Dark winters 'led to bigger human brains'

Humans living at high latitude have bigger eyes and bigger brains to cope with poor light during long winters and cloudy days, UK scientists have said.
The Oxford University team said bigger brains did not make people smarter. Larger vision processing areas fill the extra capacity, they write in the Royal Society's Biology Letters journal.
The scientists measured the eye sockets and brain volumes of 55 skulls from 12 populations across the world, and plotted the results against latitude. Lead author Eiluned Pearce told "We found a positive relationship between absolute latitude and both eye socket size and cranial capacity."
Eiluned Pearce said: "Both the amount of light hitting the Earth's surface and winter day-lengths get shorter as you go further north or south from the equator.
"We found that as light levels decrease, humans are getting bigger eye sockets, which suggests that their eyeballs are getting bigger.
"They are also getting bigger brains, because we found this increase in cranial capacity as well.
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"In the paper, we argue that having bigger brains doesn't mean that high-latitude humans are necessarily smarter. It's just they need bigger eyes and brains to be able to see well where they live."
The work indicates that humans are subject to the same evolutionary trends that give relatively large eyes to birds that sing first during the dawn chorus, or species such as owls that forage at night.
The team, from the Institute of Cognitive and Evolutionary Anthropology, used skulls dating from the 1800s kept at museums in Oxford and Cambridge.
The skulls were from indigenous populations ranging from Scandinavia to Australia, Micronesia and North America.
The largest brain cavities came from Scandinavia, while the smallest were from Micronesia.
Co author Prof Robin Durbar said: "Humans have only lived at high latitudes in Europe and Asia for a few tens of thousands of years, yet they seem to have adapted their visual systems surprisingly rapidly to the cloudy skies, dull weather and long winters we experience at these latitudes."

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Boehner pulls out of White House debt talks

ruHouse Speaker John Boehner abruptly broke off talks with President Barack Obama Friday night on a deal to make major cuts in federal spending and avert a threatened government default, sending already uncertain compromise efforts into instant crisis. 


Within minutes, an obviously peeved Obama virtually ordered congressional leaders to the White House Saturday morning for fresh negotiations on raising the nation's debt limit. "We've got to get it done. It is not an option not to do it," he declared.
For the first time since talks began, he declined to offer assurances, when asked, that default would be avoided. Moments later, however, he said he was confident of that outcome.
"This was an extraordinary fair deal," said the president. "If it was unbalanced, it was unbalanced in the direction of not enough revenue."
"We have now run out of time," said Obama. "What we're not going to do is continue to play games and string this along," said the president. "I've been left at the altar now a couple of times."
He added, "I cannot believe that Congress would be that irresponsible that they would not pass a package to avoid a self inflicted wound."
  At a rebuttal news conference of his own a short while later in the Capitol, Boehner said, "I want to be entirely clear, no one wants default on the full faith and credit of the United States government, and I'm convinced that we will not."
"It's time to get serious ... if the White House won't get serious, we will," said Boehner.
"We've put plan after plan on the table ... never once did the president come to the table with a plan," said Boehner. "We were always pushing."



Barring action by Congress by an Aug 2 deadline, the Treasury will be unable to pay all its bills. Officials say a default could destabilize the already weakened U.S. economy and send major ripple effects across the globe.
Even by the recent standards of divided government, Boehner's decision triggered an extraordinary evening as first the Democratic president and then the Republican speaker maneuvered for political position on an issue of enormous national import.
Unspoken, yet unmistakable in all the brinkmanship was the 2012 election campaign, still 18 months away, with the White House and both houses of Congress at stake. 

Analysis: 'As bad as it gets' in dysfunctional DC


In a letter circulated earlier to the House Republican rank and file, Boehner said he had withdrawn from the talks because the president wanted to raise taxes and was reluctant to agree to cuts in benefit programs.
The disconnect was "not because of different personalities but because of different visions for our country," he said, and he announced he would now seek agreement with the Democratic-controlled Senate.
Obama was having none of that, announcing instead a morning White House meeting where he said he expected to hear proposed solutions from the top leaders of both parties in both houses.
"One of the questions the Republican Party is going to have to ask itself is, 'Can they say yes to anything?'" Obama said.
The president avoided direct criticism of Boehner, although he did mention that his phone calls to the speaker had gone unreturned during the day.
A White House official told  that the president called Boehner on Thursday night, but did not hear back. Then, Friday afternoon, the speaker's office reportedly emailed the White House to say Boehner would be available to talk at 5:30 p.m. ET. The White House called the speaker's office after that email was received to ask if they just talk right then, but his aides reiterated that Boehner would be availabe at 5:30 p.m. ET. It was during that call that the speaker walked away from the talks.
Boehner said he would attend the Saturday meeting at the White House.
  Private, sometimes-secret negotiations had veered uncertainly for weeks, generating reports as late as Thursday that the two sides were possibly closing in on an agreement to cut $3 trillion in spending and add as much as $1 trillion in possible revenue while increasing the government's borrowing authority of $2.4 trillion.
That triggered a revolt among Democrats who expressed fears the president was giving away too much in terms of cuts to Medicare and Social Security while getting too little by way of additional revenues
"Failing to raise the debt ceiling would do irreparable harm to our credit standing, would undermine our ability to lead on global economic issues and would damage our economy," former Treasury Secretary Henry Paulson, a Republican, told reporters during the day. 

Current administration officials and Federal reserve Chairman Ben Bernanke have said much the same thing for weeks — while gridlock persisted in Congress. 

Obama said his only requirement for an agreement was legislation that provides the Treasury enough borrowing authority to tide the government over through the 2012 election.
Senate Majority Leader Harry Reid, D-Nev., agreed in a written statement, saying a shorter-term extension was unacceptable.

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