Week 9 Flashcards
(27 cards)
1
Q
Early hominin identification
A
- Africa (Chad, Kenya, ethiopia)
- hominin characteristics: bipedal with reduced non-honing canines
2
Q
Non-honing canines
A
- canines not designed to be sharpened by a lower neighboring tooth
- greaty reduced compared to old world monkeys
- hominins are changing from sexually diamorphic
3
Q
Origins of bipedal locomotion
A
- bipedalism is highly efficient
- thermoregulation (less solar radiation) + energy efficiency + freeing the hands
4
Q
The foramen magnum
A
- large hole in the middle of the bottom of our skull
- balanced on our vertebra perfectly
- allows more bipedal
- the foramen magnum in a gorilla is at the back of the skull, allowing quadrupedalism
5
Q
A
6
Q
The vertebral column
A
- in hominins, distributes body weight in front/behind spine
- transmits body weight through pelvis into lower limb
- S curve (sigmoid curve in spine)
- as it goes down, it increases in spine
- in primates and monkeys, their spine isn’t as curvy
7
Q
S curve (sigmoid curve)
A
- curve in the spine of a human
- doesn’t engage upper body muscles to stand
8
Q
The pelvis in hominin
A
- bipedal accommodates body weight on 2 limbs than 4
- differences in structure = difference in function
- pelvis is SHORT and BROAD
9
Q
Gorrila pelvis
A
- Pelvis is TALL and NARROW
10
Q
The power limb
A
- elongated hindlimb which allows bigger stride length
- femur angled towards the knee (valgus): brings center of gravity over knee = balance
11
Q
The foot
A
- function: platform vs grasping organ
- stable ankle joint
- large, non-divergent big toe: balance and propulsion
- arches: weight transfer, stabilization of foot
12
Q
Sahekanthropus
A
- ~7 Million yrs ago
- found in Chad
- combination of primitive and derived (more modern) morphology (mosaic evolution)
- more central foramen magnum = earliest bipedal
- ape-like postranial skeleton
13
Q
Ardipithecus
A
- around 5.8-4.4 million yrs
- found in Ethiopia
- same traits as Sahelanthropus
- very long arms, big hands with curved fingers
- divergent big toe!! = different kind of bipedalism
14
Q
Mosaic evolution
A
- when characters evolve at different rates
- combination of primitive and derived traits
15
Q
Australopithecus
A
- 4.2-2 million yrs ago
- in east and south Africa, Chad
- prognathic, megadont, large fafes with large attachments sites for chewing muscles
16
Q
Primitive and derived traits
A
- primitive: traits inherited from older generations
- derived traits: newer traits and adaptations, changed, modified
17
Q
Paranthropus
A
- 3 species
- South and east Africa around 2.5-1 mill yrs ago
- larger brain size, massive faces
- megadont
18
Q
Australopiths
A
- made from australopithecus and parathropus
- relations are unclear but they were still arboreal
- a grade is a grouping that doesn’t imply specific evolutionary relationships
- small brained and bodied
- megadont
- bipedal with arboreal retentions: long arms, curved phalanges, relatively short legs
19
Q
Megadont
A
- big big teeth so large cheek teeth
20
Q
Prognathic
A
- jaw that juts forward, typically lower jaw or mouth
21
Q
Orthographic
A
- face is more or less vertical and less forwards
- humans are orthographic
22
Q
Lucy
A
- australopithecus afarensis species
- female
- 3.9-3 mill years ago
- her pelvis was shorter and wider than a quadruped, larger than ours
- her femur is the same length as a chimpanzees, but it’s valgus (oriented on an incline)
23
Q
Material culture in tool making
A
- indication of human Adaption and technological complexity
24
Q
Knapping
A
- shape (a piece of stone, typically flint, of striking stones together to make stone tools or weapons to give a flat faced stone for building walls)
- hammerstone (stone) against core (big stone) to make a flake (piece of stone)
25
Extant analogues
- use of animal models
- tool use in last common ancestor (LCA) of chimps and humans in 6-9 mill years ago
- modify hammers and anvils, twigs, leaf sponges
- chimps don't knap, only food procurement
26
Early tool users: homo habilis
- handy man discovered in 1960, Tanzania, olduvai gorge
- East and South Africa, 2.5-1.4 mill yrs ago
- larger brain
- associated with stone tools
- more orthographic
- smaller teetb but still had thick enamel and strong jass
- short
- mosaic of morphological features
27
Encephalization
- evolutionary incraze in brain size relative to body size, measured in EQ