Answer
Adaptation,
Explanation:
The set of characteristic an organism exhibit in order to survive in an environment is called adaptation. This may be changes in physical characteristic or adjustment in the usual behaviour.
Generally for an organims to survive in his habitat adaptation is important.It is usually due to interaction of the effects of environments with the genotype and phenotype of the organism. Thus mutation which gives variation is the factor which makes organism to adjust to the habitat. Therefore adaptation of organism to the habitat is dictated by the selective pressure in the habitat. And this is passed down to subsequent generation.
Thus Shamar sensory cells gained adaptation with time, and she was able to sit comfortably in the tub. The behavioural and physical changes she demonstrated at onset were the necessary changes needed to adapt.
Generally it can be physiological, behavioural, physical or structural depending on the need to adjust to the habitat.
