What are the key concepts in the evolution theory of Darwin ?

$I.$ Use and disuse of organs

$II.$ Inheritance of acquired characters

$III.$ Branching descent

$IV.$ Natural selection

$V.$ Mutation

$VI.$ Reproductive isolation

The two key concepts of Darwinism from the given options are

Comment on the statement that ''evolution and natural selection are end result or consequence of some other processes but themselves are not processes''.

Assertion : Human ancestors never used their tails and so the tail expressing gene has disappeared in them.

Reason : Lamarck's theory of evolution is popularly called theory of continuity of germ plasm.