Compare the functions of stabilizing and driving selection in evolution

Driving selection – manifests itself when the conditions of existence of a species change In this case, the selection is directed in favor of individuals with deviations from the average norm of the trait either in the direction of its strengthening, or in the direction of its weakening.
Stabilizing selection – acts in a long unchanging conditions of existence. The pressure of this form of selection is directed in favor of those individuals who have average values ​​of any trait, against individuals who have extreme values ​​of this trait. As a result of this form of selection, the average norm of traits is strengthened. Thanks to stabilizing selection, where environmental conditions did not change, the most ancient species of animals and plants have been preserved for many millions of years: the cross-finned coelacanth fish, the beak-headed reptile-tuatara and others.