UCLA psychologists have used brain-imaging techniques to study what happens to the human brain when it slips into unconsciousness. Their research, published Oct. 17 in the online journal PLOS Computational Biology, is an initial step toward developing a scientific definition of consciousness.
"In terms of brain function, the difference between being conscious and unconscious is a bit like the difference between driving from Los Angeles to New York in a straight line versus having to cover the same route hopping on and off several buses that force you to take a 'zig-zag' route and stop in several places," said lead study author Martin Monti, an assistant professor of psychology and neurosurgery at UCLA.
Monti and his colleagues used functional magnetic resonance imaging (fMRI) to study how the flow of information in the brains of 12 healthy volunteers changed as they lost consciousness under anesthesia with propofol. The participants ranged in age from 18 to 31 and were evenly divided between men and women.
The psychologists analyzed the "network properties" of the subjects' brains using a branch of mathematics known as graph theory, which is often used to study air-traffic patterns, information on the Internet and social groups, among other topics.
"It turns out that when we lose consciousness, the communication among areas of the brain becomes extremely inefficient, as if suddenly each area of the brain became very distant from every other, making it difficult for information to travel from one place to another," Monti said.
The finding shows that consciousness does not "live" in a particular place in our brain but rather "arises from the mode in which billions of neurons communicate with one another," he said.
When patients suffer severe brain damage and enter a coma or a vegetative state, Monti said, it is very possible that the sustained damage impairs their normal brain function and the emergence of consciousness in the same manner as was seen by the life scientists in the healthy volunteers under anesthesia.
"If this were indeed the case, we could imagine in the future using our technique to monitor whether interventions are helping patients recover consciousness," he said.
"It could, however, also be the case that losing consciousness because of brain injury affects brain function through different mechanisms," said Monti, whose research team is currently addressing this question in another study.
"As profoundly defining of our mind as consciousness is, without having a scientific definition of this phenomenon, it is extremely difficult to study," Monti noted. This study, he said, marks an initial step toward conducting neuroscience research on consciousness.
The research was conducted at Belgium's University Hospital of Liege.
Monti's expertise includes cognitive neuroscience, the relationship between language and thought, and how consciousness is lost and recovered after severe brain injury. He was part of a team of American and Israeli brain scientists who used fMRI on former Israeli Prime Minister Ariel Sharon in January 2013 to assess his brain responses.
Read more at Science Daily
Oct 19, 2013
Adolescence: When Drinking, Genes May Collide
Many negative effects of drinking, such as transitioning into heavy alcohol use, often take place during adolescence and can contribute to long-term negative health outcomes as well as the development of alcohol use disorders. A new study of adolescent drinking and its genetic and environmental influences has found that different trajectories of adolescent drinking are preceded by discernible gene-parenting interactions, specifically, the mu-opioid receptor (OPRM1) genotype and parental-rule-setting.
Results will be published in the March 2014 issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.
"Heavy drinking in adolescence can lead to alcohol-related problems and alcohol dependence later in life," said Carmen Van der Zwaluw, an assistant professor at Radboud University Nijmegen as well as corresponding author for the study. "It has been estimated that 40 percent of adult alcoholics were already heavy drinkers during adolescence. Thus, tackling heavy drinking in adolescence may prevent later alcohol-related problems."
Van der Zwaluw said that both the dopamine receptor D2 (DRD2) and OPRM1 genes are known to play a large role in the neuro-reward mechanisms associated with the feelings of pleasure that result from drinking, as well as from eating, having sex, and the use of other drugs.
"Different genotypes may result in different neural responses to alcohol or different motivations to drink," she said. "For example, OPRM1 G-allele carriers have been shown to experience more positive feelings after drinking, and to drink more often to enhance their mood than people with the OPRM1 AA genotype. In addition, we chose to examine the influence of parental alcohol-specific rules because research has shown that, more than general measures of parental monitoring, alcohol-specific rule-setting has a considerable and consistent effect on adolescents' drinking behavior."
Van der Zwaluw and her colleagues used data from the Dutch Family and Health study that consisted of six yearly waves, beginning in 2002 and including only adolescents born in the Netherlands. The final sample of 596 adolescents (50% boys) were on average 14.3 years old at Time 1 (T1), 15.3 at T2, 16.3 at T3, 17.7 at T4, 18.7 years at T5, and 19.7 years at T6. Saliva samples were collected in the fourth wave to enable genetic testing. Participants were subsequently divided into three distinct groups of adolescent drinkers; light drinkers (n=346), moderate drinkers (n=178), and heavy drinkers (n=72).
"It was found that adolescent drinkers could be discriminated into three groups: light, moderate, and heavy drinkers," said Van der Zwaluw. "Comparisons between these three groups showed that light drinkers were more often carriers of the OPRM1 AA 'non-risk' genotype, and reported stricter parental rules than moderate drinkers. In the heavy drinking group, the G-allele carriers, but not those with the AA-genotype, were largely affected by parental rules: more rules resulted in lower levels of alcohol use."
Van der Zwaluw explained that although evidence for the genetic liability of heavy alcohol use has been shown repeatedly, debate continues over which genes are responsible for this liability, what the causal mechanisms are, and whether and how it interacts with environmental factors. "Longitudinal studies examining the development of alcohol use over time, in a stage of life that often precedes serious alcohol-related problems, can shed more light on these issues," she said. "This paper confirms important findings of others; showing an association of the OPRM1 G-allele with adolescent alcohol use and an effect of parental rule-setting. Additionally, it adds to the literature by demonstrating that, depending on genotype, adolescents are differently affected by parental rules."
Read more at Science Daily
Results will be published in the March 2014 issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.
"Heavy drinking in adolescence can lead to alcohol-related problems and alcohol dependence later in life," said Carmen Van der Zwaluw, an assistant professor at Radboud University Nijmegen as well as corresponding author for the study. "It has been estimated that 40 percent of adult alcoholics were already heavy drinkers during adolescence. Thus, tackling heavy drinking in adolescence may prevent later alcohol-related problems."
Van der Zwaluw said that both the dopamine receptor D2 (DRD2) and OPRM1 genes are known to play a large role in the neuro-reward mechanisms associated with the feelings of pleasure that result from drinking, as well as from eating, having sex, and the use of other drugs.
"Different genotypes may result in different neural responses to alcohol or different motivations to drink," she said. "For example, OPRM1 G-allele carriers have been shown to experience more positive feelings after drinking, and to drink more often to enhance their mood than people with the OPRM1 AA genotype. In addition, we chose to examine the influence of parental alcohol-specific rules because research has shown that, more than general measures of parental monitoring, alcohol-specific rule-setting has a considerable and consistent effect on adolescents' drinking behavior."
Van der Zwaluw and her colleagues used data from the Dutch Family and Health study that consisted of six yearly waves, beginning in 2002 and including only adolescents born in the Netherlands. The final sample of 596 adolescents (50% boys) were on average 14.3 years old at Time 1 (T1), 15.3 at T2, 16.3 at T3, 17.7 at T4, 18.7 years at T5, and 19.7 years at T6. Saliva samples were collected in the fourth wave to enable genetic testing. Participants were subsequently divided into three distinct groups of adolescent drinkers; light drinkers (n=346), moderate drinkers (n=178), and heavy drinkers (n=72).
"It was found that adolescent drinkers could be discriminated into three groups: light, moderate, and heavy drinkers," said Van der Zwaluw. "Comparisons between these three groups showed that light drinkers were more often carriers of the OPRM1 AA 'non-risk' genotype, and reported stricter parental rules than moderate drinkers. In the heavy drinking group, the G-allele carriers, but not those with the AA-genotype, were largely affected by parental rules: more rules resulted in lower levels of alcohol use."
Van der Zwaluw explained that although evidence for the genetic liability of heavy alcohol use has been shown repeatedly, debate continues over which genes are responsible for this liability, what the causal mechanisms are, and whether and how it interacts with environmental factors. "Longitudinal studies examining the development of alcohol use over time, in a stage of life that often precedes serious alcohol-related problems, can shed more light on these issues," she said. "This paper confirms important findings of others; showing an association of the OPRM1 G-allele with adolescent alcohol use and an effect of parental rule-setting. Additionally, it adds to the literature by demonstrating that, depending on genotype, adolescents are differently affected by parental rules."
Read more at Science Daily
Oct 18, 2013
Gravitational Waves Help Us Understand Black-Hole Weight Gain
A paper in today's issue of Science pits the front-running ideas about the growth of supermassive black holes against observational data -- a limit on the strength of gravitational waves, obtained with CSIRO's Parkes radio telescope in eastern Australia.
"This is the first time we've been able to use information about gravitational waves to study another aspect of the Universe -- the growth of massive black holes," co-author Dr Ramesh Bhat from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR) said.
"Black holes are almost impossible to observe directly, but armed with this powerful new tool we're in for some exciting times in astronomy. One model for how black holes grow has already been discounted, and now we're going to start looking at the others."
The study was jointly led by Dr Ryan Shannon, a Postdoctoral Fellow with CSIRO, and Mr Vikram Ravi, a PhD student co-supervised by the University of Melbourne and CSIRO.
Einstein predicted gravitational waves -- ripples in space-time, generated by massive bodies changing speed or direction, bodies like pairs of black holes orbiting each other.
When galaxies merge, their central black holes are doomed to meet. They first waltz together then enter a desperate embrace and merge.
"When the black holes get close to meeting they emit gravitational waves at just the frequency that we should be able to detect," Dr Bhat said.
Played out again and again across the Universe, such encounters create a background of gravitational waves, like the noise from a restless crowd.
Astronomers have been searching for gravitational waves with the Parkes radio telescope and a set of 20 small, spinning stars called pulsars.
Pulsars act as extremely precise clocks in space. The arrival time of their pulses on Earth are measured with exquisite precision, to within a tenth of a microsecond.
When the waves roll through an area of space-time, they temporarily swell or shrink the distances between objects in that region, altering the arrival time of the pulses on Earth.
The Parkes Pulsar Timing Array (PPTA), and an earlier collaboration between CSIRO and Swinburne University, together provide nearly 20 years worth of timing data. This isn't long enough to detect gravitational waves outright, but the team say they're now in the right ballpark.
"The PPTA results are showing us how low the background rate of gravitational waves is," said Dr Bhat.
"The strength of the gravitational wave background depends on how often supermassive black holes spiral together and merge, how massive they are, and how far away they are. So if the background is low, that puts a limit on one or more of those factors."
Armed with the PPTA data, the researchers tested four models of black-hole growth. They effectively ruled out black holes gaining mass only through mergers, but the other three models are still a possibility.
Read more at Science Daily
Elusive Goblin Shark Has World’s Most Terrifying Jaws
But in the deep seas around the world swims a true goblin king with no interest in righteous hairstyles: the mysterious goblin shark, whose spring-loaded jaws are surely the animal kingdom’s most incredible chompers. Freaky freaky, as Bowie might say.
First described in 1898, the goblin shark had already been known to Japanese fishermen, who called it tengu-zame, tengu being a mythical goblin with an extremely long nose that looked a bit like Pinocchio, except like Jareth it kidnapped children instead of teaching them not to lie. The shark, which grows up to 12.5 feet long, swims at depths of over 4,000 feet and remains poorly understood, though with each new specimen we’re building a better picture of its incredible adaptations to the deep-sea lifestyle.
Most dramatic, of course, are its highly protrusive jaws packed with needle-like teeth meant to trap, not slice. Sharks are able to project their mouths in this manner because the jaw is suspended by ligaments and cartilage instead of being fused to the skull. And the goblin shark takes this to the extreme with a jaw that pretty much looks like it’s trying to escape from the animal’s face.
“Goblin sharks have a very large mouth relative to their size,” added Duffy, and the skin and muscles that comprise it are very loose, “allowing it to expand considerably when the mouth is opened and the jaws protruded.” The rapid expansion “probably creates a vacuum that sucks prey into the shark’s mouth.” (See the first footage of the goblin feeding in the Shark Week video below.)
Aiding this vacuum effect is the goblin shark’s highly developed, highly mobile basihyal — a structure analogous to a tongue, except made out of cartilage — making the creature sort of like the Gene Simmons of the deep. As the jaws fire out, the giant basihyal is depressed, providing even more suction, though not substantially more rock and roll, as far as scientists can tell.
Such a large mouth, according to Duffy, is an adaptation to an environment that’s poor in food choices, allowing “consumption of a wide range of prey sizes from small crustaceans to large-bodied squid and fish.” We see this mirrored in many other deep-sea predators, from the fangtooth to the wait-a-second-this-shouldn’t-exist gulper eel.
Though we can’t yet say for certain that the goblin shark does the same, we can confidently assume it isn’t just wasting the shark family’s most remarkable sense: It’s likely following its nose, only it’s not hunting for Froot Loops, because they’d be super soggy down there.
“The elongated snout is filled with ampullae of Lorenzini,” said Duffy. “These are highly sensitive electroreceptors and probably help the goblin shark detect approaching prey, be it lantern fish or shrimps in the darkened water column, or small benthic fish resting or buried in the sea floor.”
Read more at Wired Science
Centuries-Old Manuscript Reveals Love for Richard III
Now, a nearly 600-year-old manuscript on display at the Yorkshire Museum reveals York's attitudes toward the medieval king while he was still alive. This is the first time the manuscript has been on display for the public, according to The Northern Echo.
"I advyse you, as honourably as your wisdomes can imagyne, to ressayve hym and the quene at their commyng, dispose you to do as well pageants with soch good speches as can goodly, thys short warnyng considered, be devised," read instructions from the King's secretary contained in the York House Books manuscript. The orders came in August 1483, as Richard III and his lords travelled to York.
The secretary went on to suggest that residents hang banners and tapestries along the streets, before adding that he was sure the residents of York already had it covered.
"Me nedeth not thus to advise you, for I doubte not ye have provided therfore better than I can advyse you," he wrote.
According to the House Books and other documents highlighted by the Richard III: Rumour and Reality Festival, which is ongoing until June 2014, the king was indeed met with great fanfare. Upon his death at the Battle of Bosworth in 1485, the city grieved.
"'King Richard late mercifully reigning upon us was thrugh grete treason of the duc of Northefolk and many othre that turned ayenst hyme, with many othre lordes and nobilles of this north parties, was pitiously slane and murdred to the grete hevynesse of this citie," the York House bookkeeper recorded.
Even now, York rallies around Richard III, with a number of Richard enthusiasts arguing that the king's remains should be reburied in the northern city. After Richard III's death in battle, his body was taken to Leicester, where it was stuffed into a hasty grave. In 2012, University of Leicester archaeologists rediscovered the grave, with the king's battle-bruised skeleton inside.
Read more at Discovery News
Biblical Theories, Conjectures and Other Heresies
Was Jesus Fictional?
Jesus Christ, founder of a faith that has endured for 2,000 years with a following of over one billion people, was a fiction, invented by Roman aristocrats to pacify the poor.
The astounding claim that Jesus was merely a propaganda tool has been made by American author and Biblical scholar Joseph Atwill, who plans to reveal proof of his hypothesis in a press conference on October 19. As Discovery News' Benjamin Radford notes: "Atwill believes that the story of Jesus was actually copied and created from the biography of the Roman emperor."
This isn't the first time that traditional Biblical scholarship has been challenged.
Man or Myth?
Tracing back to the 18th century, the earliest theories challenging the historical veracity of Jesus suggesting that he was in fact a combination of other mythological -- and often pagan -- traditions that share similar characteristics, such as virgin birth, sacrifice in death and resurrection.
Biblical and historical scholars, however, almost universally agree that Jesus was a living, breathing human being during the first century.
Married to Jesus?
Mary Magdalene, a former prostitute who Jesus saved from death by stoning, was one of Jesus' most committed followers. But was she also his wife?
Fans of Dan Brown's "The Da Vinci Code" may be familiar with this theory, which very nearly got a small boost last year thanks to the alleged discovery of a 1,600-year-old papyrus fragment. Karen L. King, a historian at Harvard Divinity school, identified and translated the scroll, which reads: "Jesus said to them, 'My wife... she will be able to be my disciple."
Although King herself cautioned the scroll did not necessarily mean Jesus had married, further research determined that the papyrus fragment, originally discovered in an antiques market, is a "clumsy forgery," according to Vatican experts.
Christ Kids
The fragment wasn't the only evidence of a possible union between Jesus and Mary Magdalene. A 2,000-year-old tomb discovered in Talpiot, Jerusalem, allegedly could have held the remains of Jesus and his family.
Based on this find, which was chronicled in the 2007 Discovery Channel documentary, "The Lost Tomb of Jesus," Jesus and Mary were not only married, but they had a son named Judah.
This theory is based on the inscriptions written on 10 limestone ossuaries (bone boxes), several of which contain names found in the New Testament: "Jesus son of Joseph," "Maria," "Mariamene e Mara," "Matthew," "Yose" and "Judah son of Jesus."
The tomb has stirred controversy among both scholars, who meet the claim with skepticism given the historic belief that Jesus never had a family, and the faithful, who reject the find given that it discredits the resurrection of Jesus.
On Thin Ice
After the image of the baby Jesus and Jesus on the cross, arguably the next most iconic image of Jesus is that of him walking on water.
While Christians take Jesus' water walk as a miracle, in 2006 Florida State University Professor of Oceanography Doron Nof came up with a much simpler explanation: Jesus walked on an isolated patch of ice.
As noted in the press release about the research, the study points to "a rare combination of optimal water and atmospheric conditions for development of a unique, localized freezing phenomenon" called "springs ice."
Parting of the Red Sea
The story of Jesus' water walk wasn't the first time that Nof put a Biblical miracle under a scientific lens.
In 1992, Nof came up with a theory for how Moses parted the Red Sea. He puts forward two possible explanations: strong winds along the Gulf of Suez pushing back the water, or a tsunami. According to his paper published in the Bulletin of the American Meteorological Society, the wind explanation is the most likely of the two.
Carl Drews, a software engineer with the National Center for Atmospheric Research, created a computer simulation in 2010 that drew upon language from the Bible to recreate the parting of the Red Sea. Drews echoed Nof's findings, suggesting that a strong wind may very well explain the temporarily receding shoreline, according to NPR.
Biblical scholars, however, contend that the crossing of the Israelites out of Egypt didn't take place on the Red Sea at all, but rather a Sea of Reeds, the location of which is disputed.
Samson the Sociopath
Samson, the famed Israelite of the Bible whose hair was the secret to his strength and the source of his downfall, was also likely a sociopath, according to University of California, San Diego researcher Eric Altschuler in 2001.
Credited with feats of strength including slaying a lion and moving the gates of Gaza, Samson also exhibited almost all of the symptoms of Antisocial Personality Disorder. Altschuler points to the following tales of Samson's questionable behavior as evidence for his diagnosis: "his failure to conform to social norms by torching the Philistines fields and then refusing arrest; ... his impulsivity as evidenced by his burning of the Philistine fields; his repeated involvement in physical fights, bullying, and cruelty to animals; ... and his lack of remorse, as evidenced by his gloating after the killing of 1,000 men."
In Altschuler's telling, Samson isn't so much a hero as he is a menace who was eventually brought under control by his fellow Israelites.
Read more at Discovery News
The astounding claim that Jesus was merely a propaganda tool has been made by American author and Biblical scholar Joseph Atwill, who plans to reveal proof of his hypothesis in a press conference on October 19. As Discovery News' Benjamin Radford notes: "Atwill believes that the story of Jesus was actually copied and created from the biography of the Roman emperor."
This isn't the first time that traditional Biblical scholarship has been challenged.
Man or Myth?
Biblical and historical scholars, however, almost universally agree that Jesus was a living, breathing human being during the first century.
Married to Jesus?
Fans of Dan Brown's "The Da Vinci Code" may be familiar with this theory, which very nearly got a small boost last year thanks to the alleged discovery of a 1,600-year-old papyrus fragment. Karen L. King, a historian at Harvard Divinity school, identified and translated the scroll, which reads: "Jesus said to them, 'My wife... she will be able to be my disciple."
Although King herself cautioned the scroll did not necessarily mean Jesus had married, further research determined that the papyrus fragment, originally discovered in an antiques market, is a "clumsy forgery," according to Vatican experts.
Christ Kids
Based on this find, which was chronicled in the 2007 Discovery Channel documentary, "The Lost Tomb of Jesus," Jesus and Mary were not only married, but they had a son named Judah.
This theory is based on the inscriptions written on 10 limestone ossuaries (bone boxes), several of which contain names found in the New Testament: "Jesus son of Joseph," "Maria," "Mariamene e Mara," "Matthew," "Yose" and "Judah son of Jesus."
The tomb has stirred controversy among both scholars, who meet the claim with skepticism given the historic belief that Jesus never had a family, and the faithful, who reject the find given that it discredits the resurrection of Jesus.
On Thin Ice
While Christians take Jesus' water walk as a miracle, in 2006 Florida State University Professor of Oceanography Doron Nof came up with a much simpler explanation: Jesus walked on an isolated patch of ice.
As noted in the press release about the research, the study points to "a rare combination of optimal water and atmospheric conditions for development of a unique, localized freezing phenomenon" called "springs ice."
Parting of the Red Sea
In 1992, Nof came up with a theory for how Moses parted the Red Sea. He puts forward two possible explanations: strong winds along the Gulf of Suez pushing back the water, or a tsunami. According to his paper published in the Bulletin of the American Meteorological Society, the wind explanation is the most likely of the two.
Carl Drews, a software engineer with the National Center for Atmospheric Research, created a computer simulation in 2010 that drew upon language from the Bible to recreate the parting of the Red Sea. Drews echoed Nof's findings, suggesting that a strong wind may very well explain the temporarily receding shoreline, according to NPR.
Biblical scholars, however, contend that the crossing of the Israelites out of Egypt didn't take place on the Red Sea at all, but rather a Sea of Reeds, the location of which is disputed.
Samson the Sociopath
Credited with feats of strength including slaying a lion and moving the gates of Gaza, Samson also exhibited almost all of the symptoms of Antisocial Personality Disorder. Altschuler points to the following tales of Samson's questionable behavior as evidence for his diagnosis: "his failure to conform to social norms by torching the Philistines fields and then refusing arrest; ... his impulsivity as evidenced by his burning of the Philistine fields; his repeated involvement in physical fights, bullying, and cruelty to animals; ... and his lack of remorse, as evidenced by his gloating after the killing of 1,000 men."
In Altschuler's telling, Samson isn't so much a hero as he is a menace who was eventually brought under control by his fellow Israelites.
Read more at Discovery News
Oct 17, 2013
Stonehenge Treasures Reveal Worshippers' Sophistication
Housed in a large, specially-designed high security and humidity-controlled exhibition facility inside the Wiltshire Museum in Devizes, 15 miles north of the megalithic stone circle, the objects make England’s largest collection of early Bronze-Age gold.
“Stonehenge is an iconic monument, but this is the first time that such a wide range of high status objects from the spectacular burials of the people who used it, has ever been put on permanent display,” David Dawson, director of the Wiltshire Museum.
Most of the 500 Neolithic objects on show were unearthed within a half mile radius of Stonehenge, including 30 gold pieces which were excavated in 1808 from a burial mound known as Bush Barrow.
Found by William Cunnington, Britain’s first professional archaeologist, the objects became known as the crown jewels of the “King of Stonehenge.”
Overlooking Stonehenge itself, the burial indeed contained the skeleton of a chieftain who lived almost 4,000 years ago. He was buried in regal splendor with the objects that showed his power and authority.
Among the treasures on display are a magnificent bronze dagger with a gold covered haft, a golden sheath for a dagger, a ceremonial axe, gold beads, necklaces, earrings, pendants and other gold jewellery, a unique jet disc (used to fasten a luxury garment), rare traces of ancient textiles and two of the finest prehistoric flint arrow head ever found.
“Many of the items may well have been worn by Bronze Age priests and chieftains as they worshiped inside Stonehenge,” Dawson said.
“Axes and daggers on display are identical to images of weapons carved into the giant stones of Stonehenge itself,” he added.
The exhibition’s centerpiece is the beautifully decorated gold lozenge found on the chest of the “King of Stonehenge.”
Although the purpose of the gold lozenge remains a mystery — interpretations have ranged from an elaborate button to an astronomical instrument — its precise decorations, made of impressed lines, reveals a detailed knowledge of mathematics and geometry.
“All this was done with the naked eye as there were no magnifying glasses or microscopes,” Dawson told London’s Times.
Read more at Discovery News
Is Being a Good Samaritan a Matter of Genes?
In Fort Lauderdale, Fla., after a woman lost control of her car on an Interstate freeway and flipped into a water-filled ditch, a man jumped in to rescue her from drowning. In Arizona, after a community college student lost a wallet containing her cash, credit cards, student ID and immigrant work permit, an unidentified person found it and dropped it off at her school's office. In Oklahoma, after a teenage skateboarder tumbled from his board and suffered a concussion, a man he didn't know found him by the side of the road and took him to get help.
What motivates people to stop and help others that they didn't previously know, with no apparent benefit to themselves?
Traditionally, we've viewed people who engage in prosocial behavior -- that is, voluntary acts performed to benefit others or society as a whole -- as being motivated by moral character or spiritual beliefs. But in recent years, increasing evidence has emerged to suggest that the tendency to be a do-gooder may be influenced by genes.
In a newly-published study in the journal Social Neuroscience, for example, researchers found that a single variation in a genotype seems to affect whether or not a person engages in prosocial acts. Individuals who have one variation of the genotype have a tendency toward social anxiety -- that is, unease around other people, and are less inclined to help others in ways that involve personal interaction.
Those who have another variation, in contrast, not only were less anxious, but also were more likely to be helpful. The genetic region involved is 5-HTTLPR, which regulates transport of serotonin, a neurotransmitter chemical in the brain. The researchers studied the genomes of 398 college students, and asked the subjects to fill out a questionnaire to provide information about their behavior and anxiety levels.
University of Missouri social psychologist Gustavo Carlo, one of the study's co-authors, said that the the genotype variation is just one "indirect pathway" that could lead a person to being a Good Samaritan. Another potential influence, he said, is the brain's ability to use dopamine, another brain chemical. Other genetic variations in brain chemistry may play a role as well.
"This is a really exciting area for research," Carlo said. "There are a lot of studies being done right now that focus on the micro-level biological processes associated with altruistic behavior."
Co-author Scott F. Stoltenberg, a researcher at the University of Nebraska-Lincoln's Behavior Genetics Laboratory, says the findings build on previous studies that suggest a link between relative levels of anxiety and prosocial behavior.
"It makes sense that people who have less social anxiety are more likely to help out," Stoltenberg explained. "When they're confronted with a situation where another person needs help, they don't have a problem going over to them and engaging." A person with social anxiety, in contrast, might experience so much discomfort that he or she would avoid the encounter.
Both serotonin and dopamine are neurotransmitters related to the sensations of pleasure and satisfaction, which may explain why people who perform selfless acts of generosity report that they feel good as a result.
Carlo cautioned that the study's findings don't necessarily mean that people with a genetic predisposition toward anxiety also lack empathy, the ability to care about others. While it may be more difficult for them to engage in public acts of prosocial behavior, they may instead make anonymous contributions to a person in need, or help in some other way that doesn't require personal interaction.
Why humans developed the capacity to be Good Samaritans is another widely-debated question. In the 1970s, evolutionary biologist Richard Dawkins, a believer in the notion that "genes are selfish," argued that prosocial behavior existed to ensure genetic continuity. His view was influenced by studies suggesting that organisms were most likely to help their own kin.
Read more at Discovery News
Out-of-Africa Skull May Trim Human Family Tree
The skull, dated to nearly 1.8 million years ago, is the earliest known human-like species outside of Africa ever found, according to a study published in the latest issue of Science.
It belonged to an adult male of the species Homo erectus, a.k.a. "Upright Man" and is called "Skull 5" because it was the fifth set of hominid remains recovered at the archeological site, Dmanisi, located in the Caucausus of the Republic of Georgia.
"All the Dmanisi individuals are around 1.77 million years old," co-author Christoph Zollikofer from the Anthropological Institute and Museum in Zurich, Switzerland, told Discovery News. "What is very special about Dmanisi Skull 5 is that it is the only known completely preserved and undeformed skull of an adult individual from these remote times."
Tim White, a professor of Integrative Biology at the University of California at Berkeley, told Discovery that these early members of our genus were fairly short in stature with large, projecting faces, big teeth and small brains. The latter confirms that big brains weren't needed to get humans out of Africa.
"They walked on two legs, and if you could look in on them, you might see them using primitive tech- stone tools- to remove meat and marrow from animal bones," said White. "You might also see them being killed and hauled off by a carnivore." (All five were found in underground dens where carnivores appear to have dragged their carcasses.)
Zollikofer, lead author David Lordkipanidze from the Georgian National Museum, and colleagues noted that the remains for the five Dmanisi individuals were very different. They attribute that to just normal variation within a single population. Moreover, they extended their comparisons to other documented Homo genus species and concluded that the variation was again reasonable for a single species.
They propose that Homo habilis, Homo rudolfensis, Homo ergaster and other early hominids from the same time were all misnamed and were really just members of the species Homo erectus. This bold theory would nearly wipe clean many early hominids.
Discovery News contacted multiple experts in early human history for their views, and received an earful of passionate, mixed opinions.
White and Dean Falk, an anthropologist at Florida State University, support the paper's conclusions. As Falk said, "I see no reason not to accept the authors' claim that the specimens all belong to one highly variable and highly sexually dimorphic species."
He further thinks that, although the Dmanisi individuals' brains were small, they were still in the process of slowly evolving into larger brains. That is significant, as some earlier studies have proposed that brain size suddenly took off around 2 million years ago.
Darren Curnoe, an associate professor in the School of Biological, Earth & Environmental Sciences at the University of New South Wales; Chris Stringer of the Natural History Museum, London; and Ian Tattersall of the American Museum of Natural History support the broader significance of the Dmanisi fossils, but doubt that all of the early Homo fossils can reasonably be lumped into an evolving Homo erectus lineage.
Tattersall said, "Paleoanthropologists are having a hard time letting go of the old idea that human evolution was a linear process, but fossils like this one from Dmanisi are making it ever clearer that hominid history has been one of diversity and evolutionary experimentation with the hominid potential."
Read more at Discovery News
Weird Out Of Whack Exoplanetary System Discovered
The Kepler observatory can detect these oscillations, much like it detected dips in target stars’ light due to planets passing by, or transiting, relative to the telescope’s line of sight.
Working both types of observations, scientists have now found the first multi-planet system that is tilted out of alignment with the host star.
“When we found this system, it was a major surprise. They didn’t form this way,” astronomer Daniel Huber, with NASA’s Ames Research Center in Moffett Field, Calif., told Discovery News.
The star, known as Kepler-56, is about 45 degrees out of alignment from the orbital plane of a pair of planets, which circle their parent star in 10- and 20 days respectively. Trying to determine what elbowed the planets out from the equatorial plane of their star led Huber and colleagues to a third, non-transiting, massive companion, which could be another planet or a star.
“We think it’s responsible for causing this misalignment,” Huber said.
The third, outer companion is inclined to the orbital plane of the inner planets. Scientists suspect its torque is tilting the orbital plane of the inner planets, with respect to the equatorial plane of the parent star.
Follow-up ground observations are underway to figure out the third body’s orbit and size, information scientists need to determine whether it is a planet, a brown dwarf star or another type of star.
“That is still a bit of an open question, but for the general conclusion of the theory of how this system formed it doesn’t really matter whether it’s a star or a planet. It just matters that you have a more massive companion in this outer orbit which can tilt the inner ones, which are much less massive,” Huber said.
The research has implications for understanding how planetary systems form and evolve. It also may help solve a long-standing mystery about how some giant planets settled into orbits far closer to their host stars than Mercury orbits the sun.
These so-called hot-Jupiters were the first planets discovered beyond the solar system.
“Some kind of dynamically disruption must have happened a long time ago that caused a planet to migrate so close to its host star,” Huber said.
The new research shows orbital upheavals are not just limited to hot-Jupiter systems.
Read more at Discovery News
Subscribe to:
Posts (Atom)