Diet and primate evolution

These observations raised a number of questions. However, because insects tend to be discretely distributed in the forest canopy and are also small in size, only small and relatively solitary primate foragers can be supported on such a diet.

But spider monkeys specialize in soft fruits and tender young leaves, not hard palm nuts. A large brain would certainly have helped spider monkeys to learn and, most important, to remember where certain patchily distributed fruit-bearing trees were located and when the fruit would be ready to eat.

The Digestive System in Mammals: The human, or Homo, genus emerged during the Pliocene.

Diet and Primate Evolution

As I Diet and primate Diet and primate evolution earlier, primates typically have larger brains than do other mammals of their size. My own field studies have provided considerable evidence that obtaining adequate Diet and primate evolution in the canopy--where primates evolved--is, in fact, quite difficult.

In fact, in its general form, our digestive tract does not seem to be greatly modified from that of the common ancestor of apes and humans, which was undoubtedly a strongly herbivorous animal.

Most of the year howlers divided their daily feeding time about equally between new leaves and fruits. To a major extent, the emergence of modern humans occurred because natural selection favored adaptations in our order that permitted primates to focus their feeding on the most energy-dense, low-fiber diets they could find.

Hence, selection had not yet begun to favor a greatly enlarged brain in our family. This research, combined with complementary work by others, has led to another realization as well: It is fair to say that primates are omnivores taking the diet from both animal and plant foods because most primates do eat some animal matter each day along with plant foods, but it is important to realize that most material entering the digestive tract of monkeys and apes is of plant rather than animal origin.

Colobine monkeys, one of the Old World primate groups in Africa and Asia, offer an excellent example of this strategy. Recall that fruits are a poor source of protein. Because plants cannot run from hungry predators, they have developed other defenses to avoid the loss of their edible components.

For instance, selection yielded hands well suited for grasping slender branches and manipulating found delicacies. The cellulose and hemicellulose components of leaves, on the other hand, require complex digestive processes, and a small animal would be unable to maintain a constant throughput.

Another monkey species often found living in the same forests as Cebus apella is the spider monkey, Ateles paniscus. Unlike the typical primate digestive tract including that of humanswith its simple acid stomach, that of colobines includes a compartmentalized, or sacculated, stomach functionally analogous to that of cows and other ruminants.

These species were replaced by the even larger-brained H. What is more, trees exhibit seasonal peaks and valleys in the production of the fruits and young leaves primates like to eat, again making reliance on a single food species untenable.

In a process known as fermentation, the bacteria break down the cellulose and hemicellulose in plant cell walls, using those substances as an energy source to fuel their own activities.

Studies done on mantled howler monkeys Alouatta palliata in the s at that very locale had inadvertently helped foster the impression that primates enjoyed the life of Riley in the canopy.

In consequence, protein and other nutritious materials that compose the cellulolytic bacteria become available for digestion by the monkeys. But its descendants came to rely substantially on edible plant parts from the canopy, a change that set the stage for the emergence of the primate order.

In contrast to colobines, humans and most other primates pass fiber basically unchanged through their acid stomach and their small intestine where most nutrients are absorbed and into the hindgut the cecum and colon.

Primates Solve Dietary Problems with Their Heads The answer is simple—primates tend to specialize on only the highest quality plant foods—foods that offer the most nutrition in exchange for the time and energy invested in finding and eating them.


But increasing numbers of stone tools and processed mammal bones in the archaeological record suggest that humans gradually turned to the hunting of larger animals. Animal protein is of high quality and easy for humans to digest.

Growing bigger has been only a limited option for most primates, however. Milton has also studied the dietary behavior of indigenous human populations living in the Amazon Basin of Brazil.

Demment of the University of California, Davis, speculates, because they were outcompeted by the digestively specialized ungulates hoofed animals.

Though insects may be scarce, any animal in the tropical forest is continuously surrounded by potential plant foods. The leaf-eating langurs have already been mentioned.

Print Advertisement As recently as 30 years ago, the canopy of the tropical forest was regarded as an easy place for apes, monkeys and prosimians to find food.Diet and Primate Evolution Background Information Strategies Brain Difficulties-Presenters: T & Philip-The author: Katharine Milton Answering Initial Questions.

Primate-like Mammals The first primate-like mammals, or proto-primates, evolved in the early Paleocene Epoch ( million years ago) at the beginning of the Cenozoic Era. They were roughly similar to squirrels and tree shrews in size and appearance. Diet and Primate Evolution In the article “Diet and Primate evolution” by Katherine Milton, it addresses the change in which the diet of primates evolves throughout millions of years and how it helps them, as a whole species, evolve and develop various characteristics, thus creating species variation.

QUESTIONS: DIET AND PRIMATE EVOLUTION Scientific American, August Dr. Milton argues that obtaining food is a major selective pressure in the evolution of primates.

She compares the diet, behavior, and physical traits of. Diet and Primate Evolution. Many characteristics of modern primates, including our own species, derive from an early ancestor's practice of. Primate - Diet: The diet of primates is a factor of their ecology that, during their evolution, has clearly played an important role in their dispersion and adaptive radiation as well as in the development of the teeth, jaws, and digestive system.

Diet and primate evolution
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