House Cats' Wild Ancestor Found
Thu Jun 28, 3:20 PM ET
Domestic cats have been traced back to a single wild ancestor whose relatives still live in the remote deserts of the Middle East today.
The transformation of a vicious predator into a docile tabby took place some 10,000 years ago, a new genetic analysis suggests. That is the same time humans adopted an agricultural lifestyle in the Fertile Crescent. So the first of the friendly cats likely acted as a mouse hunter for grain-storage areas.
“We think that was the beginning of one of the most interesting natural history experiments ever done,” said Stephen O’Brien, a geneticist at the National Cancer Institute in Maryland, “which is the changing of a wild, ferocious predator into a friendly mouser that decided to hang its wagon on humankind.”
Until now, scientists knew close to nil about the genetic relationships between different types of cats, including wild versus domestic varieties.
Well-kempt housecats can and often do breed with wild species, which has made it tricky for scientists to distinguish between a hybrid wild-domestic feline and a purely wild or house variety.
Kitty genes
The key difference between the two is behavior. Domestic cats can live in groups and are generally not afraid of people. Since behavioral analyses of a large and diverse group of cats would be nearly impossible, an international research team turned to genetics.
Carlos Driscoll of the National Cancer Institute and his colleagues analyzed genetic material from nearly 1,000 cats, including domestic cats and the wild cat subspecies: the European wildcat, Near Eastern wildcat, Central Asian wildcat, southern African wildcat and Chinese desert cat.
They found that each wild group represents a subspecies of the wildcat Felis silvestris. The DNA from domestic cats matched up with that of the Near Eastern wildcat subspecies Felis silvestris lybica, which lives in the remote deserts of Israel and Saudi Arabia.
They detail the results this week in the online version of the journal Science.
Feline family
The lineage that includes the domestic cat and its wild relatives originated earlier than previously thought, about 130,000 years ago.
The cats probably took two separate routes out of the Middle East, the scientists speculate. One group trekked to Egypt while the others traveled from Mesopotamia to India, then to China and much later made their way to Japan.
As to when domestic cats popped onto the scene, Driscoll said they don’t have the information to make a valid estimate.
To solve that puzzle, scientists are turning to written historical records and archaeological evidence. For instance, Egyptian tomb paintings indicate that by 3,600 years ago domestic cats were living in Egypt, Driscoll said. And a cat and human burial site dating back 9,500 years was unearthed in Cyprus recently.
A possible boon to this puzzle, O’Brien mentioned, is the completion of the cat genome. O’Brien and his colleagues sequenced and characterized the genetic material from a domestic cat named Cinnamon living in Columbia, Missouri. They hope to find specific genes related to cat tameness.
And in other news, Scientists are still puzzled over the exact mechanism of purring.
Friday, June 29, 2007
Wednesday, June 27, 2007
not even swiffer can clean it up
Huge Dust Storm Breaks Out on Mars
Wed Jun 27, 2:45 PM ET
A major dust storm has developed on the red planet, blocking sunlight and prompting Mars mission managers to keep a close eye on it, SPACE.com has learned.
It is not known how large the storm might grow, but already it is thousands of miles across. If it balloons, as dust storms have done in the past, it could hamper operations of NASA's Mars rovers Spirit and Opportunity.
For now, officials don't think the storm will threaten rover operations, however. In fact, the windy conditions on the planet have blown off large amounts of dust from the rovers' solar arrays, giving them more power. The power boost may lend a helping hand to the Opportunity rover, should officials decide to send it into Victoria Crater.
"We've been watching this storm for about six days now," said Steven Squyres of Cornell University, who is the lead scientist of the Mars Exploration Rover Project. "It's not unheard of for Martian dust storms to cover half the planet, and this one is now a regional storm."
Squyres wasn't certain of the storm's exact size, but said it appears to be thousands of miles in diameter and "ain't no little hurricane." In fact, "it's one of the most sunlight-blocking storms we've seen on Mars," he said.
According to reports from the Mars Reconnaissance Orbiter, which Squyres deemed as Mars' weather satellite, the storm has grown in size and is lifting up dust about 560 miles (900 KM) east of Opportunity, which is presently at Meridiani Planum. "The Mars Reconnaissance Orbiter team is watching this closely, because we worry about dust in the atmosphere obscuring the sunlight," Squyres said.
Experienced amateur astronomers have spotted the storm with large telescopes. Paul Maxson of Phoenix, Arizona, was one of the first to image the storm.
Dust storms on Mars occur regularly, but seldom do they grow beyond regional proportions. A storm in 2001, however, engulfed the entire planet in red dust.
"If the storm continues to get worse, it could cut into our activities," Squyres said. One of those activities, should the team decide it's not too risky, could be the descent of Opportunity into the massive Victoria Crater. A press conference is planned for Thursday to discuss the decision.
"The upshot of all this wind is that the arrays are so clean that the dust is insignificant right now," he said. "But this is Mars, and we can't predict the weather-we can only to react to it."
Diana Blaney, the deputy project manager for the Mars exploration rovers at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, said dust levels can significantly impact the rovers' missions. "When big dust storms like this come along, they decrease the energy the rovers can work with," Blaney said.
JPL spokesperson Guy Webster said Mars mission managers will be monitoring the storm's progress and how it may affect the planned descent into the crater. "They've really been paying attention to the storm and been getting regular reports of its progress," Webster said.
Wed Jun 27, 2:45 PM ET
A major dust storm has developed on the red planet, blocking sunlight and prompting Mars mission managers to keep a close eye on it, SPACE.com has learned.
It is not known how large the storm might grow, but already it is thousands of miles across. If it balloons, as dust storms have done in the past, it could hamper operations of NASA's Mars rovers Spirit and Opportunity.
For now, officials don't think the storm will threaten rover operations, however. In fact, the windy conditions on the planet have blown off large amounts of dust from the rovers' solar arrays, giving them more power. The power boost may lend a helping hand to the Opportunity rover, should officials decide to send it into Victoria Crater.
"We've been watching this storm for about six days now," said Steven Squyres of Cornell University, who is the lead scientist of the Mars Exploration Rover Project. "It's not unheard of for Martian dust storms to cover half the planet, and this one is now a regional storm."
Squyres wasn't certain of the storm's exact size, but said it appears to be thousands of miles in diameter and "ain't no little hurricane." In fact, "it's one of the most sunlight-blocking storms we've seen on Mars," he said.
According to reports from the Mars Reconnaissance Orbiter, which Squyres deemed as Mars' weather satellite, the storm has grown in size and is lifting up dust about 560 miles (900 KM) east of Opportunity, which is presently at Meridiani Planum. "The Mars Reconnaissance Orbiter team is watching this closely, because we worry about dust in the atmosphere obscuring the sunlight," Squyres said.
Experienced amateur astronomers have spotted the storm with large telescopes. Paul Maxson of Phoenix, Arizona, was one of the first to image the storm.
Dust storms on Mars occur regularly, but seldom do they grow beyond regional proportions. A storm in 2001, however, engulfed the entire planet in red dust.
"If the storm continues to get worse, it could cut into our activities," Squyres said. One of those activities, should the team decide it's not too risky, could be the descent of Opportunity into the massive Victoria Crater. A press conference is planned for Thursday to discuss the decision.
"The upshot of all this wind is that the arrays are so clean that the dust is insignificant right now," he said. "But this is Mars, and we can't predict the weather-we can only to react to it."
Diana Blaney, the deputy project manager for the Mars exploration rovers at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, said dust levels can significantly impact the rovers' missions. "When big dust storms like this come along, they decrease the energy the rovers can work with," Blaney said.
JPL spokesperson Guy Webster said Mars mission managers will be monitoring the storm's progress and how it may affect the planned descent into the crater. "They've really been paying attention to the storm and been getting regular reports of its progress," Webster said.
larger than some adults, but not me
Ancient penguins waddled, swam in warm locales
Mon Jun 25, 8:55 PM ET
WASHINGTON (Reuters) - Penguins were waddling and swimming in warm locales tens of millions of years earlier than previously thought, according to scientists who described on Monday fossils of two previously unknown types found in Peru.
One of the two, named Icadyptes salasi, lived about 36 million years ago, possessed a long, spear-like beak, and stood 5 feet tall.
"This one had a beak you had to reckon with," North Carolina State University paleontologist Julia Clarke, who led the research, said in a telephone interview.
It was bigger than any penguin alive today and the third-largest penguin known to have lived, Clarke said.
The earliest known fossil of these aquatic flightless birds, found in New Zealand, dates to about 61 million years ago, not long after the extinction of the dinosaurs and many other life forms 65 million years ago.
The largest penguin around today is the Emperor Penguin, which stands almost 4 feet tall.
The second newly discovered species was smaller and slightly older than Icadyptes.
Perudyptes devriesi lived about 42 million years ago and was about the size of today's King Penguin, about 2-1/2 to 3 feet tall. It is thought to represent an early part of penguin evolutionary history.
Both of these ancient penguins lived on Peru's southern coast and were found relatively close to one another in a coastal Peruvian desert in 2005. Penguins still live on Peru's coast.
These remains are among the most complete ever found of extinct penguins and throw into doubt existing notions about the timing and pattern of penguin evolution and expansion.
Many scientists had believed that penguins did not leave cold-weather regions like Antarctica and New Zealand for warmer, more equatorial regions until perhaps 4 million to 8 million years ago, but these two newly discovered species indicate this took place tens of millions of years earlier.
Penguins, denizens of the Southern Hemisphere, populate cold climates such as Antarctica, but also inhabit warmer regions closer to the Equator like the Galapagos Islands.
They are beautifully adapted to life in the ocean, with wings that have evolved into flippers, allowing them to swim gracefully through the water, catching fish, squid and other food.
The research, which also included scientists from Peru and Argentina, was published in the journal Proceedings of the National Academy of Sciences.
Mon Jun 25, 8:55 PM ET
WASHINGTON (Reuters) - Penguins were waddling and swimming in warm locales tens of millions of years earlier than previously thought, according to scientists who described on Monday fossils of two previously unknown types found in Peru.
One of the two, named Icadyptes salasi, lived about 36 million years ago, possessed a long, spear-like beak, and stood 5 feet tall.
"This one had a beak you had to reckon with," North Carolina State University paleontologist Julia Clarke, who led the research, said in a telephone interview.
It was bigger than any penguin alive today and the third-largest penguin known to have lived, Clarke said.
The earliest known fossil of these aquatic flightless birds, found in New Zealand, dates to about 61 million years ago, not long after the extinction of the dinosaurs and many other life forms 65 million years ago.
The largest penguin around today is the Emperor Penguin, which stands almost 4 feet tall.
The second newly discovered species was smaller and slightly older than Icadyptes.
Perudyptes devriesi lived about 42 million years ago and was about the size of today's King Penguin, about 2-1/2 to 3 feet tall. It is thought to represent an early part of penguin evolutionary history.
Both of these ancient penguins lived on Peru's southern coast and were found relatively close to one another in a coastal Peruvian desert in 2005. Penguins still live on Peru's coast.
These remains are among the most complete ever found of extinct penguins and throw into doubt existing notions about the timing and pattern of penguin evolution and expansion.
Many scientists had believed that penguins did not leave cold-weather regions like Antarctica and New Zealand for warmer, more equatorial regions until perhaps 4 million to 8 million years ago, but these two newly discovered species indicate this took place tens of millions of years earlier.
Penguins, denizens of the Southern Hemisphere, populate cold climates such as Antarctica, but also inhabit warmer regions closer to the Equator like the Galapagos Islands.
They are beautifully adapted to life in the ocean, with wings that have evolved into flippers, allowing them to swim gracefully through the water, catching fish, squid and other food.
The research, which also included scientists from Peru and Argentina, was published in the journal Proceedings of the National Academy of Sciences.
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