unit 2 quiz - Human origins

Sivapithecus

extinct genus of ape from the Miocene epoch (around 12 to 8.5 million years ago) in South Asia

Sivapithecus

Close relative of the modern orangutan due to shared facial features like a concave face, large cheekbones, and narrow-set eyes.

Gigantopithecus

the largest primate to ever live, an extinct genus of ape that inhabited southern China and Southeast Asia, possibly as recently as 100,000 years ago

Proconsul

an extinct genus of early Miocene primates (roughly 23–14 million years ago) from East Africa that represents a critical transitional fossil between monkeys and apes

Dryopithecus

a genus of extinct great apes from the Miocene epoch (12.5 to 11.1 million years ago) in Europe, known as the "tree ape" for its arboreal lifestyle, likely swinging through trees (brachiation) and walking on the flats of its hands.

Dryopithecus

crucial link in the evolutionary history of great apes and humans, possessing a mix of primitive and advanced features, and is thought to be a distant ancestor of gorillas and chimpanzees, possibly even an early gorilla relative.

Miocene hominoid characteristics

loss of a tail, Y-5 molar patterns, increased brain size, and greater mobility in the shoulder and elbow, allowing for varied, mostly arboreal locomotion (the movement of animals in trees

y-5 molar pattern

a distinct lower molar shape featuring five cusps separated by a Y-shaped groove, primarily found in humans, apes, and their ancestors

canine sectorial complex

a dental adaptation in many primates, consisting of large, projecting upper canines, a diastema (gap), and a sectorial lower first premolar.

Behaviors of primates

highly social, intelligent, and communicative behaviors

Anatomy of primates

grasping hands and feet with opposable thumbs/big toes, flattened nails instead of claws, and forward-facing eyes providing stereoscopic vision. They possess large brains relative to body size, reduced olfactory senses,

Anatomy of anthropoids

a larger, more complex brain, forward-facing eyes with stereoscopic vision, and a fully enclosed bony eye socket (postorbital plate). They have relatively flat faces, smaller snouts, improved color vision, and grasping hands/feet with opposable thumbs

Behavior of anthropoids

complex social structures, high intelligence, and advanced cognitive abilities

Behavior strepsirhine

reliance on smell, nocturnal habits, and an arboreal (tree-dwelling) lifestyle.

Anatomy of strepsirhines

a moist nose (rhinarium) linked to the upper lip, a specialized toothcomb for grooming, and a grooming claw on the second toe. They are primarily nocturnal with large eyes, a tapetum lucidum for night vision, and a strong sense of smell

Anatomy of hominoids

absence of a tail, a larger brain-to-body size ratio, and a broadened torso with dorsal scapulae. They possess highly mobile shoulder joints, a short, inflexible lower back, and orthograde (upright) posture, facilitating diverse locomotion

Behavior of hominoids

high intelligence, complex social structures, and extended parental care.

Old World Monkeys dental formula

2:1:2:3 and 2:1:2:3

New World Monkey dental formula

2:1:3:3 and 2:1:3:3

encephalization

an evolutionary increase in the complexity or relative size of the brain, involving a shift of function from noncortical parts of the brain to the cortex.

arboreality

the state or quality of living in trees

sociality

the tendency of individuals, both human and animals, to associate in social groups, form communities, and engage in cooperative behavior

nocturnal eye size

proportionally larger eyes with wider pupils and larger lenses

diurnal eye size

specialized for activity during the day, much smaller corneas

superfamily hominoidea

a taxonomic group within the primate order that includes all apes and humans. Defined primarily by the absence of tails, they are characterized by larger brains, flexible shoulder joints for climbing, and complex cognitive abilities

sociobiology

behavior is predetermined by ones genes

behavioral ecology

behaviors evolved through natural selection

Monogamy

just a male and female

polygyny

two females and a male

polyandry

one female and two males

polygynadry

two females and two makes

Sexual selection

operates on only one sex within a species; its the result of competition for mates, and it can lead to sexual dimorphism

infanticide

an adaptive mechanism to increase fitness