Two zoogeographical regions separated by high mountain ranges are

Select the correct match from the following:

Which animals have evolved from reptiles?

Darwinian theory was unable to explain:

Long-term adaptation is helpful in which of the following?

Scientists believe that evolution is gradual. However,extinction,which is a part of the evolutionary story,is often 'sudden' and 'abrupt' and also group-specific. Comment on whether a natural disaster can be the cause of the extinction of species.