Question

_____P_____represent one of the best examples of Adaptive radiation. Another example is___Q____. A number of _____Q_____, each different from the other evolved from an ancestral stock, but all within the Australian island continent. When more than one adaptive radiation appeared to have occurred in an isolated geographical area (representing different habitats), one can call this _____R_____.

• A.

  P	Q	R
  Australian placentals	Darwin’s finches	Convergent evolution

• B.

  P	Q	R
  Darwin’s finches	Australian placentals	Convergent evolution

• C.

  P	Q	R
  Australian placentals	Darwin’s finches	Divergent evolution

• D.

  P	Q	R
  Darwin’s finches	Australian placentals	Divergent evolution

Answer 1

Answer: (B)

The evolution of Darwin’s finches on the Galapagos Islands is a classic example of species formation and illustrates how adaptation to local conditions produces the divergence that is the heart of species formation, i.e., such an evolutionary process, giving rise to new species adapted to new habitats and ways of life, is called adaptive radiation or divergent evolution.
Furthermore, Australia is the home to the great diversity of pouched mammals (marsupials) but relatively few placental mammals. Darwin explained that adaptive radiation gave rise to a variety of marsupials in Australia in the same process of adaptive radiation as found in the finches in the Galapagos Islands. The evolutionary process, giving rise to new species adapted to new habitats and ways of life, is called adaptive radiation.
A number of Australian marsupials and placental mammals each different from the other have evolved from an ancestral stock within the Australian island continent. This is a type of convergent evolution because more than one adaptive radiation occurred in isolated geographical area.