Ch 22: The evolution of primates

hominoids

Superfamily: Gibbons, orangutans, gorillas, chimpanzees, autrolopithecus, homo

Hominids

Family: orangutans, gorillas, chimpanzees, autrolopithecus, homo

hominines

subfamily: gorillas, chimpanzees, autrolopithecus, homo

hominins

Tribe: autrolopithecus, homo

Lesser apes

A group of primates that includes gibbons and siamangs, known for their brachiation and smaller size compared to great apes.

great apes

The group of primates that includes orangutans, gorillas, chimpanzees, and humans. Great apes are characterized by their larger body size, lack of tails, and advanced cognitive abilities.

new world monkeys

A group of primates native to Central and South America, characterized by their prehensile tails and arboreal lifestyle.

old world monkeys

A group of primates that includes baboons, macaques, and vervet monkeys, characterized by their downward-facing nostrils and larger body size compared to New World monkeys.

3 Suborders of primates

The three suborders of primates are Strepsirrhini, Haplorhini, and Tarsiiformes. These suborders encompass various species, including lemurs, tarsiers, and monkeys, each with distinct evolutionary traits.

Brachiation

A form of locomotion in which primates swing from branch to branch using their arms, allowing for efficient movement through trees.

Knuckle walking

A form of locomotion used by some primates, such as chimpanzees and gorillas, where they walk on all fours with their knuckles touching the ground.

Upright walking

A bipedal form of locomotion where primates, including humans, walk on two legs, allowing for the use of hands for tool-making and other activities.

Human’s first toe compared to a gorilla’s first toe

The human first toe is more aligned and shorter, allowing for better balance and bipedal locomotion, while the gorilla's first toe is opposable, aiding in grasping and climbing.

Human’s pelvis compared to a gorilla’s pelvis

The human pelvis is shorter and broader, providing a stable base for bipedal locomotion, while the gorilla's pelvis is longer and narrower, adapted for knuckle walking and climbing.

Human’s vertebral column compared to a gorilla’s vertebral column

The human vertebral column is S-shaped, which helps to support an upright posture and bipedal movement, whereas the gorilla's vertebral column is more curved, suited for quadrupedal locomotion.

Human’s foramen magnum compared to a gorilla’s foramen magnum

The human foramen magnum is positioned more centrally beneath the skull, facilitating an upright posture, while the gorilla's foramen magnum is located towards the back of the skull, reflecting its quadrupedal stance.

Human’s supraorbital ridge compared to a gorilla’s supraorbital ridge

The human supraorbital ridge is less pronounced and flatter, contributing to a more rounded forehead, whereas the gorilla's supraorbital ridge is prominent and robust, indicating stronger facial musculature.

Human’s jaw compared to a gorilla’s jaw

The human jaw is smaller and less protruding, allowing for a more varied diet and speech, while the gorilla's jaw is larger and more robust, adapted for grinding tough plant material.

Which class gave rise to humans and hominoids

The class Mammalia, specifically the order Primates, gave rise to humans and hominoids, evolving distinct traits such as larger brains and advanced social behaviors.

What are some vestigial structures humans still have from our primate ancestors

Humans still possess several vestigial structures from our primate ancestors, including the appendix, wisdom teeth, and body hair. These structures are remnants of evolutionary adaptations that were once more functional.