Answer: Species stay the same for a long time and then
change quickly due to environmental changes.
A punctuated equilibrium theory
states that
individual species tend to stay the same or no change over a long period of
time and then enter a period of rapid change due to environmental changes,
which gives rise to new species. Moreover, it generally applies to sexually
reproducing organisms but other biologists have applied the model to non-sexual
species like virus.
