Carrier's constraint is the observation that air-breathing vertebrates with two lungs that flex their bodies sideways during locomotion find it difficult to move and breathe at the same time, because the sideways flexing expands one lung and compresses the other, shunting stale air from lung to lung instead of expelling it completely to make room for fresh air.[1]
It was named by English paleontologist Richard Cowen for David R. Carrier, who wrote his observations on the problem in 1987.[2][3][4]
- ^ Carrier, D.R. (1987). "The evolution of locomotor stamina in tetrapods: circumventing a mechanical constraint". Paleobiology. 13 (3): 326–341. doi:10.1017/s0094837300008903. S2CID 83722453.
- ^ Cowen, Richard (1996). "Locomotion and Respiration in Aquatic Air-Breathing Vertebrates". In Jablonski, David; et al. (eds.). Evolutionary Paleobiology. Chicago: University of Chicago Press. p. 337+. ISBN 0-226-38911-1.
- ^ Cowen, Richard (2003). "Respiration, Metabolism, and Locomotion". Richard Cowen, University of California, Davis. Archived from the original on October 21, 2014. Retrieved October 21, 2014.
If the animal is walking, it may be able to breathe between steps, but sprawling vertebrates cannot run and breathe at the same time. I shall call this problem Carrier's Constraint.
- ^ Shipman, Pat (January 2008). "Freed to Fly Again". American Scientist. 96 (1). Research Triangle Park: Sigma Xi: 20. doi:10.1511/2008.69.20. Archived from the original on March 4, 2016. Retrieved October 21, 2014.
Carrier's constraint is named for David R. Carrier at the University of Utah in Salt Lake City, who observed that the typical sprawling gait of a lizard restricts the animal's ability to breathe while running or walking.