Define phenotypic adaptation. Give one example.

Explanation

It is a non neneic change in physical and physiological characteristics like external appearance, behaviour and physiology which develop in response to the changes in the environment and are useful to organisms in adjustment to prevailing environmental condition.
Exaple 1: Appearance of mountain sickness at high attitude and its disappearance as one becomes acclimated through increased production of RBC, decreased binding capacity of haemoglobin and increased rate of breathing.