Quadrapedalism

1.) Quadrapedalism- Using all four limbs to support the body during locomotion. The majority of quadropedal primates are arboreal, such as the bearded saki, there are some terrestrial quadropedal primates though, such as the savanna babboon. Typically, the limbs of terrestrial quadrupeds are of equal length. In arboreal quadrupeds forelimbs are shorter and may be 70-80% as long as the hind limbs.

Brachiation- Arm swinging. An example of a primate that uses brachiation exclusively is siamangs of Southeast Asia. Other primates are called seminbrachiators, use a combination of brachiation and leaping, such as the spider monkey. These primates are mainly arboreal, and are characterized by arms longer then legs, short lumbar spines long fingers and small thumbs.

Vertical clinging and leaping- A form of locomotion in which the organism supports itself vertically by grasping onto tree trunks while their knees and ankles are flexed tightly. These primates, such as the indri, are characterized by their long hind limbs, and long fingers. These primates are mainly arboreal.

2.) When Darwin was developing his theories on evolution, he was afaid to publish his findings due to the christian beliefs that were widely accepted at the time. Religious knowledge would have it that god created all species, and therefore since the creation no new species could have come into existence. Through science we have discovered evolution, variation and extinction. These beliefs obviously contradict one another, and often they confuse us. There are some similarities in these beliefs though, christian belief in the “Great chain of being” resemble the invention of Linnaus, the taxonomic system.

3.) Variation is the inherited difference between individuals, in effect these difference may increase or decrease the organisms ability to reproduce successfully, this process is called natural selection. The basic evolutionary sources of variation are mutation, recombination, natural selection, drift and gene flow.

5.) Primates and all mammals share a series of characteristics such as: body hair, long gestation and live birth, mammary glands, different types of teeth, ability to maintain a constant body temperature, increased brain size and a considerable capacity for learning. Scientists created a special order called primates, because they share many characteristics unique to their order: a tendency toward erect posture, a flexible, generalized limb structure, hands and feet w/ a high degree of apprehensibility, retention of 5 digits on hands and feet, an opposable thumb, nails instead