An evolutionary pattern characterised by a rapid increase in number and kinds of closely related species is called

The correct option is A Divergent evolution

Adaptive radiation:

Adaptive radiation is the development of different functional structures in organisms having a common ancestor.

As the organisms diverge from the common ancestor they form species which are closely related but vary slightly according to the habitat. For example the Australian marsupials having the common ancestor diverged due to difference in the feeding habits.

Final answer:

(A) Adaptive radiation