Category: Science News

{In the race towards the discovery of a ninth planet in our solar system, scientists from around the world strive to calculate its orbit using the tracks left by the small bodies that move well beyond Neptune. Now, astronomers have confirmed, with new calculations, that the orbits of the six extreme trans-Neptunian objects that served as a reference to announce the existence of Planet Nine are not as stable as it was thought.}

At the beginning of this year, the astronomers K. Batygin and M. Brown from the California Institute of Technology (Caltech, USA) announced that they had found evidence of the existence of a giant planet ‑with a mass ten times larger than Earth’s‑ in the confines of the Solar System. Moving in an unusually elongated orbit, the mysterious planet will take between 10,000 and 20,000 years to complete one revolution around the Sun.

In order to arrive at this conclusion, Batygin and Brown run computer simulations with input data based on the orbits of six extreme trans-Neptunian objects (ETNOs). Specifically, these ETNOs are: Sedna, 2012 VP113, 2004 VN112, 2007 TG422, 2013 RF98 and 2010 GB174.

Now, however, brothers Carlos and Raúl de la Fuente Marcos, two freelanceSpanish astronomers, together with scientist Sverre J. Aarseth from the Institute of Astronomy of the University of Cambridge (United Kingdom), have considered the question the other way around: How would the orbits of these six ETNOs evolve if a Planet Nine such as the one proposed by K. Batygin and M. Brown really did exist? The answer to this important question has been published in the journal ‘Monthly Notices of the Royal Astronomical Society’ (MNRAS).

“With the orbit indicated by the Caltech astronomers for Planet Nine, our calculations show that the six ETNOs, which they consider to be the Rosetta Stone in the solution to this mystery, would move in lengthy, unstable orbits,” warns Carlos de la Fuente Marcos.

“These objects would escape from the Solar System in less than 1.5 billion years, -he adds-, and in the case of 2004 VN112, 2007 TG422 and 2013 RF98 they could abandon it in less than 300 million years; what is more important, their orbits would become really unstable in just 10 million years, a really short amount of time in astronomical terms.”

According to this new study, also based on numerical (N-body) simulations, the orbit of the new planet proposed by Batygin and Brown would have to be modified slightly so that the orbits of the six ETNOs analysed would be really stable for a long time.

These results also lead to a new question: Are the ETNOs a transient and unstable population or, on the contrary, are they permanent and stable? The fact that these objects behave in one way or another affects the evolution of their orbits and also the numerical modelling.

“If the ETNOs are transient, they are being continuously ejected and must have a stable source located beyond 1,000 astronomical units (in the Oort cloud) where they come from,” notes Carlos de la Fuente Marcos. “But if they are stable in the long term, then there could be many in similar orbits although we have not observed them yet.”

In any case, the statistical and numerical evidence obtained by the authors, both through this and previous work, leads them to suggest that the most stable scenario is one in which there is not just one planet, but rather several more beyond Pluto, in mutual resonance, which best explains the results. “That is to say we believe that in addition to a Planet Nine, there could also be a Planet Ten and even more,” the Spanish astronomer points out.

{{International race to discover Planet Nine}}

These studies are only a few of the countless international peer-reviewed articles published or in preparation about the search for Planet Nine with the help of N-body simulations and other techniques. Batygin and Brown are going to present soon new models of the orbit of the mysterious Planet Nine with up-to-date data. On the other side of the Atlantic, in France, Professor Jacques Laskar’s team from the Paris Observatory is also attempting to be the first to compute the position of the hypothetical Planet Nine in order to then observe it.

This situation is reminiscent of the discovery of Neptune, in which the French mathematician Urbain Le Verrier was the first to “discover” a new planet using laborious hand calculations based on the positions of Uranus; later, the German astronomer J. G Galle directly observed it.

“If Neptune was the first planet discovered using pen and paper, Planet Nine could be the first to be discovered using entirely computerized numerical calculations.” notes de la Fuente Marcos, although he points out that the results of the French team are based on residuals in the tracking data from the Cassini spacecraft, in orbit around Saturn, caused by the presence of the hypothetical planet, but NASA has denied it, suggesting that it could simply be statistical noise in the signal.

{{Could Planet Nine be an exoplanet?}}

One of the most revolutionary studies from recent months, also with computational simulations and participation of French institutions, was led by the researcher Alexander Mustill from Lund University (Sweden), who raised the idea that Planet Nine may have come from outside the Solar System, that is to say, that it could be an exoplanet.

His hypothesis is that around 4.5 billion years ago, our then young Sun “stole” this planet from a neighbouring star with the help of a series of favourable conditions (proximity of stars within a star cluster, a planet in a wide and elongated orbit,…). Other scientists, however, believe that this scenario is improbable.

The debate is on. What all astronomers do agree on is the importance of closely tracking the motions of the extreme trans-Neptunian objects to be able to adjust the calculations that should lead the way to the location of Planet Nine, without forgetting that the best evidence will be its direct observation, a race which several research teams are fighting to win.

{New research reports that, contrary to popular belief, mammals began their massive diversification 10 to 20 million years before the extinction of the dinosaurs.}

The study, involving Elis Newham from the University of Southampton, questioned the familiar story that dinosaurs dominated their prehistoric environment, while tiny mammals took a backseat, until the dinosaurs (besides birds) went extinct 66 million years ago, allowing mammals to shine.

Elis Newham, PhD student in Engineering and the Environment and co-author of the study, which is published Proceedings of the Royal Society B, said: “The traditional view is that mammals were suppressed during the ‘age of the dinosaurs’ and underwent a rapid diversification immediately following the extinction of the dinosaurs. However, our findings were that therian mammals, the ancestors of most modern mammals, were already diversifying considerably before the extinction event and the event also had a considerably negative impact on mammal diversity.”

The old hypothesis hinged upon the fact that many of the early mammal fossils that had been found were from small, insect-eating animals — there didn’t seem to be much in the way of diversity. However, over the years, more and more early mammals have been found, including some hoofed animal predecessors the size of dogs. The animals’ teeth were varied too.

The researchers analysed the molars of hundreds of early mammal specimens in museum fossil collections. They found that the mammals that lived during the years leading up to the dinosaurs’ demise had widely varied tooth shapes, meaning that they had widely varied diets. These different diets proved key to an unexpected finding regarding mammal species going extinct along with the dinosaurs.

Not only did mammals begin diversifying earlier than previously expected, but the mass extinction wasn’t the perfect opportunity for mammal evolution that it’s traditionally been painted as. Early mammals were hit by a selective extinction at the same time the dinosaurs died out — generalists that could live off of a wide variety of foods seemed more apt to survive, but many mammals with specialised diets went extinct.

The scientists involved with the study were surprised to see that mammals were initially negatively impacted by the mass extinction event. “I fully expected to see more diverse mammals immediately after the extinction,” said lead author David Grossnickle, a Field Museum Fellow and PhD candidate at the University of Chicago. “I wasn’t expecting to see any sort of drop. It didn’t match the traditional view that after the extinction, mammals hit the ground running. It’s part of the reason why I went back to study it further — it seemed wrong.”

The reason behind the mammals’ pre-extinction diversification remains a mystery. Grossnickle suggests a possible link between the rise of mammals and the rise of flowering plants, which diversified around the same time. “We can’t know for sure, but flowering plants might have offered new seeds and fruits for the mammals. And, if the plants co-evolved with new insects to pollinate them, the insects could have also been a food source for early mammals,” he said.

Grossnickle notes that the study is particularly relevant in light of the mass extinction the earth is currently undergoing. He said: “The types of survivors that made it across the mass extinction 66 million years ago, mostly generalists, might be indicative of what will survive in the next hundred years, the next thousand.”

{Psychological characteristics link genes with upward social mobility, according to data collected from almost 1,000 individuals over four decades. The data suggest that various psychological factors play a role in linking a person’s genetic profile and several important life outcomes, including professional achievement, financial security, geographic mobility, and upward social mobility.}

The findings are published in Psychological Science, a journal of the Association for Psychological Science.

The study, led by psychological scientist Daniel W. Belsky of Duke University School of Medicine, builds on previous research indicating a genetic continuum that predicts individuals’ educational achievement.

In the earlier study, the Social Science Genetic Association Consortium examined millions of genetic variants in more than 100,000 people and found that these variants could be aggregated and turned into a “polygenic score” that was linked with educational attainment. Participants with polygenic scores above zero were more likely to complete more years of schooling, whereas those with scores below zero were likely to complete fewer years of schooling.

“Getting a good education requires many of the same skills and abilities needed to get ahead in life more generally, so we hypothesized that the same genetics that predicted success in schooling would predict success in life,” says Belsky.

Belsky and colleagues capitalized on longitudinal data from the Dunedin Study, an ongoing study that has followed individuals in New Zealand from birth through their fourth decade. The study includes a representative sample and has had a very low dropout rate.

Over the course of the study, participants have completed assessments evaluating their developmental milestones in childhood; their traits, behaviors, and aspirations through adolescence; and their attainments and outcomes in adulthood.

Belsky and colleagues matched the genotypes of Dunedin Study participants with the genome-wide associations with educational attainment that had been reported previously.

The results revealed that genetic links with educational attainment predict outcomes that go well beyond the completion of schooling, as Belsky and colleagues hypothesized.

The researchers found that individuals with higher polygenic scores were more likely to move away from home in search of professional opportunities, they built more successful careers, they were better at managing their money, and they had spouses with higher levels of education and greater earnings.

Importantly, the results indicated that higher polygenic scores were associated with social mobility — children with higher polygenic scores tended to achieve more socioeconomic success even if they were born into families that were relatively poor.

Intelligence partly accounted for the association between genes and life outcomes, but so did other psychological characteristics, including self-control and interpersonal skills (e.g., being friendly).

But there were some important life outcomes that the polygenic scores did not predict. When the researchers looked at whether polygenic score predicted children’s physical health — measured from repeated clinical exams across childhood — they found no evidence of an association.

Together, the findings provide glimpses into how genes may ultimately shape our lives over time, but the researchers emphasize that the associations between polygenic score and life outcomes are small:

“We can make only very weak predictions about how far a child can go in life based on their genes,” Belsky explains.

The data currently available do not provide sufficient information to guide educational interventions or other real-world applications; nonetheless, they raise provocative questions that ought to be discussed among scientists, policymakers, and the members of the public.

“‘Precision education’ or other tailoring of environments to children’s genomes is not possible with the data we have in hand today, but our findings suggest that such data may someday become available,” Belsky says. “It is vital to have the conversation about what that might mean and how we will deal with it before it happens.”

{Babies appeal to all our senses and even smell cute, triggering key parental behaviors.}

What is it about the sight of an infant that makes almost everyone crack a smile? Big eyes, chubby cheeks, and a button nose? An infectious laugh, soft skin, and a captivating smell? While we have long known that babies look cute, researchers have found that cuteness is designed to appeal to all our senses to trigger vital caregiving behaviors.

What is it about the sight of an infant that makes almost everyone crack a smile? Big eyes, chubby cheeks, and a button nose? An infectious laugh, soft skin, and a captivating smell? While we have long known that babies look cute, Oxford University researchers have found that cuteness is designed to appeal to all our senses.

They explain that all these characteristics contribute to ‘cuteness’ and trigger our caregiving behaviours, which is vital because infants need our constant attention to survive and thrive. The study is published in the journal Trends in Cognitive Sciences.

Morten Kringelbach, who together with Eloise Stark, Catherine Alexander, Professor Marc Bornstein and Professor Alan Stein, led the work in the Department of Psychiatry at the University of Oxford, said: ‘Infants attract us through all our senses, which helps make cuteness one of the most basic and powerful forces shaping our behaviour.’

Reviewing the emerging literature on how cute infants and animals affect the brain, the Oxford University team found that cuteness supports key parental capacities by igniting fast privileged neural activity followed by slower processing in large brain networks also involved in play, empathy, and perhaps even higher-order moral emotions.

The data shows that definitions of cuteness should not be limited just to visual features but include positive infant sounds and smells. From an evolutionary standpoint, cuteness is a very potent protective mechanism that ensures survival for otherwise completely dependent infants.

Professor Kringelbach said: ‘This is the first evidence of its kind to show that cuteness helps infants to survive by eliciting caregiving, which cannot be reduced to simple, instinctual behaviours. Instead, caregiving involves a complex choreography of slow, careful, deliberate, and long-lasting prosocial behaviours, which ignite fundamental brain pleasure systems that are also engaged when eating food or listening to music, and always involve pleasant experiences.’

The study shows that cuteness affects both men and women, even those without children.

‘This might be a fundamental response present in everyone, regardless of parental status or gender, and we are currently conducting the first long-term study of what happens to brain responses when we become parents.’ said Kringelbach.

{Researchers have found evidence that demonstrates Aboriginal people were the first to inhabit Australia.The work refutes an earlier landmark study that claimed to recover DNA sequences from the oldest known Australian, Mungo Man.}

Griffith University researchers have found evidence that demonstrates Aboriginal people were the first to inhabit Australia.

The work refutes an earlier landmark study that claimed to recover DNA sequences from the oldest known Australian, Mungo Man.

This earlier study was interpreted as evidence that Aboriginal people were not the first Australians, and that Mungo Man represented an extinct lineage of modern humans that occupied the continent before Aboriginal Australians.

Scientists from Griffith University’s Research Centre for Human Evolution (RCHE), recently used new DNA sequencing methods to re-analyse the remains of Mungo Man from the World Heritage listed landscape of the Willandra Lakes region, in far western New South Wales.

Professor Lambert, from RCHE, said it was clear that incorrect conclusions had been drawn in relation to Mungo Man in the original study.

“The sample from Mungo Man which we retested contained sequences from five different European people suggesting that these all represent contamination,” he said.

“At the same time we re-analysed more than 20 of the other ancient people from Willandra. We were successful in recovering the genomic sequence of one of the early inhabitants of Lake Mungo, a man buried very close to the location where Mungo Man was originally interred.

“By going back and reanalysing the samples with more advanced technology, we have found compelling support for the argument that Aboriginal Australians were the first inhabitants of Australia.”

Professor Lambert explained that the results proved that the more advanced genomic technology was capable of unlocking further secrets from Australia’s human past.

“We now know that meaningful genetic information can be recovered from ancient Aboriginal Australian remains,” he said.

“This represents the first time researchers have recovered an ancient mitochondrial genome sequence from an Aboriginal person who lived before the arrival of the Europeans.”

The research, which has just been published in the journal Proceedings of the National Academy of Sciences, was planned and conducted with the support of the Barkindjii, Ngiyampaa and Muthi Muthi indigenous people.

There has been considerable debate in Australia and around the world about the origins of the first Australians since the publication in 1863 of Thomas Henry Huxley’s Man’s Place in Nature.

{In a study performed by North Carolina State University researchers, zebrafish that were bred to be more bold — quantified by the shorter amount of time they remained motionless when placed in new surroundings — displayed a sleeker body shape and an ability to dart around the water more quickly when startled than those bred to be more shy.}

Brian Langerhans, an assistant professor of biological sciences at NC State and a senior author on a paper describing the study, says the research could help scientists learn about the connectedness of what seem to be disconnected animal traits.

“Complex behaviors, like the behaviors we call ‘personality’ or ‘temperament,’ can be associated — genetically correlated — with other traits that one might think are independent of such behaviors, like body shape and swimming abilities,” he said. “In other words, traits that seem unrelated may not be unrelated.”

In the study, the researchers used zebrafish lines that had been selected to be bolder by breeding fish that stayed still for a maximum of 50 seconds after being introduced into new surroundings, while shy fish — those that stayed still for more than 3 minutes when dropped into a new area — were bred to create a shy line.

After just a few generations with these breeding regimens, the researchers began to see interesting changes to the different fish lines. Not only did a range of behaviors associated with stressful situations change, but bold fish lines also displayed a more elongate body with a larger tail region and generated higher velocity and acceleration during fast-start startle responses. Shy fish lines had less sleek bodies and slower startle responses.

“We think pleiotropy, or one gene affecting two or more phenotypes, may explain the correlation between personality and locomotion,” Langerhans said. “On the other hand, the association between personality and body shape seems to reflect linkage disequilibrium that is not caused by pleiotropy or physical genetic linkage. That means these traits may owe their association to recurrent natural selection acting on combinations of traits — being bolder and sleeker may help zebrafish survive to adulthood or to mate more successfully, resulting in fish tending to have those combinations of traits/genes.”

Langerhans said that a major goal of his lab is to understand how organisms evolve integrated suites of traits, rather than thinking about traits in isolation.

“This is one of the first studies linking personality variation to these other types of traits, and I think many more will emerge in the coming years,” Langerhans said.

{VLA maps ammonia gases, revealing upwellings, downwellings that shape cloud structure}

{Using the upgraded Very Large Array, astronomers have produced a detailed radio map of the upper 100 kilometers of Jupiter’s atmosphere, revealing the complex movement of ammonia gas that shapes the colorful clouds observed in the optical. The map will help understand how global circulation and cloud formation are driven by Jupiter’s powerful internal heat source, and shed light on similar processes on giant planets in our solar system and around distant stars.
}

Astronomers using the upgraded Karl G. Jansky Very Large Array in New Mexico have produced the most detailed radio map yet of the atmosphere of Jupiter, revealing the massive movement of ammonia gas that underlies the colorful bands, spots and whirling clouds visible to the naked eye.

The University of California, Berkeley researchers measured radio emissions from Jupiter’s atmosphere in wavelength bands where clouds are transparent. The observers were able to see as deep as 100 kilometers (60 miles) below the cloud tops, a largely unexplored region where clouds form.

The planet’s thermal radio emissions are partially absorbed by ammonia gas. Based on the amount of absorption, the researchers could determine how much ammonia is present and at what depth.

By studying these regions of the planet’s atmosphere, astronomers hope to learn how global circulation and cloud formation are driven by Jupiter’s powerful internal heat source. These studies also will shed light on similar processes occuring on other giant planets in our solar system and on newly discovered giant exoplanets around distant stars.

“We in essence created a three-dimensional picture of ammonia gas in Jupiter’s atmosphere, which reveals upward and downward motions within the turbulent atmosphere,” said principal author Imke de Pater, a UC Berkeley professor of astronomy.

The map bears a striking resemblance to visible-light images taken by amateur astronomers and the Hubble Space Telescope, she said.

The radio map shows ammonia-rich gases rising into and forming the upper cloud layers: an ammonium hydrosulfide cloud at a temperature near 200 Kelvin (minus 100 degrees Fahrenheit) and an ammonia-ice cloud in the approximately 160 Kelvin cold air (minus 170 degrees Fahrenheit). These clouds are easily seen from Earth by optical telescopes.

Conversely, the radio maps show ammonia-poor air sinking into the planet, similar to how dry air descends from above the cloud layers on Earth.

The map also shows that hotspots — so-called because they appear bright in radio and thermal infrared images — are ammonia-poor regions that encircle the planet like a belt just north of the equator. Between these hotspots are ammonia-rich upwellings that bring ammonia from deeper in the planet.

“With radio, we can peer through the clouds and see that those hotspots are interleaved with plumes of ammonia rising from deep in the planet, tracing the vertical undulations of an equatorial wave system,” said UC Berkeley research astronomer Michael Wong.

The final maps have the best spatial resolution ever achieved in a radio map: 1,300 kilometers.

“We now see high ammonia levels like those detected by Galileo from over 100 kilometers deep, where the pressure is about eight times Earth’s atmospheric pressure, all the way up to the cloud condensation levels,” de Pater said.

De Pater, Wong and their colleaugues will report their findings and highly detailed maps in the June 3, 2016 issue of the journal Science.

Prelude to Juno’s arrival

The observations are being reported just one month before the July 4, 2016 arrival at Jupiter of NASA’s Juno spacecraft, which plans, in part, to measure the amount of water in the deep atmosphere where the Very Large Array looked for ammonia.

“Maps like ours can help put their data into the bigger picture of what’s happening in Jupiter’s atmosphere,” de Pater said, noting that her team will observe Jupiter with the VLA at the same time as Juno’s microwave instruments are probing for water.

Key to the new observations was an upgrade to the VLA that improved sensitivity by a factor of 10, said Bryan Butler, a co-author and staff astronomer at the National Radio Astronomy Observatory in Socorro, New Mexico, which operates the VLA. “These Jupiter maps really show the power of the upgrades to the VLA.”

The team observed over the entire frequency range between 4 and 18 gigahertz (1.7 — 7 centimeter wavelength), which enabled them to carefully model the atmosphere, said David DeBoer, a research astronomer with UC Berkeley’s Radio Astronomy Laboratory.

“We now see fine structure in the 12 to 18 gigahertz band, much like we see in the visible, especially near the Great Red Spot, where we see a lot of little curly features,” Wong said. “Those trace really complex upwelling and downwelling motions there.”

The observations also resolve a puzzling discrepancy between the ammonia concentration detected by the Galileo probe when it plunged through the atmosphere in 1995 — 4.5 times the abundance observed in the sun — and VLA measurements from before 2004, which showed much less ammonia gas than measured by the probe.

“Jupiter’s rotation once every 10 hours usually blurs radio maps, because these maps take many hours to observe,” said co-author Robert Sault, of the University of Melbourne in Australia. “But we have developed a technique to prevent this and so avoid confusing together the upwelling and downwelling ammonia flows, which had led to the earlier underestimate.”

This research was supported by Planetary Astronomy and Outer Planets Research Program awards from the National Aeronautics and Space Administration. NRAO is a National Science Foundation facility operated under cooperative agreement by Associated Universities, Inc.

{The question, ‘Where do domestic dogs come from?’, has vexed scholars for a very long time. Some argue that humans first domesticated wolves in Europe, while others claim this happened in Central Asia or China. A new paper, published in Science, suggests that all these claims may be right. Supported by funding from the European Research Council and the Natural Environment Research Council, a large international team of scientists compared genetic data with existing archaeological evidence and show that man’s best friend may have emerged independently from two separate (possibly now extinct) wolf populations that lived on opposite sides of the Eurasian continent. This means that dogs may have been domesticated not once, as widely believed, but twice.}

A major international research project on dog domestication, led by the University of Oxford, has reconstructed the evolutionary history of dogs by first sequencing the genome (at Trinity College Dublin) of a 4,800-year old medium-sized dog from bone excavated at the Neolithic Passage Tomb of Newgrange, Ireland. The team (including French researchers based in Lyon and at the National Museum of Natural History in Paris) also obtained mitochondrial DNA from 59 ancient dogs living between 14,000 to 3,000 years ago and then compared them with the genetic signatures of more than 2,500 previously studied modern dogs.

The results of their analyses demonstrate a genetic separation between modern dog populations currently living in East Asia and Europe. Curiously, this population split seems to have taken place after the earliest archaeological evidence for dogs in Europe. The new genetic evidence also shows a population turnover in Europe that appears to have mostly replaced the earliest domestic dog population there, which supports the evidence that there was a later arrival of dogs from elsewhere. Lastly, a review of the archaeological record shows that early dogs appear in both the East and West more than 12,000 years ago, but in Central Asia no earlier than 8,000 years ago.

Combined, these new findings suggest that dogs were first domesticated from geographically separated wolf populations on opposite sides of the Eurasian continent. At some point after their domestication, the eastern dogs dispersed with migrating humans into Europe where they mixed with and mostly replaced the earliest European dogs. Most dogs today are a mixture of both Eastern and Western dogs — one reason why previous genetic studies have been difficult to interpret.

The international project (which is combining ancient and modern genetic data with detailed morphological and archaeological research) is currently analysing thousands of ancient dogs and wolves to test this new perspective, and to establish the timing and location of the origins of our oldest pet.

Senior author and Director of Palaeo-BARN (the Wellcome Trust Palaeogenomics & Bio-Archaeology Research Network) at Oxford University, Professor Greger Larson, said: ‘Animal domestication is a rare thing and a lot of evidence is required to overturn the assumption that it happened just once in any species. Our ancient DNA evidence, combined with the archaeological record of early dogs, suggests that we need to reconsider the number of times dogs were domesticated independently. Maybe the reason there hasn’t yet been a consensus about where dogs were domesticated is because everyone has been a little bit right.’

Lead author Dr Laurent Frantz, from the Palaeo-BARN, commented: ‘Reconstructing the past from modern DNA is a bit like looking into the history books: you never know whether crucial parts have been erased. Ancient DNA, on the other hand, is like a time machine, and allows us to observe the past directly.’

Senior author Professor Dan Bradley, from Trinity College Dublin, commented: ‘The Newgrange dog bone had the best preserved ancient DNA we have ever encountered, giving us prehistoric genome of rare high quality. It is not just a postcard from the past, rather a full package special delivery.’

Professor Keith Dobney, co-author and co-director of the dog domestication project from Liverpool University’s Department of Archaeology, Classics and Egyptology, is heartened by these first significant results. ‘With the generous collaboration of many colleagues from across the world-sharing ideas, key specimens and their own data — the genetic and archaeological evidence are now beginning to tell a new coherent story. With so much new and exciting data to come, we will finally be able to uncover the true history of man’s best friend.’

{Adult songbirds modify their vocalizations when singing to juveniles in the same way that humans alter their speech when talking to babies. The resulting brain activity in young birds could shed light on speech learning and certain developmental disorders in humans, according to a study by McGill University researchers.}

Lead author Jon Sakata, a professor of neurobiology at McGill, says that songbirds learn vocalizations like humans learn speech. “Songbirds first listen to and memorize the sound of adult songs and then undergo a period of vocal practice-in essence, babbling-to master the production of song.”

Researchers have been studying song learning in birds for some time. But the degree to which social interaction with adult birds contributes to that learning has been unclear. That’s because, unlike this current work, past studies didn’t control for the time exposed to song and the presence of other birds.

Vocal learning

In this study, published in the journal Proceedings of the National Academy of Sciences, a group of juvenile zebra finches was allowed to interact with an adult. Another group simply heard adult songs played through a speaker. After a brief period of “tutoring” the juveniles were house individually for months as they practiced their tunes.

Sakata and his team found that avian pupils who socialized with an adult learned the adult’s song much better. That was true even if the social tutoring lasted just one day. In analyzing why this would be so, Sakata and his team made a surprising discovery.

Adult zebra finches change their vocalizations when singing to juveniles. Sakata says just as people speak more slowly and repeat words more often when speaking to infants, so do these birds. “We found that adult zebra finches similarly slow down their song by increasing the interval between song phrases and repeat individual song elements more often when singing to juveniles.”

What’s more, the researchers found that juvenile birds pay more attention to this “baby talk” compared to other songs. And the more the juveniles paid attention, the better they learned.

Activating neurons

The researchers took their work a step further by examining the activity of certain neurons in parts of the brain associated with attention. They found that more neurons that produce the chemicals dopamine and norepinephrine were turned on after socially interacting with a singing adult than after simply hearing song through a speaker.

Dr. Sakata says this finding could have implications beyond the avian world. “Our data suggest that dysfunctions in these neurons could contribute to social and communicative disorders in humans. For example, children who suffer from autism spectrum disorders have difficulty processing social information and learning language, and these neurons might be potential targets for treating such disorders.”

Dr. Sakata is now testing whether raising dopamine and norepinephrine levels in the brain can help birds learn song when they only hear adult songs. As he puts it, “We are testing whether we can “trick” a bird’s brain into thinking that the bird is being socially tutored.”

{Study sheds light on influence of peers and much more}

{Teenagers’ brains have been scanned while they used social media in a first-of-its-kind study. Among the new findings: The same brain circuits that are activated by eating chocolate and winning money are activated when teenagers see large numbers of ‘Likes’ on their own photos, and teenagers are definitely influenced by their online ‘friends,’ even if they barely know them.}

The same brain circuits that are activated by eating chocolate and winning money are activated when teenagers see large numbers of “likes” on their own photos or the photos of peers in a social network, according to a first-of-its-kind UCLA study that scanned teens’ brains while using social media.

The 32 teenagers, ages 13-18, were told they were participating in a small social network similar to the popular photo-sharing app, Instagram. In an experiment at UCLA’s Ahmanson-Lovelace Brain Mapping Center, the researchers showed them 148 photographs on a computer screen for 12 minutes, including 40 photos that each teenager submitted, and analyzed their brain activity using functional magnetic resonance imaging, or fMRI. Each photo also displayed the number of likes it had supposedly received from other teenage participants — in reality, the number of likes was assigned by the researchers. (At the end of the procedure, the participants were told that the researchers decided on the number of likes a photo received.)

“When the teens saw their own photos with a large number of likes, we saw activity across a wide variety of regions in the brain,” said lead author Lauren Sherman, a researcher in the brain mapping center and the UCLA branch of the Children’s Digital Media Center, Los Angeles.

A region that was especially active is a part of the striatum called the nucleus accumbens, which is part of the brain’s reward circuitry, she said. This reward circuitry is thought to be particularly sensitive during adolescence. When the teenagers saw their photos with a large number of likes, the researchers also observed activation in regions that are known as the social brain and regions linked to visual attention.

In deciding whether to click that they liked a photo, the teenagers were highly influenced by the number of likes the photo had.

“We showed the exact same photo with a lot of likes to half of the teens and to the other half with just a few likes,” Sherman said. “When they saw a photo with more likes, they were significantly more likely to like it themselves. Teens react differently to information when they believe it has been endorsed by many or few of their peers, even if these peers are strangers.”

The study is published in the journal Psychological Science.

In the teenagers’ real lives, the influence of their friends is likely to be even more dramatic, said Mirella Dapretto, professor of psychiatry and biobehavioral sciences at UCLA’s Semel Institute of Neuroscience and Human Behavior.

“In the study, this was a group of virtual strangers to them, and yet they were still responding to peer influence; their willingness to conform manifested itself both at the brain level and in what they chose to like,” said Dapretto, a senior author of the study. “We should expect the effect would be magnified in real life, when teens are looking at likes by people who are important to them.”

Should parents be worried about social media? Much like other media, social media have both positive and negative features, the researchers said.

Many teenagers and young adults befriend people online whom they don’t know well, and parents are right to be concerned, Dapretto said. “That opens up the possibility of a child being more influenced by people who may engage in more risk-taking behavior than your child or your child’s immediate friends,” she said.

“Parents used to know their child’s friends, but when they have several hundred friends, there’s no way parents can know who they are,” said Patricia Greenfield, director of UCLA’s Children’s Digital Media Center, Los Angeles and the study’s other senior author.

But Sherman points out a possible advantage of social networks. “If your teen’s friends are displaying positive behavior, then it’s fabulous that your teen will see that behavior and be influenced by it,” she said. “It’s important for parents to be aware of who their teens interact with online and what these friends and acquaintances are posting and liking. In addition, teens’ self-identity is influenced by the opinions of others, as earlier studies have shown. Our data certainly seem to reflect that as well.”

Peer pressure to conform has long existed, but online likes are different. “In the past, teens made their own judgments about how everyone around them was responding,” Sherman said. “When it comes to likes, there’s no ambiguity.”

The teenagers in the study viewed “neutral” photos — which included pictures of food and of friends — and “risky” photos — including of cigarettes, alcohol and teenagers wearing provocative clothing.

“For all three types of photographs — neutral, risky and even their own — the teens were more likely to click like if more people had liked them than if fewer people liked them,” said Greenfield, a UCLA distinguished professor of psychology. “The conformity effect, which was particularly large for their own pictures, shows the importance of peer-approval.”

When teenagers looked at risky photos compared with neutral photos, they had less activation in areas associated with “cognitive control” and “response inhibition,” including the brain’s dorsal anterior cingulate cortex, bilateral prefrontal cortices and lateral parietal cortices.

These brain regions are involved in decision-making and can inhibit us from engaging in certain activities, or give us the green light to go ahead, Dapretto said.

Seeing photos that depict risky behavior seems to decrease activity in the regions that put the brakes on, perhaps weakening teens’ “be careful” filter, she said.