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Research suggests that Carolina dogs are without some genetic markers indicative of European origin, suggesting they arrived from Asia.

JOHN W. ADKISSON • New York Times,

THINK YOU HAD A LONG DAY? YOU MIGHT BE RIGHT

Three times in the past decade, the Earth’s spin has missed a beat as seemingly random blips cause days to temporarily stretch and shrink. They have emerged from the clearest-ever view of how long a day is.

Richard Holme of the University of Liverpool looked at 50 years of GPS and astronomical data to see how day length varied during that time. His analysis highlighted a well-known cycle of slow changes at the Earth’s core, which lengthen days by a few milliseconds over roughly a decade, then shorten them again. There’s also a 5.9-year cycle, due to persistent friction between the Earth’s fluid outer core and its surrounding mantle, a wobble that changes day length by fractions of milliseconds a year.

When Holme stripped away both of these regular cycles, though, sudden unexpected jumps in day length emerged. Three times in recent years — 2003, 2004 and 2007 — our planet’s spin has stuttered, a change that lasted several months.

Satellite readings of the planet’s magnetic field over the past 20 years show that the field also undergoes sudden jerks, and Holme found that they coincide with the jumps in the Earth’s spin. He says the sudden changes probably occur when a patch of molten outer core temporarily sticks to the mantle, causing a steep change in angular velocity.

NEW SCIENTIST

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The geothermal power plants at Southern California’s Salton Sea don’t just produce electricity, they also trigger thousands of earthquakes not far from one of the West Coast’s most dangerous fault lines, a new study says.

Research published online recently in the journal Science found that as production rose at the Imperial County geothermal field, so did the number of earthquakes. From 1981 through 2012, more than 10,000 earthquakes above magnitude 1.75 were recorded in the area.

“That group of earthquakes . is connected to the production,” said Emily Brodsky, a University of California, Santa Cruz, geophysicist and the paper’s lead author.

The largest quake during the three-decade study period was magnitude 5.1. The vast majority of quakes were small. But they are occurring about 12 miles from the southern end of the San Andreas fault, which seismologists predict will eventually rock Southern California with a devastating quake.

LOS ANGELES TIMES

New DNA findings support popular belief about breed's ancient origins

  • Article by: JACK HITT
  • New York Times
  • July 20, 2013 - 9:45 PM

Inside a fenced acre on the swampy Lynches River flood plain in central South Carolina, seven of Don Anderson’s primitive dogs spring into high alert at approaching strangers.

These are Carolina dogs, and though they are friendly, one can instantly sense they are different from other dogs; their jackal ears fully erect, their fishhook tails twitching like flags in a stiff wind.

Walking into the pen is dangerous for only one reason: one of the dogs’ defining habits is digging snout pits, or gallon-size holes in the ground, perhaps to root for grubs or eat the soil for nutrients.

“It’s like a lunar landscape,” Anderson warns as we tread carefully into the underbrush.

Some Carolina dogs still live in the wild, and local people have long thought they were one of the few breeds that predated the European arrival in the Americas:

“Our native dog,” as Michael Ruano, another enthusiast who often works with Anderson, put it. “America’s natural dog.”

Now, a new study of canine DNA backs up the folklore. A team led by Peter Savolainen at the Royal Institute of Technology in Sweden has reported that several dog breeds in the Americas — among them the Peruvian hairless, the Chihuahua and the Carolina dog — are without some genetic markers indicative of European origin, suggesting they arrived in an earlier migration from Asia.

The study also reawakens the long debate about where and how dogs were domesticated. Current theory speculates that they are descended from wolves that somehow became attached to humans perhaps 12,000 to 33,000 years ago.

China hypothesis

But where that may have happened is not entirely settled. Some say the earliest dogs emerged in the Middle East. Others point to an area south of the Yangtze River in China. Savolainen’s study provides more evidence for the China hypothesis and, as a result, lends support to the idea that the earliest domesticated dogs crossed the ice age land bridge known as Beringia some 12,000 years ago.

Anderson, 79, is a Virginian who moved to South Carolina in 1961. He remembers the day, back in the Nixon administration, when he had his first encounter with these wild dogs. Down by a nearby water hole on his land, he spied a mother and three pups, and they immediately bolted.

“Two of the puppies went east, and one puppy tried to get out west and he got stuck,” he explained. He took the pup home and named him Tadpole.

Anderson soon learned that others called them Carolina dogs, a name given to them by I. Lehr Brisbin, a biologist with the Savannah River nuclear power plant, near Aiken, and the man most responsible for the current interest in the breed.

In the early 1970s, Brisbin was employed checking out the wildlife on the periphery of the plant and often came upon these wild dogs in the swampier parts of his domain. He took a few in and today maintains an 18-acre enclosure where he has his own pack.

Rare traits

Brisbin got the Carolina dog recognized by the United Kennel Club and was the first to describe some of the breed’s rare traits, including the fishhook tail; the pointed, somewhat lupine face; and the habit of digging snout pits.

The dogs cooperate as a pack when they hunt a field mouse or a rabbit, possibly using their white hindquarters as signals.

“That white fishhook can be hoisted like a white-tailed deer’s and can flash back and forth,” Brisbin explained. “I saw them do it, and I saw the rest of the pack honor it.”

Carolina dogs typically go into heat once a year, like wolves, instead of twice, like domesticated dogs. They cover up their scat by pushing dirt over it with their noses, not by using their hindquarters to scratch the ground. Some have tiny patches, right above their distinctive almond eyes, that look like a spare set of eyes. Some have an unusual white stripe at the shoulder. There are the noticeable ears and the tail, but also the athletic tucked-in stomach (like a Doberman).

DNA studies may soon make it easier to assert the Carolina’s distinctions from other dogs.

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