Before revision:  Our analysis supports the hypothesis that the mammals' allometric scaling laws of tidal volumes and breathing rates at a given metabolic rate are driven by a few core geometrical characteristics shared by the mammals' lungs and  the physical processes of the respiratory gas transport.
After revision:  Our analysis supports the hypothesis that the mammals' allometric scaling laws of tidal volumes and breathing rates at a given metabolic rate are driven by a few core geometrical characteristics shared by the mammals' lungs and by the physical processes of the respiratory gas transport.