The Story of Us: White skin is not about making vitamin D. It's about preventing dehydration.

Credit: © cristovao31 / Fotolia

The Elias lab has shown that pigmented skin provides a better skin barrier,

which was critically important for protection against dehydration.

You're writing a story about the migration of ancient humans into Europe.  As always, you need crisis as a way of furthering the story.  Here's one, minor though it may seem:  On the trip, members of your band with dark skin are much more likely to die of dehydration than members with a lighter skin tone.

Really?  Sure.  Read the following which debunks the Vitamin D theory of why people with lighter colored skin survived as they followed the glaciers north after the last Ice Age. 

The popular idea that Northern Europeans developed light skin to absorb more UV light so they could make more vitamin D – vital for healthy bones and immune function – is questioned by UC San Francisco researchers in a new study published online in the journal Evolutionary Biology.
 

Suggested reading
click on image

Ramping up the skin’s capacity to capture UV light to make vitamin D is indeed important, according to a team led by Peter Elias, MD, a UCSF professor of dermatology. However, Elias and colleagues concluded in their study that changes in the skin’s function as a barrier to the elements made a greater contribution than alterations in skin pigment in the ability of Northern Europeans to make vitamin D.

Elias’ team concluded that genetic mutations compromising the skin’s ability to serve as a barrier allowed fair-skinned Northern Europeans to populate latitudes where too little ultraviolet B (UVB) light for vitamin D production penetrates the atmosphere.

Among scientists studying human evolution, it has been almost universally assumed that the need to make more vitamin D at Northern latitudes drove genetic mutations that reduce production of the pigment melanin, the main determinant of skin tone, according to Elias.

“At the higher latitudes of Great Britain, Scandinavia and the Baltic States, as well as Northern Germany and France, very little UVB light reaches the Earth, and it’s the key wavelength required by the skin for vitamin D generation,” Elias said.

Skin color has nothing to do with production of Vitamin D
“While is seems logical that the loss of the pigment melanin would serve as a compensatory mechanism, allowing for more irradiation of the skin surface and therefore more vitamin D production, this hypothesis is flawed for many reasons,” he continued. “For example, recent studies show that dark-skinned humans make vitamin D after sun exposure as efficiently as lightly-pigmented humans, and osteoporosis – which can be a sign of vitamin D deficiency – is less common, rather than more common, in darkly-pigmented humans.”

"Dark-skinned humans make vitamin D after sun

exposure as efficiently as lightly-pigmented humans."

Furthermore, evidence for a south to north gradient in the prevalence of melanin mutations is weaker than for this alternative explanation explored by Elias and colleagues.

Skin as a barrier to water loss
In earlier research, Elias began studying the role of skin as a barrier to water loss. He recently has focused on a specific skin-barrier protein called filaggrin, which is broken down into a molecule called urocanic acid – the most potent absorber of UVB light in the skin, according to Elias. “It’s certainly more important than melanin in lightly-pigmented skin,” he said.

In their new study, the researchers identified a strikingly higher prevalence of inborn mutations in the filaggrin gene among Northern European populations. Up to 10 percent of normal individuals carried mutations in the filaggrin gene in these northern nations, in contrast to much lower mutation rates in southern European, Asian and African populations.

Moreover, higher filaggrin mutation rates, which result in a loss of urocanic acid, correlated with higher vitamin D levels in the blood. Latitude-dependent variations in melanin genes are not similarly associated with vitamin D levels, according to Elias. This evidence suggests that changes in the skin barrier played a role in Northern European’s evolutionary adaptation to Northern latitudes, the study concluded.

Yet, there was an evolutionary tradeoff for these barrier-weakening filaggrin mutations, Elias said. Mutation bearers have a tendency for very dry skin, and are vulnerable to atopic dermatitis, asthma and food allergies. But these diseases have appeared only recently, and did not become a problem until humans began to live in densely populated urban environments, Elias said.

The Elias lab has shown that pigmented skin provides a better skin barrier, which he says was critically important for protection against dehydration and infections among ancestral humans living in sub-Saharan Africa. But the need for pigment to provide this extra protection waned as modern human populations migrated northward over the past 60,000 years or so, Elias said, while the need to absorb UVB light became greater, particularly for those humans who migrated to the far North behind retreating glaciers less than 10,000 years ago.

The data from the new study do not explain why Northern Europeans lost melanin. If the need to make more vitamin D did not drive pigment loss, what did? Elias speculates that, “Once human populations migrated northward, away from the tropical onslaught of UVB, pigment was gradually lost in service of metabolic conservation. The body will not waste precious energy and proteins to make proteins that it no longer needs.”

*  *  *  *  *

Story Source:  The above story is based on materials provided by University of California, San Francisco (UCSF), written by Jeffrey Norris.  1.Jacob P. Thyssen, Daniel D. Bikle, Peter M. Elias. Evidence That Loss-of-Function Filaggrin Gene Mutations Evolved in Northern Europeans to Favor Intracutaneous Vitamin D3 Production. Evolutionary Biology, 2014

CHARACTER DEVELOPMENT: Science confirms ~ some people enjoy suffering

www.empower2themax.com.au

Here's a story ready for the writing.

Okay, yes, it's been done, but if you're looking for something meaty to sink your creative teeth into, think about this.  How do people who dislike themselves react when you try to cheer them up?  When you put a positive spin on their lives?  They ignore you, right?

This study suggests that you may want to rethink cheering up your friends who have low self-esteem because, they don't want to hear it.  It's not that they're happy the way they feel about themselves.  It's that they only hear things that confirm their opinion of themselves.

People with low self-esteem have overly negative views of themselves, and often interpret critical feedback, romantic rejections, or unsuccessful job applications as evidence of their general unworthiness. On top of this, researchers at the University of Waterloo and Wilfrid Laurier University found that this person likely doesn't want you to try to boost their spirits.  They're happy, so to speak, mucking about in their emotional pity-pot.

Suggested reading
click on image

"People with low self-esteem want their loved ones to see them as they see themselves. As such, they are often resistant to their friends' reminders of how positively they see them and reject what we call positive reframing-expressions of optimism and encouragement for bettering their situation," said Professor Denise Marigold, from Renison University College at Waterloo, and lead author of the study.

These individuals usually prefer negative validation, which conveys that the feelings, actions or responses of the recipient are normal, reasonable, and appropriate to the situation. So a friend could express understanding about the predicament or for the difficulty of a situation, and suggest that expressing negative emotions is appropriate and understandable.

The researchers found no evidence that positive reframing helps participants with low self-esteem. And in fact, the people providing support to friends with low self-esteem often feel worse about themselves when you attempt to cheer them up. Oy.  What to do?

Some study participants indicated that supporting friends with low self-esteem could be frustrating and tiring. The researchers found that when these support providers used positive reframing instead of negative validation in these situations, they often believed the interaction went poorly, perhaps because the friends with low self-esteem were not receptive and the efforts didn't work.

"If your attempt to point out the silver lining is met with a sullen reminder of the prevailing dark cloud, you might do best to just acknowledge the dark cloud and sympathize," said Professor Marigold.

Ah, ha! So, acknowledge the "dark cloud" and "sympathize", then clam up.  In other words, don't encourage, don't point out the positive, don't put a good spin on things.  Agree with them, sympathize, let them sink in their own swamp, and let them work it out for themselves.

In fiction and film, doesn't the reader or viewer want the protagonist, in this case the person with the I'm-not-worth-a-shit attitude, to figure it out for themselves?  Don't we all enjoy a story where the main character grows and changes - through their own efforts?  It seems that what works in fiction is what works in real life.  People don't change until they are good and ready.  Right?

There's the plot, fellow writers.  What do you think you can do with it?

*  *  *  *  *

Story Source:  Materials provided by University of Waterloo. Denise C. Marigold, Justin V. Cavallo, John G. Holmes, Joanne V. Wood. You can’t always give what you want: The challenge of providing social support to low self-esteem individuals. Journal of Personality and Social Psychology, 2014

Scientists predict Higgs boson probably should have caused our universe to collapse? But it didn't. Why?

www.answers.com

One possible signature of a Higgs boson from a simulated collision 

between two protons. It decays 

 almost 

immediately 

into two 

jets 

of hadrons and two. . . are you following this? I'm not.

I think we all know that we're living in an age of amazing scientific research and discovery.  It's a given that most of the scientists who ever lived in the 6.5 million year history of the human animal are alive and working today.

It's safe to say that we're in the beginning of a remarkable scientific golden age.  At the beginning?  Yep.  Which means that there is far more that we don't know than we do.  And you're safe in assuming we don't know much given that we live on a hinky-dinky little planet way out in the boondocks of space, far, far away from the galactic center.

Science is a process that accretes knowledge much as a pearl accretes around a grain of sand in an oyster.  You start with a question.  You seek an answer to that question.  You find an answer to that question.  

And the answer poses ten or twenty or a hundred new questions.

Take the Higgs boson, a particle that existed very briefly immediately after the Big Bang.  The theory was that this particle is what gives all other particles mass.  Don't ask me how, I've read and reread the reports, and it sounds a bit like voodoo.  But, this is how cosmologists and physicists and mathematicians had it worked out.  

So the quest was to prove the theory by finding a Higgs boson.  How do you find something incredibly small that only existed very briefly at the beginning of time?  Obviously, to some at least, you create a machine that recreates the conditions that existed at the beginning of time.  The CERN particle collider in Switzerland, a huge, expensive set of magnets and computers that accelerates particles to damn near the speed of light then sets them up for head on collisions.  How cool is that?  Makes crashing toy cars together seem like child's play.  Which it is.

The CERN Large Hadron Collider is built.  (Hadron?  Beats me, maybe a reader know what it is. I haven't a clue.)

Anyway, the experiment is on.  Only, some theorists say, "Wait.  If you succeed in creating a real Higgs boson, it could create a black hole which could end the planet."

More theoretical work, mostly in the language of math, and it was determined that the probability of this happening was acceptably low. (To whom is this risk acceptable is the question.  They never asked me.  Did they ask you?) So they run the experiments, scientists and observers giggling like school boys as they slam elementary particles together resulting in spectacular collisions (except for one neurotic guy in the back who was waiting for it all to come crashing down into a black hole.  Luckily, he was wrong.)

And then, in July 2012, they find the particle in question, THE Higgs boson.  Of course, they don't know this for the months it took to analyze the data, but eventually, someone stood up and said, "Eureka.  We found it.  Probably."  

Probably?  Yes, because the best we can say about any subatomic particle is probably. Particle physics is all about the odds of something being somewhere sometime probably spinning this way or that but probably not.  And the probability that we found the Higgs boson is such that we can conclude that we found it.  

Probably.

Where is this leading?  To one of the questions that arose from the analysis of the results of all those collisions.

According to Robert Hogan, a PhD student at King's College London, we shouldn't be here.  The universe as we know it shouldn't exist.  It should have collapsed back into itself right after the Big Bang as a Great Big Thud.

While some might argue that our universe, or at least the Earth, is a Great Big Thud, obviously we are here and able to ask the question many cosmologists are asking today, "WTF?"

Here's the story from the Royal Astronomical Society's National Astronomy Meeting in Portsmouth as it's being presented today, 24 June 2014:

British cosmologists are puzzled: they predict that the Universe should not have lasted for more than a second. This startling conclusion is the result of combining the latest observations of the sky with the recent discovery of the Higgs boson.

After the Universe began in the Big Bang, it is thought to have gone through a short period of rapid expansion known as 'cosmic inflation'. Although the details of this process are not yet fully understood, cosmologists have been able to make predictions of how this would affect the Universe we see today.

In March 2014, researchers claimed to have detected one of these predicted effects. If true, their results are a major advance in our understanding of cosmology and a confirmation of the inflation theory, but they have proven controversial and are not yet fully accepted by cosmologists.

In the new research, scientists investigated what the observations mean for the stability of the Universe. To do this, they combined the results with recent advances in particle physics. The detection of the Higgs boson by the Large Hadron Collider was announced in July 2012; since then, much has been learnt about its properties.

Measurements of the Higgs boson have allowed particle physicists to show that our universe sits in a valley of the 'Higgs field', which describes the way that other particles have mass. However, there is a different valley which is much deeper, but our universe is preventing from falling into it by a large energy barrier.

The problem is that the results predict that the universe would have received large 'kicks' during the cosmic inflation phase, pushing it into the other valley of the Higgs field within a fraction of a second. If that had happened, the universe would have quickly collapsed in a Big Crunch.

"This is an unacceptable prediction of the theory because if this had happened we wouldn't be around to discuss it" said Robert Hogan, a PhD student at King's College London, who led the study.

Perhaps the results contain an error. If not, there must be some other -- as yet unknown -- process which prevented the universe from collapsing.

"If is shown to be correct, it tells us that there has to be interesting new particle physics beyond the standard model" Hogan said.

And the process goes on.  

*  *  *  *  *

Story Source: Materials provided by Royal Astronomical Society (RAS). "Should the Higgs boson have caused our universe to collapse? Findings puzzle cosmologists." ScienceDaily.

Impress your friends: Be an Instant Soccer Expert!

www.npr.org

  Clint Dempsey scored Team USA's first goal during the
FIFA World Cup 2014 Group G preliminary match against Ghana.

Well, maybe not an expert, but by reading these five short stories you will be much better prepared to hold your own in our quaternary obsession with Futbol!   GOOOOOOOAAAAAALLLLLL!


FIFA World cup qualification: is it a fair game?
FIFA has 208 member football associations from around the world all clamoring to qualify for each World Cup tournament and reap the massive $8 million appearance fee as well as further windfalls and lucrative merchandising revenues. With fierce competition for qualification, is FIFA allocating the 32 places fairly or are processes biased by finances and politics? New research, published in the journal Soccer & Society, suggests that a more transparent allocation processes is urgently required. Without this, experts at Canada's Sprott School of Business argue, FIFA will be open to the accusation it is more concerned with financial gain from the World Cup than showcasing the very best football.

Highly recommended
click on image

In their new article, "Unfair play in World Cup qualification? An analysis of the 1998-2010 FIFA World Cup performances and the bias in the allocation of tournament berths," Christian Stone and Michel Rod studied the match results for 1st round tournament matches 1998-2010 to assess the adequacy of the qualification process. This demonstrated that the current system of qualification is not based on ensuring the qualification of the best 32 teams in the world, nor does it fairly allocate qualification spots on the number of teams per federation or any other metric. Such findings suggest things could be done differently and identify the need for a more dynamic system with fewer fixed spots and more opportunity for inter-confederation play, giving those at the top of their game the opportunity to shine and for a truer representation of the best during the World Cup.

The World Cup generates 90% of FIFA revenues. Stone and Rod believe that this economic success should be used by FIFA, in the cause of corporate social responsibility, to expand participation. Without that, the question is asked "has world football become the means to an end in terms of money as the ultimate objective?"

• Story Source: Materials provided by Taylor & Francis. Christian Stone, Michel Rod. Unfair play in World Cup qualification? An analysis of the 1998–2010 FIFA World Cup performances and the bias in the allocation of tournament berths. Soccer & Society, 2014

New ball to showcase talent in World Cup
Physics experts believe the new soccer ball created for the 2014 FIFA World Cup is a “keepers’ ball”. The new ball, called Brazuca, should be much more predictable than the 2010 World Cup ball, Jabulani, which was less-than-affectionately labelled a 'beach ball' because of its sometimes erratic flight path.

"The Brazuca has very deep grooves -- it's much rougher than Jabulani -- and this creates a different pattern of air flow around the ball," says Professor Derek Leinweber, Professor of Physics in the University's School of Chemistry and Physics. He has previously written about and lectured on the aerodynamics of cricket balls, golf balls and earlier World Cup soccer balls.

"The Jabulani was much smoother than the Brazuca with smaller grooves and ridges across its surface," says Professor Leinweber. "That meant the ball had to be moving much faster before the airflow around the ball changed from smooth to turbulent. As this shift to turbulent airflow occurred at high speeds, the ball could make some pretty erratic movements on the way to the net.

"In contrast the Brazuca, with its deeper grooves, hits that turbulent air flow at a lower speed with the result that the ball is much more predictable. In many ways, it's a return to the aerodynamics of the old 32-panel ball."

Mr Kiratidis says he believes players taking hard and fast shots in this World Cup won't find the Brazuca as easy to bend into the net as they did with the Jabulani.

• Story Source: Materials provided by University of Adelaide. "New ball to showcase talent in World Cup." ScienceDaily. 

How does a soccer ball swerve? 
It happens every four years: The World Cup begins and some of the world's most skilled players carefully line up free kicks, take aim -- and shoot way over the goal.

The players are all trying to bend the ball into a top corner of the goal, often over a wall of defensive players and away from the reach of a lunging goalkeeper. Yet when such shots go awry in the World Cup, a blame game usually sets in. Players, fans, and pundits all suggest that the new official tournament ball, introduced every four years, is the cause.

Many of the people saying that may be seeking excuses. And yet scholars do think that subtle variations among soccer balls affect how they fly. Specifically, researchers increasingly believe that one variable really does differentiate soccer balls: their surfaces. It is harder to control a smoother ball, such as the much-discussed "Jabulani" used at the 2010 World Cup. The new ball used at this year's tournament in Brazil, the "Brazuca," has seams that are over 50 percent longer, one factor that makes the ball less smooth and apparently more predictable in flight.

"The details of the flow of air around the ball are complicated, and in particular they depend on how rough the ball is," says John Bush, a professor of applied mathematics at MIT and the author of a recently published article about the aerodynamics of soccer balls. "If the ball is perfectly smooth, it bends the wrong way."

By the "wrong way," Bush means that two otherwise similar balls struck precisely the same way, by the same player, can actually curve in opposite directions, depending on the surface of those balls. Sound surprising?

How a ball curves:  The Magnus Effect
It may, because the question of how a spinning ball curves in flight would seem to have a textbook answer: the Magnus Effect. This phenomenon was first described by Isaac Newton, who noticed that in tennis, topspin causes a ball to dip, while backspin flattens out its trajectory. A curveball in baseball is another example from sports: A pitcher throws the ball with especially tight topspin, or sidespin rotation, and the ball curves in the direction of the spin.

In soccer, the same thing usually occurs with free kicks, corner kicks, crosses from the wings, and other kinds of passes or shots: The player kicking the ball applies spin during contact, creating rotation that makes the ball curve. For a right-footed player, the "natural" technique is to brush toward the outside of the ball, creating a shot or pass with a right-to-left hook; a left-footed player's "natural" shot will curl left-to-right.

So far, so intuitive: Soccer fans can probably conjure the image of stars like Lionel Messi, Andrea Pirlo, or Marta, a superstar of women's soccer, doing this. But this kind of shot -- the Brazilians call it the "chute de curva" -- depends on a ball with some surface roughness. Without that, this classic piece of the soccer player's arsenal goes away, as Bush points out in his article, "The Aerodynamics of the Beautiful Game," from the volume "Sports Physics," published by Les Editions de L'Ecole Polytechnique in France.

"The fact is that the Magnus Effect can change sign," Bush says. "People don't generally appreciate that fact." Given an absolutely smooth ball, the direction of the curve may reverse: The same kicking motion will not produce a shot or pass curving in a right-to-left direction, but in a left-to-right direction.

Why is this? Bush says it is due to the way the surface of the ball creates motion at the "boundary layer" between the spinning ball and the air. The rougher the ball, the easier it is to create the textbook version of the Magnus Effect, with a "positive" sign: The ball curves in the expected direction.

"The boundary layer can be laminar, which is smoothly flowing, or turbulent, in which case you have eddies," Bush says. "The boundary layer is changing from laminar to turbulent at different spots according to how quickly the ball is spinning. Where that transition arises is influenced by the surface roughness, the stitching of the ball. If you change the patterning of the panels, the transition points move, and the pressure distribution changes." The Magnus Effect can then have a "negative" sign.

From Brazil: The "dove without wings"
If the reversing of the Magnus Effect has largely eluded detection, of course, that is because soccer balls are not absolutely smooth -- but they have been moving in that direction over the decades. While other sports, such as baseball and cricket, have strict rules about the stitching on the ball, soccer does not, and advances in technology have largely given balls sleeker, smoother designs -- until the introduction of the Brazuca, at least.

There is actually a bit more to the story, however, since sometimes players will strike balls so as to give them very little spin -- the equivalent of a knuckleball in baseball. In this case, the ball flutters unpredictably from side to side. Brazilians have a name for this: the "pombo sem asa," or "dove without wings."

In this case, Bush says, "The peculiar motion of a fluttering free kick arises because the points of boundary-layer transition are different on opposite sides of the ball." Because the ball has no initial spin, the motion of the surrounding air has more of an effect on the ball's flight: "A ball that's knuckling … is moving in response to the pressure distribution, which is constantly changing." Indeed, a free kick Pirlo took in Italy's match against England on Saturday, which fooled the goalkeeper but hit the crossbar, demonstrated this kind of action.

Bush's own interest in the subject arises from being a lifelong soccer player and fan -- the kind who, sitting in his office, will summon up clips of the best free-kick takers he's seen. These include Juninho Pernambucano, a Brazilian midfielder who played at the 2006 World Cup, and Sinisa Mihajlovic, a Serbian defender of the 1990s.

And Bush happily plays a clip of Brazilian fullback Roberto Carlos' famous free kick from a 1997 match against France, where the player used the outside of his left foot -- but deployed the "positive" Magnus Effect -- to score on an outrageously bending free kick.

"That was by far the best free kick ever taken," Bush says. Putting on his professor's hat for a moment, he adds: "I think it's important to encourage people to try to understand everything. Even in the most commonplace things, there is subtle and interesting physics."

YouTube Video:  Bending it like Beckham

• Story Source:  Materials provided by Massachusetts Institute of Technology, original article was written by Peter Dizikes. J.W.M. Bush. The Aerodynamics of the beautiful game. Sports Physics, 2013

Soccer-related facial fractures examined
Fractures of the nose and other facial bones are a relatively common and potentially serious injury in soccer players, reports a Brazilian study. Through their analysis, researchers report that he nose and upper jaw (maxilla) accounted for 35 percent of fractures and the cheekbone (zygomatic bone) for another 35 percent. Most of the remaining fractures were of the lower jaw (mandible) and eye socket (orbit). Eighty-seven percent of the injuries were caused by collision with another player; the rest occurred when the player was struck by the ball.

• Story Source: Materials provided by Wolters Kluwer Health: Lippincott Williams and Wilkins. Dov C. Goldenberg, Gal M. Dini, Max D. Pereira, Augusto Gurgel, Endrigo O. Bastos, Purushottam Nagarkar, Rolf Gemperli, Lydia M. Ferreira. Soccer-related Facial Trauma. Plastic & Reconstructive Surgery Global Open, 2014

Why reaching the top in soccer is all in the mind, not the feet
The mental edge that drives Premier League soccer players to succeed from a young age, including dealing with criticism, confronting challenges after repeated failures, and not being intimidated by others, has been outlined by researchers. "The report found that mentally tough players demonstrated a commitment to learning, had a strong level of trust with their coach, were more compliant with instructions and were always seeking ways to improve," researchers say.

• Story Source: Materials provided by University of Lincoln. Clive Cook, Lee Crust, Martin Littlewood, Mark Nesti, Jacquelyn Allen-Collinson. ‘What it takes’: perceptions of mental toughness and its development in an English Premier League Soccer Academy. Qualitative Research in Sport, Exercise and Health, 2014

The Story of Us: Did Neandertal evolve all at once? Or slowly over time?

Credit: Image © Javier Trueba / Madrid Scientific Films

Skull 17 from the Sima de los Huesos site in Sierra de Atapuerca, Spain.

Trying to keep up with the latest research in the middle of the Scientific Revolution is a task beyond my capabilities, though it is fun trying.
Take, for instance, one of our predecessor species, Neandertal.  Type the name into a science search site, and over a dozen breakthrough studies were published just over the last several years.  These studies deal with the ancient but help explain how we got be the thinking animal we are.

One question of debate in some circles is: do species evolve all at once?  Or slowly over time?

For a writer, all at once is a bonanza of potential conflict and crises.  Slowly over time, less so, but still rife with those with a new feature such as a dominant brow ridge being ostracized - a theme in Jean Aul's delightful series, Earth's Children.

Here is a story of a study that compares and contrasts skulls with a mix of Neandertal and more primitive traits that help illuminate human evolution.


Researchers studying a collection of skulls in a Spanish cave identified both Neandertal-derived features and features associated with more primitive humans in these bones. This "mosaic pattern" supports a theory of Neandertal evolution that suggests Neandertals developed their defining features separately, and at different times -- not all at once. Having this new data from the Sima de los Huesos site, as the Spanish cave is called, has allowed scientists to better understand hominin evolution during the Middle Pleistocene, a period in which the path of hominin evolution has been controversial.

*  *  *  *  *

Period of maximum glaciation during the Pleistocene.
Note that southern Europe is clear of ice. 

The Pleistocene Epoch is typically defined as the time period that began about 1.8 million years ago and lasted until about 11,700 years ago. The most recent Ice Age occurred then, as glaciers covered huge parts of the planet Earth.

There have been at least five documented major ice ages during the 4.6 billion years since the Earth was formed — and most likely many more before humans came on the scene about 2.3 million years ago.

The Pleistocene Epoch is the first in which Homo sapiens evolved, and by the end of the epoch humans could be found in nearly every part of the planet.

Source: livescience.com

*  *  *  *  *

"The Middle Pleistocene was a long period of about half a million years during which hominin evolution didn't proceed through a slow process of change with just one kind of hominin quietly evolving towards the classic Neandertal," said lead author Juan-Luis Arsuaga, Professor of Paleontology at the Complutense University of Madrid.

"With the skulls we found," co-author Ignacio Martínez, Professor of Paleontology at the University of Alcalá, added, "it was possible to characterize the cranial morphology of a human population of the European Middle Pleistocene for the first time."

About 400 to 500 thousand years ago, in the heart of the Pleistocene, archaic humans split off from other groups of that period living in Africa and East Asia, ultimately settling in Eurasia, where they evolved characteristics that would come to define the Neandertal lineage. Several hundred thousand years after that, modern humans -- who had evolved in Africa -- settled in Eurasia, too. They interbred with Neandertals, but even then showed signs of reproductive incompatibility. Because of this, modern humans eventually replaced Neandertals.

The degree of divergence between Neandertals and modern humans over such a short period of time has surprised scientists. Why did Neandertals differentiate so quickly from other early hominins? What pattern of changes did Neandertals undergo?

To answer these questions, scientists have needed an accurate picture of European populations around 400,000 years ago, the early stages of the Neandertal lineage. This has been challenging, however, because the European fossil record -- an important tool for answering these questions -- is isolated and dispersed, consisting of remains from disparate timelines. Samples at the Sima de los Huesos site in Atapuerca, Spain, however, are different.

"What makes the Sima de los Huesos site unique," Arsuaga said, "is the extraordinary and unprecedented accumulation of hominin fossils there; nothing quite so big has ever been discovered for any extinct hominin species -- including Neanderthals."

"This site has been excavated continuously since 1984," Martínez added. "After thirty years, we have recovered nearly 7,000 human fossils corresponding to all skeletal regions of at least 28 individuals. This extraordinary collection includes 17 fragmentary skulls, many of which are very complete."

The 17 skulls belong to a single population of a fossil hominin species. Some of have been studied before, but seven are presented anew here, and six are more complete than ever before. With these intact samples at their fingertips, the researchers made progress characterizing defining features.
Their work has helped address hypotheses about Neandertal evolution, specifically the accretion model hypothesis, which suggests that Neandertals evolved their defining features at different times, not in a single linear sweep.

Highly rated
click on image

"For decades the nature of the evolutionary process that gave rise to Neanderthals has been discussed," explained Martínez. "An important question in these debates was whether the 'neandertalization process' involved all regions of the skull from the beginning, or if, on the contrary, there were various stages in this process that affected different parts of the skull at different times."

The researchers' skull samples showed Neandertal features present in the face and teeth, but not elsewhere; the nearby braincase, for example, still showed features associated with more primitive hominins.

"We think based on the morphology that the Sima people were part of the Neanderthal clade," Arsuaga said, "although not necessarily direct ancestors to the classic Neanderthals." They were part of an early European lineage that includes Neanderthals, but is more primitive than the later Pleistocene variety.

Critically, many of the Neandertal-derived features the researchers observed were related to mastication, or chewing. "It seems these modifications had to do with an intensive use of the frontal teeth," Arsuaga said. "The incisors show a great wear as if they had been used as a 'third hand," typical of Neanderthals."

The work of Arsuaga et al. suggests that facial modification was the first step in Neandertal evolution. This mosaic pattern fits the prediction of the accretion model.

"One thing that surprised me about the skulls we analyzed," Arsuaga said, "is how similar the different individuals were. The other fossils of the same geological period are different and don´t fit in the Sima pattern. This means that there was a lot of diversity among different populations in the Middle Pleistocene."

Indeed, other European Middle Pleistocene Homo sapiens do not exhibit the suite of Neandertal-derived features seen in this fossil group. Thus, more than one evolutionary lineage appears to have coexisted during the European Middle Pleistocene, with that represented by the Sima sample being closer to the Neandertals.

Arsuaga and his team were delighted to work on this effort. "Finding a single tooth is a great success in any other site of comparable age, so imagine what it is like to painstakingly reconstruct 17 skulls," he said. "It's like finding a treasure."

So 17 skulls at one site, skulls with a variety of features, but showing a tendency to use the teeth as "a third hand."  What was going on there - socially and culturally?  Were food sources changing?  Was competition from other hominid groups increasing?  Well, speculate away as speculation is the mother of interesting fiction.

*  *  *  *  *

Story Source:  Materials provided by American Association for the Advancement of Science. J. L. Arsuaga, I. Martínez, L. J. Arnold, A. Aranburu, A. Gracia-Téllez, W. D. Sharp, R. M. Quam, C. Falguères, A. Pantoja-Pérez, J. Bischoff, E. Poza-Rey, J. M. Parés, J. M. Carretero, M. Demuro, C. Lorenzo, N. Sala, M. Martinón-Torres, N. García, A. Alcázar de Velasco, G. Cuenca-Bescós, A. Gómez-Olivencia, D. Moreno, A. Pablos, C.-C. Shen, L. Rodríguez, A. I. Ortega, R. García, A. Bonmatí, J. M. Bermúdez de Castro, and E. Carbonell. Neandertal roots: Cranial and chronological evidence from Sima de los Huesos. Science, 2014

The next generation of Invisibility Cloaks: "You can't touch this."

canadianawareness.org

A prototype invisibility cloak for use by soldiers in combat.  Someday.

Frodo's ring and Harry Potter's cloak gave them invisibility, actually an old fantasy realized by science over the past few years. Today, objects really can be hidden from light, heat or sound. However, hiding of an object from being touched still remained to be accomplished. 

Now scientists from the Karlsruhe (Germany) Institute of Technology (KIT) have succeeded in creating a method that "hides" an object from a person's sense of touch, sort of making the pea under the mattress not noticeable to the princess.

The "touch" invisibility" device developed by KIT prevents  a person's sense of touch responding to the object.  Here's an explanation from the press release of how the KIT technology works:

The invisibility cloak is based on a so-called metamaterial that consists of a polymer. Its major properties are determined by the special structure. "We build the structure around the object to be hidden. In this structure, strength depends on the location in a defined way," explains Tiemo Bückmann, KIT, the first author of the article. "The precision of the components combined with the size of the complete arrangement was one of the big obstacles to the development of the mechanical invisibility cloak." The metamaterial is a crystalline material structured with sub-micrometer accuracy. It consists of needle-shaped cones, whose tips meet. The size of the contact points is calculated precisely to reach the mechanical properties desired. In this way, a structure results, through which a finger or a measurement instrument cannot feel its way.

In the invisibility cloak produced, a hard cylinder is inserted into the bottom layer. Any objects to be hidden can be put into its cavity. If a light foam or many layers of cotton would be placed above the hard cylinder, the cylinder would be more difficult to touch, but could still be felt as a form. The metamaterial structure directs the forces of the touching finger such that the cylinder is hidden completely. "It is like in Hans-Christian Andersen's fairy tale about the princess and the pea. The princess feels the pea in spite of the mattresses. When using our new material, however, one mattress would be sufficient for the princess to sleep well," Bückmann explains.

Implementation of such a mechanical invisibility cloak is rather complex. After the definition of the desired mechanical properties, the physical basic equations are inverted mathematically in order to draw conclusions with respect to the structure of the metamaterial. Using this method, materials not encountered in nature can be planned. Examples are solids which are stiff to pressure, but soft to shear. For manufacture from the polymer, the direct laser writing method of the KIT spinoff Nanoscribe is applied. It reaches the required precision over the complete sample length of several millimeters.

The mechanical invisibility cloak represents pure physical fundamental research, but might open up the door to interesting applications in a few years from now, as it allows for producing materials with freely selectable mechanical properties. Examples are very thin, light, and still comfortable camping mattresses or carpets hiding cables and pipelines below.

Suggested reading
click on image

How you or any writer uses this technology in combination with other invisibility techniques is up to your imagination.  I do seem to remember a scene in Tom Clancy's The Cardinal of the Kremlin in which a woman is submerged in a sensory deprivation tank resulting in her complete mental collapse.  With these type of devices would it be possible to do much the same without the expense of a special tank?  Simply disoriented a character in your story by suppressing their five (or six) senses?

This would be an interesting thought experiment indeed.

*  *  *  *  *

Story Source: Materials provided by Karlsruhe Institute of Technology. T. Bückmann, M. Thiel, M. Kadic, R. Schittny, M. Wegener. An elasto-mechanical unfeelability cloak made of pentamode metamaterials. Nature Communications, 2014

What Bronze Age Brits used for jewelry

A Stone Age burial dating from 5000-7000 BC shows
the skeletons of two women who were buried wearing
necklaces made of numerous shells.

A new study by scientists at the University of York has shed new light on the use of mollusk shells as personal adornments by Bronze Age people.

The research team used amino acid racemisation analysis (a technique used previously mainly for dating artifacts), light microscopy, scanning electron microscopy and Raman spectroscopy, to identify the raw materials used to make beads in a complex necklace discovered at an Early Bronze Age burial site at Great Cornard in Suffolk, UK.

They discovered that Bronze Age craftspeople used species like dog whelk and tusk shells, both of which were likely to have been sourced and worked locally, to fashion tiny disc-shaped beads in the necklace.

About Tusk Shells
Tusk shells (left) or Scaphopoda, meaning literally "boat-footed" are a class of shelled marine mollusks. Shells range from about 0.5 to 15 cm in length. These mollusks live on soft substrates offshore (usually not intertidally). Because of this subtidal habitat and the small size of most species, many beachcombers are unfamiliar with them; their shells are usually not nearly as common or as easily visible in the beach drift as the shells of sea snails and clams.

The shells of scaphopods are conical and curved and they are usually whitish in color. Because of these characteristics, the shell somewhat resembles a miniature elephant's tusk, hence the common name tusk shell. However, unlike an elephant's tusk, the shells of these molluscs are hollow and open at both ends.

About the Dog Whelk

The dog whelk, dogwhelk, or Atlantic dogwinkle, scientific name Nucella lapillus, is a species of predatory sea snail, a carnivorous marine gastropod mollusc in the family Muricidae, the rock snails.

This species is found around the coasts of Europe and in the northern west Atlantic coast of North America. It is also can be found in estuarine waters along the Atlantic coasts. This species prefers rocky shores, where it eats mussels and acorn barnacles

The researchers included archaeologists, mathematicians, chemists and physicists, the latter from the BioArCh and York Centre for Complex Systems Analysis (YCCSA) and the Departments of Archaeology, Mathematics, Chemistry and Physics at the University of York. Dr Sonia O'Connor, of the University of Bradford's Department of Archaeological Sciences, carried out the light and electron microscopy, and prehistoric jewellery specialist Dr Alison Sheridan, of National Museums Scotland, facilitated access to the Great Cornard necklace, which had been excavated by Suffolk Archaeology.

When it was first established that the tiny white beads had been made from shell, the question arose as to its source. Had the shell been obtained locally or did it originate from a species from further afield, perhaps even the Mediterranean thorny oyster (Spondylus)? The Mediterranean thorny oyster is a shell of long-standing symbolic and cultural significance which is known to have been used on the Continent around the time when the Great Cornard necklace was made.

But this collaborative research, led by Dr Beatrice Demarchi, of York's Department of Archaeology and BioArCh, and Dr Julie Wilson, of the Departments of Chemistry and Mathematics and YCCSA, has shown this not to be the case, and has suggested an alternative possibility.

Dr Demarchi said: "Dog whelks and tusk shells were likely to be available locally so these people did not have to travel far to get hold of the raw materials for their beads.

"There is evidence, from elsewhere in Britain and further afield, for the use of tusk shells at various times in the past. This may well be because they are relatively easy to work and their hollow shape is very distinctive."

*  *  *  *  *

Story Source:  Materials provided by University of York. Beatrice Demarchi, Sonia O'Connor, Andre de Lima Ponzoni, Raquel de Almeida Rocha Ponzoni, Alison Sheridan, Kirsty Penkman, Y. Hancock, Julie Wilson. An Integrated Approach to the Taxonomic Identification of Prehistoric Shell Ornaments. PLoS ONE, 2014.