Index of environmental health is determined by the change in the composition of

$A$ : Population ecology is a link of ecology to population genetics and evolution.
$R$ : Natural selection operates at population level to evolve the desired traits.

Ruthless exploitation and pollution of the environment has increased the magnitude of waste materials which has disturbed the operations of all important

The study of inter-relationship between living organisms and their environment is called

Select the incorrect statement w.r.t. ecotypes