The utility of a good sense of direction is largely lost in an age where humans stumble forward, head bowed to the glow of a smartphone. In fact, the idea itself used to lack much scientific proof, but new research suggest that it may be related to a "sixth sense" in humans and animals. Published Tuesday in the journal Nature Communications, a study of how monarch butterflies navigate the air using earth's magnetic fields revealed that humans possess the same abilities, but the sense's power has waned in age of electronics.
In studying light-sensitive proteins, researchers wondered how the monarchs could find their way even in the dark and hypothesized that sensitivity to magnetic fields may help navigation. They isolated the appropriate gene, a cryptochrome gene, by manipulating the genetic structure of fruit flies and found that it had quite a lot in common with the same gene in humans. As The New York Times notes in its coverage of the study:
The human cryptochrome gene is highly active in the eye, raising the possibility that the magnetic field might in some sense be seen, if the cryptochromes interact with the retina…
In fact, the cryptochrome system might supply a grid imposed on all the landmarks in a visual scene, helping a squirrel find a buried acorn, or a fox integrate its visual scene with what it hears. “This is the fun stage where we are not constrained by many facts,” Dr. Phillips said.
If butterflies, birds and foxes possess such a wonderful system, why would it ever have died out in the human lineage? “It may be that our electromagnetic world is interfering with our ability to do this kind of stuff,” Dr. Phillips said.
This discovery makes those jokes about how smartphones and GPS make us more oblivious painfully prescient, and accordingly, much funnier.