Vijay Barve
Snakes can hear through their jaws
WASHINGTON: A new research by US and German scientists has shown that snakes have a second hearing system through their jaws, which can provide valuable insight into their evolution.According to a report in Discovery News , snakes pick up their prey's vibrations via their jaws, and then send these patterns to their brains for processing.
For years, it was assumed that snakes couldn't hear, that they sensed prey by smell, taste, and in some species, special heat-sensing pits near the nose.
Though basic experiments during the 1970s showed snakes could hear, they didn't explain how.
Now, the new research has proved that with each tiny footstep, a mouse or other prey radiates waves through the ground and air the same way drops of water ripple through a pool and produce a single drip sound.
Just as a ship bobs up and down in response to a wave in the ocean, a snake jaw resting on the ground responds to sound waves carried by the ground.
"The lower jaw of a snake is essentially a ridged cylinder," said Bruce Young, a biology professor at Washburn University. "So in that respect it's not terribly different from a ship," he added.
Therefore, for their research, the scientists borrowed techniques from nautical engineers.
The researchers used the exact equations that measure a ship's movement to model how a snake's jaw would move in response to waves moving through sand or earth.
Just as a ship can move in six different directions - heave, pitch, roll, etc, so can a snake's jaw - up, down, side to side, etc.
Also, just as a ship is more stable the deeper it rides in the water, snakes often bury themselves in sand to make their hearing more precise.
When buried, a snake can more easily detect the differences in the way its jaw moves.
After a snake’s jawbones pick up a sound, it travels into the cochlea, where nerves pick up the signal and transmit it to the brain.
According to the researchers, by hearing through their jaw bone and through a traditional ear, snakes essentially evolved a second way to hear.
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Labels: wildlife
posted by Vijay Barve @ 9:32 PM
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