Darwinian fitness can be estimated by
How long different individual in a population survive
Number of offsprings produced by different individual in population
Individual have a large size in population
Species recover after mass extinction
Write short note on Adaptive Radiation and Marsupials of Australia
$A$ : 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.
Kangaroo is a member of which order
Darwin's finches discovered from the Galapagos