Read the passage about punctuated equilibrium.
The theory of punctuated equilibrium states that many species did not evolve for thousands of years. Instead, evolution took place when environmental conditions shifted, causing individuals to be in more extreme competition with one another. The theory of punctuated equilibrium is supported by fossil evidence of many periods of stasis.
Which of the following statements does the theory of punctuated equilibrium challenge?
a
Evolution is a gradual process taking place in a stable environment.
b
Evolution occurs in groups of organisms through natural selection.
c
Many species remain in stasis for long periods of time.
d
Many organisms share a common ancestor.