Comparative Primate Comparative Primate AnatomyAnatomy

The Hardware of Human CultureThe Hardware of Human Culture

A language to communicate with and to use A language to communicate with and to use for learningfor learning

An ability to make and use toolsAn ability to make and use tools All the abilities that standing and walking on All the abilities that standing and walking on

two feettwo feet

*understanding our anatomy, we can *understanding our anatomy, we can understand our cultureunderstand our culture

Comparative Hominid AnatomyComparative Hominid Anatomy Anatomically, we are Anatomically, we are

very similar to apes and very similar to apes and even to monkeys but even to monkeys but not identicalnot identical*Humans are fully *Humans are fully bipedal, for example, bipedal, for example, while chimps are notwhile chimps are not

We have two arches in We have two arches in our foot; chimps do notour foot; chimps do not

Overview: The Human SkeletonOverview: The Human Skeleton

The Roots of Culture: The BrainThe Roots of Culture: The Brain

If culture is symbolic, then it is founded on If culture is symbolic, then it is founded on languagelanguage

The source of language is located in parts of The source of language is located in parts of the brainthe brain

Our ability to make and use tools is also Our ability to make and use tools is also begins in the brainbegins in the brain

Structure of the Brain: Description IStructure of the Brain: Description I

Lateralization: Lateralization: The division in the organization and The division in the organization and operation of the brainoperation of the brain

Frontal Lobe: Frontal Lobe: The lobe that allows us to think and The lobe that allows us to think and plan aheadplan ahead

Motor Cortex: Motor Cortex: Moves the facial muscles (lips, Moves the facial muscles (lips, tongue, vocalization) and the arm, hand, and finger tongue, vocalization) and the arm, hand, and finger musclesmuscles

Parietal Lobe: Parietal Lobe: The lobe that enables us to touch and The lobe that enables us to touch and tastetaste

Structure of the Brain: Description IIStructure of the Brain: Description II

Occipital Lobe: Occipital Lobe: The lobe of the brain that The lobe of the brain that enables us to seeenables us to see

Temporal Lobe: Temporal Lobe: The lobe that enables us to The lobe that enables us to hearhear

Olfactory Bulb: Olfactory Bulb: The part of the brain that The part of the brain that enables us to smellenables us to smell

Supplementary Motor CortexSupplementary Motor Cortex: The part that : The part that provides sensory feedback from an action provides sensory feedback from an action involving the motor cortexinvolving the motor cortex

Structure of the Brain: DiagramStructure of the Brain: Diagram

Frontal Lobe and Motor Frontal Lobe and Motor CortexCortex::

Cognition: Thinking AbilityCognition: Thinking Ability Motor AbilitiesMotor Abilities Parietal Lobe:Parietal Lobe: Touch and Touch and

TasteTaste Temporal Lobe:Temporal Lobe: Hearing Hearing Occipital Lobe:Occipital Lobe: Vision Vision Olfactory BulbOlfactory Bulb: Smell: Smell

The Motor CortexThe Motor Cortex Lower partLower part: The strip regulates the facial and oral : The strip regulates the facial and oral

musclesmusclesThey include the tongue, the lips, the organs for They include the tongue, the lips, the organs for vocalization, and the jawsvocalization, and the jawsThese are related to the language functionThese are related to the language function

Upper partUpper part: The strip regulates the arm, the hand, : The strip regulates the arm, the hand, and their fingersand their fingersThese are related to the tool manufacture and use These are related to the tool manufacture and use functions.functions.

Parts of the Brain: Motor CortexParts of the Brain: Motor Cortex

Related to LanguageRelated to Language: : Lower PartLower Part

LipsLips TongueTongue VocalizationVocalization Related to Tool Making Related to Tool Making

and Use: and Use:

Upper partUpper part Fingers and ThumbFingers and Thumb HandHand ArmArm

Language Functions of the Brain: Language Functions of the Brain: Description IDescription I

The language functions all occur on the left hemisphere of the The language functions all occur on the left hemisphere of the brain in most humansbrain in most humans

Broca’s AreaBroca’s Area functions to process the generating of speech functions to process the generating of speech Wernicke’s Area Wernicke’s Area functions to process the reception of speechfunctions to process the reception of speech

Parts of the Brain: Language Parts of the Brain: Language CentersCenters

Parts of CerebrumParts of Cerebrum• Frontal LobeFrontal Lobe• Motor CortexMotor Cortex• Broca’s AreaBroca’s Area• Temporal LobeTemporal Lobe• Auditory CortexAuditory Cortex• Wernicke’s AreaWernicke’s Area• Arcuate FasciculusArcuate Fasciculus• Parietal LobeParietal Lobe• Occipital LobeOccipital Lobe• Angular GyrusAngular Gyrus

Comic Relief, Anyone?Comic Relief, Anyone?(Courtesy of Geico)(Courtesy of Geico)

So easy a caveman can do it. . . .?So easy a caveman can do it. . . .?

So Why Do We Pick on the Bones?So Why Do We Pick on the Bones?

Bones are all we have to reconstruct past Bones are all we have to reconstruct past human and humanlike life formshuman and humanlike life forms- to coordinate what we know about - to coordinate what we know about anatomy—human and nonhuman primateanatomy—human and nonhuman primate- to reconstruct what our ancestors might have - to reconstruct what our ancestors might have

been like. been like. Bottom Line: We rely heavily on inference to Bottom Line: We rely heavily on inference to

trace our ancestrytrace our ancestry

Human Skill: A DescriptionHuman Skill: A Description

The forehead is high, making room for the The forehead is high, making room for the frontal lobefrontal lobe

The skull is rounded, allowing a greater The skull is rounded, allowing a greater volume for the entire brainvolume for the entire brain

There is no brow ridge or There is no brow ridge or supraorbital torus supraorbital torus The jaw does not jut forward; it is not The jaw does not jut forward; it is not

prognathousprognathous

Human Skull: Bones that Cover the Human Skull: Bones that Cover the LobesLobes

The bones of the skull are named after the The bones of the skull are named after the lobes they coverlobes they cover

The The frontal bone frontal bone covers the covers the frontal lobefrontal lobe The The parietal bone parietal bone covers the covers the parietal lobeparietal lobe The The occipital bone occipital bone covers the covers the occipital lobeoccipital lobe The The temporal bone temporal bone covers the covers the temporal lobetemporal lobe

Human Skull: The DiagramHuman Skull: The Diagram

Note the following:Note the following: High foreheadHigh forehead Rounded skullRounded skull No brow ridgeNo brow ridge Chin is presentChin is present Teeth are smallTeeth are small The bones are named The bones are named

after the lobes of the after the lobes of the brain they coverbrain they cover

Comparative Primate Anatomy: Comparative Primate Anatomy: Human and ChimpanzeeHuman and Chimpanzee

The area for brain of a chimp is more limited than The area for brain of a chimp is more limited than human brain because human brain because sloping forehead sloping forehead andand the heavy the heavy supraorbital torus supraorbital torus

that covers much of the foreheadthat covers much of the forehead the chimp jaw has a the chimp jaw has a prognathism prognathism absent in humansabsent in humans chimps have larger chimps have larger canine canine teeth than humans; so much teeth than humans; so much

so that there is a so that there is a diastema diastema (gap) for the opposite (gap) for the opposite canine to fitcanine to fit

Skull Morphology: Chimp and Skull Morphology: Chimp and HumanHuman

Note the followingNote the following Larger brow ridge (supraorbital torus) of chimp compared to humanLarger brow ridge (supraorbital torus) of chimp compared to human Sloping forehead of chimp compared to humanSloping forehead of chimp compared to human More prognathous (jutting) jaw of chimp compared to humanMore prognathous (jutting) jaw of chimp compared to human Larger canine and gap (diastema) of chimp compared to humanLarger canine and gap (diastema) of chimp compared to human

Comparative Brain Structure: Comparative Brain Structure: Human and ChimpanzeeHuman and Chimpanzee

The human brain has a The human brain has a Broca’s area Broca’s area for processing for processing speech.speech.

The chimp brain has a Brodman’s area, where calls The chimp brain has a Brodman’s area, where calls may originate, but no speechmay originate, but no speech

Our Our Wernicke’s area, Wernicke’s area, which receives speech,which receives speech, is at is at the same place as the the same place as the planum temporaleplanum temporale among the among the chimpschimps

Human and Chimp Skulls Human and Chimp Skulls Compared: Brain StructureCompared: Brain Structure

Compare the followingCompare the following Chimp’s brain is much smaller Chimp’s brain is much smaller

(400cc vs. 1400cc)(400cc vs. 1400cc) It has reduced frontal lobeIt has reduced frontal lobe It has no Broca’s or Wernicke’s It has no Broca’s or Wernicke’s

areaarea It does have Brodmann’s area It does have Brodmann’s area

10, where calls may originate—10, where calls may originate—but no speechbut no speech

It does have planum temporale, It does have planum temporale, where calls are received—but where calls are received—but not processed as languagenot processed as language

What This All MeansWhat This All Means

Our brains are larger than the chimps’Our brains are larger than the chimps’ We have a well-developed frontal lobeWe have a well-developed frontal lobe We have well developed language areas: We have well developed language areas:

Broca’s and Wernicke’s areaBroca’s and Wernicke’s area The motor strip is more well developed among The motor strip is more well developed among

humans than among chimpshumans than among chimps

Comparative Primate Anatomy: Comparative Primate Anatomy: Chewing MechanismChewing Mechanism

dentition dentition (structure of teeth)(structure of teeth) dental arcade dental arcade (arrangement of teeth) is more (arrangement of teeth) is more

rounded (arc-like) than the chimpsrounded (arc-like) than the chimps Chimpanzee have a more rectangular dental arcade, Chimpanzee have a more rectangular dental arcade,

with the back teeth more parallelwith the back teeth more parallel Our teeth are much smaller than the chimps’Our teeth are much smaller than the chimps’ We have small canines (jagged teeth)We have small canines (jagged teeth) Chimps have large canines- gap Chimps have large canines- gap (diastema)(diastema)

Human Dentition: DiagramHuman Dentition: Diagram

For each jaw (upper or For each jaw (upper or maxillamaxilla or lower or or lower or mandible:mandible:

IncisorsIncisors (4) in the front (4) in the front for cutting food)for cutting food)

CaninesCanines (cuspid) (2) for (cuspid) (2) for piercingpiercing

Premolars Premolars (4) for light (4) for light grinding of foodgrinding of food

Molars Molars (6) in back for (6) in back for heavy grinding of foodheavy grinding of food

Chimp and Human DentitionChimp and Human Dentition

Note the following:Note the following: Dental Arcade: Humans’ are arc-like; apes, parallel back Dental Arcade: Humans’ are arc-like; apes, parallel back

teethteeth Canines and Diastema (gap): Apes have larger canines Canines and Diastema (gap): Apes have larger canines

and gaps in opposite jaw to fit them; humans do not and gaps in opposite jaw to fit them; humans do not

Comparative Primate Anatomy: Comparative Primate Anatomy: Hand Structure Hand Structure

Our fingers are straight; that of the chimps and Our fingers are straight; that of the chimps and other apes are curvedother apes are curved

We have a much longer thumb than do the We have a much longer thumb than do the apesapes

Importance: we are capable of a more precise Importance: we are capable of a more precise grip than the apesgrip than the apes

This implies that we can make finer tools than This implies that we can make finer tools than those apes who can make and use toolsthose apes who can make and use tools

Human Hand Structure: DiagramHuman Hand Structure: Diagram

Our digits are straightOur digits are straight Our thumb is opposableOur thumb is opposable The thumb is longThe thumb is long

Ape and Human Hands: Ape and Human Hands: DiagramDiagram

Hands of orangutan, chimpanzee, gorilla and human Hands of orangutan, chimpanzee, gorilla and human Our thumbs are longer than the others’Our thumbs are longer than the others’ Less visible: apes’ digits are curved, ours are straightLess visible: apes’ digits are curved, ours are straight

Power and Precision GripPower and Precision Grip

Power grip:Power grip: Fingers Fingers and thumbs wrap and thumbs wrap around the objectaround the object

Precision grip:Precision grip: Forefingers and thumb Forefingers and thumb hold the objecthold the object

Importance: Importance: We can do We can do finer work compared to finer work compared to nonhuman primatesnonhuman primates

Comparative Primate Anatomy: Comparative Primate Anatomy: Bipedalism vs. QuadrupedalismBipedalism vs. Quadrupedalism

Humans are capable of Humans are capable of bipedalismbipedalism**the ability to stand and walk entirely on two feetthe ability to stand and walk entirely on two feet

Chimpanzees can walk on two feet, but they are Chimpanzees can walk on two feet, but they are closer to closer to quadrupedalismquadrupedalism**the ability to move around on four feetthe ability to move around on four feet

Advantages of BipedalismAdvantages of Bipedalism

Efficient locomotionEfficient locomotion Freeing of hands for many proposesFreeing of hands for many proposes::

Foraging and hunting/scavengingForaging and hunting/scavenging

Tool making and useTool making and use

Care and provisioning of offspringCare and provisioning of offspring Increased height for viewing across landscapeIncreased height for viewing across landscape::

Tracking migrating herdsTracking migrating herds

Predator avoidancePredator avoidance

Bipedalism: DiagramBipedalism: Diagram apes are semi-bipedal, but use apes are semi-bipedal, but use

their knuckles to get around their knuckles to get around

the “quadrupedalism” of a the “quadrupedalism” of a human with that of a chimphuman with that of a chimp*the human is on his knees, not *the human is on his knees, not just his feetjust his feet*the chimp is using its hind *the chimp is using its hind feet, not its kneesfeet, not its knees

Comparative Human Anatomy: Comparative Human Anatomy: Locomotion Locomotion

Pelvis: length of the iliumPelvis: length of the ilium Arm lengthArm length Leg bonesLeg bones Foot structureFoot structure

Chimp and Human Locomotion Chimp and Human Locomotion ComparedCompared

Vertebral Column and PelvisVertebral Column and Pelvis Note the following:Note the following: Human vertebral column Human vertebral column

is S-shaped, supporting is S-shaped, supporting the upper torsothe upper torso

Chimp vertebral column is Chimp vertebral column is bow-shapedbow-shaped

Human pelvis, with ilium, Human pelvis, with ilium, is bowl-shaped; muscles is bowl-shaped; muscles from the thigh keep him from the thigh keep him uprightupright

Chimp pelvis is long, with Chimp pelvis is long, with flat ilium flat ilium

Pelvis and FemurPelvis and Femur Longer ilium of chimpLonger ilium of chimp Shorter, more curved Shorter, more curved

ilium of humanilium of human Straight vertical Straight vertical

orientation of chimp orientation of chimp femurs, do not support femurs, do not support the upper body wellthe upper body well

Inward angle of human Inward angle of human femurs, support the femurs, support the upper body more upper body more efficientlyefficiently

Foot StructureFoot Structure

Note the following:Note the following: Large toe of chimp foot Large toe of chimp foot

(right) is opposable to other (right) is opposable to other digitsdigits

Large toe of human foot Large toe of human foot (left) is aligned with other (left) is aligned with other digitsdigits

Ankle bones (tarsals) of Ankle bones (tarsals) of human foot are larger and human foot are larger and more rigid than the chimps more rigid than the chimps

Foot Arch: Longitudinal and Foot Arch: Longitudinal and TransverseTransverse

Note the following:Note the following: Longitudinal arch that runs Longitudinal arch that runs

from the first metatarsal to from the first metatarsal to the calcaneus (heel bone)the calcaneus (heel bone)

Large tarsals to the rear Large tarsals to the rear contribute to the rigid contribute to the rigid structure of the foot and its structure of the foot and its archarch

Transverse arch can be Transverse arch can be inferred from lower inferred from lower placement of outside foot to placement of outside foot to the instepthe instep

The chimp chromosomes 2a and 2b fused to The chimp chromosomes 2a and 2b fused to form the human chromosome 2form the human chromosome 2

Human

Great apes

Chromosome 2Chromosome 2

4444

2. Chimp genome sequence is 98.8% identical with 2. Chimp genome sequence is 98.8% identical with respect to single-base pair differencesrespect to single-base pair differences