Why Omnivores Can Consume Both Meat and Plants

Most carnivores are incapable of digesting vegetation, and one large meat animal can replace a truckload of plant nutrition. This is a short question that requires a detailed explanation. Animals have digestive systems specialized to eat certain types of food. Carnivores need meat to survive, as they are unable to digest most plant matter. Omnivores, on the other hand, have digestive systems capable of digesting both meat and plants, while herbivores have digestive systems better suited for plant matter but struggle with meat.

It is not uncommon to see carnivores consuming plants and herbivores consuming meat. In both cases, some digestion of the consumed food can occur, although it is not optimal for them.

An organism that can eat both meat and plants is called an omnivore. The term 'omnivore' is a human invention to describe animals like us that eat anything. The ancestral population of modern omnivores faced significant selection pressures in the past where scarcity of food favored those with the ability to eat a broader range of foods. Members of the population who could not consume and digest a wide variety of foods were less likely to thrive or even survive, leading to fewer opportunities for gene transmission.

This situation likely resulted in a population where the collective genome was more favorable for an omnivorous diet because they could survive according to the available food at the time. Conversely, individuals who could not adapt or eat a range of food types were more likely to die or not reproduce successfully, meaning their genes were not passed down as often as the genes of omnivores. Therefore, it is the genes of ancestors who were able to eat a range of foods during a time of food crisis that have been passed down to the current population of extant omnivores.