Natures wonders: animals sense magnetic fields (Introduction)

by David Turell , Thursday, February 25, 2016, 01:24 (3193 days ago) @ David Turell

A small number of animals have eyes with a special molecule that senses magnetic fields, but isn't known as yet whether the animals are using that molecule for that purpose:-http://www.sciencealert.com/dogs-and-some-primates-might-be-able-to-see-magnetic-fields?cmpid=NL_LS_weekly_2016-2-24-"Birds are able to navigate their way across thousands of kilometres to precisely the same spot year after year, thanks to their ability to perceive Earth's magnetic fields - a sense known as magnetoreception. Now researchers have shown that the eyes of dogs, certain primates, and bears contain the same molecule thought to be responsible for this ability in birds, suggesting that these mammals might be able to do the same thing. -"The molecule believed to be responsible for this 'sixth sense' - one that humans have unfortunately lost - is known as cryptochrome 1a, and it's part of the group of light-sensing molecules that help bacteria, plants, and mammals to regulate their circadian rhythms.-***-"Now a team of researchers led by the Max Planck Institute in Germany has shown for the first time that a mammalian version of this molecule, which they're simply calling cryptochrome 1, is present in the retinas of dog-like carnivores, such as dogs, wolves, bears, foxes, and badgers. -"It was also present in the retinas of certain primates, including orangutans and some macaque species. -"To be clear, simply having cryptochrome 1 doesn't necessarily mean that these animals are able to perceive magnetic fields like birds do - the molecule could be playing some other type of role in their eyes.-*** -"Secondly, based on its location at the edge of the mammals' cone cells, it was unlikely that it controls the circadian rhythm or acts as a visual pigment for colour perception, the researchers report. "Therefore, it is possible that these animals also have a magnetic sense that is linked to their visual system," the researchers conclude in Nature Scientific Reports. -"So assuming that's true, what are these species using the ability for? That's not clear just yet, but it's well known that dogs prefer to poop along a north-south axis, and they're not the only ones that show some magnetic preference. -"'When hunting, foxes are more successful at catching mice when they pounce on them in a northeast direction," George Dvorsky adds over at Gizmodo. "For primates, this built-in compass may help with bodily orientation, or it could be a vestigial evolutionary trait that's largely unused.'" -***-"The researchers now need to work out whether or not dogs, bears, and the primate species really are using the magnetoreception powers of cyrptochrome 1, or whether the molecule serves some other purpose in their eyes."-Comment: Interesting find.