Question

The fossil record shows that many species remain constant for long periods of time, but then speciation episodes occur rapidly. This is best described as ___

Answer 1

The biological theory describing the rapid events of speciation among many species that remained constant for long periods of time is known as punctuated equilibrium. This theory suggests that many species undergo least amount of change over the time remaining constant and stable until some rare events such as cladogenesis, which causes significant evolutionary changes to occur.

Hence, the correct answer is 'punctuated equilibrium'.