Tag: diet (page 2 of 5)

Is an Abundance of Arsenic Found in Rice Increasing Risk of Cancer?

May 21, 2015 / / 0 Comments

Brett Wilbanks, Staff WriterArsenic is a common element found in nature. It occurs naturally in a variety of sources, from soil and water, to foods that we eat on a regular basis. There are several forms of arsenic, and some, particularly certain inorganic forms, are more harmful than others.According to the International Agency for Research on Cancer, two compounds found in inorganic arsenic are known carcinogenic substances and are associated with a number of devastating health eff [...]

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How to Turn Milk Into Healthy Probiotic Medicine

May 18, 2015 / / 0 Comments

Anna Hunt, Staff WriterOur sterile, pre-packaged, convenient foods, coupled with a diet high in antibiotic-filled, factory-farmed meats, have resulted in an increased need for probiotic-rich foods and supplements if we are to maintain a healthy gut flora. An ideal balance of good and bad bacteria in the digestive system means improved digestion and better body function in general.Probiotic supplements, such as the high-quality brands BioImmersion and Kla [...]

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7 Reasons You Need More Magnesium

May 16, 2015 / / 0 Comments

Margie King, GuestMagnesium is the fourth most abundant mineral in your body.  But few people fully appreciate this miraculous mineral. The human genome project reveals that 3,751 human proteins have binding sites for magnesium.[i]  And so far we know this one essential mineral activates over 350 biochemical processes in the body to keep things flowing.Here are just seven good reasons to get more magnesium today. 1. Prevent Migraines. According to University of Vermo [...]

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11 Common Symptoms of the Global Depopulation Slow Kill

May 13, 2015 / / 0 Comments

Sigmund Fraud, Staff Writer“Maintain humanity under 500,000,000 in perpetual balance with nature.” – The Georgia GuidestonesThe full-spectrum global attack on human health is quite obvious to see for anyone who is paying attention and in search of wellness. So many of the factors that are negatively influencing public heath could easily be prevented or removed from society, yet the decisions of the ruling class continue to ensure that our food supply [...]

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Flawed Medical Research May Be Ruining Your Health & Your Life

May 8, 2015 / / 0 Comments

Robert Oliva, Collective-EvolutionThere is a cancer eating at the core of medical research.You’ve most likely heard of medical reports touting the effectiveness of a diet plan, a new drug, a supplement, or medical procedure. You may have even decided on a course of action based on these findings, only to find out later that they have been refuted by new studies.Strikingly, the odds are that the studies that influenced your decision, and possibly the decision of your doctor, wer [...]

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Did natural selection make the Dutch the tallest people on the planet?

April 9, 2015 / / 0 Comments

Dutch national women's field hockey team



Excerpt from news.sciencemag.org
ByMartin Enserink

AMSTERDAM—Insecure about your height? You may want to avoid this tiny country by the North Sea, whose population has gained an impressive 20 centimeters in the past 150 years and is now officially the tallest on the planet. Scientists chalk up most of that increase to rising wealth, a rich diet, and good health care, but a new study suggests something else is going on as well: The Dutch growth spurt may be an example of human evolution in action.
The study, published online today in the Proceedings of the Royal Society B, shows that tall Dutch men on average have more children than their shorter counterparts, and that more of their children survive. That suggests genes that help make people tall are becoming more frequent among the Dutch, says behavioral biologist and lead author Gert Stulp of the London School of Hygiene & Tropical Medicine.

"This study drives home the message that the human population is still subject to natural selection," says Stephen Stearns, an evolutionary biologist at Yale University who wasn't involved in the study. "It strikes at the core of our understanding of human nature, and how malleable it is." It also confirms what Stearns knows from personal experience about the population in the northern Netherlands, where the study took place: "Boy, they are tall."

For many years, the U.S. population was the tallest in the world. In the 18th century, American men were 5 to 8 centimeters taller than those in the Netherlands. Today, Americans are the fattest, but they lost the race for height to northern Europeans—including Danes, Norwegians, Swedes, and Estonians—sometime in the 20th century.

Just how these peoples became so tall isn't clear, however. Genetics has an important effect on body height: Scientists have found at least 180 genes that influence how tall you become. Each one has only a small effect, but together, they may explain up to 80% of the variation in height within a population. Yet environmental factors play a huge role as well. The children of Japanese immigrants to Hawaii, for instance, grew much taller than their parents. Scientists assume that a diet rich in milk and meat played a major role.

The Dutch have become so much taller in such a short period that scientists chalk most of it up to their changing environment. As the Netherlands developed, it became one of the world's largest producers and consumers of cheese and milk. An increasingly egalitarian distribution of wealth and universal access to health care may also have helped.

Still, scientists wonder whether natural selection has played a role as well. For men, being tall is associated with better health, attractiveness to the opposite sex, a better education, and higher income—all of which could lead to more reproductive success, Stulp says.
Yet studies in the United States don't show this. Stulp's own research among Wisconsinites born between 1937 and 1940, for instance, showed that average-sized men had more children than shorter and taller men, and shorter women had more children than those of average height. Taken together, Stulp says, this suggests natural selection in the United States pulls in the opposite direction of environmental factors like diet, making people shorter instead of taller. That may explain why the growth in average American height has leveled off.

Stulp—who says his towering 2-meter frame did not influence his research interest—wondered if the same was true in his native country. To find out, he and his colleagues turned to a database tracking key life data for almost 100,000 people in the country's three northern provinces. The researchers included only people over 45 who were born in the Netherlands to Dutch-born parents. This way, they had a relatively accurate number of total children per subject (most people stop having children after 45) and they also avoided the effects of immigration.

In the remaining sample of 42,616 people, taller men had more children on average, despite the fact that they had their first child at a higher age. The effect was small—an extra 0.24 children at most for taller men—but highly significant. (Taller men also had a smaller chance of remaining childless, and a higher chance of having a partner.)  The same effect wasn't seen in women, who had the highest reproductive success when they were of average height.  The study suggests this may be because taller women had a smaller chance of finding a mate, while shorter women were at higher risk of losing a child.

Because tall men are likely to pass on the genes that made them tall, the outcome suggests that—in contrast to Americans—the Dutch population is evolving to become taller, Stulp says. "This is not what we've seen in other studies—that's what makes it exciting," says evolutionary biologist Simon Verhulst of the University of Groningen in the Netherlands, who was Stulp's Ph.D. adviser but wasn't involved in the current study. Verhulst points out that the team can't be certain that genes involved in height are actually becoming more frequent, however, as the authors acknowledge.

The study suggests that sexual selection is at work in the Dutch population, Stearns says: Dutch women may prefer taller men because they expect them to have more resources to invest in their children. But there are also other possibilities. It could be that taller men are more resistant to disease, Stearns says, or that they are more likely to divorce and start a second family. "It will be a difficult question to answer.”

Another question is why tall men in Holland are at a reproductive advantage but those in the United States are not. Stulp says he can only speculate. One reason may be that humans often choose a partner who's not much shorter or taller than they are themselves. Because shorter women in the United States have more children, tall men may do worse than those of average height because they're less likely to partner with a short woman.

In the end, Stearns says, the advantage of tall Dutchmen may be only temporary. Often in evolution, natural selection will favor one trend for a number of generations, followed by a stabilization or even a return to the opposite trend. In the United States, selection for height appears to have occurred several centuries ago, leading to taller men, and then it stopped. "Perhaps the Dutch caught up and actually overshot the American men," he says.

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Citizen Scientists Find Green Blobs in Hubble Galaxy Shots

April 3, 2015 / / 0 Comments





Excerpt from wired.com

In 2007, A Dutch schoolteacher named Hanny var Arkel discovered a weird green glob of gas in space. Sifting through pictures of galaxies online, as part of the citizen science project Galaxy Zoo, she saw a cloud, seemingly glowing, sitting next to a galaxy. Intrigued, astronomers set out to find more of these objects, dubbed Hanny’s Voorwerp (“Hanny’s object” in Dutch). Now, again with the help of citizen scientists, they’ve found 19 more of them, using the Hubble space telescope to snap the eight haunting pictures in the gallery above.



Since var Arkel found the first of these objects, hundreds more volunteers have swarmed to help identify parts of the universe in the Galaxy Zoo gallery. To find this new set, a couple hundred volunteers went through nearly 16,000 pictures online (seven people went through all of them), clicking yes/no/maybe as to whether they saw a weird green blob. Astronomers followed up on the galaxies they identified using ground-based telescopes, and confirmed 19 new galaxies surrounded by green gas.



What causes these wispy tendrils of gas to glow? Lurking at the center of each of these galaxies is a supermassive black hole, millions to billions times as massive as the sun, with gravity so strong that even light can’t escape them. As nearby gas and dust swirls into the black hole, like water circling a drain, that material heats up, producing lots of radiation—including powerful ultraviolet. Beaming out from the galaxy, that ultraviolet radiation strikes nearby clouds of gas, left over from past collisions between galaxies. And it makes the clouds glow an eerie green. “A lot of these bizarre forms we’re seeing in the images arise because these galaxies either interacted with a companion or show evidence they merged with a smaller galaxy,” says William Keel, an astronomer at the University of Alabama, Tuscaloosa.



The eight in this gallery, captured with Hubble, are especially weird. That’s because the quasar, the black-hole engine that’s supposed to be churning out the ultraviolet radiation, is dim—too dim, in fact, to be illuminating the green gas. Apparently, the once-bright quasar has faded. But because that UV light takes hundreds of thousands of years to travel, it can continue to illuminate the gas long after its light source has died away.  


Hubble finds phantom objects close to dead quasars

That glowing gas can tell astronomers a lot about the quasar that brought it to light. “What I’m so excited about is the fact that we can use them to do archaeology,” says Gabriela Canalizo, an astronomer at the University of California, Riverside, who wasn’t part of the new research. Because the streaks of gas are so vast, stretching up to tens of thousands of light years, the way they glow reveals the history of the radiation coming from the quasar. As the quasar fades, so will the gas’s glow, with the regions of gas closer to the quasar dimming first. By analyzing how the glow dwindles with distance from the quasar, astronomers can determine how fast the quasar is fading. “This was something we’ve never been able to do,” Canalizo says.

Measuring how fast the quasar fades allows astronomers to figure out exactly what’s causing it to turn off in the first place. “What makes them dim is running out of material to eat,” Canalizo says. That could happen if the quasar is generating enough radiation to blow away all the gas and dust surrounding the black hole—the same gas and dust that feeds it. Without a steady diet, the quasar is powerless to produce radiation. Only if more gas happens to make its way toward the black hole can the quasar turn on again. The glowing gas can provide details of this process, and if other mechanisms are at play.

With more powerful telescopes, astronomers will likely find many more. Hanny’s Verwoort, it turns out, may not be that weird after all.

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What happens to your body when you give up sugar?

March 4, 2015 / / 0 Comments





Excerpt from independent.co.uk
By Jordan Gaines Lewis


In neuroscience, food is something we call a “natural reward.” In order for us to survive as a species, things like eating, having sex and nurturing others must be pleasurable to the brain so that these behaviours are reinforced and repeated.
Evolution has resulted in the mesolimbic pathway, a brain system that deciphers these natural rewards for us. When we do something pleasurable, a bundle of neurons called the ventral tegmental area uses the neurotransmitter dopamine to signal to a part of the brain called the nucleus accumbens. The connection between the nucleus accumbens and our prefrontal cortex dictates our motor movement, such as deciding whether or not to taking another bite of that delicious chocolate cake. The prefrontal cortex also activates hormones that tell our body: “Hey, this cake is really good. And I’m going to remember that for the future.”
Not all foods are equally rewarding, of course. Most of us prefer sweets over sour and bitter foods because, evolutionarily, our mesolimbic pathway reinforces that sweet things provide a healthy source of carbohydrates for our bodies. When our ancestors went scavenging for berries, for example, sour meant “not yet ripe,” while bitter meant “alert – poison!”
Fruit is one thing, but modern diets have taken on a life of their own. A decade ago, it was estimated that the average American consumed 22 teaspoons of added sugar per day, amounting to an extra 350 calories; it may well have risen since then. A few months ago, one expert suggested that the average Briton consumes 238 teaspoons of sugar each week.
Today, with convenience more important than ever in our food selections, it’s almost impossible to come across processed and prepared foods that don’t have added sugars for flavour, preservation, or both.
These added sugars are sneaky – and unbeknown to many of us, we’ve become hooked. In ways that drugs of abuse – such as nicotine, cocaine and heroin – hijack the brain’s reward pathway and make users dependent, increasing neuro-chemical and behavioural evidence suggests that sugar is addictive in the same way, too.

Sugar addiction is real

Anyone who knows me also knows that I have a huge sweet tooth. I always have. My friend and fellow graduate student Andrew is equally afflicted, and living in Hershey, Pennsylvania – the “Chocolate Capital of the World” – doesn’t help either of us. But Andrew is braver than I am. Last year, he gave up sweets for Lent. “The first few days are a little rough,” Andrew told me. “It almost feels like you’re detoxing from drugs. I found myself eating a lot of carbs to compensate for the lack of sugar.”
There are four major components of addiction: bingeing, withdrawal, craving, and cross-sensitisation (the notion that one addictive substance predisposes someone to becoming addicted to another). All of these components have been observed in animal models of addiction – for sugar, as well as drugs of abuse.
A typical experiment goes like this: rats are deprived of food for 12 hours each day, then given 12 hours of access to a sugary solution and regular chow. After a month of following this daily pattern, rats display behaviours similar to those on drugs of abuse. They’ll binge on the sugar solution in a short period of time, much more than their regular food. They also show signs of anxiety and depression during the food deprivation period. Many sugar-treated rats who are later exposed to drugs, such as cocaine and opiates, demonstrate dependent behaviours towards the drugs compared to rats who did not consume sugar beforehand.
Like drugs, sugar spikes dopamine release in the nucleus accumbens. Over the long term, regular sugar consumption actually changes the gene expression and availability of dopamine receptors in both the midbrain and frontal cortex. Specifically, sugar increases the concentration of a type of excitatory receptor called D1, but decreases another receptor type called D2, which is inhibitory. Regular sugar consumption also inhibits the action of the dopamine transporter, a protein which pumps dopamine out of the synapse and back into the neuron after firing.
In short, this means that repeated access to sugar over time leads to prolonged dopamine signalling, greater excitation of the brain’s reward pathways and a need for even more sugar to activate all of the midbrain dopamine receptors like before. The brain becomes tolerant to sugar – and more is needed to attain the same “sugar high.”

Sugar withdrawal is also real

Although these studies were conducted in rodents, it’s not far-fetched to say that the same primitive processes are occurring in the human brain, too. “The cravings never stopped, [but that was] probably psychological,” Andrew told me. “But it got easier after the first week or so.”
In a 2002 study by Carlo Colantuoni and colleagues of Princeton University, rats who had undergone a typical sugar dependence protocol then underwent “sugar withdrawal.” This was facilitated by either food deprivation or treatment with naloxone, a drug used for treating opiate addiction which binds to receptors in the brain’s reward system. Both withdrawal methods led to physical problems, including teeth chattering, paw tremors, and head shaking. Naloxone treatment also appeared to make the rats more anxious, as they spent less time on an elevated apparatus that lacked walls on either side.
Similar withdrawal experiments by others also report behaviour similar to depression in tasks such as the forced swim test. Rats in sugar withdrawal are more likely to show passive behaviours (like floating) than active behaviours (like trying to escape) when placed in water, suggesting feelings of helplessness.
A new study published by Victor Mangabeira and colleagues in this month’s Physiology & Behavior reports that sugar withdrawal is also linked to impulsive behaviour. Initially, rats were trained to receive water by pushing a lever. After training, the animals returned to their home cages and had access to a sugar solution and water, or just water alone. After 30 days, when rats were again given the opportunity to press a lever for water, those who had become dependent on sugar pressed the lever significantly more times than control animals, suggesting impulsive behaviour.
These are extreme experiments, of course. We humans aren’t depriving ourselves of food for 12 hours and then allowing ourselves to binge on soda and doughnuts at the end of the day. But these rodent studies certainly give us insight into the neuro-chemical underpinnings of sugar dependence, withdrawal, and behaviour.
Through decades of diet programmes and best-selling books, we’ve toyed with the notion of “sugar addiction” for a long time. There are accounts of those in “sugar withdrawal” describing food cravings, which can trigger relapse and impulsive eating. There are also countless articles and books about the boundless energy and new-found happiness in those who have sworn off sugar for good. But despite the ubiquity of sugar in our diets, the notion of sugar addiction is still a rather taboo topic.
Are you still motivated to give up sugar? You might wonder how long it will take until you’re free of cravings and side-effects, but there’s no answer – everyone is different and no human studies have been done on this. But after 40 days, it’s clear that Andrew had overcome the worst, likely even reversing some of his altered dopamine signalling. “I remember eating my first sweet and thinking it was too sweet,” he said. “I had to rebuild my tolerance.”
And as regulars of a local bakery in Hershey – I can assure you, readers, that he has done just that.
Jordan Gaines Lewis is a Neuroscience Doctoral Candidate at Penn State College of Medicine

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Mummified monk revealed inside Buddha statue

February 23, 2015 / / 0 Comments


635603189441117628-mummy-buddha



Excerpt from usatoday.com

The mummified remains of a monk have been revealed inside a nearly 1,000-year old Chinese statue of a Buddha.

The mummy inside the gold-painted papier-mâché statue is believed to be that of Liuquan, a Buddhist master of the Chinese Meditation School who died around the year 1100, researchers said. It's the only Chinese Buddhist mummy to undergo scientific research in the West.

The statue was on display last year at the Drents Museum as part of an exhibit on mummies. It was an cited as an example of self-mummification, an excruciating, years-long process of meditation, starvation, dehydration and poisoning that some Buddhist monks undertook to achieve enlightenment and veneration.

When the exhibit ended in August, a CT scan at the Meander Medical Center in the Netherlands revealed the seated skeleton. Samples taken from organ cavities provided one big surprise: paper scraps printed with ancient Chinese characters indicating the high-status monk may have been worshiped as a Buddha.

A CT scan has revealed a mummified Chinese monk inside a Buddha statue. The remains date back about 1,000 years. Video provided by Newsy Newslook
The finding was first reported in December but did not get wide notice. Irish Archaeology carried a report over the weekend, which apparently started the news ball rolling.

But the revelation is not, as some reports claim, "a shocking discovery," The History Blog notes: "It was known to be inside the statue all along ... that's why it was sent to the Drents Museum in the first place as part of the Mummies exhibition."

The mummy's existence was discovered in 1996 when the statue was being restored in the Netherlands, Live Science writes, explaining what was found, how its age was determined and when the first detailed skeletal imaging was performed.




DNA tests were conducted on bone samples, and the Dutch team plans to publish its finding in a forthcoming monograph.
Researchers still have not determined whether the monk mummified himself, a practice that was also widespread in Japan and that was outlawed in the 19th century. If he did, the process was gruesome, as Ancient Origins explains:
For the first 1,000 days, the monks ceased all food except nuts, seeds, fruits and berries and they engaged in extensive physical activity to strip themselves of all body fat. For the next one thousand days, their diet was restricted to just bark and roots. Near the end of this period, they would drink poisonous tea made from the sap of the Urushi tree, which caused vomiting and a rapid loss of body fluids. It also acted as a preservative and killed off maggots and bacteria that would cause the body to decay after death.
In the final stage, after more than six years of torturous preparation, the monk would lock himself in a stone tomb barely larger than his body, where he would go into a state of meditation. He was seated in the lotus position, a position he would not move from until he died. A small air tube provided oxygen to the tomb. Each day, the monk rang a bell to let the outside world know he was still alive. When the bell stopped ringing, the tube was removed and the tomb sealed for the final thousand day period of the ritual.
At the end of this period, the tomb would be opened to see if the monk was successful in mummifying himself. If the body was found in a preserved state, the monk was raised to the status of Buddha, his body was removed from the tomb and he was placed in a temple where he was worshiped and revered. If the body had decomposed, the monk was resealed in his tomb and respected for his endurance, but not worshiped
If you find yourself in Budapest before May, the Buddha mummy statue is on display at the Hungarian Natural History Museum.

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History Repeating? Study shows Ancient cities were bigger and denser, just like modern cities

February 21, 2015 / / 0 Comments




Excerpt from  thenextdigit.com

Recently, a new research has been done, which found that the ancient cities were similar to the current modern-day cities in terms of size as well as the density of those settlements. In the research paper, the researcher explains that modern cities with large amount of populations as well as density, are similar to the characteristics of ancient cities. The research claims that the character of the inhabitants of ancient cities is similar to those of inhabitants of modern cities.

 The study was done by the researchers at Santa Fe Institute and at the University of Colorado Boulder. The main objective of the researchers is to find the functionality of the settlements and they started to find out whether current cities and ancient cities are similar in nature.

Scott Ortman, Researcher at Department of Anthropology, University of Colorado Boulder says,
“Our findings indicate the fundamental processes behind the emergence of scaling in modern cities have structured human settlement organization throughout human history, and that contemporary urban systems are best-conceived as lying on a continuum with the smaller-scale settlement systems known from historical and archaeological research.”
The researcher grouped together and analyzes the structures as well as dimensions of both cities and estimated the way of construction of monuments, housing styles, the amount of people stayed in a region and so on. They found the place or region where the density was high, the productivity was more.

Ortman also said that the results were amazing and unbelievable for them and added that the modern world is radically different from the ancient world with its capitalism, democracy, industrialization and so on. They also noticed that, once the population of a particular area grew, then the productivity of that same place rose high. Even a few patterns that are used in the ancient human societies were same as that we are following in our modern urban system.
“It was amazing and unbelievable,” Ortman said. “We’ve been raised on a steady diet, telling us that, thanks to capitalism, industrialization, and democracy, the modern world is radically different from worlds of the past. What we found here is that the fundamental drivers of robust socioeconomic patterns in modern cities precede all that.”

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10 Tips for Easy & Healthy Transition to a Vegan Diet ~ With Teshia Maher

October 19, 2014 / / 0 Comments

I've been getting a lot of questions from you guys regarding going vegan. So I invited over my friend Teshia Maher, a talented yoga instructor and a holistic nutritionist, to share with me and all of you her top 10 tips on how to become a vegan.&nbs...

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Mysteries of the Early Human Ancestors #1 ~ Why did we grow large brains?

September 25, 2014 / / 0 Comments

Human brains are about three times as large as those of our early australopithecines ancestors that lived 4 million to 2 million years ago, and for years, scientists have wondered how our brains got so big. A new study suggests social competition could be behind the increase in brain size. Credit NIH, NADA

livescience.com

There are many ways to try to explain why human brains today are so big compared to those of early humans, but the major cause may be social competition, new research suggests. 

But with several competing ideas, the issue remains a matter of debate. 

Compared to almost all other animals, human brains are larger as a percentage of body weight. And since the emergence of the first species in our Homo genus (Homo habilis) about 2 million years ago, the human brain has doubled in size. And when compared to earlier ancestors, such as australopithecines that lived 4 million to 2 million years ago, our brains are three times as large. For years, scientists have wondered what could account for this increase.

The three major hypotheses have focused on climate change, the demands of ecology, and social competition. A new statistical analysis of data on 175 fossil skulls supports the latter hypothesis. 

Behind the hypotheses

The climate idea proposes that dealing with unpredictable weather and major climate shifts may have increased the ability of our ancestors to think ahead and prepare for these environmental changes, which in turn led to a larger, more cognitively adept brain.
The ecology hypothesis states that, as our ancestors migrated away from the equator, they encountered environmental changes, such as less food and other resources. "So you have to be a little bit more clever to figure it out," said David Geary, a professor from the University of Missouri. Also, less parasite exposure could have played a role in the makings of a bigger brain. When your body combats parasites, it cranks up its immune system, which uses up calories that could have gone to boost brain development. Since there are fewer parasites farther away from the equator, migrating north or south could have meant that our predecessors had more opportunity to grow a larger brain because their bodies were not fighting off as many pathogens.

Finally, other researchers think that social competition for scarce resources influenced brain size. As populations grow, more people are contesting for the same number of resources, the thinking goes. Those with a higher social status, who are "a little bit smarter than other folks" will have more access to food and other goods, and their offspring will have a higher chance of survival, Geary said.

Those who are not as socially adept will die off, pushing up the average social "fitness" of the group. "It's that type of process, that competition within a species, for status, for control of resources, that cycles over and over again through multiple generations, that is a process that could easily explain a very, very rapid increase in brain size," Geary said.

Weighing the options

To examine which hypothesis is more likely, Geary and graduate student Drew Bailey analyzed data from 175 skull fossils — from humans and our ancestors — that date back to sometime between 10,000 ago and 2 million years ago.

The team looked at multiple factors, including how old the fossils were, where they were found, what the temperature was and how much the temperature varied at the time the Homo species lived, and the level of parasites in the area. They also looked at the population density of the region in order to measure social competition, "assuming that the more fossils you find in a particular area at a particular time, the more likely the population was larger," Geary said.

They then used a statistical analysis to test all of the variables at once to see how well they predicted brain size. "By far the best predictor was population density," Geary said. "And in fact, it seemed that there was very little change in brain size across our sample of fossil skulls until we hit a certain population size. Once that population density was hit, there was a very quick increase in brain size," he said.

Looking at all the variables together allowed the researchers to "separate out which variables are really important and which variables may be correlated for other reasons," added Geary. While the climate variables were still significant, their importance was much lower than that of population density, he said. The results were published in the March 2009 issue of the journal Human Nature.

Questions linger

The social competition hypothesis "sounds good," said Ralph Holloway, an anthropologist at Columbia University, who studies human brain evolution. But, he adds: "How would you ever go about really testing that with hard data?" 

He points out that the sparse cranium data "doesn’t tell you anything about the differences in populations for Homo erectus, or the differences in populations of Neanderthals." For example, the number of Homo erectus crania that have been found in Africa, Asia, Indonesia and parts of Europe is fewer than 25, and represent the population over hundreds of thousands of years, he said. 

"You can't even know the variation within a group let alone be certain of differences between groups," Holloway said. Larger skulls would be considered successful, but "how would you be able to show that these were in competition?" 

However, Holloway is supportive of the research. "I think these are great ideas that really should be pursued a little bit more," he said. 

Alternative hypotheses

Holloway has another hypothesis for how our brains got so big. He thinks that perhaps increased gestation time in the womb or increased dependency time of children on adults could have a played role. The longer gestation or dependency time "would have required more social cooperation and cognitive sophistication on the part of the parents," he said. Males and females would have needed to differentiate their social roles in a complementary way to help nurture the child. The higher level of cognition needed to perform these tasks could have led to an increase in brain size.


Still other hypotheses look at diet as a factor. Some researchers think that diets high in fish and shellfish could have provided our ancestors with the proper nutrients they needed to grow a big brain.
And another idea is that a decreased rate of cell death may have allowed more brain neurons to be synthesized, leading to bigger noggins. 

Ultimately, no theory can be absolutely proven, and the scant fossil record makes it hard to test hypotheses. "If you calculate a generation as, let's say, 20 years, and you know that any group has to have a minimal breeding size, then the number of fossils that we have that demonstrates hominid evolution is something like 0.000001 percent," Holloway said. "So frankly, I mean, all hypotheses look good."

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The Light Side of the Dark Night of the Soul

September 24, 2014 / / 0 Comments

by Kim Hutchinson Clayhut Healing CentreThe phenomenon known as the Dark Night of the Soul is something which many spiritual seekers experience on their journey to re-enlightenment. It can be a painful and frightening process, but it can also be liberating and empowering. It all depends on your perspective and your ability to remain detached. Peeling the Onion The word ‘night’ is misleading. This is a process, and thankfully so. I doubt you would want to experience [...]

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