The Los Angeles Zoo has a number of primate species. Background information indicates that there are a number of species of monkeys and apes in the zoo. The New World Monkeys are located in the South American section of the zoo and include the Black-handed spider monkey, the crested capuchin monkey, the black-howler monkey and the squirrel monkey. Of the four species of great apes, three that are exhibited at the Zoo include chimpanzees, orangutans, and gorillas. In the “Red Ape Rain Forest”, the orangutans are divided into a couple of groups. An in-depth observation shows that each group centers on a male. The orangutans exhibit one of the most extreme examples of sexual dimorphism with the males twice as large as the females.
Taxonomically, Orangutans belong to the kingdom Animalia and phylum Chordata. They belong to the class Mammalia because they have mammary glands. The order Primates describes physiognomies inherent in Orangutans such as five digits in their feet, differentiated tibia and fibula, and ulna and radius. They are in family Hominidae because they exhibit both an opposable thumb and big toe, and lack tails. Orangutans are further separated into the genus Pongo because they exhibit fewer similar characteristics with humans than do higher primates.
Despite their apparent large size, Orangutans are highly specialized for suspensory behavior. They have long forelimbs compared to their hind limbs with relatively reduced thumb. These long arms act as hooks during brachiating. As a consequence of their arboreal lifestyles, Orangutans possess a big opposable toe and a highly mobile hip. While on the ground, they walk quadrupedally on their fists and occasionally move bipedally (Rowe as cited in Lang).
Orangutans are solitary animals. The males, however, are the most solitary. They are intolerant and aggressive towards each other. They only have sexual contact with females during mating. Their young ones usually accompany females. The adult male Orangutan possesses cheek pads and a rather drooping laryngeal throat pouch. These special characteristics not only intimidate their rivals, but also help the male in making his long call.
Of the monkeys in the zoo, the spider monkeys are light in color, very active and, therefore, very easy to observe. Their features include a hairless area at the tip of their snout and the presence of a grooming claw on the second toe. The howler monkey is famous for its special call and sexual dichromatism. The capuchin monkeys are quadrupeds while on land. The squirrel monkey does not exhibit much dimorphism except for minimal color variations. Monkey squirrels are the smallest of all monkeys. Taxonomically, they differ from orangutans and are placed in the family cebidae. The Saimiri sciureus species found in the Los Angeles Zoo is an active, tree-dwelling primate with distinctly colored short fur. Its body is majorly olive or yellow in color, while its face is white. Monkey squirrels are omnivores feeding on plants, small animals and insects.
Unlike orangutans, monkey squirrels are very social and move around in big troops of 40 to 50 monkeys. These troops contain sub-groups within which they feed during the day. Unlike orangutans, their tails are very long nearing 30cm that serve to give them balance as they move through trees. Furthermore, squirrel monkeys have higher intelligence than orangutans. Thus, they have highly vocalized forms of communications such as varying their tones, pitch or noises to depict different messages. In addition, the eyesight of monkey squirrels are more developed than orangutans, and they can observe the color.
Apes differ from monkeys in several ways. For instance, the primary method of locomotion for apes is brachiation while monkeys jump from one tree to another. Apes have short and broad trunk, no tail, shorter legs but very long arms and fingers. Conversely, monkeys have long and narrow trunks, prehensile tails and no considerable difference in length between hands and legs.
Despite their similarities as primates, humans, orangutans and monkeys are completely dissimilar animals in a number of perspectives. Firstly, unlike apes and monkeys, humans are “knock-kneed”, ensuring that one foot always leans slightly away from the center of gravity when the other is lifted off the ground during locomotion. Orangutans lack special locomotor adaptation and therefore sway sideways when attempting to walk on two. Monkeys are absolute quadrupeds. Secondly, humans have a large forward pointing big toe. In apes and monkeys, this big toe is directed sideways. The human feet serve as a firm platform for movement. In contrast, the non-human primates use the foot as a prehensile structure for mobility while brachiating.
Thirdly, human hands differ considerably from that of the non-human primates especially orangutans. The orangutan’ hand is relatively longer with curved phalanges compared to the relatively shorter human hand and straight phalanges. In apes, the hands are curved as they emulate hooks during brachiating. The fourth contrasting trait between this two species is the skin appearance. Just as much as humans, the non-human primates have similar body hairs per square centimeter of skin. The difference exists on hair color, length and texture. The human primate has short and very fine hair that give the impression of nakedness.
Fifthly, dental structure and arcade in humans differ considerably with its primate’s counterparts. The human teeth, for example, are much smaller due to reduced enamel thickness. Noticeable differences are in the reduction of the size of incisors and canines. For instance, the orangutans have long canines in their lower jaws. Furthermore, the teeth row in humans is parabolic with a reduced lower jaw size. The non-human primates have a u shaped dental arcade with a rather elongated lower jaw.
Evolutionary, as the human ancestors adapted to the changing world they evolved and developed unique sets of characteristics that define the human species today. The Pongo pygmaeus belongs to Hominidae. This grouping contains gibbons and siamangs (Hylobatidae) and orangutans, humans and other greater apes like the bonobos and gorillas. (Hartwig as cited in Gosselin-IIdari). The evolutionary path of the orangutan is traced back to a Miocene hominoid sivapithecus. These two species share several features including prognathism, narrow nasal apertures and zygotic arches in their cranium (Fleaggle as cited in Gosselin-IIdari).
Monkeys are classified in two ways depending partly on their geographical range. These are the Old World Monkeys and the New World monkeys. Physically, the New World monkeys and Old World monkeys look very different. They show a marked difference in features such as nose types, cheeks and rumps. These differences are evolutionary traits acquired by the animals in the course of time as they exploited different environments and occupied dissimilar ecological niche.
Fossil records show that humans originated from apelike ancestors. Several physical, genetic and behavioral traits shared with people and non-human primates compounds the evidence supporting the common ancestry. Just as Humans, for example, monkeys communicate with one another. They produce different noises, diverse facial expressions and calculated body movements to communicate with each other. For instance, a monkey's grin symbolizes aggression. By grooming each other which corresponds to human embrace, monkeys express affection and make peace with others.
Physically, the other primates occasionally exhibit bipedalism, the ability to walk on two. The shared bipedalism shows evolution divergent that occurred between the two species. Other important human characteristics such as language capacity and the knowledge and use of tools, are depicted by these organisms when need arises. The orangutan, for example, makes long vocal noises to communicate emotions to others.
All species originated from their ancestral parents through the process of biological evolution. Evolution occurs through the changes in the genetic material (DNA).The parents pass down this changes to their offspring from one generation to the next. Information contained in the DNA can however change by a process known as mutation. The genetic mutation, on the other hand, alters the expression of the affected sets of genes and how these genes in turn influences the body or behavior of an organism. Together with natural selection, genes affect how the body and behavior of an organism and which determines the likelihood of an organism’s survival and reproduction over time.
In conclusion, it is paramount to understand that evolution changes the hereditary means of growth and development that typify a population. Parents pass these adaptive genetic changes to their offspring. These inherited adaptations enhance their chances of survival, growth and development despite the constantly changing environment.
Work cited
Gosselin-Ildari, A. “Pongo pygmaeus, Orangutan.” 18 Dec. 2006. Web. 8 Nov. 2014. <http://digimorph.org/specimens/Pongo_pygmaeus/>.
Lang, C. K. A. “Primate Factsheets: Orangutan (Pongo) Taxonomy, Morphology and Ecology.” 13 June. 2005. Web. 8 Nov. 2014. <http://pin.primate.wisc.edu/factsheets/entry/orangutan>.
