Despite their descent from wolves and classification as Carnivora, dogs are variously described in scholarly and other writings as carnivores[164][165] or omnivores.[3][166][167][168] Unlike obligate carnivores, such as the cat family with its shorter small intestine, dogs can adapt to a wide-ranging diet, and are not dependent on meat-specific protein nor a very high level of protein in order to fulfill their basic dietary requirements. Dogs will healthily digest a variety of foods, including vegetables and grains, and can consume a large proportion of these in their diet.[3] Compared to their wolf ancestors, dogs have adaptations in genes involved in starch digestion that contribute to an increased ability to thrive on a starch-rich diet.[169]