Many plants, such as the potato plant, avoid insect predation by producing highly toxic sap. However, the potato bug, unlike most insects, has adapted to the toxins and can still eat the potato plant. In turn, over a long period of time, potatoes are likely to develop more chemical defenses against the potato bugs. This type of consistent adaptation between two species is known as

An adaptation can be defined as the changes that occur in the body of the organism which allows it survive in the surrounding changing environment. The physiological adaptation is the adaptation in which the internal systematic responses that an organism produce against an external stimuli in order to sustain it's life.

The given situation is an example of physiological adaptation because potato plant will produce toxic sap in response to external stimuli bugs, the bugs later on attains adaptation to resist the effects of toxic sap.