The fossil record shows that for many plant and animal groups, the time between speciation events
A)is usually about 50,000 years.
B)varies greatly, but averages 6.5 million years.
C)is usually greater than 40 million years.
D)is equivalent to the length of one hundred generations of a species.

Question

Quizplus · Accepted Answer

The fossil record shows that the time between speciation events varies greatly, but the average time is around 6.5 million years. This phenomenon is known as the "punctuated equilibrium" in which the evolution of species happens in rapid bursts followed by long periods of stability.

The Fossil Record Shows That for Many Plant and Animal