Comparative Primate Comparative Primate AnatomyAnatomy

The Hardware of Human CultureThe Hardware of Human Culture

The Hardware of Human CultureThe Hardware of Human Culture

We could not be us without. . .We could not be us without. . . 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 feet allow ustwo feet allow us So without understanding our anatomy, we So without understanding our anatomy, we

cannot understand our culturecannot understand our culture

Comparative Hominid AnatomyComparative Hominid Anatomy

Anatomically, we are very similar to apes and Anatomically, we are very similar to apes and even to monkeyseven to monkeys

But we are not identical: Humans are fully But we are not identical: Humans are fully bipedal, for example, while chimps are not.bipedal, for example, while chimps are not.

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

Therefore we need to compare our own Therefore we need to compare our own anatomy with (a) other living primates and (b) anatomy with (a) other living primates and (b) fossil hominin forms.fossil hominin forms.

Overview: The Human SkeletonOverview: The Human Skeleton

You do need to know You do need to know some of the parts of some of the parts of the human skeletonthe human skeleton

Use the online Use the online graphics (such as this) graphics (such as this) or your printed or your printed handoutshandouts

We make a detailed We make a detailed comparison of skeletal comparison of skeletal parts laterparts later

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

Therefore, we start by examining the parts of Therefore, we start by examining the parts of the brain the brain

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

You may want to switch back and forth between the You may want to switch back and forth between the description in the next two slides and the diagram that description in the next two slides and the diagram that follows them in the third slidefollows them in the third slide

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: The strip along the edge of the motor The strip along the edge of the motor cortex that moves the facial muscles (lips, tongue, cortex that moves the facial muscles (lips, tongue, vocalization) and the arm, hand, and finger musclesvocalization) and the arm, hand, and finger muscles

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 The next diagram gives a schematic view of the The next diagram gives a schematic view of the

functions of the motor cortex or stripfunctions of the motor cortex or strip Lower partLower part: The strip regulates the facial and oral : The strip regulates the facial and oral

musclesmuscles They include the tongue, the lips, the organs for They include the tongue, the lips, the organs for

vocalization, and the jawsvocalization, and the jaws These 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 fingers These 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

Again, you may want to move back and forth between the Again, you may want to move back and forth between the descriptions and the diagram that follows the descriptionsdescriptions and the diagram that follows the descriptions

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 Notice that it is located at the base of the motor cortex, which Notice that it is located at the base of the motor cortex, which

handles the tongue, vocalization, and lip movements handles the tongue, vocalization, and lip movements Wernicke’s Area Wernicke’s Area functions to process the reception of speechfunctions to process the reception of speech Notice its location in the temporal lobe, which processes Notice its location in the temporal lobe, which processes

hearinghearing

Language Functions of the Brain: Language Functions of the Brain: Description IIDescription II

The The angular gyrus angular gyrus is the part that coordinates all the is the part that coordinates all the sense functions housed in the brainsense functions housed in the brain

They coordinate the senses of sight from the occipital They coordinate the senses of sight from the occipital lobe, of the touch and taste of the parietal lobe, of the lobe, of the touch and taste of the parietal lobe, of the smell from the olfactory lobe, and of hearing from the smell from the olfactory lobe, and of hearing from the temporal lobetemporal lobe

If you smell the scent of a rose and visualize a rose in If you smell the scent of a rose and visualize a rose in the mind’s eyethe mind’s eye

Its function for language is to translate all the sensory Its function for language is to translate all the sensory information into the sense of hearing so we can information into the sense of hearing so we can assign meaning to speech. assign meaning to 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?

With few exceptions bones are all we have to With few exceptions bones are all we have to reconstruct past human and humanlike life reconstruct past human and humanlike life formsforms

Therefore we have to coordinate what we Therefore we have to coordinate what we know about anatomy—human and nonhuman know about anatomy—human and nonhuman primate—to reconstruct what our ancestors primate—to reconstruct what our ancestors might have been like. might have 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 Refresh your memory: what are each of these Refresh your memory: what are each of these

lobes for?lobes for?

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

In the next diagrams, the differences are significant to In the next diagrams, the differences are significant to biological capacity for culturebiological capacity for culture

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 of its human brain because of its sloping forehead sloping forehead andand the the heavy heavy supraorbital torus supraorbital torus that covers much of the that covers much of the foreheadforehead

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 teeth than humans; so

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

In the next diagram, the human brain has a In the next diagram, the human brain has a Broca’s Broca’s area area for processing speech.for processing 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

The chimp brain is much smaller than humans’—400 The chimp brain is much smaller than humans’—400 cubic centimeters compared with our 1400 cc. cubic centimeters compared with our 1400 cc.

The frontal lobe of the chimp is smaller than the The frontal lobe of the chimp is smaller than the human’s, partly owing to the sloping foreheadhuman’s, partly owing to the sloping forehead

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

The next diagrams compare human The next diagrams compare human dentition dentition (structure of teeth) with that of the chimps(structure of teeth) with that of the chimps

Our overall Our overall dental arcade dental arcade (arrangement of teeth) is (arrangement of teeth) is more rounded (arc-like) than the chimpsmore rounded (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, so large that they need a Chimps have large canines, so large that they need a

gap gap (diastema) (diastema) in the opposite jaw for them to fitin the opposite jaw for them to fit

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 for (4) in the front for cutting food)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

Note The Following:Note The Following: 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 Note the following:Note the following: Our thumbs are longer than the others’Our thumbs are longer than the others’ We can make a finer grip than the others canWe can make a finer grip than the others can Less visible: apes’ digits are curved, ours are straightLess visible: apes’ digits are curved, ours are straight

Power and Precision GripPower and Precision Grip

Note the Following:Note the Following: 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

Homo sapiens Homo sapiens is the only mammal capable of is the only mammal capable of bipedalism, bipedalism, or the ability to stand and walk entirely or the ability to stand and walk entirely on two feet. on two feet.

Kangaroos stand on two feet, but they hop rather than Kangaroos stand on two feet, but they hop rather than walk and their forepaws are too small for any walk and their forepaws are too small for any function. function.

Chimpanzees can walk on two feet, but not very Chimpanzees can walk on two feet, but not very efficiently; they are closer to efficiently; they are closer to quadrupedalism, quadrupedalism, or the or the ability to move around on four feet. ability to move around on four feet.

What are the advantages of bipedalism over What are the advantages of bipedalism over quadrupedalism. Answer the question and then look quadrupedalism. Answer the question and then look at the next slide.at the next slide.

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 We are the only mammals We are the only mammals

that can stand and walk on that can stand and walk on two feettwo feet

Apes are semi-bipedal, but Apes are semi-bipedal, but use their knuckles to get use their knuckles to get around (top photo)around (top photo)

The bottom photo compares The bottom photo compares the “quadrupedalism” of a the “quadrupedalism” of a human with that of a chimphuman with that of a chimp

Notice the human is on his Notice the human is on his knees, not just his feetknees, not just his feet

The chimp is using its hind The chimp is using its hind feet, not its knees.feet, not its knees.

Comparative Human Anatomy: Comparative Human Anatomy: Locomotion Locomotion

You will need to make a close comparison of human You will need to make a close comparison of human and chimp anatomy in the next diagramand chimp anatomy in the next diagram

Pelvis: Compare the length of the ilium of the chimp Pelvis: Compare the length of the ilium of the chimp with that of the humanwith that of the human

Compare the arm length of the chimp with the humanCompare the arm length of the chimp with the human Compare the leg bones of the chimp with the humanCompare the leg bones of the chimp with the human Compare the foot structure of the chimp with the Compare the foot structure of the chimp with the

humanhuman What are the differences between each set of What are the differences between each set of

characteristics? Write your answers, then look at each characteristics? Write your answers, then look at each of these characteristics in detail.of these characteristics in detail.

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

Note the following:Note the following: Longer ilium of chimpLonger ilium of chimp Shorter, more curved ilium Shorter, more curved ilium

of humanof human Straight vertical orientation Straight vertical orientation

of chimp femurs, which do of chimp femurs, which do not support the upper body not support the upper body wellwell

Inward angle of human Inward angle of human femurs, which support the femurs, which support the upper body more efficientlyupper body more efficiently

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 food are larger and human food 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

What We Have LearnedWhat We Have Learned

We have learned the hardware essential to cultureWe have learned the hardware essential to culture They include our brain, where language and tool use They include our brain, where language and tool use

originateoriginate We have learned about our ability to stand and walk We have learned about our ability to stand and walk

on two feet and the importance of this abilityon two feet and the importance of this ability We have also learned about the characteristics of ape We have also learned about the characteristics of ape

anatomyanatomy This comparison gives us a clue on the next phase of This comparison gives us a clue on the next phase of

this unit, human biological evolutionthis unit, human biological evolution