Читать книгу Anthropology For Dummies - Cameron M. Smith - Страница 82

Although the following sections show some exceptions, most primates are rather omnivorous, eating a variety of foods from bird eggs to leaves to seeds and even grasses, insects, tree gum, and flowers. This is in pretty stark contrast to, say crocodiles, who eat meat (fish and any vertebrate that falls into the water), or zebras, who eat only vegetation (grass and shrubs). Those animals are dietary specialists; primates, generally speaking, are generalists. Chimpanzees, for example, eat lots of fruit, snack on termites, and occasionally hunt down small monkeys; some monkeys savor bird eggs; and gorillas live in a giant salad bowl, eating just about whatever vegetation is in reach. This dietary diversity is reflected in the nature of our versatile mouth.

The average primate mouth reflects the order’s tendency toward omnivory in the teeth. We have several kinds of teeth:

 Incisors are the thin, blade-like teeth at the front of the mouth for snipping and clipping.

 Canines are the pointed, conical teeth used for puncturing and light crushing; many primate species use these teeth to defend and threaten, so they’re much larger than in our species.

 Premolars are the somewhat-pointed-but-somewhat-jagged teeth immediately before the molars, and they do the light crushing.

 Molars are the heavy, flattish teeth in the back of the mouth that do the heavy crushing.

You can see that this multitalented mouth can process just about any food, so primates generally fall into the category of heterodont (different-teeth) rather than homodont (same-teeth). Your dog and cat are homodont — both are carnivores (at least evolutionarily) — and omnivores, such as people and pigs, are heterodont.

Technically speaking, homodonty really means that all the teeth have the same form, as in crocodiles. Because dogs and cats (mentioned in the preceding paragraph) do have differences between their incisors and molars, for example, they’re technically heterodont. However, relatively speaking, all their teeth are for processing a meat diet, so compared to primates (who eat a more varied diet), they’re considered homodont.

A trained anthropologist can learn an enormous amount from a single fossil tooth. Under a microscope, scratches and polishing, called dental microwear, can reveal how the jaws worked and even whether the diet was moist or dry. Knowing that it was moist or dry, in turn, can tell you something about the general conditions in which the animal survived. Extrapolations like these are used to reconstruct the lives of ancient species.