Human Evolution > Test 2 > Flashcards

Test 2 Flashcards

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1
Q

What are the overall trends of Australopithecus and Paranthropus?

A
  • Post crania getting larger
  • canines and incisors getting smaller
  • mixture of attributes
    • long faces and small brain: p. aethiopicus
    • long faces and larger brains: au. africanus
    • shorter faces and larger brains: later paranthropus
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2
Q

Where were australopithecines located and when

A

ca. 7 to 4.4 Ma in the upper East African Rift Valley

ca. 4.2 to 1 Ma in East African Rift Valley descending all the way to South Africa

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3
Q

What is the East African Rift Valley and why is it so fossil rich

A
  • formed when Africa tried to break from Eur-Asia

- constantly filled with sediments from earthquakes and geological shifts

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4
Q

What is the oldest Australopithecine

A

Australopithecus anamensis

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5
Q

When and where did anamensis live

A

4.2-3.9 Ma in Kenya and Ethiopia

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6
Q

What environment did anamensis inhabit and how do we know

A
  • forest ecology
    • arboreal animals found at same site (monkeys)
    • pollen
    • chemical signals from sediments
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7
Q

What are some physical attributes of anamensis

A
  • large canines but trending towards to smaller ones
  • vertical palate
  • inclined symphysis
    • potentially for large teeth
  • shorter arms than ardipithecus (similar to pan)
    • less tree oriented
  • robust knee and tibia
    • legs getting longer and heavier…pendulum
  • strong sexual dimorphism
    • similar to pan
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8
Q

How does anamensis and pan compare (teeth and mandible-maxilla)

A
  • shorter more vertical face
  • shorter canines
  • large dentin pools
  • canine and p3 are about the same size
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9
Q

Describe the cranial features of anamensis

A

-large zygoma (strong masseter attachment/correlates w/robust mandible and large teeth)
-large front teeth for ape-like chewing (past nasal aperture)
-forward-positioned sagittal crest (separate and give more room for temporalis)
-large face …prognathic lower face
-flared mastoid processes (more space for temporalis and wide mandible)
-long and narrow brain case
-

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10
Q

What is the cranial capacity of anamensis and what is it similar to

A

365-370 cc

Similar to Sahelanthropus and Ardipithecus

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11
Q

Describe the biomechanics of anamensis joints (proximal tibia, distal tibia, distal humerus)

A

Proximal Tibia: robust, weight-bearing plateau (polygon) for referral condyle attachment
-modern looking
-for running and jumping…biped
Distal tibia: squared ankle, large malleolus (stable)
-perpendicular condition of join for talus attachment
-prominent medial malleolus
Distal humerus: (elbow) robust suggestion climbing
-large with deep groove
-chimp-like

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12
Q

When and where did Australopithecus afarensis live

A
  1. 9-3.0 Ma
    - in Hadar (Ethiopia), Laetoli (Tanzania), Kenya
    - widely distributed
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13
Q

What environments did afarensis prefer

A

Mixed forest-open ecology

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14
Q

Describe afarensis mandible

A

-smaller canines
-larger premolars
-large molars
-long jaws
-large jaws
Brains larger than Pan but smaller than Homo (still overlap)

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15
Q

Compare afarensis cranium to anamensis

A
  • more robust face
  • somewhat large size of the back teeth+more powerful chewing muscles
  • average size 470cc
  • more slender and gracile canine
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16
Q

Describe afarensis post crania

A

-broad, short, lateral pelvis
-large sacrum
-valgus knee and robust (anamensis too but less)
-shorter arms and forelimbs
-chimp-sized (30-60kg)
-shorter and less curved fingers (away from trees)
-

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17
Q

The Laetoli footprints (who, what)

A
  • afarensis
  • addicted toe
  • arch
  • heel-strike (deep heel impression)
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18
Q

Australopithecus africanus (where, when)

A

South Africa

3.5-2.5 Ma

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19
Q

africanus environment

A
  • mixed forest-open ecology

- same as africanus

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20
Q

What two Australopithecines are similar sized

A

africanus+afarensis

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21
Q

What was the first australopithecine found

A

Taung Child

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22
Q

How does africanus compare to afarensis

A
  • larger molars
  • smaller front teeth
  • more massive face
  • 485cc (a little bigger)
  • identical post crania
    • obligate biped with climbing abilities
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23
Q

What makes Australopithecus africanus different from Homo

A
  • long femoral necks
  • small femoral heads
  • flared ilia
  • small boy size
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24
Q

Feature different between africanus and Ardipithecus (pelvis)

A

Shorter ilia and ischia

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25
What two taxa fall under Australopithecines
Australopithecus and Paranthropus
26
Paranthropus description (when, where, what comparatively)
- Generally later than Australopithecus - 2.5-1.0Ma - east and south Africa - more massive faces with larger chewing muscles - larger postcanines - smaller front teeth - larger brains - similar in mass, dimorphism, and postcrania morphology with Australopithecus
27
Where did Paranthropus aethiopicus live
- west turkana and Ethiopia | - 2.5 Ma
28
Environment of aethiopicus
Lake margin (forest), grassland
29
Unusual anatomy of aethiopicus
- primitive traits - small brain (410cc) - prognathic (most of any human) - large front teeth - flat cranial base - derived traits - huge back teeth - huge chewing muscles - very large face
30
Describe the cranium of aethiopicus
- huge face - huge sagittal crest - strong prognathism - flat base of cranium (changes in later Paranthropus) - small brain - dramatic postorbital gaps - small brain - huge chewing muscles - posterior temporalis - huge teeth
31
In what ways is aethiopicus closer to afarensis
- prognathism - brain size - basicranium - temporalis angle
32
In what ways is aethiopicus similar to boisei
- size of postcanines - size of face - size of muscles
33
In what ways is boisei similar to early Homo
- brain size - orthognathy - basicranium (flexed) - temporalis angle (vertical)
34
When and where did Paranthropus robustus live
- South Africa (only) - swartkrans, kromdraai - 2.0-1.0 Ma
35
robustus environment and habits
- Mixed forest, grassland - not slicing teeth but more tubors and roots - possible tool makers - Homo erectus other candidate
36
Paranthropus boisei (when, where)
2.0-1.0 Ma | Kenya, Ethiopia, Malawi, many sites
37
Boisei environment
Mixed lake margin, river margin forests and open plains
38
Describe robustus and boisei cranium
- orthognathic - broad faces - facial pillars - flexed cranial bases - small front teeth - larger brains (ca 550-600cc) - massive chewing muscles - large premolars (look like molars) - large molars - flat canines - Massive mandibles with tall rami
39
Describe the jaws of boisei and robustus
- massive mandibles - huge premolars - tiny front teeth - canine much smaller than p3
40
What did Australopithecines do (diet/ecology/social)
-Diet: omnivores, extract challenges resources (digging and cracking), Paranthropus possible folivorous -Ecology: forest mosaic, sometimes more open, specialized generalists -Social: dimorphism in body size, reduced canine dimorphism, unlike modern primates (female selection for larger males)
41
Describe evidence for Australopithecus tool use
- meat-marrow exploitation - purposeful cut marks - marrow extraction
42
Overall trend in crania
Small brain and bigger faces —->big brain and small face
43
Time range of Homo rudolfensis
2.5-1.8 Ma
44
Time scale of Homo habilis
2.8-1.5 Ma
45
Where were early Homo found?
- East African Rift Valley - southeastern Europe (Georgia) and Indonesia - weirdly dispersed unlike Australopithecus
46
Early evolution of genus Homo
- occupation sites - tools - organization - movement/transport - distribution range and habitat movement - hunting/scavenging - no projectiles
47
What are the benefits of increased brain size in Homo?
- stone tools - cut-marked bones - higher quality, broader diet, protein/fat rich - better ability to survive shortages
48
Which Homo has larger body size and what are they comparable to?
- H. Rudolfensis has a larger body size - about the size of the smallest modern humans - H.habilis is Australopithecus-like in size
49
When and where was early Homo? | Name the sites
2. 8-1.5 Ma - east Africa - koobi fora (east turkana), Kenya - olduvai gorge, Tanzania - Hadar. Ethiopia - Ledi-Gerard, Ethiopia - South Africa (sterkfontein West) - Malawi
50
Early Homo environment
River margin settings - larger ranges - flood plaines - more ecological diversity - diff microclimates - more open country - less dependent on trees
51
What is Kenyanthropus
- from Lomekwi - 3.3 Ma - possible cracked Australopithecine - shares cranial similarities with H.rudolfensis - broad zygoma - brain case smaller tho - more slope in temporal bones
52
Describe the Homo habilis and it’s mandible
- 2.8 Ma - Lexi-Geraru, Afar, Ethiopia - wooded grasslands - robust and deep mandible - small premolars (getting smaller) - Small canines - long molars
53
Is habilis prognathic or orthognathic? Less that what
Orthognathic compared to A. afarensis
54
Describe cranium of habilis
- facial reduction - brain size increase (close to 600cc) - smaller temporal fossa - thus smaller temporalis muscles - less post orbital constriction - large brain in frontal region - greatly reduced mastoid process - expanded parietals and occipital
55
Describe post crania of habilis
- long arms - short legs - Australopithecine-like
56
Compare habilis to Australopithecus (skull)
- cranial vault changes - larger reorganized brain - complex behaviours (tools) - smaller jaws and teeth - less molarized premolars - more proportionate front and back teeth - stone tool use - food preparation
57
Where and when was the earliest Homo rudolfensis located
- Uraha, Malawi | - 2.5Ma
58
Describe rudolfensis jaws
- robust jaws and large teeth but less so than Australopiths - slightly bigger than habilis - long molars - small premolars - deep mandibles - proportionate anterior teeth
59
Describe rudolfensis cranium
- tall frontal bone - overall bigger than habilis but very similar proportions and level of orthognathism - large face (wide) - large brain (720/750cc) - larger brain case bones to adjust - bigger bodies
60
Early Homo comparison
habilis: - small face (larger than Australopithecus) - Orthognathic - small teeth - small brains (530-650cc) - Australopithecine-like in skeleton rudolfensis: - broad, flat, orthognathic face - large overall - larger brains (720cc) (relatively the same as habilis) - more modern skeleton
61
What are the different sections of the brain? (2) then (5)
Cerebrum and cerebellum - frontal - parietal - temporal - occipital
62
Give the brain sizes of Australopithecus, early Homo, H. Erectus and pan
``` 450 600 900 320 -sapien is 1200cc ```
63
What are the attributes of the unman brain
- huge proportionate to its body mass - complex - highly convoluted cortex-more surface area comp vol - highly interconnected - grey matter (100 billion neurons) - white matter (10-15 trillion axons) - lateralization and specialization - left Sid elf cerebellum controls right side of the body - specialized higher function also lateralized - language, music, geometry, math
64
Name the parts of the brain responsible for language (4)
- Wernicke’s area: cognitive, meaning - Broca’s area: vocal cords, physical aspect - somatosensory cortex: sensory information - motor cortex: moving and manipulation
65
What is produced as a result of human experiences and learning
Axons
66
How do we know early Homo had foresight
The flake and hammer production | -lomekwi, Kenya 3.3Ma
67
Uses for tools
- meat-marrow exploitation | - hunting or scavenging
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