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Information About

Carriers Constraint




  • the sideways flexing expands one lung and compresses the other.




CONSEQUENCES OF CARRIER'S CONSTRAINT

Most lizards move in short bursts, with long pauses for breath.


WAYS OF AVOIDING CARRIER'S CONSTRAINT



Partial solutions


Sea snakes have only one lung.

Monitor Lizard s increase their stamina by using bones and muscles in the throat and floor of the mouth to "gulp" air.2

Crocodilians have three modes of locomotion: crawling for short distances (this sprawling gait is subject to Carrier's Constraint); "high walk" for longer distances (the erect limb posture minimizes sideways flexing); "gallop" in emergencies (avoids Carrier's Constraint but they can only gallop for a few seconds).


Complete solutions


Bird s have erect limbs and rigid bodies, and therefore do not flex sideways when moving. In addition many of them have a mechanism which pumps both lungs simultaneously when the birds rock their hips.

Most Mammal s have erect limbs and flexible bodies, which makes their bodies flex vertically when moving fast. This aids breathing as it expands and compresses both lungs simultaneously.


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