the pallas's pika and many other subspecies show a mechanism called microbial nitrogen fixation. this is a very important mechanism consisting of an isolation of a bacterial community in the cecum and colon of the pika called the nifh gene. since pallas's pika's diet consist of such poor feed, they need to have an adaptation such as this in order to provide the essential amino acids to their diet. these essential amino acids are supplied by the microorganisms produced by microbial nitrogen fixations.