Scientists have found that people from northern parts of the world have larger eyeballs and brains to help them deal with long, dark winters.
But the Oxford University study does not make a link between bigger brains and smarter people, perhaps to the chagrin of some northern Canadians.
Researchers with Oxford's Institute of Cognitive and Evolutionary Anthropology studied the eye sockets and cranial capacity of 55 human skulls from a dozen regions around the world and found that the farther away people live from the equator, the larger their eyes and heads are.
People who live closer to the North and South Poles have evolved larger brains and eyes so they can cope with the short days and low light levels they experience every winter, the scientists said in a report published online Wednesday in the journal Biology Letters.
"In order to maintain good vision, high-latitude humans are having to increase the size of the eyes in order to cope with those lower light levels," Eiluned Pearce, one of the report's authors, told CBC News.
Pearce said her findings suggest that the influence that ambient light levels have in the eye size of birds and primates also applies to humans' eyes.
Brains grow to accommodate eyes
Larger eyes give more visual input into the brain, so specific areas of the brain seem to increase to accommodate the eyes, according to the Oxford report.
But having a bigger head is not necessarily a sign that people in the North are smarter, Pearce said.
"This research doesn't support that, I'm afraid," she said with a laugh.
But the research findings had Yellowknife Mayor Gordon Van Tighem wondering if bigger eyes and heads could be a sign of northerners' potential.
"With the long hours of darkness in wintertime, they would need to avoid being lulled into complacency and use their advanced vision to read more books and make better observations about what's going on around them to then become smarter than everyone else," Van Tighem suggested.
Others in the Northwest Territories' capital city were skeptical about the Oxford researchers' findings.
"My eyes look pretty normal, so I think that's kind of baloney," one man told CBC News on the streets of downtown Yellowknife on Wednesday.
"They are Oxford, so you can't really say that kind of stuff about them, but [it] seems far-fetched to me."
Local truck driver Alex Debogorski, who is known around the world from the History Channel reality series Ice Road Truckers, has his own theory about the effect that driving on ice roads in the dark has on his brain.
"When the roads are real rough, I get a sore neck from holding my head up. All that bouncing around, trying to hold my head up, makes me smarter just from having blood flowing through my head," he said with a hearty laugh.