| Multiple waves of migration revealed in first detailed genetic history of Europe!

Modern Europe’s Genetic History Starts in Stone Age ~ Ker Than, for National Geographic News.

Scientists create the first detailed genetic history of modern Europe.

Young men in Breisgau, Germany, in the 1920s.

A group of men from the German-based Breisgau corps pose for a picture in the 1920s. Photograph by Hans Hildenbrand, National Geographic

Europeans as a people are younger than we thought, a new study suggests.

DNA recovered from ancient skeletons reveals that the genetic makeup of modern Europe was established around 4,500 B.C. in the mid-Neolithic—or 6,500 years ago—and not by the first farmers who arrived in the area around 7,500 years ago or by earlier hunter-gatherer groups. (Read about Europes oldest known town.)

“The genetics show that something around that point caused the genetic signatures of previous populations to disappear,” said Alan Cooper, director of the Australian Centre for Ancient DNA at the University of Adelaide, where the research was performed.

“However, we don’t know what happened or why, and [the mid-Neolithic] has not been previously identified as [a time] of major change,” he said.

Furthermore, the origins of the mid-Neolithic populations that did form the basis of modern Europe are also unknown.

“This population moves in around 4,000 to 5,000 [B.C.], but where it came from remains a mystery, as we can’t see anything like it in the areas surrounding Europe,” Cooper said.

The surprising findings are part of a new study, published in this week’s issue of the journal Nature Communications, that provides the first detailed genetic history of modern Europe.

The study shows that “relatively recent migrations seem to have had a significant genetic impact on the population of Central Europe,” said study co-author Spencer Wells, who leads National Geographics Genographic Project. (Read about Europe’s “Wild Men” in National Geographic magazine.)

Genetic Signature

In the study, Cooper and his colleagues extracted mitochondrial DNA—which children inherit only from their mothers—from the teeth and bones of 39 skeletons found in central Germany. The skeletons ranged in age from about 7,500 to 2,500 years old.

The team focused on a group of closely related mitochondrial lineages—mutations in mitochondrial DNA that are similar to one another—known as haplogroup H, which is carried by up to 45 percent of modern Europeans.

Cooper and his colleagues focused on haplogroup H because previous studies have indicated the mutations might have been present in Europeans’ genetic makeup for several thousand years.

It’s unclear how this haplogroup became dominant in Europe. Some scientists have proposed that it spread across the continent following a population boom after the end of the last ice age about 12,000 years ago.

But the new data paint a different picture of the genetic foundation of modern Europe: Rather than a single or a few migration events, Europe was occupied several times, in waves, by different groups, from different directions and at different times.

The first modern humans to reach Europe arrived from Africa 35,000 to 40,000 years ago. By about 30,000 years ago, they were widespread throughout the area while their close cousins, the Neanderthals, disappeared. Hardly any of these early hunter-gatherers carried the H haplogroup in their DNA.

About 7,500 years ago during the early Neolithic period, another wave of humans expanded into Europe, this time from the Middle East. They carried in their genes a variant of the H haplogroup, and in their minds knowledge of how to grow and raise crops. (Related: Egypts Earliest Farming Village Found.)

Archeologists call these first Central European farmers the linear pottery culture (LBK)—so named because their pottery often had linear decorations.

The genetic evidence shows that the appearance of the LBK farmers and their unique H haplogroups coincided with a dramatic reduction of the U haplogroup—the dominant haplogroup among the hunter-gatherers living in Europe at that time.

Farmers Move In

The findings settle a longstanding debate among archaeologists, said Wells, who is also a National Geographic explorer-in-residence.

Archaeology alone can’t determine whether cultural movements—such as a new style of pottery or, in this case, farming—were accompanied by the movements of people, Wells said in an email.

“In this study we show that changes in the European archaeological record are accompanied by genetic changes, suggesting that cultural shifts were accompanied by the migration of people and their DNA.”

The LBK group and its descendants were very successful and spread quickly across Europe. “They became the first pan-European culture, if you like,” Cooper said.

Given their success, it would be natural to assume that members of the LBK culture were significant genetic ancestors of many modern Europeans.

But the team’s genetic analysis revealed a surprise: About 6,500 years ago in the mid-Neolithic, the LBK culture was itself displaced. Their haplogroup H types suddenly became very rare, and they were subsequently replaced by populations bearing a different set of haplogroup H variations.

Mysterious Turnover

The details of this “genetic turnover” event are murky. Scientists don’t know what prompted it, or even where the new colonizers came from.

“The extent or nature of this genetic turnover are not clear, and we don’t know how widespread it is,” Cooper said.

If this turnover were widespread, it could have been prompted by climate change or disease, he said.

“All we know is that the descendants of the LBK farmers disappeared from Central Europe about 4,500 [B.C.], clearing the way for the rise of populations from elsewhere, with their own unique H signatures.”

Peter Bogucki, an archeologist at Princeton University who has studied early farming societies in Europe, called the finding “really interesting” and noted the timing of the genetic turnover is curious.

“At the end of the fifth millennium—[about] 4,000 B.C.—there are a lot of changes in the archeological record,” said Bogucki, who was not involved in the study.

For example, the long houses that LBK farmers and their descendants favored became less common. Also, the settlement patterns of people living in Central Europe began changing, as did their stone tools.

“There are major transformations during this time that haven’t really been all that well explained in interior Central Europe,” Bogucki said.

“It looks like the whole system of agricultural settlement that got established with the LBK ran its course through the fifth millennium and something caused people to change.”

Of Unknown Origins

Bogucki agrees that climate change might have been a trigger for the change in Europe’s genetic makeup, but he thinks it was only a factor and not the sole cause.

One thing that is clear from the genetic data is that nearly half of modern Europeans can trace their origins back to this mysterious group.

“About [4,500 B.C.], you start seeing a diversity and composition of genetic signatures that are beginning to look like modern [Central] Europe,” Cooper said. “This composition is then modified by subsequent cultures moving in, but it’s the first point at which you see something like the modern European genetic makeup in place.”

Whatever prompted the replacement of genetic signatures from the first pan-European culture, Cooper is clearly intrigued. “Something major happened,” he said in a statement, “and the hunt is now on to find out what that was.”

Correction: The original version of this article stated that the genetic makeup of modern Europeans emerged 4,500 years ago. The text has been updated to reflect the correct timing as 4,500 B.C., or 6,500 years ago.

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anti-racismA

Racism Wrong

| Friday the 13th: Why We Fear It; Why It Can’t Strike Again in 2012!

Friday the 13th: Why We Fear It; Why It Can’t Strike Again in 2012! ~ John Roach, National Geographic News.

 

Today is third Friday the 13th of the year—the maximum possible.

 

A painting of Cain killing Abel.

The biblical figure Cain is said to have killed his brother, Abel, on Friday the 13th.

Photograph by A. De Gregorio, DEA/Getty Images

 

Triskaidekaphobia sufferers, your nightmare is nearly over. Though today is the third Friday the 13th of 2012, another is impossible, at least as long as we mark time with the Gregorian calendar.

“You can’t have any [years] with none, and you can’t have any with four, because of our funny calendar,” mathemetician Underwood Dudley said.

In many ways the Gregorian calendar, which Pope Gregory XIII ordered the Catholic Church to adopt in 1582, works just like its predecessor, the Julian calendar—with a leap year every four years.

But the Gregorian calendar skips leap year on century years except those divisible by 400. For example, there was no leap year in 1900, but there was one in 2000. This trick keeps the calendar in tune with the seasons.

The result is an ordering of day-dates that repeats itself every 400 years, noted Dudley, a professor emeritus at DePauw University in Indiana, and author ofNumerology: Or, What Pythagoras Wrought.

As time marches through the order, some years appear with three Friday the 13ths. Other years have two or, like 2011, one.

“It’s just that curious way our calendar is constructed, with 28 days in February and all those 30s and 31s,” Dudley said.

When the 400-year order is laid out, another revelation occurs: The 13th falls on Friday more often than on any other day of the week. “It’s just a funny coincidence,” Dudley said.

(Related: “Leap Year: How the World Makes Up for Lost Time.”)

Friday the 13th Superstitions

Friday the 13th superstitions are rooted in ancient bad-luck associations with the number 13 and the day Friday, said Donald Dossey, a folklore historian and author of Holiday Folklore, Phobias and Fun.

The two unlucky entities ultimately combined to make one super unlucky day.

Dossey traces the fear of 13 to a Norse myth about 12 gods having a dinner party. In walks the uninvited 13th guest, the mischievous Loki. Once there, Loki arranges for Hoder, the blind god of darkness, to shoot Balder the Beautiful, the god of joy and gladness, with a mistletoe-tipped arrow.

“Balder died, and the whole Earth got dark. The whole Earth mourned. It was a bad, unlucky day,” Dossey said.

There is also a biblical reference to 13 as an unlucky number. Judas, the apostle said to have betrayed Jesus, was the 13th guest to the Last Supper. (See “Lost Gospel Revealed; Says Jesus Asked Judas to Betray Him.”)

Meanwhile, in ancient Rome, witches reportedly gathered in groups of 12. The 13th was believed to be the devil.

Thomas Fernsler, an associate policy scientist in the Mathematics and Science Education Resource Center at the University of Delaware in Newark, said the number 13 suffers because of its position after 12.

According to Fernsler, numerologists consider 12 a “complete” number. There are 12 months in a year, 12 signs of the zodiac, 12 gods of Olympus, 12 labors of Hercules, 12 tribes of Israel, and 12 apostles of Jesus.

Fernsler said 13’s association with bad luck “has to do with just being a little beyond completeness. The number becomes restless or squirmy.”

As for Friday, it’s well known among Christians as the day Jesus was crucified. Plus, some biblical scholars believe Eve tempted Adam with the forbidden fruit on Friday. Perhaps most significant is a belief that Abel was slain by his brother Cain on Friday the 13th.

Paralyzed with Fear on Friday the 13th

Some people are so paralyzed with superstition on Friday the 13th that they refuse to fly, buy a house, or act on a hot stock tip.

“It’s been estimated that [U.S] $800 or $900 million is lost in business on this day because people will not fly or do business they would normally do,” said Dossey, who is also the founder of the Stress Management Center and Phobia Institute in Asheville, North Carolina.

Among other services, Dossey’s organization counsels clients on how to overcome fear of Friday the 13th, a phobia that he estimates afflicts 17 to 21 million people in the United States.

Symptoms range from mild anxiety to full-blown panic attacks. The latter may cause people to reshuffle schedules or miss an entire day’s work.

When it comes to bad luck of any kind, Richard Wiseman—a psychologist at the University of Hertfordshire in Hatfield, England—found that people who consider themselves unfortunate are more likely to believe in superstitions associated with bad luck.

“Their beliefs and behavior are likely to be part of a much bigger worldview,” he said. “They will believe that luck is a magical force and that it can ruin their lives.”

Where’s the 13th Floor?

This fear of 13 can be seen even in how societies are built. More than 80 percent of high-rise buildings lack a 13th floor, for example. And many airports skip the 13th gate. Hospitals and hotels regularly have no room number 13.

On streets in Florence, Italy, the house between number 12 and 14 is addressed as 12 1/2. In France socialites known as the quatorziens(fourteeners) once made themselves available as 14th guests to keep a dinner party from an unlucky fate.

DePauw University’s Dudley said nobody really knows why Friday the 13th is considered unlucky.

“You’ve got to have something that is unlucky, and somehow they hit on 13,” he said. “But all these explanations are just moonshine.”

| Partial Lunar Eclipse Monday—During a “Supermoon!”

Partial Lunar Eclipse Monday—During a “Supermoon” ~ Ker Than, National Geographic News.

Earth’s shadow to take bite out of larger-than-normal full moon.

 

A partial lunar eclipse above Greek mountains.

A partial lunar eclipse stains the full moon red in an undated file picture.

Photograph by Detlev van Ravenswaay, Picture Press/Alamy

 

Earth‘s dark shadow will appear to take a bite out of the full moon Monday during a partial lunar eclipse.

At the same time, the moon will be at perigee—the lunar orb’s closest approach during its egg-shaped orbit around our planet—creating an eclipsed “supermoon.”

Lunar eclipses happen when the full moon, Earth, and the sun are lined up so that the moon crosses through Earth’s shadow. (See lunar eclipse pictures.)

“It’s a very cool kind of thing to see. It gives us an almost 3-D feeling for space that we don’t normally get,” said Mark Hammergren, an astronomer at the Adler Planetarium in Chicago.

Coined in 1979, the term “supermoon” is often used to describe a full or new moon that coincides with perigee—something that happens about once a year, on average. (Related: Titanic Sunk by ‘Supermoon’ and Celestial Alignment?”)

We don’t see an eclipse with every full moon because our natural satellite follows a tilted orbit around Earth. This tilt also means that an eclipse can be full or partial, depending on how much of the lunar disk falls in our planet’s shadow.

The last total lunar eclipse was in December 2011, and the next one doesn’t happen until April 2014.

Monday’s partial eclipse will be visible to sky-watchers in most of North and South America during the early hours before sunrise.

Meanwhile, observers in Australia, the eastern parts of Asia, and across the Pacific Ocean will see the partial lunar eclipse Monday evening just after sunset.

The eclipse will last for more than two hours and will reach its peak around 4 a.m. PT, when about a third of the moon’s disk will be covered in shadow.

Lunar Eclipse Writ Large

In early May the moon was at perigee within minutes of the official full moon phase, creating a supermoon that appeared 16 percent bigger and 30 percent brighter than the year’s other full moons.

Next week the moon will officially reach perigee the day before the full moon, swinging just 222,750 miles (358,482 kilometers) from Earth.

But the lunar orb is only 0.26 percent farther away on the days before and after its closest approach, Hammergren said.

That means the full moon will still look slightly larger than normal during Monday’s partial eclipse.

“It won’t be a very noticeable effect,” Hammergren said. “The full moon will look only about 5 percent larger than it does on average, appearing perhaps just a little bigger than it usually does.”

Still, he added in an email, a supermoon eclipse is a relatively rare sight.

“If you restrict the label of ‘perigee’ to within only one day of true perigee, then such eclipses will only occur every 10 to 12 years.”

(Related: “Lunar Eclipse + Winter Solstice—First in 372 Years.”)

Eclipse “Visible Proof” of Earth’s Shape

While partial lunar eclipses are entertaining events for modern sky-watchers, in ancient times they served as some of the first evidence that Earth is not flat, Hammergren added.

“The Greeks understood that lunar eclipses happen when the shadow of the Earth is falling on the moon,” Hammergren said.

(Related: “Ancient Eclipse Found in The Odyssey, Scientists Say.”)

During a partial eclipse, Earth’s shadow on the moon’s face clearly traces a circle.

“No matter what your angle was when the eclipse occurred, the shadow was always circular. And the only thing that projects a circular shadow no matter its orientation is a sphere,” he said.

If Earth was flat, by contrast, the shadow would sometimes appear as a thin line or a squashed oval.

An eclipse, therefore, is “visible proof that anyone can see.”