Eideard

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Posts Tagged ‘long distance

Humans may have — or have had — geomagnetic sight

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“Why is my attention drawn to this woman?”

The ability to see Earth’s magnetic field, thought to be restricted to sea turtles and swallows and other long-distance animal navigators, may also reside in human eyes.

Tests of cryptochrome 2, a key protein component of geomagnetic perception, found that its human version restored geomagnetic orientation in cryptochrome-deficient fruit flies.

Flies are a long, long way from people, but that the protein worked at all is impressive. There’s also a whole lot of it in our eyes.

“Could humans have this cryptochrome heavily expressed in the retina as a light-sensitive magnetoreceptor?” said University of Massachusetts neuroscientist Steven Reppert, lead author of…a study. “We don’t know if the molecule will do this in the human retina, but this suggests the possibility.”

Reppert, whose laboratory specializes in the biological mechanisms underlying long-distance butterfly migration, showed three years ago that cryptochrome allowed fruit flies to geomagnetically orient themselves using light…

Many gaps still remain in cryptochrome theory, but it’s generally thought that the cryptochrome system may be active across the animal kingdom, from fish to reptiles to birds. Humans, however, were thought to be an exception. Our own cryptochrome is considered a piece of circadian machinery, part of our molecular clock rather than any optical compass.

The new study, however, suggests that cryptochrome may be more than a clock…Whether any of this is linked to high levels of cryptochrome in human eyes — and, if so, whether that quantum compass system still works for us — is completely speculative, but it’s speculation that Reppert welcomes…

Reppert himself is now concentrating on how brains read their cryptochrome compass. “At the most fundamental level, we’re interested in how cryptochrome information is transferred to the nervous system,” he said. “Nobody knows how that occurs.”

Yet. Seems like a worthwhile study. Of course, just about any and all basic research is worthwhile. If it’s basic enough – you can’t really foretell where the results will lead.

Written by eideard

June 23, 2011 at 6:00 am

Little birdy backpacks don’t slow the critters down at all!

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Little songbirds cover more than 300 miles a day on their annual migrations, flabbergasting researchers who expected a much slower flight. For the first time, scientists were able to outfit tiny birds with geolocators and track their travel between North America and the tropics, something only done previously with large birds such as geese.

New tracking equipment, weighing only a little more than a paper clip, is now allowing the tracking of purple martins and wood thrushes, researchers report…

“We were flabbergasted by the birds’ spring return times. To have a bird leave Brazil on April 12 and be home by the end of the month was just astounding. We always assumed they left sometime in March,” said Bridget Stutchbury, a professor of biology.

I don’t think anybody had an idea that these little songbirds could travel that fast,” she said.

The purple martins migrated to the Amazon basin in Brazil for the winter, while the wood thrushes wintered in a narrow band of Nicaragua and Honduras. Some of the birds took pauses along the way, spending a few days in the southeastern United States or in Mexico’s Yucatan area.

Stutchbury said she initially worried that the tracking devices would slow down the little birds, “but those worries kind of ceased when I looked at their spring migration speeds.”

Look! Up in the sky. It’s a bird, it’s a plane, it’s Superman! Nope – it’s a very fast wee bird.

Written by eideard

February 14, 2009 at 6:00 am

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