Darwin’s finches are a good example of

What is the most important pre-condition for adaptive radiation ?

State the modifications of forelimb in animals as an example of homology.
 

$A$ : Placental wolf and Tasmanian wolf (a marsupial) show convergent evolution.
$R$ : Like marsupials placental mammals in other parts of world also exhibit adaptive radiation in evolving into varieties of such placental mammals each of which appears to be similar to a corresponding marsupial.