Discuss how classification systems have undergone several changes over a period of time ?

Why are classification systems changing every now and then ?

Write one word for the formation of new species due to gradual change over long period of time.

[A] : Every biological system resists a change and wants to remain in a state of equilibrium . [R] : Climax communities of an ecosystem are produced after several changes it has gone through succession .

An electron is accelerated in the direction of the electric filed. What will happen to its acceleration over a period of time?