By taking an example of some of australian marsupials &australian placental mammals briefly explain adaptive radiation and convergent evolution in different species

adaptive radiation means " it is the process of evolution from a restricted geographical area and common origin, from a ecological niche different species literaly radiate to other ecological niche."

australian marsupials :

first the australian marsupials are from only australia, i.e. restricted geographical area , and also from a common origin. When continental drift happened the marsupials got seperated from other placental mammals. So they all came from common origin. hence this is an example of adptive radiation. 

also convergent evolution means development of similar adaptive structures in unrelated organisms, due to similar needs. different animals  from different parts of the world  in australia are marsupials, it is an example of convergent evolution.