A clenched human fist (Photo: Ralpharama via Wikimedia Commons)

The human hand is a sophisticated work of art and science. Refined through centuries of evolution, hands enable us to perform unique functions which help us to not only survive but also to thrive as a species.

New research suggests the evolution of the modern human hand may be due to a very basic need: for use as a weapon.

In a study published in The Journal of Experimental Biology,  University of Utah scientists theorize human hands evolved their unique square palms and long thumb in order to stabilize the fist, providing a built-in compact club early humans could use in combat.

An impassioned conversation with a colleague inspired David Carrier to pursue research on the matter.

In the course of their conversation, Frank Fish, an expert in biomechanics, formed a fist and said, “I can hit you in the face with this, but that is not what it evolved for.”

Fish’s proclamation made Carrier stop and think. While the human hand evolved to allow great dexterity, according to Carrier, a chimpanzee can also manipulate its hands in a way that would give it greater manual dexterity, but they still may not necessarily be able to form their hands like humans do.

Modern chimpanzees, according to Carrier, have long palms and fingers with a short thumb, while the human palm and fingers are much shorter and the thumb longer and stronger.

Three views of a clenched human fist show how we buttress the fist to reduce the chance of hand injury when punching. (Photo: Denise Morgan for the University of Utah)

This difference brought on by evolution, allows us to clench our hand into a fist whenever we fold our thumb across the fingertips.  A chimpanzee’s fingers, on the other hand, forms the shape of what he describes as an open doughnut shape when curled.

Carrier said that he wondered if the tightly-packed human fist provides some internal support to our fingers in order to protect them from being damaged during an altercation and if it also provides humans with the ability to deliver a more powerful blow against their opponents, as compared to the slap of an open hand.

Carrier and Morgan decided to find out whether hands are more effective when balled into a fist or used as an open-handed slap.

“Fortunately, Michael had a lot of experience with martial arts and he knew people who were willing to serve as subjects,” said Carrier.

First, the test subjects were asked to smack a punching bag with their hands formed into a wide variety shapes; from the open-handed slap to the tightly-clenched fist, using various styles to deliver the blows, such as over the arm, sideways and head on. As each of the fighters walloped their punching bag foe, the researchers would measure the force of each impact.

But after looking at the results of that experiment, the researchers were surprised to see the punch did not deliver more force per blow.

“In terms of the peak forces or the impulse, it did not matter whether the subjects were hitting with a clenched fist or open palm,” said Carrier.

Fists formed only by a human hand can be used as a weapon without causing injury to the person delivering the punch. (Photo: Courtney “Coco” Mault/Wikipedia Commons via Flickr)

Morgan and Carrier then wanted to find out whether supporting the hand, by curling the fingers and thumb, stiffens the structure of the hand. Asking their test subjects to form their hands into various fist shapes, the researchers measured the rigidity of the first knuckle joint of their subject’s index finger, first with the support of the thumb over the finger and then without the support of the thumb. They found the knuckle joint was four times more rigid when supported by the thumb.

Next, the researchers measured the amount of force that the fighters could deliver through the fist surface of their index and middle fingers. Again, they found that by using the thumb in forming a fist, the test subjects doubled the delivered force by transmitting it to the wrist through the palm bones of the thumb and the index finger.

The results of their experiments led Carrier and Morgan to conclude  the square-shaped palms of today’s humans are perfectly proportioned to stiffen into a fist to be used as a weapon that delivers powerful punches without injuring ourselves.

DNA structure (Image: Michael Ströck via Wikimedia Commons)

Prevailing wisdom holds that every cell in the body contains identical DNA.

But Yale researchers say they examined skin stem cells and found a number of genetic variations in a variety of skin tissue.

The study, published in Nature, could have profound implications for genetic screening.

“We found that humans are made up of a mosaic of cells with different genomes,” said lead author Flora Vaccarino, M.D., from the Yale Child Study Center. “We saw that 30 percent of skin cells harbor copy number variations (CNV), which are segments of DNA that are deleted or duplicated. Previously it was assumed that these variations only occurred in cases of disease, such as cancer. The mosaic that we’ve seen in the skin could also be found in the blood, in the brain, and in other parts of the human body.”

It’s been long believed that all of our cells have the very same DNA sequence.

Other scientists conducting similar genetic research have theorized the DNA sequence of a cell could be modified during the cell’s development – when DNA is copied from a mother cell to a daughter cell.  These many changes to a cell’s original DNA, they say, could affect an entire group of genes.

While it’s difficult for scientists to actually test these theories, the Yale researchers say they have been able to do so for their new study.

To reach their findings, the research team used whole genome sequencing – a genome is a complete set of hereditary information – to study induced pluripotent stem cells (iPS), which are genetically engineered stem cells developed from a mature-differentiated cell.

The team grew cells taken from the inner upper arms of people from two families. For two years, the researchers examined their genetically engineered iPS cell lines, compared them to the original skin cells, and noted any differences between each cell’s DNA.

The team also conducted further experiments to see what might have caused the differences to occur.

While the research in the project outlined in this recent study was limited to finding variations in DNA sequencing within skin cells, the Yale team is continuing its studies to see if these same DNA variations can be found in developing brain cells of animals as well as humans.

Speculation is mounting that physicists at the world’s largest atom smasher plan to announce Wednesday that they’ve pretty much found the most sought-after particle in modern science.

Experiments at the Large Hadron Collider in Europe could establish the existence of the Higgs boson, a particle believed to be a building block of the universe. (AP/CERN)

Scientists in Geneva reportedly believe they have enough evidence to confirm the existence of the Higgs boson, an elusive particle believed to give all objects mass.

The discovery could reshuffle our understanding of why matter has mass which, combined with gravity, gives an object its weight.

On Monday, scientists working with the US Department of Energy’s Tevatron collider at the Fermilab in Chicago announced their data  pointed to the existence of the Higgs boson, but stopped short of claiming a discovery.

European scientists might go a step further Wednesday.

According to the Associated Press, researchers at the European Organization for Nuclear Research (CERN), say that they have compiled data that show the “footprint and shadow” of the particle, even though it has never actually been glimpsed.

Two independent teams of physicists have been working to prove the Higgs boson exists, and are expected to stop short of announcing they’ve actually found the elusory particle when they make their big announcement on Wednesday.

Rob Roser, who leads the search for the Higgs boson at the Fermilab in Chicago, compared the latest development to finding the fossilized imprint of a dinosaur, telling the Associated Press, “You see the footprints and the shadow of the object, but you don’t actually see it.”

However, while scientists in Geneva might announce the discovery of  an entirely new particle, Nature reports more data is needed to prove whether the new find actually is the long-awaited “God Particle.”

The magazine quotes one member of the team as saying, “Without a doubt, we have a discovery…It is pure elation!”

(Written by Dora Hasan Mekouar, Science World Online Editor)

Stonehenge (Photo: Rupert Jones via Flicker/Creative Commons)

As crowds converged on Stonehenge last week for the summer solstice, a new study based on 10 years of archaeological investigations revealed the ancient monument was built to unify all of the people of Britain.

For years, experts have tried to uncover the many mysteries of Stonehenge, one of the world’s most famous prehistoric sites, which was built about 4,500-to- 5,000 years ago in South Central England.

Stonehenge has long been thought to be a prehistoric observatory, a sun temple, a place of healing and a temple of the ancient druids.  But a team of archeologists, working on the Stonehenge Riverside Project, rejected all those possibilities.

Summer solstice sunrise at Stonehenge (Photo: AP Photo/Lefteris Pitarakis)

According to the research team, the Neolithic and Bronze Age structure was built after years of struggle and conflict between the people of eastern and western Britain.

The stones symbolize the ancestors of different farming communities in Great Britain, according to the researchers.

The building of Stonehenge also corresponded with a shift of identity for the British.

“When Stonehenge was built, there was a growing island-wide culture – the same styles of houses, pottery and other material forms were used from Orkney to the south coast,” said Mike Parker Pearson,  a member of the Stonehenge Riverside Project.  “This was very different to the regionalism of previous centuries. Just the work itself, requiring everyone literally to pull together, would have been an act of unification.”

The construction of Stonehenge required thousands of laborers to move the monolithic stones from as far away as west Wales.  Many more people were needed to shape and erect the stones after such a long journey.

Crowd gathers for 2012 Summer Solstice at Stonehenge (AP Photo/Lefteris Pitarakis)

Archeologists believe Stonehenge was built in stages from about 3000 BC to 2000 BC.

The location for Stonehenge wasn’t a random choice,  according to researchers.  The spot had a long-held, special significance to the prehistoric people of Britain.

The research team found that Stonehenge’s collection of stones, which are aligned with the solstices, actually sits on a series of natural landforms that form an axis between the directions of midsummer sunrise and midwinter sunset.

“When we stumbled across this extraordinary natural arrangement of the sun’s path being marked in the land,” says Parker Pearson, “we realized that prehistoric people selected this place to build Stonehenge because of its pre-ordained significance. This might explain why there are eight monuments in the Stonehenge area with solstitial alignments, a number unmatched anywhere else. Perhaps they saw this place as the center of the world”.

The ancient giant griffinfly Meganeura monyi had a wingspan of up to 75 centimeters (Artwork: Dodoni)

Some 300 million years  super-sized insects – some as large as  hawks – swarmed the Earth.  The largest of these mega-insects was a predatory dragonfly-like creature with a wingspan of up to 75 centimeters.

That was during the late Carboniferous- early Permian periods, when the atmosphere was rich with oxygen. But then, 150 million years ago, birds showed up and the downsizing of insects began.

Scientists at the University of California, Santa Cruz believe high concentrations of oxygen in the atmosphere – over 30 percent of the air was 0² versus the 21 percent we have in today’s atmosphere – were responsible for the insects’ large size.

Insects have small breathing tubes instead of lungs, so the higher oxygen levels allowed them to take in and use more of the life-sustaining gas which encouraged their super sizes.

This fossil insect wing (Stephanotypus schneideri) from about 300 million years ago measures 19.5 centimeters. For comparison, the inset (left) shows the wing of the largest dragonfly of the past 65 million years. (Photo: Wolfgang Zessin)

To reach their findings, the scientists examined data from more than 10,500 fossil wing lengths taken from various published records.  They checked the size of the insects versus oxygen levels as they evolved over a period of hundreds of millions of years.

“Maximum insect size does track oxygen surprisingly well as it goes up and down for about 200 million years,” said Matthew Clapham, an assistant professor at UC Santa Cruz, who c0-authored a study published online in Proceedings of the Academy of Science. “Then right around the end of the Jurassic and beginning of the Cretaceous period, about 150 million years ago, all of a sudden oxygen goes up but insect size goes down. And this coincides really strikingly with the evolution of birds.”

With all over those hungry birds around, insects needed to become more maneuverable.  Survival was a driving force in the evolution of flying insects.  As result, the insects became smaller, which allowed them to survive and thrive, while their giant relatives died off.

Another transition in insect size took place more recently, at the end of the Cretaceous period some 90 and 65 million years ago, according to  Clapman and Jered Karr, a UCSC graduate student who co-authored the study.  They think several factors, such as the continued specialization of birds, along with the evolution of bats, and a mass extinction at the end of the Cretaceous period, may be behind this evolutionary transition.  A shortage of fossils from that period has made it difficult for scientists to track insect sizes.

Drawing of the Ichthyornis dispar, a bird from the Late Cretaceous of North America (Artwork: ArthurWeasley via Wikimedia Commons)

“I suspect it’s from the continuing specialization of birds,” Clapham said. “The early birds were not very good at flying. But by the end of the Cretaceous, birds did look quite a lot like modern birds.”

Clapham emphasizes their study wasn’t about determining average insect size during this time period, because the fossil records tended to favor the larger sized insects over the smaller ones, but instead concentrated on changes in the maximum size of insects over time.

“There have always been small insects,” he said. “Even in the Permian when you had these giant insects, there were lots with wings a couple of millimeters long. It’s always a combination of ecological and environmental factors that determines body size, and there are plenty of ecological reasons why insects are small,” said Clapman.

A catastrophic event such as increased volcanism may have contributed to massive extinction event (Photo: National Park Service)

More than 250 million years ago, most life on Earth was wiped out by a catastrophic event called the Permian–Triassic extinction. New research suggests it took our planet 10 million years to recover from what is now known as “The Great Dying.”

The Great Dying took place millions of years earlier than the Cretaceous-Tertiary extinction, which killed off the dinosaurs 65 million years ago. It was also much more devastating, destroying 90 percent of all plants and animals.

Scientists theorize a “perfect storm” of conditions – global-warming, acid rain, ocean acidification and ocean anoxia (loss of oxygen) – followed by a catastrophic event such as increased volcanism, contributed to Earth’s most dramatic and devastating biological crisis.

For some time now, they’ve debated how quickly life on Earth bounced back from this mass extinction. A new article in Nature Geoscience puts that number at 10 million years.

Artist rendering of The Great Dying in which 90 percent of all marine species are thought to have perished. (Image: Lunar and Planetary Institute)

So why did it take our planet so long to recover from this devastating loss of life? Why didn’t life just “bounce back?”

The sheer intensity of this crisis, coupled with the bleak conditions which remained on Earth after that first devastating surge of extinction, are the reasons for the delay, according to the report authors.

These bleak conditions continued, in bursts, for some five-to-six million years after the initial calamity, triggering repeated environmental crises.

“Life seemed to be getting back to normal when another crisis hit and set it back again,” said Michael Benton, one of the report authors who is a professor at England’s University of Bristol. “The carbon crises were repeated many times and then, finally, conditions became normal again after five million years or so.”

Map of the world around the time of the Great Dying (Image: Dr. Ron Blakey via Wikimedia Commons)

While certain groups of marine and land animals recovered quickly to a certain point, they suffered continual setbacks with each of these bursts of dire conditions following the initial crisis because, according to the researchers, their permanent ecosystems were not firmly established.

But after the waves of environmental devastation began to wane, not only did life return to Earth, but much more complex ecosystems were formed, allowing for much more sophisticated life forms which eventually led to human life.

“We often see mass extinctions as entirely negative but in this most devastating case, life did recover, after many millions of years, and new groups emerged,” Benton said. “The event had re-set evolution. However, the causes of the killing – global warming, acid rain, ocean acidification – sound eerily familiar to us today. Perhaps we can learn something from these ancient events.”

Boy checks on his steak (Photo: woodleywonderworks via Flickr/Creative Commons)

Vegetarians and animal right groups may take issue with this, but a new study has revealed that when humans started to include meat in their diets, mothers were able to wean their children earlier, which allowed them to have more children, which in turn helped the human species spread throughout the world.

Researchers from Lund University in Sweden, conducting a comparison study of 67 mammalian species that included humans, apes, mice, and killer whales and others, say they found a solid connection between meat eating and shorter periods of weaning their offspring.

“Eating meat enabled the breast-feeding periods and thereby the time between births to be shortened,” said Elia Psouni, a clinical psychologist and the study’s lead author. “This must have had a crucial impact on human evolution.”

Compared to the mostly plant-eating chimpanzee, man’s closest evolutionary cousin, the study showed that humans tend to breastfeed their young for a shorter average duration, despite having nearly twice the maximum lifespan. Female chimpanzees breastfeed their young for four-to-five years, but humans only do so for an average of two years and four months.

Over the years, a number of researchers tied the human’s relatively shorter breastfeeding period to other aspects such as social and behavioral theories of parenting along with family size.

But this new research shows that breastfeeding for all species generally ends once the brains of the young reach a certain stage of development.

For their study, the Swedish researchers categorized the species into three categories: carnivores, or species whose diets take at least 20 percent of their energy content from meat, herbivores, or species whose diets only consist of plant life, and omnivores, or species who take their nourishment from both plant life and meat. For this study, the authors considered humans carnivores, despite that human diets often consist of both plant life and meat.

In comparing the weaning times for humans to the great apes such as gorillas, orangutans and chimpanzees, the researchers say that the differences seem to come down to the differences in diet composition.

“That humans seem to be so similar to other animals can of course be taken as provocative,” Psouni says. “We like to think that culture makes us different as a species. But when it comes to breast-feeding and weaning, no social or cultural explanations are needed; for our species as a whole it is a question of simple biology.”

Psouni did emphasize that the results of her study only provided insight into how the addition of meat to their diets may have contributed to early humans spreading on Earth, and that it doesn’t advocate whether humans should or should not eat meat.

The study is published in the journal PLoS ONE.

Artist's conception of exoplanet GJ1214b orbiting a red dwarf star 40 light-years from Earth (Photo: David A. Aguilar (CfA))

Data from the Hubble Space Telescope has revealed a new class of planet, one which is water-covered and has a steamy atmosphere.

We currently have three types of planets in our Solar System; rocky (Earth, Venus, Mercury and Mars), gas giants (Saturn and Jupiter) and ice giants (Uranus and Neptune).

While studying the exoplanet, GJ 1214b, astronomers found it to be like no other known planet because a significant portion of its mass is made up of water.

The GJ 1214b, discovered back in 2009, is about 2.7 times Earth’s diameter and weighs almost seven times as much.

GJ 1214b orbits a red-dwarf star every 38 hours at a distance of two million kilometers, and scientists estimate that it has a temperature of 230 degrees Celsius.

Scientists determined a type of haze that surrounds the planet is, most likely, the result of the planet’s steamy atmosphere.

Astronomers calculate the exoplanet has more water and is less rocky than Earth.

The astronomers say that GJ 1214b is located in the constellation of Ophiuchus (The Serpent Bearer), about 40 light-years from Earth.

>>> Read more…

Why Earth has active volcanoes while the moon doesn’t

Image of an artificial moon rock sample, measuring about half a millimeter across (Image: Nature)

Earth is in a constant state of change and evolution thanks in part to the active volcanism taking place throughout our planet.

The moon also has a history of volcano activity, but evidence of its volcanic past dates back billions of years.

So, if both the Earth and moon have a history of volcanism, why doesn’t the moon currently have active volcanoes?

Scientists are puzzled because many of the rocks on the moon’s surface are thought to be molten and recent moon-quake data suggests there is a huge supply of liquid magma deep within its surface.

A team of European scientists now thinks the reason the moon lacks current volcanic activity is because the magma – hot, molten rock deep within the moon’s interior – might be so dense that it is simply too heavy to rise to the surface.

The researchers created microscopic copies of moon rock collected by the Apollo missions and then melted them at the extremely high pressures and temperatures found inside the moon. They then measured the density of these melted rocks with powerful x-rays.

The scientists found small droplets of titanium-rich glass that produce a liquid magma as dense as the rocks that are found in the deepest parts of the lunar mantle today.

Scientists say, since the magma was so dense, it would not be able to move towards the surface the same way magma on Earth does during a volcanic eruption.

>>> Read more…

Ancient rock art found in Brazil

This is the oldest reliably dated petroglyph ever found in the New World. (Photo/Image: Neves WA, Araujo AGM, Bernardo DV, Kipnis R, Feathers JK (2012) Rock Art at the Pleistocene/Holocene Boundary in Eastern South America. PLoS ONE 7(2): e32228. doi:10.1371/journal.pone.0032228)

Back on Earth, researchers recently found an extremely old human-like figure engraved in rock in central Brazil.

The engraving, or petroglyph,was found in an ancient limestone rock shelter called Lapa do Santo.

According to the researchers’ report, the petroglyph dates back to between 9,000 and 12,000 years ago, which would make it  the oldest reliably-dated specimen of this kind of rock art ever found in the Americas.

New World art produced during the time this discovery was engraved is quite rare.  Because of the rarity of this type of rock art, scientists know little about the differences of symbolic thinking of those who settled the Americas thousands of years ago.

Authors of this study suggest symbolic thought in South America was very diverse at that time, and that their discovery shows humans settled the New World earlier than first thought.

>>> Read more…

Scientists find new life forms deep within the Earth’s surface

Plutomurus ortobalaganensis found nearly two kilometers underground. (Image: University of Navarra)

Scientists exploring what’s been called the world’s deepest cave say that they’ve found a new species of arthropod that lives and thrives deep underground.

The creature, Plutomurus ortobalaganensis, is a tiny, primitive, wingless and eyeless, six-legged insect which lives in total darkness.

The scientists say the discovery of life in such a deep environment should provide new insight into how we look at life on Earth.

Since they live without light and have extremely limited food resources, animals such as the Plutomurus ortobalaganensis have had to develop some uncommon methods of surviving in its subterranean environment.

The new creature was found 1,980 meters below ground level in the Krubera or Voronja Cave, located in Abkhazia, a remote area near the Black Sea in the mountains of Western Caucasus.

The Krubera/Voronja cave reaches a depth of more than two kilometers below the surface of the Earth.

>>> Read more…

Peter Higgs is best known for his theory explaining the origin of mass of elementary particles in general and the Higgs boson in particular. (Photo: Gert-Martin Greuel via Wikipedia Commons)

Scientists might be zeroing in on just where the Higgs boson – the hypothetical sub-atomic particle believed to be a building block of the universe – may be hiding.

Many expected CERN scientists to announce the discovery of the mysterious Higgs boson at a  Dec. 13 seminar.  Observers didn’t hear what they had hoped to hear. Instead they were told that, while scientists are seeing hints of the Higgs boson, they haven’t actually found it yet.

The status of two experiments (Atlas and CMS)  – tasked with finding the Higgs boson, if it exists – was announced at CERN headquarters in Geneva, Switzerland Tuesday.

The results so far indicate that, while they’ve made significant progress in the search for the hypothetical sub-atomic particle, they haven’t found enough evidence to conclusively rule whether or not Higgs exists.

While tantalizing hints have been seen in both experiments, they’re not strong enough to claim a discovery.

CERN says the analysis of both experiments will be refined in the coming months.

However, a definitive statement on the existence or non-existence of the Higgs will require more data, and is not likely until later in 2012.

>>> Read more…

NASA scientists want to get a sample of a speeding comet as it makes its way through the inner solar system.

To get their sample, the researchers plan to send a spacecraft to rendezvous with a comet, then fire a harpoon which would take rapid samples with surgical precision from specific locations, all while hovering above the target.

Using, what they call, the “standoff” technique would allow scientists to gather samples even from areas that are too rugged or dangerous to permit the landing and safe operation of a spacecraft.

“One of the most inspiring reasons to go through the trouble and expense of collecting a comet sample is to get a look at the ‘primordial ooze’ – biomolecules in comets that may have assisted the origin of life,” said NASA Goddard‘s Donald Wegel, the lead engineer on the project.

Comets are frozen chunks of ice and dust left over from the formation of our Solar System. As such, the scientists want to take a closer look for clues to the origin of planets and ultimately, ourselves.

>>> Read more…

Was Darwin wrong about emotions?

(Image artist: Simon alias Sympho via Wikipedia Commons)

Researchers in Massachusetts are studying the link between emotions and facial expressions.

According to their research,  people don’t all have the same set of biologically basic emotions.

And those emotions are not automatically expressed on the faces of those around us, contrary to what many psychological scientists think today.

A commonly-held belief by scientists is that certain facial expressions have evolved over time to express certain mental states and prepare our bodies to react in certain ways to certain situations.

For example, there’s the belief that widening your eyes when you’re scared might help you take in more information about the scene, while at the same time signaling  to people around you that something dangerous is happening.

But lead author Lisa Feldman,  of Northeastern University, says expressions are not inborn emotional signals that are automatically expressed on the face.

The theory that emotional expressions evolved for specific functions is normally attributed to Charles Darwin, in his book “The Expression of the Emotions in Man and Animals.”

>>> Read more…

Cholesterol-reducing drugs may do more

Cholesterol-lowering drugs called statins not only lower cholesterol levels, but also promote the breakdown of plaque in the arteries, according to researchers at New York University’s Langone Medical Center.

That gives hope to people with atherosclerosis, also called hardening of the arteries.

Up until this study, the researchers say that it was not fully understood how these statin medications could reduce atherosclerosis, which is the accumulation of fat and cholesterol in the bloodstream which eventually hardens into plaque in the arteries.

In time, plaque builds up along the walls of the arteries, causing them to narrow, reducing the blood flow.  Blood clots can then form, or bits of the plaque can break off, causing blockages in the vessels which can lead to a potentially fatal heart attack or stroke.

Dr. Edward Fisher, co-author of the study, says, “Our new research shows statins actually promote the regression of atherosclerosis by altering the expression of a specific cell surface receptor within plaque cells. This molecular phenomenon helps dissolve plaque by expelling coronary artery disease-causing cells from the plaque lining the arteries.”

>>> Read more…