Two organs which are similar in structure and origin, but not necessarily in function are called

$A$ : During industrialisation dark-winged or melanised moths were more abundant.
$R$ : They were able to camouflage themselves, hide in the background and survived.

The peppered moth (Biston betularia), the black-coloured form becomes dominant over the lightcoloured form of moth in England during industrial revolution. This is an example of