What is least likely to change the gene pool of a population of chipmunks

loss of sensation to pressure and touch

the dorsal column–medial lemniscus pathway (dcml) (also known as the posterior column-medial lemniscus pathway (pcml)) is a sensory pathway of the central nervous system that conveys sensations of fine touch, vibration, two-point discrimination, and proprioception (position) from the skin and joints.