factors,” says Kelly, a co-author of the study. “This result agrees with Professor Thompson’s earlier suggestions that these tropical glaciers are shrinking very rapidly today because of a warming climate.”
Furthermore, the ebbs and flows of other glaciers in tropical South America are similar to the Qori Kalis extents, indicating a regionally consistent pattern of past climate conditions. On a global scale, the results suggest that glaciers were larger than present and depositing moraines in both northern and southern hemispheres at about the same time, indicating that the climate mechanisms which caused the late Holocene cooling likely influenced a globally synchronous pattern of cooling.