Question

A certain widely distributed mammalian species remained unchanged for about 30 million years. Most members of this species lived on a fertile plain, but some members (that were less well adapted) survived in low numbers in the surrounding mountains. They adapted and evolved to this area and became significantly different from their relatives on the plain. A sudden meteorite attack struck the plain and destroyed the plain population. The mountain population was unaffected and as the plain environment recovered moved to the plain. In the absence of competitors, they underwent a very rapid population explosion. Which mode of evolution does this example explain

Answer 1

Punctuated equilibrium is the answer.

Answer 2

For the answer to the question above, punctuated equilibrium (also called punctuated equilibria) is a theory in evolutionary biology which proposes that most species will exhibit little net evolutionary change for most of their geological history, remaining in an extended state called stasis. When significant evolutionary change occurs, the theory proposes that it is generally restricted to rare and rapid (on a geologic time scale) events of branching speciation called cladogenesis. Cladogenesis is the process by which a species splits into two distinct species, rather than one species gradually transforming into another.