Monkeys have vocal tools, but not brains, to talk like humans

Macaque monkeys would be quite talkative if only their brains cooperated with their airways, a new study suggests.

These primates possess the vocal equipment to speak much as people do, say evolutionary biologist and cognitive scientist W. Tecumseh Fitch of the University of Vienna and colleagues. But macaques lack brains capable of transforming that vocal potential into human talk. As a result, the monkeys communicate with grunts, coos and other similar sounds, the scientists conclude December 9 in Science Advances.

“Macaques have a speech-ready vocal tract but lack a speech-ready brain to control it,” Fitch says.

His team took X-ray videos of an adult macaque’s vocal tract while the animal cooed, grunted, made threatening sounds, smacked its lips, yawned and ate various foods. Measures of shifting shapes during these vocalizations allowed the researchers to estimate what types of speech sounds the monkey could potentially utter.
Monkeys, and presumably apes, have mouths, vocal cords and other vocal tract elements capable of articulating at least five vowel sounds, the researchers say. These consist of vowel pronunciations heard in the words bit, bet, bat, but and bought.
Consonant sounds within monkeys’ reach include those corresponding to the letters p, b, k, g, h, m and w, the scientists add.

An animal that can voice those vowels and consonants is capable of making understandable statements in English and many other languages, they conclude.

The new findings expand monkeys’ gab potential beyond that described in a pioneering 1969 study led by anthropologist and cognitive scientist Philip Lieberman, Fitch claims. Lieberman, now at Brown University in Providence, R.I., devised a computer model of a macaque’s speech potential based on measures of a cadaver monkey’s vocal tract.
Lieberman regards the new study as a replication of his 1969 report. Both investigations find that monkeys can emit a partial range of vowel sounds, Lieberman says. Each paper also determines that two especially distinctive vowel sounds, found in the words beet and boot, lie outside macaques’ vocal realm.

Hearing those sounds is another issue. Acoustic properties of the vowel sounds monkeys can produce make them relatively difficult for people to identify while listening to someone talk, Lieberman emphasizes. “If monkeys had humanlike brains, they could talk, but their speech would sound indistinct,” he says.

Fitch disagrees. By studying a living monkey’s vocal tract in action, the new study finds that these animals can make a broader range of sounds related to each of the five key vowels than reported by Lieberman, he argues. A talking monkey “would be distinct enough to understand, no worse than a foreign accent,” Fitch says. A computer-generated version of the spoken phrase “Will you marry me?” — based on newly calculated properties of the macaque’s vocal tract — is easily grasped by a listener, although less clear than the same phrase spoken by a human female, Fitch says.

Fitch and colleagues confirm a growing body of evidence that monkeys have speech-ready vocal tracts, says biological anthropologist Adriano Lameira of Durham University in England. It’s too soon, though, to say that monkeys’ brains aren’t at least partially speech-ready, he argues. Recent studies of apes, some conducted by Lameira, find that these close relatives of humans exert considerable control over their vocal tracts, allowing them to learn novel calls containing sounds similar to vowels and consonants. Neural control of various parts of the vocal tract is needed to master these sounds, Lameira says. Little is known about whether monkeys can do the same.

An aptitude for incorporating new sounds into vocal communication possibly originated in ancient primates, laying the evolutionary groundwork for human speech, Lameira proposes.

Facial-processing area of brain keeps growing throughout childhood

A part of the brain that’s responsible for recognizing faces seems to grow new tissue throughout childhood. That’s surprising, because brain development during childhood usually involves pruning back neural connections rather than growing new ones, researchers report in the Jan. 6 Science.

The research shows that “pruning isn’t the only game in town,” says Brad Duchaine, a psychologist at Dartmouth College who wasn’t part of the study. “I’m really excited about it.”

Researchers used magnetic resonance imaging, or MRI, to identify regions of the brain’s visual cortex that showed more activity when processing faces versus regions that lit up when processing photos of places like cityscapes or hallways. Then the scientists compared the structures of those regions in 22 kids’ brains (ages 5 to 12) with those of 25 young adults (ages 22 to 28).
The place-sensitive area — the collateral sulcus — didn’t change dramatically between childhood and adulthood. But face-sensitive areas in a region called the fusiform gyrus did.

Adults had denser fusiform gyrus brain tissue than kids and that tissue contained a different composition of cells and proteins, the researchers found.

MRI scans alone can’t reveal exactly what types of cells and structures are behind the increased tissue seen in adults’ fusiform gyrus. But evidence from previous studies suggests that the effect might come in part from increases in dendrites — the fingerlike projections of nerve cells that receive messages from other nerve cells. Dendrites might branch out more, making more connections. Another culprit might be the oligodendrocytes, brain cells that produce nerve cells’ insulating myelin coating. The actual number of nerve cells isn’t increasing, though, says Jesse Gomez, a neuroscientist at the Stanford University School of Medicine who led the study.

The visual cortex contains regions specific to processing many different types of visual stimuli — faces and places but also movement and colors. Since this study compared only facial processing and location processing, it’s not clear yet whether the increase in brain tissue is really limited to facial recognition areas, Duchaine says. But the finding does show that the brain circuits behind different types of visual processing don’t all develop in the same way.

Humans take longer to develop facial recognition skills than other types of visual processing, which could help explain the effect, the researchers propose.
“Throughout development, our social circle grows,” Gomez says. “That might be one reason why the region continues to grow — that piece of hardware in the brain itself just takes time to develop.” The current data can’t pin down the age cutoff for tissue growth, but Gomez and his colleagues are following their subjects over time to try to figure that out.

The team thinks similar tissue growth might occur in other parts of the visual cortex, too. In future studies, they hope to investigate the development of these other specialized regions.

A message to rock climbers: Be kind to nature

For the millions of people who have taken up the sport of rock climbing, a cliff face is a challenge, a vertical puzzle solved only with the proper placement of hands and feet. Look closely, though, and those crevices and cracks that provide hand- and footholds also provide homes for a variety of plants, invertebrates and other easily overlooked species.

People who participate in outdoor sports like rock climbing may not think about the environmental impact of what they’re doing. After all, how big of an impact can one person really have on a rock? But there is a potential for harm, notes ecologist Andrea Holzschuh of the University of Würzburg in Germany. Finding evidence of that harm, though, is a challenge — the features that make some cliffs fun to climb, or not, also make for complicated research.

Holzschuh became interested in the effects that climbers are having on the environment in part because she is a climber herself, partial to tackling rocks in the Frankenjura region of Germany, which is noted for having some of the best climbing in Europe. The plants, animals and other species that make the cliffs their home, she notes, are often specialists that have found ways to adapt and even thrive in the extreme conditions found on the rock face. They may be rare or completely absent from nearby spots, and they often are slow-growing and their numbers grow only in spurts.

And then come the climbers, who may trample what grows at the bottom of a cliff, dig out whatever is growing in a crevice to gain a better handhold, spread species not native to the area or taint the rock face with chalk, altering pH or nutrient conditions for whatever is growing there. Rock climbing isn’t quite as impact-free as some might assume.

But scientists haven’t really been able to adequately assess that impact. Holzschuh went looking for research on this topic and found only 22 studies that tested how rock climbing might affect plants or animals. She tossed out six of those studies because they failed to make comparisons with unclimbed areas or had other major design problems that made it impossible to tease out effects. The remaining 16 studies found a variety of impacts on organisms ranging from lichens to snails to cedar trees. Holzschuh’s review appears in the December Biological Conservation.

But what the review really highlights is just how difficult it is to study rock climbing’s potential impacts. Holzschuh says a big challenge is in finding appropriate unclimbed cliff faces to compare to those that rock climbers frequent — ones that share traits such as slope and how much sunlight the face gets. “Often, all cliffs in a regions that are attractive for climbers are climbed and only cliffs that do not resemble the climbed cliffs in all abiotic traits remain unclimbed,” she notes. “Then no reliable study can be conducted.”

And then, of course, there’s the inaccessibility of many cliffs and the difficulty in studying even the accessible ones. “How many people have these skills and the flexibility to work on these projects?” says Michael Tessler of the American Museum of Natural History and Fordham University. Plus, he notes that a subset of rock climbing called bouldering — in which climbers tackle boulders or short cliff faces measuring less than 3.5 meters high, without using safety ropes — is especially popular with younger people. “Professors inherently aren’t always young,” he notes.
Tessler and colleague Theresa Clark of the University of Nevada, Las Vegas published the first ever analysis attempting to quantify the impact of bouldering on the environment. This type of climbing has similar potential for ecosystem damage as roped rock climbing, they note, plus a couple of additional ones: Boulderers often clear the ground below of rocks and logs so that they can place crash pads in case of falls, and they may be more likely to trample anything at the top of a boulder or cliff, rather than coming directly down.

Tessler and Clark tried to measure the impact of climbers at bouldering routes in the Shawangunk Ridge, a popular climbing site in New York where Tessler climbs. They compared transects in climbed boulder routes with transects along nearby unclimbed sections of rock and found differences in lichen, moss and woody plants. None of this added up to a major threat, but conservation managers might want to monitor these activities in remote sites and shut down certain routes that are proving too popular — and potentially too harmful to whatever is growing there, Tessler and Clark suggest in the December Biological Conservation.

While we still can’t really say how much impact climbers might be having on the rocky environments they climb, there is a definite need for more scientists to strap on their climbing shoes and tackle the questions of climbing’s impact. (Try it! It’s lots of fun!) But climbers, too, can do their part, Holzschuh and Tessler say.

“I think climbers can easily minimize their impact on the cliff vegetation if they do not willingly remove vegetation from the cliff to ‘clean’ hand- and footholds in the climbing route. Climbers should not access the cliff plateau [and should] leave this cliff part completely undisturbed,” Holzschuh says. “At the cliff base, bags and gear should be laid down within a small area to reduce the effects of trampling.”

Tessler also has advice. “Boulderers should be aware that even infrequent climbing leaves some impression on rock-associated vegetation,” he says. “They should remove as little vegetation and soil when climbing and establishing climbs. Also, if a climb is wet, dirty or covered in vegetation, maybe go to another one. This is an easy way to ensure that some rock faces can stay more natural.”

And if climbing is restricted because, say, rare birds are breeding there, rock climbers should obey the restriction and go climb somewhere else, Holzschuh says. There are plenty of other cliffs to be conquered.

New claim staked for metallic hydrogen

A team of scientists may have given hydrogen a squeeze strong enough to turn it into a metal. But critics vigorously dispute the claim.

Researchers from Harvard University report that under extremely high pressures hydrogen became reflective — one of the key properties of a metal. The feat required compressing hydrogen to 4.9 million times atmospheric pressure, the scientists report online January 26 in Science.

If correct, the result would be the culmination of a decades-long search for a material that could have unusual properties such as superconductivity — the ability to conduct electricity without resistance.
But physicist Eugene Gregoryanz of the University of Edinburgh, who works on similar experiments, decries the study’s publication as a failure of the journal’s review process. Given the evidence presented in the paper, Gregoryanz is skeptical that the claimed pressures were actually reached and notes that the researchers presented results from only one experiment. “How is it possible to do only one experiment and claim such a big thing?” he says.

Physicist Alexander Goncharov of the Carnegie Institution for Science in Washington, D.C., also takes issue with the researchers’ conclusions. “It’s not shown whether they have hydrogen at all at high pressure,” Goncharov says.

Not everyone is so skeptical. “I think there’s a good chance that it’s correct,” says theoretical physicist David Ceperley of the University of Illinois at Urbana-Champaign. The pressure at which the hydrogen became reflective is about where theoretical physicists have calculated that a metal should form, Ceperley says.

Theorists’ calculations also indicate that metallic hydrogen could be a high-temperature superconductor (SN: 8/20/16, p. 18). Most superconductors work only in extreme cold, but metallic hydrogen might function even at room temperature — higher than any other known superconductor. If so, its discovery would raise hopes that superconducting metallic hydrogen could be used in power lines, making transmission of electricity vastly more efficient.

To put the pressure on hydrogen, scientists capture it as a gas between the tips of two diamonds and squeeze them together. It’s no easy task. “The problem in making metallic hydrogen has been that the predicted pressures have been very high,” says physicist Isaac Silvera of Harvard University, a coauthor of the study. “Diamonds always break before you can obtain those pressures.”
To stave off breakage, the scientists smoothed the surface of the diamonds to remove any defects and covered the gems in a thin layer of aluminum oxide to prevent hydrogen from diffusing inside and creating cracks. The researchers also cooled the setup to temperatures of 83 kelvins (−190° Celsius) or below. As the scientists ratcheted up the pressure, the hydrogen first turned black, indicating a possible semiconducting phase, then became reflective, indicating a metal. The metallic hydrogen could be either a solid or a liquid, Silvera says.

But such experiments are tricky — only a few teams of researchers in the world are capable of performing them. One of the pitfalls can be that the hydrogen escapes from the chamber without the scientists realizing it. However, Silvera says, “We’re sure we have hydrogen in there.”

Some previous metallic hydrogen experiments have monitored hydrogen as the pressure is ramped up to help ensure that the hydrogen hasn’t escaped and to study its evolution. To do so, scientists use a technique called Raman spectroscopy, which involves shining a laser through the diamonds and observing the scattered light. But at pressures this high, lasers could cause the diamonds to break, Silvera says. So the researchers used lasers only after the sample had reached the metallic state.

Silvera’s group is not the first to announce the discovery of metallic hydrogen. Earlier claims of finding the metal have been overturned (SN: 12/17/11, p. 9). “It’s not the last word,” says Ceperley. “It should encourage all the other groups to come out and try to reproduce it.”

Pinhead-sized sea creature was a bag with a mouth

A roughly 540-million-year-old creature that may have once skimmed shorelines was a real oddball.

Dozens of peculiar, roundish fossils discovered in what is now South China represent the earliest known deuterostomes, a gigantic category of creatures that includes everything from humans to sea cucumbers.

No bigger than a pinhead, the fossils have wrinkly, baglike bodies and gaping mouths that are pleated around the edges like an accordion, researchers report January 30 in Nature. Unlike most other deuterostomes, the animals don’t seem to have an anus. Instead, the ancient oddities, named Saccorhytus coronarius, may have leaked waste (and other bodily fluids like mucus and sex cells) out of tiny holes lining their sides. These holes may have later evolved into gill slits.

A tough, flexible skin would have protected Saccorhytus as it wriggled through grains of dirt, the authors suggest. The find supports previous suggestions that the earliest deuterostomes were actually a kind of water-dwelling worm.

The animal guide to finding love

Are you feeling the pressure of Valentine’s Day and in need of advice on how to find someone special? The animal world has some advice for you.

Make sure you look nice.
There’s no need to go for an entire makeover, but looking your best is usually a good idea when on the search for a partner. Male black-and-white snub-nosed monkeys appear to have taken a lesson from Revlon — they go for the rouge-lipped look during the mating season. Those with bright, red lips tend to be surrounded by females.
Learn to dance …
As anyone who has ever watched John Travolta in Saturday Night Fever knows, having the right dance moves can make finding a mate easier. For some animals, it’s essential. That’s true for male peacock spiders, which raise colorful flaps on their behinds and wave them while lifting their third legs in an adorable dance aimed at luring a mate. And if a guy doesn’t have the best moves or try hard enough, females don’t just reject him — they get aggressive.

… and how to flirt.
Even if you’re an expert dancer, you’ll probably need to do at least a little flirting. It may be a bit more subtle than torrent frogs, though, who turn flirting into a big production. A male frog will get a female’s attention by first calling out and puffing up his vocal sacs. Then he’ll shake his hands and feet and wiggle his toes. If he’s successful, the female will let him know with a special call.

Attend a party.
The best place to put all of this on display is, of course, a party! And there are parties everywhere, even at the bottom of the ocean. Scientists exploring a seamount off the Pacific coast of Panama in 2015 found an enormous party of small, red crabs swarming all over each other. Such large aggregations are common among crab species and may be linked to reproduction.

Practice, practice, practice.
Once you’ve landed a partner, you might want to serenade him or her with the perfect love song. But first you’ll need to practice, just like great reed warblers (probably) do. Males spend their entire winter vacation singing the songs they seem to use to woo the ladies come spring. All that singing cuts into time the guys could spend foraging for food or resting, but that practice might pay off because female warblers prefer males that sing more complex tunes.

Keep an eye on the competition.
You may not be the only one interested in your partner, so make like a peacock and check out your competition. Peacocks fan out their feathers to lure the ladies, but females only pay attention to what’s happening at the bottom of the show, studies have revealed. Males do likewise, keeping their gaze tuned to the bottom of the competition’s display.

Bring a gift.
You probably don’t need to worry that your partner will go cannibal, but that doesn’t mean you can’t take a hint from a species where that does happen. When approaching a female, male nursery spiders are smart to bring a gift of a big dead insect wrapped up in silk. The gift will not only keep the female busy while the male mates with her, but it can also double as a shield if she sees him as a potential meal rather than a mate.

Rare triplet of high-energy neutrinos detected from an unknown source

Three high-energy neutrinos have been spotted traveling in tandem.

The IceCube Neutrino Observatory in Antarctica detected the trio of lilliputian particles on February 17, 2016. This is the first time the experiment has seen a triplet of neutrinos that all seemed to come from the same place in the sky and within 100 seconds of one another. Researchers report the find February 20 on arXiv.org.

Physicists still don’t know where high-energy neutrinos are born. The three neutrinos’ proximity in time and space suggests the particles came from the same source, such as a flaring galaxy or an exploding star. But the scientists couldn’t rule out the possibility of a fluke — the triplet could simply have been the result of accidental alignment between unassociated neutrinos.

Eight different telescopes followed up on the neutrino triplet, checking for some sign of the particles’ origins. The telescopes, which searched for gamma rays, X-rays and other wavelengths of light, found nothing clearly associated with the particles. But scientists were able to rule out some possible explanations, like a nearby stellar explosion caused by the collapse of a dying star.

Online reviews can make over-the-counter drugs look way too effective

Here’s one good reason why people often take medications and use health products that don’t live up to expectations or just don’t work — digital word of mouth.

The reviews can be glowing. Take this scuttlebutt about a cholesterol treatment: “I have been using this product for 2 years. Within the first 3 – 4 months my cholesterol was down 30 points. Just got cholesterol tested last week: down from 245 to 196.”

That’s incredible. It might even be true. But the big picture is alarming: Patients’ online reviews of three over-the-counter drugs — two for lowering cholesterol and one for losing weight — greatly exaggerate how well these substances actually work for most people, says psychologist Mícheál de Barra of the University of Aberdeen in Scotland. Online reviewers portray these medications as working three to six times better than they do in clinical trials that randomly assign drugs or placebos to broad samples of volunteers, he says.

“To learn what works in medicine, you need systematically collected data, usually randomized clinical trials,” de Barra says. “It’s very risky to rely on observations and word of mouth, whether it’s electronic or in person.”

Online reviewers probably aren’t lying, at least not in most cases. Neither are online review readers unrealistically optimistic about health treatments. The problem is that people who benefit most from a medication are especially apt to post their experiences online. Review readers get bamboozled by a wave of positive recommendations that don’t accurately represent how a drug works, or doesn’t work, for people in general.

The duping doesn’t end there. Direct word of mouth about medical treatments, as well as glowing testimonials about health products in advertisements, also traffic in positively skewed information.

In some cases, science does, too. Researchers have recently raised alarms about the “file-drawer problem,” in which studies that find no statistical effects are not published (SN: 5/19/12, p. 26). Published studies reporting positive effects then look unjustifiably bulletproof.

Clinical trials can tilt results in other ways as well. Authors of published trials often fail to preregister details of what they plan to study and how they’ll measure it, enabling data manipulation, selective reporting of results and self-serving interpretations of findings. Clinical trials report patients’ “average” responses to, say, an anticholesterol drug, but do a poor job of predicting which individuals will benefit from that treatment. “Published evidence from randomized trials is already an amalgam of evidence-based medicine and hearsay,” notes Stanford University epidemiologist John Ioannidis.
Online reviews are just old-fashioned word of mouth with a global bullhorn. But they offer one way to quantify the positive bias inherent in so much communication about medical treatments. Patients’ medication reviews that include numerical information, such as cholesterol levels before and after taking an anticholesterol drug, represent what Ioannidis calls “evidence-based hearsay.” Even if patients’ reviews rate treatments with a star system rather than including quantified measures of some kind, those opinions become powerful hearsay evidence for other patients, Ioannidis suspects.

De Barra evaluated 908 online reviews of two cholesterol reduction products, Benecol caramel smart chews and CholestOff, written on or before March 18, 2015. He also assessed 767 reviews of a weight-loss drug, Alli (orlistat), written on or before February 28, 2015.

Benecol reviewers reported a not-too-shabby average cholesterol decline of 45 milligrams per deciliter, versus a small average decline of 14 milligrams per deciliter in nine clinical trials. Respective numbers for CholestOff were 31 milligrams per deciliter and 13 milligrams per deciliter. Alli reviewers reported an average weight loss of about 10 kilograms after taking the drug for three months, versus an average of about two or three kilograms in two clinical trials. That disparity widened slightly after taking Alli for seven months.

Each drug garnered mainly positive reviews, some reporting effects far larger than the average, peppered with a few pans, De Barra reports in the March Social Science & Medicine.

What’s particularly concerning is that these three medications displayed small or negligible effects in clinical trials that probably already inflated how well the drugs work, Ioannidis says. So people searching for help in lowering cholesterol or shedding pounds may instead be getting a massive dose of disappointment from online reviews.

Online reviews can also exaggerate a treatment’s worst effects, whether real or alleged. Evidence-based hearsay may be particularly catchy online and in person when it’s frightening, de Barra suspects.

The anti-vaccination movement provides a potent example, due in part to the success of vaccines. When people face no immediate threat from measles or other infectious diseases, anti-vaccine stories may go viral, so to speak, thanks to misapplied but deeply felt intuitions. Two cognitive scientists, Helena Miton of Central European University in Budapest and Hugo Mercier of the Cognitive Sciences Institute in Bron, France, proposed this scenario in the November 2015 Trends in Cognitive Sciences.

However medical treatments acquire halos or horns, only well-conducted, transparent clinical trials can identify effective medical treatments, such as childhood vaccinations, and their potential side effects, Ioannidis says. But an ominous research trend is gathering steam, he warns. Researchers, professional societies, funders and lobbyists increasingly push to replace clinical trials of randomly selected volunteers with studies of interventions for select samples of people who eat certain foods, take certain drugs or behave in certain ways. The latter investigations may inflate a treatment’s effects even more than online patient reviews do, Ioannidis asserts.

Perhaps a new wave of studies showing how evidence-based hearsay misrepresents many medications will be just what the doctor ordered to resuscitate evidence-based medicine, he muses.

Palace remains in Mexico point to ancient rise of centralized power

Remnants of a royal palace in southern Mexico, dating to between around 2,300 and 2,100 years ago, come from what must have been one of the Americas’ earliest large, centralized governments, researchers say.

Excavations completed in 2014 at El Palenque uncovered a palace with separate areas where a ruler conducted affairs of state and lived with his family, say archaeologists Elsa Redmond and Charles Spencer, both of the American Museum of Natural History in New York City. Only a ruler of a bureaucratic state could have directed construction of this all-purpose seat of power, the investigators conclude the week of March 27 in Proceedings of the National Academy of Sciences.

The royal palace, the oldest such structure in the Valley of Oaxaca, covered as many as 2,790 square meters, roughly half the floor area of the White House. A central staircase connected to an inner courtyard that probably served as a place for the ruler and his advisors to reach decisions, hold feasts and — based on human skull fragments found there — perform ritual sacrifices, the scientists suggest. A system of paved surfaces, drains and other features for collecting rainwater runs throughout the palace, a sign that the entire royal structure was built according to a design, the researchers say.

El Palenque’s palace contains no tombs. Its ancient ruler was probably buried off-site, at a ritually significant location, Redmond and Spencer say.

New worm-snail is a super slimer

A new species of worm-snail is rather snotty. Thylacodes vandyensis shoots out strands of mucus that tangle together, building a spiderweb-like trap for plankton and other floating snacks, researchers report April 5 in PeerJ.

Other worm-snails use this hunting technique, but T. vandyensis stands out because of the “copious amounts of mucus” it ejects, says coauthor Rüdiger Bieler. This goo net, which can stretch up to 5 centimeters across, exits the animal’s tentacles at, of course, “a snail’s pace,” jokes Bieler, a curator at the Field Museum of Natural History in Chicago.

Like other worm-snails, T. vandyensis permanently glue themselves to spots. Bieler found T. vandyensis, which typically grow half as tall as a pinkie finger, on the hull of a sunken ship in the Florida Keys. But they don’t belong there: DNA analysis shows that this invasive species’ closest relatives are in the Pacific Ocean. The worm-snail may have made its way to the Atlantic as a stowaway on a ship.