ANT 101 - Part 2

Catarrhines

(Old World Monkeys, Apes, and Humans

Primate Suborder: Haplorhines

Greater reliance on sight • Full post-orbital closure •No tapetum lucidum •Decreased reliance on smell •"Dry nose" (no rhinarium) •Reduced snout •Larger brain •Nails, no claws •No dental comb

Why be Social?

Group living evolved as an adaptive response to various ecological variables and has served primates throughout evolutionary history

Femur - quadrupeds vs. bipeds

The key morphological differences between bipeds and quadrupeds' femur is the way is affects their stance. Humans are "Knocked Kneed" with a valgus(inward) angle of the femoral shaft. Quadrupeds have a 90-degree angle.

These fossil primates are classified as "true primates". They were large, arboreal, and demonstrated lemurlike traits. Fossil evidence further indicates that there were more than 37 genera and nearly 90 species of this fossil primate.

adapoids

In general, members of the Primate order

have teeth that are generalized for eating a range of food types

Primate-wide trends in behavior include all of the following EXCEPT

male-female competition

Primate-wide trends in behavior include all of the following EXCEPT:

male-female competition

Principle of Superposition

Oldest sediments usually in the lower strata, while newer sediments in the higher strata

Patchy Forest Hypothesis

• More efficient movement between dispersed resources • Good support for this model

Diversity

Diversity among closely-related organisms who experience different ecological conditions reflects adaptive responses to the local environment

Mid-Miocene (~17 Million Years Ago)

Hominoids also appear in southern Europe and Asia - Gigantopithecus

Fibula

Smaller of the two lower leg bones; doesn't touch the femur

Foramen Magnum

"Big hole": Located in the inferior region of the skull • Anteriorly positioned in bipeds • Allows head support in upright posture

Australopithecus africanus

"Taung Child" discovery in South Africa in 1924 by Raymond Dart

Phalanges

(14 of them): Finger bones

Metatarsals

(5 of them): Foot bones

Metacarpals

(5 of them): Hand bones

Cenozoic Era

(65 million years ago): the Age of Mammals

Tarsal bones

(7 of them, together form the tarsus): The ankle

Carpal bones

(8 of them, together form the carpus): The wrist

Advantages to being Social

- Access to food - Defense of food - Predator defense - Mate access - Assistance in care of young

Disadvantages to being Social

- Competition for food - Visibility to predators - Competition for mates - Risk of social tension and violence

Proprimates: Plesiadapiformes

- Group of early mammals considered related to primates - Experienced adaptive radiation in Europe and North America. • Non-Primate Features such as - No orbital convergence - Limited to no grasping hands or feet - Small brain - Specialized, rodent like teeth • Why possible primates? - More flexible ankle - Nails on big toes - Molars similar to primates

Increased dependency

- Importance of mother-infant bond - Increased opportunities for infant learning

Euprimates

- Meet criteria for "true" primates • Grasping hands and feet • Post-orbital bar or plate • Forward-facing eyes • Nails instead of claws • Larger brains • Generalized teeth - Diversification into two groups: Adapoids and Omomyoids • Adapoids: Fairly large, arboreal; similar to lemurs • Omomyoids: Narrow snouts, large eyes; similar to tarsiers

Fossil record incomplete and biased

- Mostly hard parts (especially teeth) - Most organisms aren't preserved - Most preserved aren't found

Anthropoids

- Traits similar to monkeys, apes, humans • Reduced snout • Bony, enclosed eye socket • Small orbits - Diversification into two groups: Parapithecids and Propliopithecids • Parapithecids: 2.1.3.3 dental formula; both primitive and derived traits • Propliopithecids: 2.1.2.3 dental formula; directed linked to modern Old World Monkeys

Hominoids

- Traits similar to apes and humans • Modifications in upper body for brachiation • Y-5 molar pattern • No tail • Larger body and brain size - Evidence suggests Africa as place of origin - Proconsul: Earliest family of hominoids • East Africa • 23 - 17 mya • Mixture of generalized anthropoid and hominoid morphology

To understand behavior, comparative primatologists focus on:

1) Primate-wide trends: Behaviors found in all or most primates - Ancestral traits favored by natural selection 2) Hominoid-wide trends: Behaviors found in all or most hominoids (e.g., apes and humans) - Traits that distinguish apes and humans from other primates 3) Human-wide trends: Behaviors found only in humans

Propliopithecids

2.1.2.3 dental formula; directed linked to modern Old World Monkeys

Parapithecids

2.1.3.3 dental formula; both primitive and derived traits

Ribs

24 of them, 12 on each side; with the sternum and thoracic vertebrae make up the thoracic cage

The first "true" primate (euprimate) is believed to have emerged approximately __________ million years ago.

53-35

Monotremes

: Lay eggs but nurse young with milk (e.g., platypus)

Piltdown "Discovery" - hoax

A barrier to acceptance ▪ "Discovered" in 1911 in southern England by Charles Dawson ▪ Cranium was modern human in form, but jaw was ape-like

Frontal

Above the orbits

Foraging

Act of seeking and processing food

Old World

Africa, India, Southeast Asia, and Japan

Ardipithecus ramidus

Age: ~4.4 mya ▪ Paleoecology: Woodland ▪ Ape-like features ▪ Chimp-sized brain ▪ Arboreal hands and feet ▪ Hominin-like features ▪ Non-honing canine ▪ Reduced prognathism ▪ Bipedal pelvis and femur ▪ Forward (anterior) foramen magnum

Orrorin tugenensis

Age: ~6 mya • Hominin status • Femoral angle • Femoral neck length • Thick molar enamel • Ape status • Partial honing canine • Curved hand bones

Half-Life

Amount of time that it takes for half of the mass of unstable isotope to transform to the stable isotope

Prognathism

Anterior projection of the mid-face (vs. orthognathic)

Oligocene (35 - 23 Million Years Ago)

Anthropoids - Traits similar to monkeys, apes, humans

Vertebrae

Back bones a. Cervical: 7 of them; neck vertebrae b.Thoracic: 12 of them; vertebrae that have ribs c.Lumbar: 5 of them; vertebrae of the abdomen

Occipital

Back of the skull

Consequences of Bipedalism

Back pain, especially in the lumbar region and Birth complications

Metabolic Demands

Basal Metabolic Rate (BMR): Energy needed to maintain basic physiological functions at rest. - Body size: Smaller animals have a higher BMR than larger animals • Smaller organs for digestion • High surface area to mass ratio • Need energy-rich diet; high in protein, fats, and carbohydrates. • BMR and body size shape diet, which affects social structure

Living primates are commonly categorized into respective subgroups

Based on Linnaean system involving morphological similarities between species ▪ More recently, comparative genomics provides a more accurate picture of evolutionary and biological relationships

Altruism

Behavior that benefits another with some cost to self ▪ Related to kin selection: Favoring of one's close genetic relatives

Parietals

Behind the frontals

Diverse (>200 species)

Between 1990 - 2009, 86 new primate species described

Foot - quadrupeds vs. bipeds

Bipeds have a double arched foot featuring as a key morphological difference. This enables the foot to act as a spring and stores energy as well as walk more efficiently. Quadrupeds tend to have more arboreal hands and feet, with an adducted big toe, long metatarsal, and short phalanges.

Sacrum

Bone at the base of the spine and at the upper and back part of the pelvic cavity

Sternum

Breast bone

Supraorbital tori/ridge

Brow ridges

Zygomatics

Cheek bones

Consequences of Bipedalism

Children born developmentally young as a result of bipedalism and relatively large brains • Life history shift and extended period of learning • Extremely pronounced in modern humans but started in Homo

Increased Reliance on Vision

Color (diurnal primates only)- Depth Perception ▪ Stereoscopic vision: Perception of objects in three dimensions ▪ Binocular vision: Overlapping visual fields provided by forward-facing eyes ▪ Visual information from each eye transmitted to visual centers in both hemispheres of the brain

Social Structure

Composition, size, and sex ratio of a group of animals

Nasals

Comprise the roof of the nose

Lumbar Curvature

Curvature of lumbar area of vertebral column: Kyphosis vs. Lordosis • Shifts center of gravity over pelvis

Qualitative methods

Data not recorded in a standardized format • Data can be informative but cannot be used to test hypotheses across studies

Quantitative methods

Data recorded in a standardized format • Able to compare numerical values across time and place • Use specific sampling protocols for data collection

Relative Dating: Faunal Correlation

Dating fossils based on correlation with fossil of known ag

Relative Dating: Fluorine Dating

Dating fossils by examining the relative amount of fluorine in the bone • Fluorine found in most groundwater; seeps into bones over time • Only useful with bones from the same location

Radiometric Dating

Dating method based on measurable rate of radioactive decay of unstable isotopes

Dating Techniques

Dating methods divided into two broad categories which are relative dating and absolute dating

Defining adaptation in hominins

Documented in early hominin fossils • Example: "Lucy" (Australopithecus afarensis at ~3.2 million years ago) • Anatomical rearrangements • Modified pelvis and lower limbs • Also, vertebral column and base of skull • Energetically efficient walking in more open environments • Health consequences: • Low back strain, birthing issues, balance

Proconsul

Earliest family of hominoids • East Africa • 23 - 17 mya • Mixture of generalized anthropoid and hominoid morphology

Problem

Earth disturbances (e.g., earthquakes, river activity) may shift strata and objects within

Dietary plasticity

Eat a variety of foods (e.g., grasses, leaves, insects, meats)

Developmental plasticity

Effects of environment on phenotype during development ▪ Example: Baboons ▪ Sexual maturity earlier in food enhanced ▪ Sexual dimorphism enhanced

Cranial/sagittal crest

Elevated bone along the midline of the cranium

Studying primates for their own sake

Emphasis on observing free-ranging primates in natural habitats, Examining diversity of living and past primates (>200 species) - Living primates found in Africa, Asia, and South/Central America, Urgency!

Suprafamily: Hominoids (Apes)

Enlarged brain and more complex behavior •Upper body modifications for brachiation •Modified dentition (simple molars with Y-5 vs. bilophodont teeth) •No tail

Eocene (53 - 35 Million Years Ago)

Euprimates - Meet criteria for "true" primate

Strepsirrhines: Lemurs

Exist solely in Madagascar ▪ Only non-human primate on island (~100 species) ▪ Have spread out and adapted to many available environments ▪ Example of adaptive radiation ▪ Range in size and behavior ▪ Larger forms are diurnal omnivores, while smaller forms are nocturnal insectivores ▪ Primarily arboreal with terrestrial exceptions (e.g., ring-tailed lemurs)

Increased Complexity of the Brain

Expanded neocortex ▪ Allows for higher mental functions (e.g., planning) ▪ Integrates incoming information from different sensory organs

Adapoids

Fairly large, arboreal; similar to lemurs

Emphasis on body fat

Fat present in other vertebrates but most developed in mammals - Fat reserves allow for energy buffering

Bipedalism: Femur

Femoral shaft is angled medially (i.e., inward, toward body) • Valgus Angle • Humans are "knock-kneed" • Brings feet closer together and keeps legs directly under the body for balance while walking

Something Old, Something New

Focus on features that are evolutionary holdovers (i.e., conserved/ancestral traits) and features that are new specializations (i.e., derived traits)

Bipedalism: Foot

Foot is double arched - Acts as a spring that stores energy during stride - Allows for more efficient walking • Adducted big toe (i.e., hallux) • In line with foot • Long metatarsals, short phalanges • Increases stride and makes gait more efficient

Incisors

For grasping and nipping

Molars

For grinding, slicing, and crushing food

Canines

For piercing, holding, and cracking open food

Premolars

For pulping and crushing food

Food Availability and Distribution

Foraging: Act of seeking and processing food • Leaves support large groups, insects do not • Fruits and nuts appear in patches and can support small groups

Bipedalism: Axial Skeleton

Foramen Magnum and Lumbar Curvature

Ulna

Forearm bone on the "pinky"-side

Radius

Forearm bone on the "thumb"-side

Vertical Clinging and Leaping

Form of locomotion▪ Animal supports itself vertically by grasping onto tree trunks and other large plants while knees and ankles are tightly flexed ▪ Able to spring powerfully away forward and backward

Challenges in Paleoanthropology

Fossil record incomplete and biased

Strepsirrhines: Galagos ("Bush Babies")

Found in forest and woodland areas of sub-Saharan Africa ▪ Mostly small and nocturnal ▪ Avoid competition with larger-bodied diurnal monkeys ▪ Primarily frugivores and insectivores ▪ Specialized lower limb morphology; allows for vertical clinging and leaping

Platyrrhines ("New World Monkeys")

Found in forested habitats of southern Mexico, Central America, and parts of South America ▪ Examples: Marmosets, tamarins, howler monkeys, spider monkeys ▪ Variation in size, diet, and ecological adaptations ▪ All diurnal (except owl monkeys) ▪ Fully arboreal and mostly quadrupedal ▪ Prehensile tail: Adapted to grasp, hold, and manipulate objects; aids arboreal monkeys in finding and eating food in the trees ▪ 2-1-3-3 dentition ▪ Broad, flat noses with outward facing nostrils

Strepsirrhines: Lorises

Found in tropical forest and woodland habitats of India, Sri Lanka, SE Asia, and Africa ▪ Most widespread of strepsirrhines ▪ Mostly nocturnal and fully arboreal ▪ Some are entirely insectivores, others are omnivores ▪ Slow, cautious climbing form of quadrupedalism

Cercopithecoids: Old World Monkeys

Found throughout sub-Saharan Africa and southern Asia ▪ Most widely distributed of all living primates ▪ Divided into two subfamilies: Cercopithecines and colobines ▪ Cercopithecines: Cheek-pouch monkeys (e.g., baboons, macaques) ▪ Colobines: Leaf-eating monkeys (e.g., African colobus monkeys)

Bilophodont molars

Four cusps oriented in two parallel rows

Affiliative Behaviors

Friendly associations between individuals ▪ Grooming: Movement of the hands and/or mouth through fur to clean dirt and other debris ▪ Alliances

Placentals

Give birth to live young; have a placenta that exchanges nutrients and waste between fetus and mother (e.g., humans)

Marsupials

Give birth to live young; most offspring carried in a pouch after birth (e.g., kangaroos)

Orangutan

Great ape •Genus Pongo •Indonesian Islands: Sumatra & Borneo

Natal Group

Group one is born into

"Typical" primates are characterized by

Habitat: Tropical and semi-tropical regions ▪ Japanese macaque ("snow monkey") is one of a few exceptions ▪ Locomotion: Arboreal and quadrupedal (i.e., use all 4 limbs) ▪ Diet: Combination of insects, fruits, leaves, nuts, and meats

Temporals

Have the ear openings

endothermy ("warm blood")

High energy costs of endothermy ("warm blood") but allows environmental diversity

Social mammals

High levels of parental investment and care

Predation Pressures

High predation risk generally leads to larger groups, especially among small animals • Use vocalizations and other behaviors to respond to predators

Unique reproductive biology

High reproductive costs, Mother buffers from external environment (e.g., climate, nutritional deficiencies, infectious disease), Increased mother-infant interaction and bonding, Typically, divergence in male and female anatomy, physiology, and behavior (sexual dimorphism)

Miocene (22 - 5 Million Years Ago)

Hominoids Traits similar to apes and humans

The Big Picture of Human Evolution

Human evolution extremely complicated and species-rich • Often, multiple species alive at one time • Multiple hominin adaptive radiations • Not one linear progression from simple to complex

An Historical Perspective

Human-like fossils found in Europe and Asia in the 19th century ▪ Neandertal fossil in Germany (1856) & Pithecanthropus erectus in Java, Indonesia (1891) Early 20th century: Most scientists believed initial change towards being human was larger brain size

piecemeal

Humans evolved in a piecemeal fashion with different functional systems having different rates of evolutio

Humans Dental Formula

Humans: 2-1-2-2

Primate Origins (Three Hypotheses)

Hypotheses based on the selective pressures that result in divergence of primates from general mammalian form. • Arboreal Hypothesis • Visual Adaptation Hypothesis • Angiosperm Radiation Hypothesis

Features

Immovable residue of human occupation (e.g., ash pit

Importance of Social Environment

Importance of mother-infant bond • Harlow psychology studies • Reared infant macaques in a nursery rather than with their mothers ("maternal deprivation") • Optimal psychological development requires proper social environment • Reproductive and social behavior are also learned

Emphasis on sociality and parental care

In general, mammals lead "slower" lives (more "K" selected) - Emphasis on quality over quantity but considerable variation

Reside in Social Groups

In most cases, primates tend to associate with other individuals

Primates Emphasize Learning

Increased capacity for memory, learning, and problemsolving ▪ Complex communication ▪ Capacity for "language"? ▪ Some non-human primates make and use tools ▪ Primates (especially chimps) make and use simple tools ▪ Not unique to humans and hominins

Similarities in behavior

Increased parental care - Reliance on behavioral flexibility and learned information - Emphasis on sociality and play

Dental Formula

Indicates the number of each type of tooth in each quadrant of the upper and lower jaws

Solitary

Individuals forage for food alone • Solitary males and females with their offspring • Examples: Nocturnal primates (e.g., lorises and tarsiers) and orangutans

Behavioral Ecology investigates

Investigates how selective pressures (i.e., forces in the environment that influence reproductive success) affect behavior - Behaviors have been favored because they increase reproductive fitness in specific environmental contexts - Thus, behaviors are adaptive and have evolved through natural selection

Increased Encephalization

Large brain relative to body size

Primate Infraorder: Anthropoids

Larger average body size •Larger brains relative to body mass• Decreased reliance on smell, increased reliance on vision• Full post-orbital closure •More generalized dentition (e.g., no tooth comb) •Longer gestation and maturation periods, with increased parental care

Hominoids: Apes and Humans

Larger average body size •No tail •Anatomical differences in shoulder joint •Allows for suspensory locomotion and feeding •Generally more complex behavior •More complex brain and enhanced cognitive abilities •Increased period of infant development

Tibia

Larger of the two lower leg bones (i.e., the "shin" bone)

Sahelanthropus tchadensis

Location: Northern Chad, Central Africa • Age: ~6 - 7 mya • Odd mixture of features: Ape or hominin? • Intermediate foramen magnum • Suggestive of bipedalism • Small brain (<400 cubic centimeters) • Large brow ridges and cranial crests • Small face

Features of mammals that are relevant to human life history:

Mammals maintain lives that are expensive in terms of energy expenditure and consumption, Mammals can inhabit many different environments, Mammals live flexible lives both in terms of behavior and biology

Humans as Mammals and Primates

Many morphological, physiological, and behavioral features of humans and non-human primates are rooted in mammalian patterns

Hominin

Member of the subfamily Homininae ▪ Includes humans and ancestors in our lineage since LCA with apes ▪ Has replaced the term "Hominid. Defined by habitual bipedal adaptation

Factors Influencing Social Structure

Metabolic Demands, Food Availability and Distribution, Predation Pressures, Dispersal

Dating Techniques: Relative Dating

Methods of dating that indicate fossil's age relative to other fossils • Tells us that something is older or younger than something else but not by how much

Three main groups of living mammals

Monotremes, Marsupials, Placentals

Locomotor adaptations

More dependent on an active life - Set adult size: Finite period of bone growth - Balancing energy—growth & reproduction

Omomyoids

Narrow snouts, large eyes; similar to tarsiers

Dispersal

Natal Group: Group one is born into • Philopatry: Remaining in one's natal group as an adult (female or male)

closest living relatives

Non-human primates are our closest living relatives

Comparative Primatology

Non-human primates provide models to understand the evolutionary roots of human biology, morphology, and behavior - An evolutionary and comparative method illuminates our common evolutionary history with other primates

Non-human primates are also diverse

Numerous morphological, ecological, and behavioral differences among non-human primate species - Size - Habitat - Diet - Behavior - Parental care

One Female, Multimale

One adult female, two or three adult males, and their offspring • Form of polyandrous mating • Males participate in infant care • Examples: New World Monkeys (e.g., marmosets, tamarins

Foramen magnum:

Opening through which the spinal cord meets the brain

One Male, One Female

Pair-Bonding: Mated pair and their offspring - Usually arboreal - Low sexual dimorphism • Least common breeding structure among nonhuman primates

Mosaic Evolution

Pattern of evolution in which the rate of evolution in one functional system varies from rate of other systems • Example: Bipedalism evolved before brain evolution

Occipital condyles

Points where the neck vertebrae articulate with the skull

Artifacts

Portable objects made or modified for use by hominins (e.g., stone tools

Arboreal heritage

Possess many behaviors and anatomical structures for life in the trees

Nuchal

Posterior side of the neck

Generalized Dentition

Primate teeth are not specialized for eating one type of food ▪ Related to lack of dietary specialization ▪ Omnivorous: Having a diet consisting of many food types (e.g., plants, leaves, insects, meat) ▪ Wide and varied menu is advantageous in unpredictable environments; can also lead to competition for resources

Arboreal Hypothesis

Primate traits come from arboreal ancestry • Arboreal food items Generalized dentition and flexible diet • Navigating trees = Binocular vision and grasping hands and feet • Complex environment = Larger brain

Visual Adaptation Hypothesis

Primate traits evolved due to predation on small prey (e.g., insects) • Forward-facing eyes, accurate 3-D vision, and grasping hands evolved for capturing insects and other small prey

Angiosperm Radiation Hypothesis

Primate traits evolved with radiation of angiosperms (flowering plants) • Forward-facing eyes, omnivorous diet, and grasping hands and feet evolved to exploit diverse foods (e.g., flowers, fruit) in a variable and multicolored environment

Four types of teeth

Primates have four types of teeth: Incisors, canines, premolars, and molars ▪ Generalized placental mammal: 3.1.4.3 ▪ Tarsiers, lemurs, and New World Monkeys: 2.1.3.3 ▪ Old World Monkeys, Apes, and Humans: 2.1.2.3

Paleocene (65 - 53 Million Years Ago)

Proprimates: Plesiadapiformes - Group of early mammals considered related to primates

Increased Parental Investment

Reduced litter size (K-selected) ▪ Long period of gestation ▪ Emphasis on learning and behavioral flexibility

Extended Ontogeny (i.e., Development across the Lifespan)

Reduced number of offspring ▪ Single births as the norm

Reduction in Olfaction (i.e., smell)

Reduction in the size of olfactory structures in brain-Decreased size of the snout in most primate species

Increased biological and behavioral flexibility

Relatively long lifespan and increased physiological and behavioral flexibility ▪ Environmental tracking

Philopatry

Remaining in one's natal group as an adult (female or male)

A primate that remains in its birth (natal) group is referred to as:

philopatric

Haplorhines: Tarsiers

Restricted to islands of SE Asia (e.g., Malaysia, Borneo) ▪ Nocturnal insectivores (also, carnivores) ▪ Specialized vertical clinging and leaping ▪ 2-1-3-3/1-1-3-3 dentition ▪ Some strepsirrhine features (e.g., grooming claw) ▪ Some "anthropoid" features (e.g., no rhinarium) ▪ Some unique features (e.g., enlarged orbits) ▪ Neck can rotate > 180

Generalized

Retain several ancestral mammalian traits that others have lost over time (e.g., horses and cattle

Prehensile Hands and Feet ("Grasping")

Retention of five digits on hands and feet ▪ Opposable thumbs (and in most species, opposable big toes) ▪ Tactile pads with sensory nerve fibers ▪ Nails instead of claws

Supraorbital torus (plural: tori)

Robust piece of bone above orbits; prominent brow ridge

Multimale-Multifemale

Several adult males, adult females, and their offspring • Dominance hierarchy common • Many males reproduce • Results in sexual dimorphism • Examples: Savanna baboons, chimpanzees, ring-tailed lemurs

• Humans are closely related to living great apes, especially chimpanzees & gorillas

Share ancestor with chimps/bonobos ~5-7 million years ago (Last common ancestor [LCA]

Share many aspects

Share many aspects of morphology, physiology, and development - Grasping hands - Well-developed vision - Larger brains relative to body size

Bipedalism: Pelvis

Short, broad, and bowlshaped ilium (i.e., uppermost and largest part of the hip bone) • Supports organs and surface area for muscle attachments (gluteus maximus) • Transmits the weight of upper body to hips in an upright posture

One Male, Multifemale

Single adult male, several adult females, and their offspring • Form of polygynous mating • Most common primate mating structure • High sexual dimorphism • Example:Gorillas

Skeletal Changes Associated with Bipedalism

Skull • Spine • Pelvis • Knee joint • Feet • Hands

Gracile

Slender bodied (versus robust)

Similarities in life history patterns

Slow growth - Extended developmental period

Coccyx

Small triangular bone at the base of the spinal column (i.e., the "tailbone")

Gibbons and Siamangs

SmallApes • Asia and Southeast Asia • Large throat sacs for vocalizing

Platyrrhines (New World Monkeys; Superfamily Ceboidea) are found in which of the following geographic regions?

South America

New World

Southern Mexico, Central America, and South America

Measuring Primate Behavior

Specific methods are used to measure primate behavior like Quantitative methods and Qualitative methods

Paleoanthropology

Study of ancient humans based on fossil evidence, tools, and other signs of habitation

Behavioral Ecology

Study of animal behavior from evolutionary and ecological perspective

Stratigraphy

Study of the sequential rock layers (i.e., strata) of the earth

Context is Everything

Systematic excavation, recovery, and documentation. Associations: Paleoecology, Artifacts, Features

Dominance Hierarchies

Systems of social organization wherein individuals within a group are ranked relative to each other • Measured by access to desired resources • Position in hierarchy changes throughout life • Position in hierarchy related to stress and health

Pelvis - quadrupeds vs. bipeds

The Pelvis of quadrupeds and bipeds have key morphological differences, these include the shape (Bipeds have bowl shape), females need assistance during birth, baby must twist out. Quadrupeds births are much less complicated with a narrow pelvis, babies come out face out.

Clavicle

The collar bone, connects sternum and scapula

Orbits

The eye sockets

Pelvis

The hip bone connects vertebral column to lower limbs a. The pelvis is comprised of three bones: Ilium, ischium, pubis b.The acetabulum is the hip socket into which the head of the femur fits

Axial Skeleton - quadrupeds vs. bipeds

The key morphological differences between quadrupeds and bipeds is that bipeds have a Foremen Magnum which is a big hole located in the inferior region of the skull and have a Lemur Curvature which is curvature of the lumber arear of the vertebral. Quadrupeds have a kyphosis and bipeds are lordosis which shifts center of gravity over the pelvis.

Patella

The knee cap

Mandible

The lower jaw

Which of the following statements is generally TRUE?

The offspring of dominant males and females have better growth and survival rates.

Scapula

The shoulder blade (together with the clavicle forms the pectoral girdle)

Taphonomy

The study of how bones and other materials came to be buried in the earth and preserved as fossils • "Taphos" means "tomb"

Maxilla

The upper jaw

Behavior

The ways in which an organism acts in response to internal or external stimuli - Includes actions and inactions - May or may not be deliberate - Has been shaped over evolutionary time by complex interactions between genetic and environmental factors

Ischial callosities

Thickened piece of skin on the buttocks; related to the sitting positions

Femur

Thigh bone in upper leg

Phalanges

Toe bones

Fossil

Traces or remnants of organisms found in geological beds on the earth's surface • Organic matter replaced by inorganic compounds

Fossil

Traces or remnants of organisms found in geological beds on the earth's surface. First, you die, Then you decay, Essential element: Burial

Gorilla (Genus: Gorilla)

Tropical Africa •Vegetarian •Knuckle Walking

Habitat

Tropical and semi-tropical regions

Chimpanzee (Genus Pan)

Two species: ▪ Pan paniscus (bonobo) ▪ Pan troglodytes (common chimp) ▪ Knuckle walking

Paleoecology

Type and abundance of animals and plants at the site to reconstruct environment

Humerus

Upper arm bone

A primate with the following characteristics: 2.1.2.3 dentition, Y-5 molars, and a post-orbital closure can be best identified as:

a hominoid

Factors influencing primate social structure and behavior include:

a) distribution of food resources b) distribution of predators c) body size and metabolism d) dispersal of individuals from the natal group

First "true" primates appea

about 60 million years ago (mya) during the Eocene

Aggressive, combative, or unfriendly behavior among primates is best known as:

agonistic behaviors

As a taxonomic group, Anthropoids include:

all monkeys, apes, and humans

Which of the following hypotheses regarding the evolution of the Primate Order states that primate traits developed for tactile and visual discrimination of flowering plants?

angiosperm radiation hypothesis

Dating methods that indicate that something is older or younger than something else:

are called relative dating methods

Portable objects (e.g., tools) that are modified or made by hominins, including anatomically modern humans, and may be used to contextualize skeletal remains are called:

artifacts

The study of behavior from ecological and evolutionary perspectives is known as:

behavioral ecology

Last common ancestor (LCA)

between chimps and humans lived 6.5 mya

is fossil primate has been identified as a possible ancestor of New World Monkeys because it displays traits such as a 2.1.3.3 dental formula, a reduced snout, and bony, enclosed eye sockets.

parapithecids

catarrhine primates Dental Formula

catarrhine primates: 2-1-2-3

Anatomical and genetic evidence suggest that humans are most closely related to _______________, and that we shared a common ancestor approximately 5-7 million years ago.

chimpanzees

The study of our closest living relatives (non-human primates) to better understand human morphology, physiology, and behavior is:

comparative primatology

Which of the following statements is true about primate diets?

d) Smaller primates tend to have higher relative basal metabolic rates (BMR); thus, they require higher-energy diets

Factors influencing primate social structure and behavior include

distribution of food resources b) distribution of predators c) body size and metabolism d) dispersal of individuals from the natal group

The increase in brain size relative to body size is known as:

encephalization

Placental mammals

endothermy ("warm blood"), Increased relative brain size, Dietary adaptations, Locomotor adaptations, Unique reproductive biology

Compared to monkeys, hominoids (i.e., apes and humans):

have larger body sizes

This fossil primate has been identified as the largest primate to ever exist

gigantopithecus

In many primate groups, ______________ have/has a central role in reinforcing friendly, social bonds.

grooming

The mammalian characteristic of having different types of teeth (e.g., incisors, canines, molars) that serve different functions is called:

heterodonty

The ability to generate and regulate an internal and constant body temperature, which is a characteristic of mammals, is:

homeothermy/endothermy

Cercopithecoids (Old World Monkeys):

include two subfamilies: cercopithecines and colobines

copithecoids (Old World Monkeys):

include two subfamilies: cercopithecines and colobines

The period during which the infant is solely reliant on others for care (e.g., nutrition, movement, protection) is known as:

infancy dependency period

The retention of the fetus inside the body of a female through the course of its prenatal development is known as:

internal gestation

This form of competition refers to contests between different species for the same resource:

interspecific competition

A behavior is considered altruistic when:

it benefits another individual at the expense of the individual engaging in the behavior

An individual that makes a call to alert close relatives of an approaching predator may increase its own risks of being eaten. Which of the following is the best explanation of how such an apparently maladaptive behavior might evolve?

kin selection

Non-human primates are a good model to understand human evolution because we share many aspects of:

morphology, physiology, behavior, life history pattern

Chimpanzees primarily live in the following type of social group:

multifemale, multimale

The evolutionary success of primates can be attributed in part to their larger brains, and in particular, the expansion of this part of the brain

neocortex

The study of ancient humans based on fossil evidence, tools, and other signs of habitation is called

paleoanthropology

The vast majority of mammals are the following type

placentals

platyrrhine primates Dental Formula

platyrrhine primates: 2-1-3-3

This group of "proprimates" are a group of mammals thought to be peripherally related to primates

plesiadapiformes

A social grouping of two or more males mated to one female is called:

polyandrous

The following are all characteristics of apes except

presence of a tapetum lucidum

According to the visual adaptation hypothesis:

primate characteristics evolved due to predation on small prey (e.g., insects)

The concept that the oldest sediments are usually in lower rock layers, while newer sediments are in higher rock layers is known as

principle of superposition

This fossil primate has been identified as the earliest family and general precursor of hominoids because it displays traits such as modifications in upper body for brachiation, a Y-5 molar pattern, and no tail.

proconsul

The following methodology involves recording data in a systematic format, such that actual numerical values can be compared across time and place

quantitative methods

Differences between the sexes of a species in body size or shape is known as:

sexual dimorphism

In general, members of the Primate order have all of the following traits EXCEPT:

small brains relative to body size

In general, members of the Primate order have all of the following traits EXCEPT:

specialized, homodont dentition

K-selection refers to:

species that produce relatively few offspring but invest in increased parental care

In laboratory experiments, monkeys who experience maternal deprivation (i.e., raised without mothers):

splayed abnormal social and reproductive behaviors throughout their life

The study of the sequential rock layers (i.e., strata) of the earth is known as

stratigraphy

strepsirrhine primates Dental Formula

strepsirrhine primates: 2-1-3-3

The order Primates can be subdivided into two main groups (called suborders). These groups are:

strepsirrhines and haplorrhines

Strepsirrhines differ from haplorrhines in that:

strepsirrhines have a dental comb b) strepsirrhines have a grooming claw c) most strepsirrhines rely heavily on their sense of smell over vision d) strepsirrhines are found only in the Old World (i.e., Africa and Asia)

This primate group shares traits with both the strepsirrhines and haplorrhines; they are small-bodied, nocturnal, have enlarged orbits, have a grooming claw, and can rotate their heads over 180 degrees.

tarsiers

Absolute Dating: Potassium/Argon (K/Ar)

• Measures decay of potassium-40 (40K) to argon-40 (40Ar) • Measure radiation from inorganic rock materials only (e.g., volcanic rocks) • Half-life = ~1.3 billion years • Important to dating early hominin sites • > 100,000 years

Dietary adaptations

to help meet relatively high and continuous energy demands (e.g., heterodont dentition

Dating Techniques: Absolute Dating

• Methods of dating that indicate the specific age (e.g., number of years) of a fossil based on: • Analysis of the fossil itself • Analysis of the rocks surrounding the fossil

The potassium/argon (K/Ar) method is most appropriate for dating which of the following materials?

volcanic rock

Increased relative brain size

with greatly enlarged cerebrum (neocortex) for processing sensory information - High metabolic demands - Increased behavioral flexibility and learning

Earliest Hominins

~5-7 million years ago (End of Miocene) ▪ Evolved in Africa and were there exclusively until ~2 mya

Hunting Hypothesis

• Bipedalism freed the hands for tool use and carrying objects • However, evidence indicates that hunting comes later

Temperature Regulation

• Bipedalism increases rate of heat loss and reduces heat stress • However, may have not been critical for survival in woodland areas where hominins evolved

Gigantopithecus

• Found in late Miocene sites in India and Pakistan • Also, Pleistocene sites in China and Vietnam • Largest primates ever! - Some exceeding 600 lbs

Male Provisioning Hypothesis

• Males carrying food for females and children • Little evidence to support pair-bonding patterns

What Makes Us Human?

• Many traits, biological and behavioral, have been used to distinguish humans from other primates, including: • Culture • Tools and technology • Language and symbolic thinking • Art • Religion • Large brain size • Bipedalism • Reproductive biology • In fact, many of these traits are present in non-human primates • Thus, it's difficult to make absolute distinctions

Absolute Dating: Carbon-14 (Radiocarbon)

• Measures decay of carbon-14 (14C) - Measure radiation from organic material only (e.g., bone, charcoal/wood, shell, etc.) - Half-life = ~5,730 years • Use: ~50 - 75,000 years ago - Accuracy reduced > 40,000 years ago

Relative Dating: Stratigraphy

• Study of the sequential rock layers (i.e., strata) of the earth • Oldest sediments usually in the lower strata, while newer sediments in the higher strata (Principle of Superposition) • Problem: Earth disturbances (e.g., earthquakes, river activity) may shift strata and objects within

Disadvantages of Bipedalism

▪ Birth more difficult ▪ Lower back stress

Advantages of Bipedalism

▪ Long distance travel ▪ Carrying objects ▪ Visual surveillance

Strepsirrhines

▪ Lorises, Galagos, and Lemurs ▪ Retain specific ancestral characteristics ▪ Greater reliance on olfaction: rhinarium ▪ Post-orbital bar ▪ Retain a tapetum lucidum ▪ Grooming claw ▪ Dental comb ▪ 2-1-3-3 dentition