UCR Anthropology 002 Midterm #2

Characteristics of Primates

-Grasping hands and feet

-Enhanced Vision

-reduced sense of smell

-large complex brains

Dental Pattern of Old World Primates

2.1.2.3 dental formula, bilophodont molar (two loafs to it)

Hominoids have Y-5 molars

Opposable big toes

Chimpanzees have these which help with grabbing in their natural environment.

Humans do not have this in order to have more efficiency when walking across the ground. The opposable big toe would mess with this efficiency.

Where do lemurs live?

Madagascar

The two suborders of primates and their noses

The platyrrhine nose is relatively flat with somewhat sideways projecting nostrils separated by a wide septum

the catarrhine nose has more downward projecting nostrils separated by a small septum

Arboreal Adaptations

(1) Clavicle acts as a strut to keep upper limbs to sides of body.

(2) Ulna and radius rotate forearm.

(3) Phalanges allow hand and foot dexterity.

(4) Opposable thumb (or big toe) allows digit to touch otherfingers.

(5) Primates have a powerful precision grip.

(6) Primates have a distinctive spinal column with five vertebraltypes

Prehensile Tail

A tail that acts as a kind of a hand for support in trees, common in New World monkeys.

Bipedal Adaptations

pelvis, femur, vertebrae, foot, and skull base

Natural Selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

sexual dimorphism

Differences in physical characteristics between males and females of the same species.

social organization

monogamous - Refers to a social group that includes an adult male, an adult female, and their offspring

polyandrous - Refers to a social group that includes one reproductively active female, several adult males, and their offspring.

polygynous - Refers to a social group that includes one adult male, several adult females, and their offspring

kin selection

Altruistic behaviors that increase the donor's inclusive fitness; that is, the fitness of the donor's relatives

gibbon social organization

monogamous, partners pair for life

paleontology

the scientific study of fossils

Earth's age

4.6 billion years old

Pangea

A hypothetical landmass in which all the continents were joined, approximately 300-200 mya.

carbon isotopes

help us track variation in atmospheric carbon and oxygen content and temperature

molecular clock

Model that uses DNA comparisons to estimate the length of time that two species have been evolving independently

foraminifera

Marine protozoans that have variably shaped shells with small holes.

visual predation

The proposition that unique primate traits arose as adaptations to preying on insects and on small animals.

Evolution of apes (Where)

Apes started evolving from africa

Adapids

Euprimates of the Eocene that were likely ancestral to modern lemurs and possibly ancestral to anthropoids.

Omoyids

Eocene euprimates that may be ancestral to tarsiers

Relative dating

Method of determining the age of a fossil by comparing its placement with that of fossils in other layers of rock

What distinguishes monkeys and apes (think about locomotion)

Monkey: Quadrupedal (either terrestrial or arboreal), Lumbar region is elongated, tails forem magnum is at the back of the skull, oreintation of scapula is on the side of the body, shortened clavicle, has elogated elbow called elecronom process. Limbs are similar lengths

Apes: brachiators (swing around with their arms), shorter lumbar region, no tails, forem magnum is at the base of the skull, scapula is more towards the back, longer clavicle, no elongated elbow, arms are longer than legs

absolute dating

A technique used to determine the actual age of a fossil

Frugivorous Primates

Fruit eating primates. They have low blunt cusps and wide incisors

Folivorous Primates

-foliage eating

-high sharp cusps

- fairly body size

Faunivorous primates

-insect eating

-high sharp cusps

-small body size

quadrupedal locomotion

walking on four legs

Knuckle walking and slow grasping

Exclusive to apes only

Characteristics of arboreal terrestrial quadruped

-chest narrow (side to side)

-downward forelimbs

-more flexible spine

arboreal quadrupedalism uses ______

Vertical leaping locomotion

Where is the scapula located in humans and apes

On our backs

Slow arboreal grasping uses ________

Suspensory locomotion

suspensory primates

-long forelimbs

-short upper arms

Prosimians

The primate suborder that includes lemurs, lorises, and tarsiers

Anthropoids

monkeys, apes, and humans (sub order)

Platyrrhines (New World Monkeys)

Infraorder: flat noses, wide range of size, die t and adaption . Dental formula: 2/1/3/3 (ancestral trait).

Anatomical features of NW monkeys

1. Broad noses, laterally facing nostrils

2. 2/1/3/3 dental formula

3. Ring like structure instead of ear tube

4. All diurnal (except for owl monkey)

5. Almost exclusively arboreal (spider monkey is semibrachiator )

6. Prehensile tail

When does anthropoid radiation begin

In the oligocene

Does the oligocene mark global warming or cooling?

Cooling, this cooling trend leads to mass extinctions

Anthropoid shared anatomical features (humans, monkeys, apes)

1. Postorbital closure (derived)

2. Fused frontal and mandibular symphysis

3. Tapetum lucidum (eye shine) absent (derived trait)

4. Tooth comb absent (derived)

5. Simple uterus (derived)

6. Mixed dental formula: 2/1/2/3 or 2/1/3/3

Characteristics shared by anthropoids

Longer gestation and maturation periods, increased parental care, complex social structures, more derived characteristics compared to prosimians, larger brains and bodies, increased color vision, reduced reliance in smell

What does LCA stand for

last common ancestor

4 types of primate movements

Quadrupedal locomotion, leaping locomotion, suspensory, and brachiation

Cartarrhines

Infraorder: old world monkeys, apes and humans. Downward facing noses, eat present, and derived dental formula (2/1/2/3)

Cercopithecoidea (Old World Monkeys)

Super family: baboons, langurs, and macques. Have ischial (hardened skin on buttocks)

Cerrcopithecoidea (langurs locomotion)

Arboreal quadruped

Cercopithecoidea (baboons locomotion)

Terrestrial quadrupeds

Cercopithecoidea (Columbus monkeys locomotion)

Semibrachiators

Order of Epochs in Cenozoic Era

Paleocene, Eocene, Oligocene, Miocene, Pliocene, pliestocene, Holocene

Eras in order from YOUNGEST to oldest

Cenozoic, Mesozoic, Paleozoic

Hominoidea shared anatomical features

1. Simple molars (derived). OW monkeys have a biolphodont

2. No tails (derived)

3. Short and broad trunks (derived)

4. Longer arm to leg ratio (derived)

5. Highly mobile joints (scapula on the back)

Brachiators adapted

Long/curved fingers, short thumbs, and monotonous social structure