Final answer:
The great enlargement of molars and premolars is an adaptation to a vegetarian diet in animals.
Step-by-step explanation:
The great enlargement of the molars and premolars in animals is an adaptation to a vegetarian diet.
This is because a vegetarian diet typically consists of plant-based foods that require more grinding and crushing to break down due to the presence of complex carbohydrates such as cellulose.
By having larger molars and premolars, herbivorous animals are able to effectively chew and break down the tough plant material to extract the nutrients.