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Flashcards in Human Evolution Deck (29):
1

What is the hominoid family

Humans and the great apes (gorilla, orangutan, chimpanzee)

2

Habitual bipedalism

Ability to stand and move on two legs for long periods of time

3

Habitually quadrupedal

Moving on all four limbs

4

How do skull of gorilla differ from human

Foramen magnum- (G) located at rear, (H) centrally located
(G) sagittal crest, (H) large rounded cranium
Brow ridge- (G) large, (H) small
Nuchal crest- (G) large, (H) small

5

Spine and ribcage of an ape

C shaped- counterbalance the downward force of organs and chest
Ribcage flattened side to side


6

Spine and ribcage of human + cost

S shaped- act as shock absorber and to keep body weight above hip joints for upright stance and movement = stability/balance
Ribcage flattened front to back

Hernia, back pain

7

Pelvis of ape

Long narrow, favours small cranium offspring
Large SA for attachment of leg muscles

8

Pelvis of human + cost

Short, wide, bowl shape support internal organs
Gluteal muscles strengthened + body weight close to spine (over COG) providing support and stability for upright stance as weight transmitted directly over legs

Birth canal = Selection pressure for cranial size

9

Femur and knee for apes

Femur hangs vertically from hip enables good swinging motion
Larger inner knee

10

Femur and knee for humans + cost

Femur long angled inwards (valgus angle) under COG improves weight bearing capacity
Outer condyle enlarged to stop sideways deflection of muscles when bearing weight
Long strides

Varicose veins
Knee problems

11

Foot for apes

Big toe opposable and spreads sideways for gripping branches, grasping food

12

Foot for humans + cost

Foot forms platform-big toe aligned to others
Foot arched for thrust and shock absorption

Collapsed arch

13

Hand for apes

Short opposable thumb + curved phalanges
Long for brachiating

14

Hand for human

Fully opposable + elongated thumb + straight phalanges
Highly developed dexterity-Precision grip

15

Advantages of bipedalism

Carrying objects
Better thermo regulation
Avoiding predators
Efficient locomotion

16

Broca's area

Allows speech

17

Wernicks area

The ability to listen

18

Order of abilities leading to brain enlargement

Bipedalism
Free hands
Development of tools+ greater access to proteins
Communication, social organisation, hunting

19

How did development of language provide adaptive advantage?

Planning hunts
Carrying out hints
Trading/negotiating exchange of resources
Passing on historical knowledge/experiences

20

How did the use of fire provide adaptive advantage?

Cooks food
Warmth
Light

21

Why did Neanderthals become extinct?

Small populations
Small and stocky
90% meat in diet, preference uncooked
Frontal cortex not so well developed
Climate warming
Competition from H. Sapiens

22

What is a hominin

The taxonomic group that includes modern humans and ancestral humans

23

What is hominid

Great apes

24

What biological evolution

Transmission of characteristics from parent to offspring via DNA at fertilisation
Dependant on natural selection
Slow

25

What is cultural evolution

Non genetic transmission of information/skills via observation, oral, written communication
Rapid rate as built on learning of previous generations + added to over time

26

Main selection pressure that favoured bipedalism

Climate change- Africa becoming cooler and drier 6mya
Dense forest gave way to open grasslands/scattered trees
Seasons became distinct-summer hot and dry

27

Skull of ape

Larger Sagittal crest- attachment for muscles that support skull during the stress of chewing
Foramen magnum located at rear underside- requires large neck muscles =large nuchal crest

28

Skull of human

Large round cranium- houses and protects large brain
Foramen magnum centralised- skull balanced on neck vertebrae little muscular energy needed to support skull=nuchal crest small

29

Which came first, biological evolution or cultural evolution?

Brain size increased to the point where significant cultural change became possible
Cultural change began to provide a stimulus for further brain development