While the human gastrointestinal tract is capable of digesting both plant and animal foods, there are indications that we evolved to digest primarily plant foods. Specifically, our teeth are composed of twenty molars, which are perfect for crushing and grinding plant foods, along with eight front incisors, which are well suited for biting into fruits and vegetables. Only our front four canine teeth are designed for meat eating, and our jaws swing both vertically to tear and laterally to crush, while carnivores' jaws swing only vertically. Additional evidence that supports the human body's preference for plant foods is the long length of the human intestinal tract. Carnivores typically have a short bowel, while herbivores have a bowel length proportionally comparable to humans.