Physiological variation relates to the differences in the ways individuals of the same species behave or react to a condition in their environment. In other words, it relates to the functioning of the body.
Differences of variation in behaviour by which organisms can be grouped into two or more classes within a population, without any graduation among them are called discontinuous variation.
Example of physiological or discontinuous variation in a human being is:-
- BEHAVIOUR:- The way individuals behave under normal circumstances varies considerably. People may be grouped as being:-
1 Aggressive or non-aggressive
2 Excitable or calm
3 Timid or brave
4 Caring or uncaring
5 Intelligent or stupid
Many behaviours patterns through may be inherited are also controlled by hormones such as thyroxine, adrenaline and sex hormones.
- Ability to roll the tongue:- Some people have the ability to roll their tongue when it is pushed out of the mouth while others cannot
- Ability to close one eye and keep the other open:- Some people are capable of opening one eye and keeping the other closed while others cannot do that.
- Ability to move the ears without moving the head:- Some people can easily move their ears without moving their heads while others cannot.