Study suggests Neanderthals not the only one humans bred with

May 13, 2010 By Leave a Comment

London, May 13 (ANI): A new study has found that Neanderthals were not the only other Homo species early Homo sapiens mixed with.

João Zilhão at the University of Bristol, UK, suggests H. sapiens migrated from Africa to meet and interbred with other Homo species that have now become extinct.

Swedish biologist Svante Svante Pääbo”s team at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany have found the first definitive evidence of interbreeding.

They reported last week that the genome of humans today is roughly 1 to 4 per cent Neanderthal.

The fact that all non-Africans have this percentage, suggests that H. sapiens and Neanderthals interbred sometime between 100,000 and 45,000 years ago, after the first humans left Africa but before they split into regional populations.

Another genetic study confirmed the suggestion made by Svante Pääbo”s team.

Jeffrey Long at the University of New Mexico in Albuquerque presented results from nearly 100 modern human populations at a meeting of the American Association for Physical Anthropologists in April.

The experts found proof that Eurasians became genetically diverse by breeding with other Homo species after they left Africa, reports New Scientist.

Also, they observed a spike in genetic diversity in Indo-Pacific peoples, dating to around 40,000 years ago. Again, it”s unlikely the diversity came from H. sapiens interbred with Neanderthals, as the latter never travelled that far south.

Meanwhile, Zilhão”s team in Portugal discovered the 25,000-year-old bones of a child they are convinced is a human-Neanderthal hybrid. Zilhão says fossils from Romania and the Czech Republic also bear Neanderthal features, though others dispute this.

Moreover, decorative artefacts characteristic of humans have cropped up at Neanderthal sites, dated to around the time of contact with humans in Africa and the Middle East. Further east, 40,000-year-old human bones from a cave near Beijing, China, have features that recall other Homo species, says Erik Trinkaus of Washington University in St Louis, Missouri.

In March, Pääbo”s team reported the discovery of DNA from a hominin that is probably neither human nor Neanderthal that lived 50,000 to 30,000 years ago in a cave in southern Siberia. They dubbed the creature X-woman, and sequencing machines are already decoding its genome, says Pääbo”s colleague Ed Green of the University of California, Santa Cruz.

Green does not wish to dismiss the idea that X-woman or its kind have bred with humans. (ANI)

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Neanderthals might have interbred with modern humans

April 21, 2010 By Leave a Comment

London, Apr 21 (ANI): Archaic humans such as Neanderthals interbred with the ancestors of modern humans twice, leaving their genes within the DNA of people today, according to a genetic analysis of nearly 2,000 people from around the world.

The discovery adds important new details to the evolutionary history of the human species and it may help explain the fate of the Neanderthals, who vanished from the fossil record about 30,000 years ago.

“It means Neanderthals didn”t completely disappear,” Nature quoted Jeffrey Long, a genetic anthropologist at the University of New Mexico, as saying.

He insisted that there is a little bit of Neanderthal leftover in almost all humans.

The researchers arrived at that conclusion by studying genetic data from 1,983 individuals from 99 populations in Africa, Europe, Asia, Oceania and the Americas.

Sarah Joyce, a doctoral student working with Long, analyzed 614 microsatellite positions, which are sections of the genome that can be used like fingerprints.

She then created an evolutionary tree to explain the observed genetic variation in microsatellites.

The best way to explain that variation was if there were two periods of interbreeding between humans and an archaic species, such as Homo neanderthalensis or H. heidelbergensis.

“This is not what we expected to find,” said Long.

Using projected rates of genetic mutation and data from the fossil record, the researchers suggest that the interbreeding happened about 60,000 years ago in the eastern Mediterranean and, more recently, about 45,000 years ago in eastern Asia.

Those two events happened after the first H. sapiens had migrated out of Africa, said Long.

However, his group failed to find evidence of interbreeding in the genomes of the modern African people included in the study.

The researchers suggest that the population from the first interbreeding went on to migrate to Europe, Asia and North America.

Then the second interbreeding with an archaic population in eastern Asia further altered the genetic makeup of people in Oceania.

The paleontological record also is producing fossils that complement such interbreeding theories.

The study was presented at the annual meeting of the American Association of Physical Anthropologists in Albuquerque, New Mexico. (ANI)

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Slow mind means more creativity

March 31, 2010 By Leave a Comment

London, March 31 (ANI): A slow brain can nurture more creative ideas, a new American research has suggested.

Rex Jung at the University of New Mexico in Albuquerque and his team discovered that creativity is associated with low levels of the chemical N-acetylaspartate, found in neurons, and seems to promote neural health and metabolism.

But neurons constitute the brain”s grey matter – the tissue long thought to be linked with thinking power, rather than creativity. Consequently, Jung is now focusing his creativity studies on white matter, which largely comprises the fatty myelin sheaths that wrap around neurons. Less myelin signifies the white matter has a lower “integrity” and transmits information more slowly.

Numerous recent studies have suggested that white matter of high integrity in the cortex, which is linked to higher mental function, means increased intelligence.

However, when Jung analysed the connection between white matter and creativity, he came across something very different.

For the study, Jung selected 72 volunteers and used diffusion tensor imaging, which measures the direction in which water diffuses through white matter – an indication of its integrity.

The subjects” capacity for divergent thinking – a factor in creativity that includes coming up with new ideas – had already been tested.

Jung saw that the most creative people had lower white-matter integrity in a region connecting the prefrontal cortex to a deeper structure called the thalamus, compared with their less creative peers.

Jung believes slower communication between some areas may actually make people more creative.

“This might allow for the linkage of more disparate ideas, more novelty, and more creativity,” New Scientist quoted Jung, as saying.

According to Jung, creativity and intelligence can still go hand in hand. Each appears to be controlled by white matter in a different region. Thus, theoretically, there”s no reason why someone might not have high integrity in the cortex, producing intelligence, but low integrity between the cortex and deeper brain regions, leading to creative thinking.

He said: “They appear to function relatively independently.”

The study has appeared in the open access journal PLoS ONE. (ANI)

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Why girls can’t resist the geeks

August 20, 2009 By Leave a Comment

London, August 20 (ANI): In what may help understand why geeks get the girls, a study on the Satin Bowerbird’s mating rituals has for the first time directly linked a male’s cognitive performance to his luck with the ladies.

“Males that are better problem-solvers are mating with more females,” New Scientist magazine quoted says Jason Keagy, a behavioural ecologist at the University of Maryland in College Park, as saying.

The researcher points out that males construct elaborate shrines – bowers – to woo females, who judge them by the quality of their ornately decorated grass bowers, and elaborate mating dances.

Keagy says that both features let males to show off their smarts.

For their study, Keagy and colleagues developed a bowerbird IQ test to record which males attracted the most females over two breeding seasons.

The tests required males to remove red blocks, a colour they find odious, from their bowers in two different ways.

In one test, the researchers placed blocks under a clear plastic container, which birds had to knock off before removing the blocks. In the second test, they presented males with an unmoveable red block screwed into the ground.

The researchers observed that the smartest males determined that covering the block with leaves was the best way to obscure it.

According to Keagy, one possibility is that the tests reflect on duties connected to mating, and males that are better at problem-solving may construct more appealing bowers.

As to why do females favour more intelligent males, the researcher says that intelligence seems to act as an indicator of the genetic quality of a potential mate, and the genes he will pass onto his offspring.

“A male that has a well functioning brain is probably going to be good at surviving. It’s almost like a way of interpreting all this information about the genetic quality of a male,” Keagy says.

Two recent studies conducted by Geoffrey Miller, of the University of New Mexico in Albuquerque, and his wife Rosalind Arden, of King’s College in London, have also shown that more intelligent men among Vietnam veterans experienced fewer health problems, such as hernias and cataracts, than less intelligent men.

They also found performance on intelligence to be associated with healthy sperm in a smaller subset of vets.

A research article describing Keagy’s study has been published in the journal Animal Behaviour. (ANI)

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Birds love soaking in the sun as much as humans do

August 19, 2009 By Leave a Comment

London, Aug 19 (ANI): Its not just humans who enjoy soaking up in the sun on the beach, for birds are fond of sunbathing too, according to the bird charity RSPB.

The charity revealed that they receive almost 100 calls during hot spells from people who are concerned with watching birds lying with their feathers and wings exposed to the sun.

However, they have said that such state of rest is not problematic, as the animals simply sunbath in this position.

Studies from the University of New Mexico have suggested that birds sun themselves to soothe their skin after heavy rain, which can cause them to suddenly lose their feathers.

The researchers believe that the sun helps straighten the birds’ feathers, and helps the preen oil to spread through.

“People become concerned about these birds, because they seem to have a glazed expression in their eyes, because they are not focusing on anything, because they are entranced by the sun,” the Telegraph quoted Gemma Rogers from the RSPB as saying.

She added: “They don’t let themselves overheat at all. The feathers would protect them as well, so I don’t think they need the factor 30.”

However, the biggest concern, according to her, is that the predators will attack while the birds enjoy a peaceful moment in the sun.

“They are on the ground, they have their heads up, their legs wide open, but usually they fly away once a predator approaches. Their hearing is very acute as well, so even if they aren’t focusing they will hear something coming,” she said.

While blackbirds are the most commonly spotted sunbathers, pigeons and sparrows also enjoy the sun.

Rogers said that sparrows apparently enjoy going to the beach as much as humans.

“Sparrows often find a hot sandy area as well to have a sand or dust bath. That looks really strange. They bed themselves down and get in there and cover their feathers,” she said. (ANI)

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Hearing the music of the brain made possible

July 8, 2009 By Leave a Comment

London, July 7 (ANI): An American expert has created a technique to turn the human brain’s flickering activity into music.

Philosopher Dan Lloyd at Trinity College in Hartford, Connecticut, believes that listening to scans may give new insights into the differences and similarities between normal and dysfunctional brains.

He points out that brain scans created using functional MRI consist of a series of images in which different areas light up with varying intensity at different times, and that these can be used to determine which parts of the brain are active during a particular task.

Lloyd revealed that to turn such scans into music, he identified regions that become active together, and assigned each of those groups a different pitch.

He later created a software program to analyse a series of scans and generate the notes at those pitches.

The researcher has revealed that each note is played at a volume that corresponds to the intensity of activity.

Upon feeding the software a set of scans of his own brain, taken as he switched between driving a virtual-reality car and resting, Lloyd observed that he could the switch-over in the sounds.

He then gave the software scans taken from volunteers with dementia and schizophrenia, and from healthy volunteers.

He found that the brains of people with schizophrenia switched between low and high activity more erratically than those of healthy subjects, allowing the two types of brain to be distinguished by sound alone.

Even though this difference can be seen by looking at the images, Lloyd’s collaborator Vince Calhoun, at the University of New Mexico in Albuquerque, says that there are variations in the music from people with schizophrenia that are not visually obvious.

“It almost sounds like there is more background warbling,” he says.

The researcher believes that such “unsteady rhythms and cadences” may be indicative of dysfunction in the brain.

Lloyd further observed that the sounds and rhythms in the brains of people with dementia also distinguished from those in the brains of healthy volunteers.

He is now keen on exploring the aesthetic aspects of brain music.

“It’s not quite like composed sound but it’s not random either, it’s ‘almost music’. My students are putting it on their playlists,” he said. (ANI)

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‘Creativity chemical’ in the brain biased towards smarter people

May 21, 2009 By Leave a Comment

London, May 21 (ANI): High levels of a so-called “creativity chemical” in a certain part of the brain is what boosts creativity in smart people, revealed a study.

People with average intelligence, on the other hand, are less ingenious because of low levels of the same chemical.

N-acetyl-aspartate, which is found in neurons, is apparently linked with neural health and metabolism.

Already, Rex Jung at the University of New Mexico in Albuquerque and his colleagues knew that high levels of NAA in the left parieto-occipital lobe, which coordinates sensory and visual information, were linked with intelligence.

In order to know whether NAA also plays a role in creativity, the researchers recruited 56 men and women aged 18 to 39, and measured the NAA levels in various regions of their brains.

The researchers also tested the volunteers’ general intelligence and, more specifically, their capacity for divergent thinking-a factor in creativity that includes coming up with novel ideas, such as new uses for everyday objects.

On the whole, volunteers’ creativity scores were concurrent with levels of NAA in a brain region called the anterior cingulate gyrus (ACG), which regulates the activity of the frontal cortex – implicated in higher mental functions.

However, while low levels of NAA in the ACG correlated with high creativity in people of average intelligence, the reverse was found to be true in people with IQs of above 120.

Jung predicted that if there is less NAA to regulate frontal cortex activity in “average” brains, they are freer to roam and find new ideas.

However, in highly intelligent people, tighter control over the frontal cortex could apparently enhance creativity.

This could be because they are more likely to come up with new ideas anyway, and the tighter control allows them to “fine-tune” that ability.

“People say you have to let your mind wonder freely to be creative. For people of average intelligence, perhaps it’s true that you need to utilise more areas of your [frontal cortex] for something truly novel and creative to emerge, but in more intelligent folks, there’s something different going on,” New Scientist magazine quoted Jung as saying.

In his opinion, the findings could shed new light on what made the brains of creative geniuses like Einstein tick. (ANI)

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Melting minerals found to be source of Tanzanian volcano’s carbon-based lavas

May 7, 2009 By Leave a Comment

Washington, May 7 (ANI): Scientists studying the world’s most unusual volcano in Tanzania have discovered the reason behind its unique carbon-based lavas, attributing them to an extremely small degree of partial melting of typical minerals in the earth’s upper mantle.

Although carbon-based lavas, known as carbonatites, are found throughout history, the Oldoinyo Lengai volcano, located in the East African Rift in northern Tanzania, is the only place on Earth where they are actively erupting.

The lava expelled from the volcano is highly unusual in that it contains almost no silica and greater than 50 percent carbonate minerals.

Typically, lavas contain high levels of silica, which increases their melting point to above 900 degree Celsius.

The lavas of Oldoinyo Lengai volcano erupt as a liquid at approximately 540 degrees C. This low silica content gives rise to the extremely fluid lavas, which resembles motor oil when they flow.

“Since the volcano was under magma pressure during the eruption, we were able to collect pristine samples of the volcanic gases, with minimal air contamination,” said Tobias Fischer, volcanologist at the University of New Mexico.

The pristine samples collected during a 2005 eruption offered the scientists a deeper look at the processes taking place in the earth’s upper mantle.

The geochemical analyses revealed that magma from the upper mantle below both the oceans and continents is a uniform and well-mixed reservoir of “typical” volcanic gases such as carbon dioxide, nitrogen, argon and helium.

The lava expelled from the volcano is highly unusual in that it contains almost no silica and greater than 50 percent carbonate minerals.

Typically, lavas contain high levels of silica, which increases their melting point to above 900 degrees C.

The lavas of Oldoinyo Lengai volcano are comprised of carbonatites, which erupts as a liquid at approximately 540 degrees C.

This low silica content gives rise to the extremely fluid lavas, which resembles motor oil when they flow.

“These finding are significant because it shows that these extremely bizarre lavas and their parent magmas, nephelinites, were produced by melting of a typical upper mantle mineral assemblage without an extreme carbon content in the magma source,” said geochemist Bernard Marty at the Centre de Recherches Petrographiques et Geochimiques in Nancy, France.

“Rather, in order to make carbonatite lavas, all you need is a very low melt fraction of 0.3 percent or less,” he added. (ANI)

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Swimming pool game ‘Marco Polo’ inspiring robot detection

March 19, 2009 By Leave a Comment

Washington, March 19 (ANI): A popular swimming pool game called ‘Marco Polo’ is guiding scientists as to how to make robots that can independently detect and capture other moving targets.

Engineers from Duke University and the University of New Mexico say that the simple pursuit-evasion game is providing them with useful information, which can be used to create such a system that will not only allow robots to “sense” a moving target but intercept it also.
The researchers say that such systems have broad applications, ranging from security systems to track unwanted intruders like enemy ships or burglars, to systems that create radiation or environmental hazard maps, or even track endangered species.

‘Marco Polo’ players include a pursuer who has to tag another person, who then becomes the new pursuer.

The pursuers, who must keep their eyes closed, can call out ‘Marco’ at any time, and everyone else must respond by saying ‘Polo’. This is how the pursuers can gradually estimate where the targets are in the pool, and where they might go.

“Games give us a good way of making these highly complex problems easier to visualize,” said Silvia Ferrari, assistant professor of mechanical engineering and materials science at Duke’s Pratt School of Engineering.

Rafael Fierro, associate professor of electrical engineering at the University of New Mexico, added: “Just as in ‘Marco Polo’, we needed to create a way that permits mobile robots to detect other moving objects and make predictions about where the targets might go. When done efficiently, the mobile sensor switches from pursuit mode to capture mode in the shortest amount of time.”

Ferrari has already developed a similar type of algorithm, known as cell decomposition. The researcher has revealed that past experiments with the algorithm allowed a robot to move through space without colliding with stationary obstacles.

The latest experiments included not only robots equipped with camera sensors, but also stationary camera sensors that allowed for “coverage” of all the cells within the space.

“The idea is that multiple sensors are deployed in the space to cooperatively detect moving targets within that space. As the sensor makes more detections, it is better able to predict the likely path of the intruder. The ultimate path taken by the robot sensor is one that maximizes the probability of detection and minimizes the distance needed to capture the target,” Fierro said.

The resarcher say that apart from security and military applications, the new algorithms may also be be used in other ways to detect targets that are not necessarily intruders.

“Targets could be completely different things, like mines or explosives, or chemical or radiation leaks. The robots can use their sensors to keep track of the detected locations and build a ‘map’ to let people know where to go or not to go,” Fierro said.

The algorithms could also be used to help explain natural phenomena, such as the behaviours of the members of a wolf pack as they chase and capture their prey.

The latest experiments, conducted at the University of New Mexico, involved intruders moving in straight lines at a constant speed.

“We are now developing algorithms that will more closely mimic the real world by giving intruders the ability to take evasive actions. The other main issue is to ensure that all the different mobile sensors can communicate with each other at all times and coordinate their activities based on that communication,” Ferrari said.

An article on the research project has been published online in the Journal on Control and Optimization, a publication of the Society for Industrial and Applied Mathematics. (ANI)

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Comedians ‘are introverts’

March 17, 2009 By Leave a Comment

London, Mar 17 (ANI): Comedians are shyer than most other people, claims a new study.

“I guess the stage gives them the opportunity to be what they want to be and may not necessarily represent their daily-life personalities,” New Scientist quoted Gil Greengross, an anthropologist at the University of New Mexico in Albuquerque, as saying.

To reach the conclusion, Greengross and colleague Geoffrey Miller assigned personality tests to 31 professional comedians.

The 60-question test gauged the “big five” classic personality traits: openness to experience, conscientiousness, extroversion, agreeableness and neuroticism.

The comedians rated their agreement with statements such as “I think it’s interesting to develop new hobbies”, “At times I have felt bitter and resentful”, and “Poetry has little or no effect on me”.

Then, the researchers compared their scores to those of 400 university students and 10 humour writers.

On average, the professional comics scored highly on openness to new experience compared with students, yet lower than comedy writers.

Also, the volunteers had lower scores on average for conscientiousness, agreeableness and extroversion, compared with the other groups. The team noticed no difference in neuroticism scores.

“The fact is that a lot of the time they spend by themselves. They also travel a lot. That might explain why they do have introverted personalities,” said Greengross, who performed the study as part of a dissertation on the evolutionary value of humour.

The study has been published in the journal Personality and Individual Difference. (ANI)

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Ancient Americans became chocoholics 400yrs earlier than believed

February 4, 2009 By 1 Comment

Washington, February 3 (ANI): Ancient Americans might have walked hundreds of miles to procure chocolates, for a new study suggests that the practice of drinking chocolate had spread in northern New Mexico by A.D. 1000 to 1125, about 400 years earlier than chocolate was thought to have reached the US.

The discovery based on the study of chemical residues found on pottery jar shards excavated from trash mounds at Pueblo Bonito, an ancient residential complex in Chaco Canyon, suggests a vast trade network helped deliver chocolate from Central America, where the seeds of the cacao tree were first transformed into beverages some 3,000 years ago.

“That’s a long way to go for something that you don’t need for survival, [something] that’s more of a delicacy,” National Geographic quoted Patricia Crown, an anthropologist at the University of New Mexico and co-author of the new study, as saying.

Appearing in the journal Proceedings of the National Academies of Science, the study suggests that the closest cacao source might have been 1,200 miles (2,000 kilometres) away.

“It suggests that the only way for this material to get (to New Mexico) is (that) either people from Chaco walked down to get it, or it was traded hand to hand from Mesoamerica to Chaco, or people from Mesoamerica came up and traded it,” Patricia said.

“There are a lot of questions about how that exchange worked. But once you had that connection and had tasted chocolate, you probably wanted to keep that exchange going, whatever the mechanism,” she added.

Patricia and her co-author Jeffrey Hurst, a biochemist at the Hershey Foods Technical Center, have revealed that they found traces of theobromine, a compound that is the principal base of cacao beans and chocolate, on the pottery shards.

The researchers said that many pottery samples in museums around the US might someday yield evidence of additional cacao use, and perhaps an even wider trade network for chocolate.

Louis Grivetti, professor of nutrition at the University of California, Davis, said that the study confirmed previous evidence of trade between Central America and Mexico, and “changes all the chronologies regarding cacao use in the Americas.”

“It’s one of the most exciting reports on the history of chocolate of the past 10 to 15 years,” he said. (ANI)

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Ancient Americans became chocoholics 400yrs earlier than believed

February 3, 2009 By 1 Comment

Washington, February 3 (ANI): Ancient Americans might have walked hundreds of miles to procure chocolates, for a new study suggests that the practice of drinking chocolate had spread in northern New Mexico by A.D. 1000 to 1125, about 400 years earlier than chocolate was thought to have reached the US.

The discovery based on the study of chemical residues found on pottery jar shards excavated from trash mounds at Pueblo Bonito, an ancient residential complex in Chaco Canyon, suggests a vast trade network helped deliver chocolate from Central America, where the seeds of the cacao tree were first transformed into beverages some 3,000 years ago.

“That’s a long way to go for something that you don’t need for survival, [something] that’s more of a delicacy,” National Geographic quoted Patricia Crown, an anthropologist at the University of New Mexico and co-author of the new study, as saying.

Appearing in the journal Proceedings of the National Academies of Science, the study suggests that the closest cacao source might have been 1,200 miles (2,000 kilometres) away.

“It suggests that the only way for this material to get (to New Mexico) is (that) either people from Chaco walked down to get it, or it was traded hand to hand from Mesoamerica to Chaco, or people from Mesoamerica came up and traded it,” Patricia said.

“There are a lot of questions about how that exchange worked. But once you had that connection and had tasted chocolate, you probably wanted to keep that exchange going, whatever the mechanism,” she added.

Patricia and her co-author Jeffrey Hurst, a biochemist at the Hershey Foods Technical Center, have revealed that they found traces of theobromine, a compound that is the principal base of cacao beans and chocolate, on the pottery shards.

The researchers said that many pottery samples in museums around the US might someday yield evidence of additional cacao use, and perhaps an even wider trade network for chocolate.

Louis Grivetti, professor of nutrition at the University of California, Davis, said that the study confirmed previous evidence of trade between Central America and Mexico, and “changes all the chronologies regarding cacao use in the Americas.”

“It’s one of the most exciting reports on the history of chocolate of the past 10 to 15 years,” he said. (ANI)

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