Q.35 The scientists believe that evolution is gradual. But extinction, part of evolutionary story, are ‘sudden’ and ‘abrupt’ and also group-specific. Comment whether a natural disaster can be the cause for extinction of species.

Yes, a natural disaster can be the cause for extinction of species. As new species evolve to

fit ever changing ecological niches, older species fade away. But, the rate of exlincition is
far from constant.

In last 500 million years, 50 - 90% or more of all species on earth have disappeared in a
geological blink of the eye. Many times, these mass extinctions had been the consequence
of anatural disaster.

The most studied mass extinction between the Cretaceous and Palaeocene periods about
65 million years ago, killed off the dinosaurs and made room for mammals to rapidly
diversify and evolve. The cause is suspected to be volcanic eruptions and impact of large
asteroids or comets striking the earth.