Prelim 2

Question 1

What are the costs of bigger body size?

Answer 1

Need more food

Question 2

What are the 3 benefits of bigger body size?

Answer 2

1. Need food less often
2. Better at intra-species competition for resources and less vulnerable to predators
3. Locomotion - once moving, can run/walk long distances

Question 3

Benefits of larger brains/CBS

Answer 3

1. Social intelligence
2. Technological intelligence
3. Control of fire

Question 4

Costs of larger brains/increased CBS

Answer 4

1. Premature/helpless infants
2. Lots of energy needed
3. Tradeoff - smaller guts & higher quality diets needed

Question 5

Expensive Tissue Hypothesis

Answer 5

Theory that increased brain size is afforded through decreased gut size - acc. Wrangham, this is possible due to cooking

Question 6

Impact of helpless infants

Answer 6

Women need constant help and must carry infant

Question 7

Morphological differences between H. erectus & sapiens

Answer 7

Below head - basically the same
H. erectus has smaller brain and more prognathic

Question 8

Radiation

Answer 8

Rapid expansion of many new, related species (due to natural selection)

Question 9

Phylogenetic Species Concept

Answer 9

Use physical traits and “clusters” of similar traits to group species together

Question 10

Miocene

Answer 10

23-5.3 MYA, more cooling, radiation of ape species - human evo. from apes begins at end of this

Question 11

Sources of variation within species

Answer 11

Age, sex, geography

Question 12

Derived characteristics

Answer 12

Characteristics that deviate from past ancestors

Question 13

How can we date human evolution?

Answer 13

1. Fossils - different strata of Earth
2. Molecular clock - DNA comparison (e.g. between humans and chimps)

Question 14

Adaptive shifts in hominid evolution

Answer 14

1. Locomotion
2. Diet & dentition
3. Brain size increase

Question 15

Obstacles to bipedalism

Answer 15

1. Loss of balance/stability
2. Difficulty of pulling leg up
3. Less speed initially

Question 16

Indications of bipedalism in fossils (5)

Answer 16

Foot - parallel big toe, 2 arches
Leg - upper femur angle
Pelvis - bowl-shaped & outward flare
Spine - double curve (vertebrae)
Skull - Foramen Magnum at bottom center

Question 17

Ardipithecus ramidus time + place

Answer 17

4.4 MYA, Ethiopia

Question 18

Ardipithecus ramidus morphology + behavior

Answer 18

Small, bipedal climbers with changing dentition

Question 19

Australopithecus afarensis morphology + behavior

Answer 19

“Bipedal apes”
Small, long armed, flared pelvis, no grasping big toe (likely poor climbers)

Question 20

Australopithecus afarensis time + place

Answer 20

4-3 MYA, Ethiopia

Question 21

First adaptive shift

Answer 21

Bipedalism

Question 22

Second adaptive shift

Answer 22

Diet + dentition

Question 23

Gracile species

Answer 23

Huge back teeth
Australopithecus africanus and A. sediba
Tiny, bipedal small-brained apes with giant molars
3-1.9 MYA

Question 24

Robust species

Answer 24

REALLY huge back teeth
Paranthropus aethiopicus, boisei, robustus
Huge chewing muscles, sagittal crest and bigger brains
Died out(?)
2.5-1.8 MYA

Question 25

Theories of bipedal advantage

Answer 25

1. Reach fruit above head 2. Scan for predators/resources 3. Free hands (for infants, food, tools) 4. More efficient locomotion (maybe not) 5. Heat stress in savanna

Question 26

Early hominid diets

Answer 26

Hard foods - USOs, nuts More flexibility in savanna - survive dry season and scattered resources

Question 27

Types of diet data

Answer 27

1. Chemical - isotopes & proportions of elements 2. Archaeological - tool marks on bones, teeth fossils 3. Ethological - examine chimp use of tools (can dig for USOs)

Question 28

Homo habilis morphology + behavior

Answer 28

1. Big brain to body ratio 2. First to fully benefit from bipedalism (Bigger bodies, longer legs, no divergent big toe) 3. Loss of Sagittal crest, but big molars 4. Extensive tool use ("handyman")

Question 29

H. naledi

Answer 29

Super recent discovery - possible offshoot of paranthropus, b/c brains are way too small Throws everything into question

Question 30

Last great adaptive shift

Answer 30

H. erectus: new range, ecology, genus

Question 31

H. erectus range

Answer 31

Africa --> Eurasia, Indonesia

Question 32

H. erectus morphology

Answer 32

Postcranium, essentially modern Less prognathic and bigger-skulled than H. habilis

Question 33

Societal implications of helpless infants

Answer 33

Mothers need much more help and must constantly attend infants, plus need more energy/food

Question 34

Acheulean tools

Answer 34

Second tool industry Hand axes, cleavers Made by intentionally shaping multiple sides of a rock

Question 35

Oldowan tools

Answer 35

First tool industry Stones with flakes taken off

Question 36

Archaic H. sapiens characteristics

Answer 36

1. Habitual use of fire 2. Better tools 3. Big game hunting

Question 37

What ecological changes led to the emergence of hominins?

Answer 37

Global drying and reduction of rainforests --> hominins move to savanna

Question 38

Pleistocene

Answer 38

2.5-.01 MYA "Ice Age" aka many glaciers, up to 70-80% of surface Sea levels fell & land bridges

Question 39

When did habitual fire use begin?

Answer 39

Direct evidence - 400,000 YA Hearths (repeat burning) and concentrated, burnt artifacts prove

Question 40

Early archaic H. sapiens

Answer 40

400,000 - 125,000 YA Brain size into modern range Reduced posterior dentition but big anterior teeth Massive brow ridge

Question 41

Levallois tools

Answer 41

Third tool industry - early H. sapiens Made out of super sharp stone flakes Sometimes lashed to a shaft to create 7ft spears

Question 42

What are the implications of big game hunting?

Answer 42

Additional intelligence to cooperate, plan, preserve meat

Question 43

What are the results of range expansion?

Answer 43

Flexibility and generalism

Question 44

When did bipedalism begin? Which species is associated with this?

Answer 44

~4 MYA, A. ramidus

Question 45

When did dentition begin to change? Which species is associated with this?

Answer 45

~2.5-1 MYA, Paranthropus genus and A. africanus/sediba

Question 46

When did brains and bodies grow bigger? Which species is associated with this?

Answer 46

~2 MYA, H. habilis/erectus

Question 47

Recent Replacement

Answer 47

Splitters H. erectus travels, dies out in other continents H. sapiens evolves in Africa and expands to other continents, maybe pushing out old erectus species

Question 48

Multi-Regional Evolution

Answer 48

Lumpers H. erectus leaves Africa, evolves into H. sapiens separately Gene flow ensures no speciation

Question 49

Neanderthal time + place

Answer 49

400,000 - 30,000 YA in Europe and Middle East

Question 50

Neanderthal morphology + behavior

Answer 50

Sloping forehead, big nose, no chin, occipital bun at back of skull Short, stocky, thick bones No evidence of diff. brain function

Question 51

The Neanderthal Question

Answer 51

Are Neanderthals 1. a different species from us which developed from H. erectus (RR)? 2. a subspecies, but still Homo sapiens (MRE)

Question 52

Flores hominins time + place

Answer 52

700,000 - 13,000 YA Indonesia

Question 53

Flores hominins morphology + behavior

Answer 53

Super tiny, simple tool use, no gene flow with other populations

Question 54

How did humans reach the Americas?

Answer 54

Land bridge during Pleistocene (low sea levels) between Russia and Alaska, then walking/rafting to Patagonia