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Human Biology: Unit 4 > Chapter - 13 Hominin Evolution > Flashcards

Chapter - 13 Hominin Evolution Flashcards

1
Q

Hominins VS Apes

A

All hominids share a common ancestor, an ape-like creature.
- from there hominins evolved
However, Differ by appearance, structure, and behaviour.

Hominins

  • relatively hairless
  • upper and lower limb structure allows for a fully bipedal way of walking
  • stand in erect posture and unique striding gait (not found elsewhere in the animal kingdom).
  • Greater development of the Brain,
  • Changes in size and shape of the teeth
  • development of speech and sexual characteristics

These separate humans from other Homonids

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2
Q

TREND during HUMAN EVOLUTION: List Them

A
  • CRANIAL CAPACITY and SKULL SIZE
  • Reduced PROGNATHISM
  • Homo sapiens also have a REDUCED BROW RIDGE
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3
Q

What was established in Early hominins?

A

BIPEDALSISM

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4
Q

Explain the TREND during HUMAN EVOLUTION: Cranial Capacity

A

GRADUAL INCREASE IN THE SIZE OF THE CRANIUM; houses a larger and MORE COMPLEX BRAIN
- SUBSEQUENT Fossil EVIDENCE confirmed a GRADUAL INCREASE IN CRANIAL CAPACITY as the HOMONIN SPECIES EVOLVED towards MODERN HUMANS.

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5
Q

DEFINE ENDOCAST

A

An Impression of the inside of the braincase, either artificial or natural, made of rock or some other solid material

ENDOCASTS HAVE BEEN USED TO CALCULATE THE CRANIAL CAPACITY OF FOSSILISED SKULLS

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6
Q

DEFINE CRANIAL CAPACITY

A

The volume of that part of the skull that is occupied by the brain.

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7
Q

Explain Australopithecines and Cranial Capacity

A
  1. Scientists infer via the use of endocasts
    - Australopithecus afarensis had a CRANIUM MUCH CLOSER IN SIZE TO THAT OF A MODERN APE THAN A MODERN HUMAN
  2. the average brain size of the 1st Australopithecus afarensis = range of MODERN GORILLA’s
    - However, the bodyweight of this fossil Australopithecines = 1/3rd of Gorilla.
    HENCE RELATIVE BRAIN SIZE = between CHIMPANZEES AND MODERN HUMANS
  3. FORAMEN MAGNUM was MORE FORWARD than it is in apes, and the SKULL MORE ROUNDED IN THE BACK.
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8
Q

What happens when fragments of the fossilised skull are found?

A

Fragments of fossil skull = w/o endocast

  • difficult in determining cranial capacity
  • expert estimates VARY
  • Such a range of figures from an examination of the SAME MATERIAL shows that the ESTIMATES of VCRANIAL CAPACITY must be TREATED WITH CAUTION.

EXAMPLE

  • 1st specimen of HOMO HABILIS was discovered in Olduvai Gorge, Tanzania in 196.
  • 3 different anthropologists gave 3 varying estimates for Cranial capacity
    • 590, 647, 710 cm^3
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9
Q

Explain the TREND during HUMAN EVOLUTION: Cranial Capacity

***CONTINUED WITH CONVOLUTIONS + FRONTAL LOBE

A

Endocasts also REVEAL GRADUAL INCREASE IN CONVOLUTIONS IN THE BRAIN AND FRONTAL LOBE SIZE INCREASE

EXAMPLE

  • trend seen in HOMO ERECTUS FOSSILS
  • over a period of time that this species lived on earth
  • CRANIAL CAPACITY OF H.erectus = 750 to 1250cm^3-
  • BRAINCASE EXPANDED,
  • the FACE tended to become = FLATTER and a NOTICEABLE FOREHEAD BEGAN IN THE LATER MEMBERS OF THE SPECIES…..PROBABLY DUE TO THE FRONTAL LOBE EXPANDING

The gradual enlargement of the cranial portion of the skull to accommodate the increasing size of the frontal region of the brain.
This led to a reduction in prognathism and in the size of the brow ridge.

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10
Q

Explain the TREND during HUMAN EVOLUTION: DENTITION AND PROGNATHISM

A

another discernible evolutionary trend

EXAMPLE

  • early hominins eg. AUSTRALOPITHECUS AFARENIS
  • LOWER JAW and a FACE that was like apes

TEETH were LARGE and there was a DISTINCT GAP BETWEEN the CANINES AND THE INCISORS
- ROWS OF TEETH PARALLEL RATHER THAN A CURVE

HOMO HABILIS
- MOLAR AND PREMOLAR teeth had become SMALLER AND NARROWER, but the CANINES were STILL PROMINENT

HOMO ERECTUS
- trend towards SMALLER MOLARS and a DECREASE in the ROBUSTNESS of the TEETH Continued

MODERN HUMANS

  • older humans (before 100,000 years ago)
  • HAD TEETH 10% larger than humans of today
  • gradually losing wisdom teeth (3rd molar) with an increasing no. of people having NO WISDOM teeth at all
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11
Q

ANATOMICAL FEATURE
**SKULL***

CHARACTERISTICS MORE APE-LIKE = MORE PRIMITIVE

VS.

CHARACTERISTICS ORE HUMAN-LIKE = MORE MODERN

A

PRIMITIVE

  • Thicker bones forming the cranium
  • face large compared to cranial size
  • smaller cranial capacity
  • heavier brow ridge
  • no forehead or slopping forehead
  • lower cranium
  • less prominent cheekbones
  • possible sagittal crest on top of the skull
  • foramen magnum towards the back of the skull (postcentral)

MODERN

  • Thinner bones forming cranium
  • Face small compared to Cranial size
  • Larger Cranial Capacity
  • Brow ridge reduced or absent
  • increasingly larger and more vertical forehead
  • dome-shaped cranium
  • more prominent cheekbones
  • NO crest on top of the skull
  • foramen magnum under the centre of the skull
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12
Q

ANATOMICAL FEATURE
**MANDIBLE AND TEETH**

CHARACTERISTICS MORE APE-LIKE = MORE PRIMITIVE

VS.

CHARACTERISTICS ORE HUMAN-LIKE = MORE MODERN

A

PRIMITIVE

  • more prognathic jaw
  • larger jaw
  • heavier, thicker mandible
  • no chin
  • larger teeth, especially molars
  • diastema present
  • canine teeth more prominent
  • difference between size of incisors and molars

MODERN

  • flatter face
  • smaller jaw
  • more slender, thinner mandible
  • increasingly definite chin
  • smaller teeth
  • NO diastema present
  • canine teeth less prominent
  • More even teeth/ little difference between size of incisors and molars
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13
Q

ANATOMICAL FEATURE
**TORSO**

CHARACTERISTICS MORE APE-LIKE = MORE PRIMITIVE

VS.

CHARACTERISTICS ORE HUMAN-LIKE = MORE MODERN

A

PRIMITIVE

  • Narrower pelvis
  • back (lumbar) vertebrae less wedge-shaped
  • wider, barrel-shaped ribcage

MODERN

  • broader pelvis
  • lumbar vertebrae are more wedge-shaped
  • smaller ribcage
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14
Q

ANATOMICAL FEATURE
**LOWER LIMBS*

CHARACTERISTICS MORE APE-LIKE = MORE PRIMITIVE

VS.

CHARACTERISTICS ORE HUMAN-LIKE = MORE MODERN

A

PRIMITIVE

  • shorter thumb that is less mobile
  • finger longer and more curved

MODERN

  • longer thumb with increased opposability
  • fingers straighter and shorter
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15
Q

ANATOMICAL FEATURE
**UPPER LIMBS**

CHARACTERISTICS MORE APE-LIKE = MORE PRIMITIVE

VS.

CHARACTERISTICS ORE HUMAN-LIKE = MORE MODERN

A

PRIMITIVE

  • femurs more parallel
  • arms longer than legs

MODERN

  • Femurs sloping inwards towards the knee
  • arms shorter than legs
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16
Q

List the ORDER OF HOMININ EVOLUTION

A
  1. Australopithecus afarensis
  2. Australopithecus africanus
  3. Paranthropus Robustus
  4. Homo Habilis
  5. Homo erectus and Homo ergaster
  6. Homo neanderthalensis
17
Q

What is culture?

Cultural evolution and why?

A

Culture = anything that is learnt
eg. Activities such as stone tool making, hunting techniques, food preparation, using language and making art.

Cultural Evolution = Cultural development that occurs as a means of overcoming environmental and other challenges.

Cultural development occurs to overcome environmental challenges faced by humans.

18
Q

What are latoli footprints?

A
  1. most likely produced by Australopithecus afarensis
  2. Subsequent layers of ash covered and preserved the ‘oldest footprints’ of early humans
  3. 3 millions years ago
  4. Near a volcano - sediment layer
19
Q

Significance of Latoli footprints

A

Indicated Bipedalism locomotion

  1. Heel hitting the ground = lateral transmission of weight
    - heel to ball of the foot
  2. Well developed longitudinal arch
  3. big toe was parallel to other digits
  4. deep impression where the toe pushed the foot forward to the next stride
20
Q

Understanding Australopithecus afarensis (11)

A
  1. 1ST FOUND - 40% COMPLETE LUCY
  2. Time of Existence 3.9 and 2.8 million years ago
  3. Location East Africa
  4. Height
    - Female 105-110 cm
    - Males: 150 cm
  5. Brain 420 cm3
  6. Skull
    - Low, sloping forehead
    - Prominent brow ridges
    - Short sagittal crest in males
  7. Teeth and Jaw
    - Prognathic jaw
    - Small canine teeth but larger than Australopithecus africanus
    - Diastema present
  8. Limbs
    - Big toe not opposable
    - Long arms, although shorter than the legs
    - Long curved fingers and toes
    - Features for bipedalism
  9. Pelvis
    - Short and wide pelvis
  10. Above waist = ape-like
    below waist = human-like
  11. Sleeps in trees at night and walked on land during the day
21
Q

Understanding Australopithecus africanus (9)

A
  1. Time - 3.2 to 2 million years ago
  2. Location - Southern Africa
  3. Height
    - Female:110cm
    - Male: 135cm
  4. Cranial Capacity - 480cm3
  5. Skull
    - Slightly arched forehead
    - Smaller brow ridge
  6. Teeth and Jaw
    - Prognathic jaw
    - Shorter and smaller incisors and canines
    - Large molar and premolars
    - No diastema
    - fully parabolic
  7. Limbs
    - Big toes not opposable
    - Long arms, although shorter than the legs
    - Some curvature of the finger and toe bones
    - Features for bipedalism
  8. Pelvis
    - Short and wide pelvis, less rounded than in modern number
  9. Small Gracile
22
Q

Understanding Paranthropus robustus (7)

A
  1. TIME - South Africa 1.8-1.2 million years ago
    • Part of an evolutionary branch with no ancestors (not ancestors of modern humans)
  • Key robust jaw and skull
  1. Location - Southern Africa
  2. HEIGHT
    - Female height approx. 1m
    - Male height approx. 1.2m
  3. Cranial capacity of 520cm3
  4. Skull
    - Large sagittal crest
    - Attachment of strong chewing muscles
    - Wide, dish-shaped face with large zygomatic arches
    - Heavy brow ridges
  5. Teeth Large molars and premolars
    - Small incisors and canines by comparison
    - tough veg diet = megadont
  6. Prognathism; less than australopithecines
  7. limbs
    Structures for bipedalism
23
Q

Understanding Homo Habilis (10)

A
  1. Adept at tool making; called the ‘handy man’
    - Thought to be the earliest tool user at the time of discovery
  2. Time = 2.3 and 1.5 million years ago
  3. Location = Eastern and Southern Africa
  4. Height
    - Female height approx.: 1.1m
    - Male height approx.. 1.3m
  5. Brain = 610cm^3
    - big jump in Cc - CONSIDERABLE LARGE BRAIN SIZE
  6. Skull
    - Rounder skull
    - Small brow ridge
    - Central foramen magnum
  7. Prognathism
    - Moderate prognathism
  8. Teeth
    - Teeth arranged in rounder arc
    - Smaller teeth as their diet included meet
  9. Limbs
    - Relatively short legs and long arms
    - Slightly curved finger bones, indicating strong power grip
    - Able to form precision grip
    - Taller and more gracile
    - Stood more erect
  10. RUDIMENTARY SPEECH
    - BULGE IN BEROCCA AREA
24
Q

Understanding Homo erectus (11)

A
  1. Pecking Man
  2. Location - Asia (china)
    - ventured out of Africa
  3. Height 1.45-1.85m with sexual dimorphism
  4. Short, stocky body with thicker bones, suggesting a demanding lifestyle
  5. Average cranial capacity of
    1050cm3
  6. Skull
    o Low, sloping forehead
    o Defined brow ridges
    o Curve of dental arcade was shorter and more rounded in front
    - Teeth were more modern; indicates they had a diet similar to ours
    - Reduced size of molars
7. Jaw 
Shorter and more compact jaw
- Large, thick jaw
o	Chin beginning to form
- But still no chin
  1. First FIRE USERS
  2. Lived in Caves
  3. Earliest Hominin to show Human-like body proportions - ratio of arms and legs
  4. Bulge in Wernickles area of the brain
25
Q

Understanding Homo neanderthalensis (12)

A
  1. Time of Existence Between 28 000 and 300 000 years ago
  2. Location Europe and the Middle East
  3. Body Type
    - Shorter, more robust and muscular than modern humans
    - Wider shoulder
  4. Height
    - Females: 156 cm
    - Males: 168 cm
  5. Brain 1485/1500cm3
  6. Skull
    - Long and low brain case
    - Occipital bun at the back of the skull
    - Thick brow ridges
    - Receding forehead, elongated skull
    - Flared zygomatic arches
    - Depression at the back of the skull for neck muscle attachment
  7. Teeth and Jaw
    - Larger, more robust prognathic jaw
    - Lacking a chin
    - Larger teeth
  8. Limbs
    - Thick limbs with large joint
    - Shorter
  9. Pelvis
    - Wider pelvis
  10. Ribcage - Barrel-shaped
  11. SQUAT BODIES
  12. Adapted for seasonally dry and cold climates
26
Q

Understanding Homo sapiens (9)

A
  1. Time - 300 000 years ago to present
  2. Location - worldwide
  3. Body type
    - Short, slender trunks and long limbs
  4. Height
    Females: 160 cm
    Males: 175cm
  5. Brain 1350cm3
  6. Skull
    - Short base and high brain case
    - Short jaw
    - Bony chin
  7. Teeth
    - Small teeth
  8. Limbs
    - Long legs compared with arms
    - Straight fingers and toes
  9. Ribcage
    - Less barrel-shaped
27
Q

Who are Cro- magnon people?

A

10 00 - 120 000 yrs ago

More modern features than H.n

orbits or eye sockets were well separated

France and spain

Aurignacian tools

28
Q

Australopithecines Culture (4)

A
  1. Home Bases: Areas occupied by australopithecines
    - From where hunters and foragers went out to search for food
  2. Tool use
    - Pebble/Oldowan tools:
    - Choppers, scrapers, flakes and chisels
    - Size of a tennis ball to a marble
    - Named after where they were discovered
     Precision grip required to use scarpers effectively
  3. 2.5 million years ago
    •Used items in their surroundings to exploit resources in their environment
    ### Allowed them to exploit a broader range of habitats
  1. No use of Fire
29
Q

Culture of Homo Habilis (6)

A
  1. Used Oldowan tools
    - Sharpened or shaped by striking one stone with another
    - FOR Skinning animals, chopping up meant, breaking open bones, crushing plants and digging up edible plant roots
  2. Lived in grasslands and were hunter-gatherers
    - Plant-based diet with supplementary meat from scavenging or hunting
    - *****Meat provided complex fats for brain growth leading to increased cranial capacity
  3. Worked in groups with specific members responsible for different tasks
    - Collecting food; brought back to home base to share
    - Social organisation
  4. Pressure for spoken language increased as communication was critical
    - Some evidence of bulge in speech producing area of the brain
    - Larynx not capable of making complex sounds
  5. Evidence of being a hunter and scavenger
    o Animal bones found at fossil sites
     Cut marks made by stone tools or teeth of a carnivore
     Tooth leaves a broad, smooth groove on the bone
     Stone tool made smaller parallel grooves in main cut
  6. Engaged in scavenging remains of prey killed by carnivores
     And consuming meat they killed and butchered
    • More scavengers’ than hunters
    o Because hunters as they evolved
30
Q

Culture of Homo Erectus (5)

A
  1. Began to Modify environment to suit their own purposes
    eg. Fire, building of shelters and range of sophisticated tools
  2. Acheulian tools flaked around all of the edges, in one direction and then in the other
    o Formed roughly two-faced (bi-faced) lumps, approximately teardrop shaped
     Used as hand axes
  3. Capable of logical thought and ability to communicate and work with others in an organised and efficient manner
  4. Drove animals into where they were trapped and then butchered by tools made of bone and stone
    o Butchery marks on the surface indicate more systematic use of tools
    o Increased commitment to meat eating
    o Remains indicated hunting was important
     Predominance of deer bones suggested inhabitants preferred this type of meat
     Fish bones showed they also fished
  5. Cultural organisation
    • Cultural changes of use of fire and manufacture of tools influenced social organisation
    o Mutual cooperation
    o Complex society established
    o Care of the young gradually more important
    o Relatively complex spoken language may have arisen
31
Q

Homo Erectus and Fire Usage (5)

A

Fire helped:
1. Keep predators away

  1. Gave warmth and light at night
  2. May have been used to stampede animals
  3. Important for migrating groups into Europe and Asia during ice ages
  4. Enabled cooking
    - Increased range of foods by improved flavour and digestibility
    - Some foods safer to eat by destroying parasites/tapeworms or detoxifying plant foods.
32
Q

Homo neanderthalensis culture (6)

A
  1. Mousterian industry: Production of stone flakes trimmed to form various cutting, scraping, piercing and gouging tools
    o Showed cultural advance over the Acheliun hand axe
  2. Levallois technique: Piece of stone trimmed into a disc-shaped core then stuck by another stone to produce flakes
    o Flat on one side and had sharp edges
    o Slow, labour-intensive process that requires planning and foresight
  3. Significant development in cognition, coinciding with evolutionary trend of increased cranial capacity
     Likely possible due to increased importance of meat in the diet
  4. Hafting: Flake tools joined on to handle, spear or arrow
    o Broadened use and increased effectiveness
     Spears for hunting larger animals
     Cutting up animals or wood
     Tools could be used to make other tools
    •
  5. Flake tools enabled those living in colder climates to become good clothes makers
  6. Scraping tools for preparing animal hides
  7. Buried their dead
    o Believed in life after death
     Grave of a youth surrounded by wild goat burial with horns thrust into ground with pointed ends downwards
     Man buried on a bed of flowers
    o Underdeveloped shoulder blade, collarbone, upper right arm bone and no lower arm bones
     Withered right arm successfully amputated above the elbow
    **Cared for disabled members and had a social system for sharing food and other resources
32
Q

Homo neanderthalensis culture (6)

A
  1. Mousterian industry: Production of stone flakes trimmed to form various cutting, scraping, piercing and gouging tools
    o Showed cultural advance over the Acheliun hand axe
  2. Levallois technique: Piece of stone trimmed into a disc-shaped core then stuck by another stone to produce flakes
    o Flat on one side and had sharp edges
    o Slow, labour-intensive process that requires planning and foresight
  3. Significant development in cognition, coinciding with evolutionary trend of increased cranial capacity
     Likely possible due to increased importance of meat in the diet
  4. Hafting: Flake tools joined on to handle, spear or arrow
    o Broadened use and increased effectiveness
     Spears for hunting larger animals
     Cutting up animals or wood
     Tools could be used to make other tools
    •
  5. Flake tools enabled those living in colder climates to become good clothes makers
  6. Scraping tools for preparing animal hides
  7. Buried their dead - CEREMONY
    o Believed in life after death
     Grave of a youth surrounded by wild goat burial with horns thrust into ground with pointed ends downwards
     Man buried on a bed of flowers
    o Underdeveloped shoulder blade, collarbone, upper right arm bone and no lower arm bones
     Withered right arm successfully amputated above the elbow
    **Cared for disabled members and had a social system for sharing food and other resources
33
Q

Homo sapiens Culture (5)

A
  1. Around 50000 years ago
    o Finer blades and projectile weapons
    ****Suggested mutation that affected the brains of a group of anatomically modern humans living in Africa or the Middle East
    **    *New neurological connections and abilities
    o Fully articulated speech
  2. 40 000 years ago modern humans moved into Europe
    o Brought innovation such as clothing which had been sewn and better shelters
    o Allowed them to survive the cold of glacial Europe
     Previously exclusive to Neanderthals but modern humans thrived and the Neanderthal population decreased
  3. Well established in Europe and were makers of blade tools
    o Flakes of stones with roughly parallel sides
  4. Had large brains housed in skulls
    o Long front to back, similarly to present people of Western and Northern Europe
  5. Cro-Magnon essentially hunters and gatherers
    o Relied on herds of animals in open plains
    o Mastered hunting bison, mammoth, reindeer etc,
     Stampeding them over cliffs or narrow ravines
     Also provided meat and skins for clothing or shelter
34
Q

List the trends in tool manufacturing (6).

A
  1. Increased manipulation of materials
  2. Increased complexity of tools
  3. Greater variety of materials used to make tools
  4. Improved workmanship and development of equipment needed to manufacture the tools
  5. Increased specialisation of tools
  6. Structural changes infer changes in lifestyles
    o Increased collaboration
    o Effective communication
    o Different members with more specific roles and skills
    o Increased importance in planning and creativity
    o Manipulating environment to meet their needs
35
Q

List the Tool Industry, Material used and Time and Who used it. (6)

A 
1. Oldowan 
Pebble stones 
2.6-1.7 mya
Olduvai Africa 
Australopithecines and Homo habilis 
2. Acheulian 
Stones (mainly)
Flint stones 
Bi-Face
1.7mya-200 000 ya
St Acheul France 
HOMO ERECTUS 
3. Mousterian 
Flintstone 
Wood = hafting 
200 000 - 40 000 ya 
Le Moustier France 
Neanderthalansis
  1. Aurignacian
    Bone, Ivory, stone (rarely /sometimes antler)
    Blade tools - flat rectangles from core stone which were easy and effective in cutting
    43000 - 26000
    Cro Magnon
5. Solutrean 
Antler, Bone, ivory, stone 
Willow and Laurel leaf designs, for ornamental and artistic purposes 
- symbol of maker's craft 
pressure flaking 
used by cro-magnon people 
solutre France
22 000 - 19 000
  1. Magdalenian
    Bone and Antler tools over flint and stone
    WORKS OF ART
    Burin or chisel like cutter - a tool used to manufacture other tools
    - SIGNIFICANT ADVANCEMENT in tool making - devised a tool to make other tools
    burin - a blade was shaped so that it had a sharp cutting point
    - BONE ANTLER AND IVORY WOULD BE CUT TO MAKE A RANGE OF TOOLS
    - NEEDLES TO BARBED SPEAR POINT AND SPEAR THROWERS
    18 000 - 12 000
    La Madeline FRANCE
36
Q

What did Cro magnon people do with their meat source?

A
  1. eat
  2. animal skin = clothing
  3. Fats = oil for lamps
  4. bones + ivory = make tools

Human Biology: Unit 4 (7 decks)

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