3.6 human evolution

Question 1

brow ridge

Answer 1

a defined area of bone around the eyes. in apes it is thick and prominent to protect the eyes from the powerful forces involved in chewing and biting. it is less prominent in humans as we have less muscles

Question 2

prognathism

Answer 2

the lower part of the face which projects forwards in apes. as humans evolved, the angle of the face decreased, becoming flatter due to smaller canines and a larger brain

Question 3

diastema

Answer 3

the space between teeth for canine teeth to fit into so other teeth are able to come together. the diastema is quite large in apes. in humans, we have a chin which allows for speech. the cause for a diastema is changed

Question 4

canines

Answer 4

apes have large canine teeth which are pointed teeth used to hunt, they are useful in tearing rough plants and meat. they are also weapons and used for aggressive display

Question 5

sagittal crest

Answer 5

a pronounced bone ridge that runs lengthwise along the midline of the top of the skull/ it is where strong jaw muscles are attached to. humans do not have a sagittal crest as we do not have as much jaw muscles, we evolved to eat softer foods and cooked meat

Question 6

premolars/molars

Answer 6

large flat teeth which crush and shear food when chewing. larger in apes than humans

Question 7

cranium

Answer 7

a part of the skull that encloses the brain and protects it from injury. humans have a much larger cranium

Question 8

foramen magnum

Answer 8

a large hole in the base of the skull where the spinal cord and arteries enter the skull. in apes, it is located at the back of the skull which connects to the spine at an angle. this helps with balance and aligns it with their centre of gravity. in humans, it is in the centre of the skull, which allows the head to rest upright. it ensures the centre of gravity is directly above the spine for better balance which is favourable for bipedalism

Question 9

mandible

Answer 9

larger in apes due to having larger and more muscle attachments for strong chewing

Question 10

nuchal crest

Answer 10

an extension of the skull where neck muscles are attached. which position, move and stabilise the head and cervical vertebrae. it is smaller in humans as our heads are kept upright. the ape head tends to droop down more as it is at an angle (due to foramen magnum) which requires a lot more muscles

Question 11

zygomatic arch

Answer 11

an arch in the cheekbone where muscles used for chewing pass through. these muscles are attached to the mandible and skull. the arch is wide and thick. it is bigger in apes as humans have less muscles

Question 12

ribs in apes

Answer 12

small and cone shaped, which allows for a wide range of shoulder and arm movement which is good for their tree top environment. it fits their gut as well

Question 13

ribs in humans

Answer 13

larger and barrel shaped to protect and suspend organs. this minimises the effect of gravity which may cause the organs to fall and get crushed. the rib shape allows for free swinging arms at the sides and assists with balance as well

Question 14

spine in apes

Answer 14

a c-shaped spine requires many muscles. the shape helps to distribute weight more evenly on the 4 limbs from quadrapedalism. it supports the abdomen and organs, absorbing impact.

Question 15

spine in humans

Answer 15

the s-shape spine helps us stand upright by ensuring our COG is aligned, which increases balance. it absorbs the impact of bipedalism

Question 16

pelvis in apes

Answer 16

longer, narrower, flatter, this allows for gluteal muscles to attach differently to assist quadrapedalism and distribute weight better

Question 17

pelvis in humans

Answer 17

broader and shorter curves to support organs in the abdomen when standing upright. its bowl-like shape helps balance torso weight. achieves smooth gait through muscle attachments which helps balanced forward walking

Question 18

valgus angle in ape femur

Answer 18

the femur is 90 degrees to the pelvis as an aligned COG is not very important for quadrupedal movement

Question 19

valgus angle in human femur

Answer 19

the femur is less than 90 degrees to the pelvis, this aligns the feet closer to the midline of the body, hence COG. the knees will go slightly inwards

Question 20

femur length and head in apes

Answer 20

apes have shorter femur bones which are less robust than humans. they do not be buttressed as weight is distributed on 4 limbs

Question 21

femur length and head in humans

Answer 21

long femur bones to increase weight transfer through hip joints and increase stability. the head and knee is more robust and buttressed to support the legs holding all body weight

Question 22

human vs apes brain size

Answer 22

humans have an increased brain size, the body size ratio is high.

humans have increased brain capacity as bipedalism allowed for more energy in development

the human brain has a higher surface area due to it being complexly folded

Question 23

differences in frontal lobe size of humans and apes

Answer 23

humans have a larger frontal lobe which is linked to abstract thought, logic, imagination, artistic ability and complex language. this had a big role in cultural evolution

Question 24

differences in cerebellum size in humans and apes

Answer 24

humans have a larger cerebellum for balance and co-ordination. this is important for bipedalism

Question 25

differences in wernicke’s and broca’s area in humans and apes

Answer 25

humans have a larger wernicke area which correlates to receiving and understanding language. we also have a larger broca’s area for a better co-ordination of muscle movements and speech.

wernicke’s area leaves an indentation in the skull, it can be seen to increase over time

Question 26

biological evolution

Answer 26

the transfer of genetic material from parent to offspring through sequences of bases in their DNA.

slow + limited by natural selection. occurs in all species.

impacted by mutations and random chance changes

Question 27

cultural evolution

Answer 27

the non-genetic transmission of information to another individual that is not necessarily related. occurs in only some species, it is purposeful and an instantaneous transmission of information that occurs in one’s lifetime.

it is built on information from past generations.

Question 28

how did tools help humans

Answer 28

• let us be the predator and not prey. it helped us hunt, thus increasing survival
• allowed us to control our environment like never before
• sharp tools let us to exploit new niches. we could butcher meat and bring it to a base
• could make clothing and shelter from bone-made tools

Question 29

tool

Answer 29

a modified or made hand-held object used to carry out a particular function. it was one way humans were distinguished from animals.

humans were the only species to use tools that left an archaeological record

Question 30

impact of tools and survival

Answer 30

tools minimised the effect of biological evolution / natural selection

Question 31

oldowan tool

Answer 31

the oldest tool

a cobble rock that had some flakes knocked off to create a sharp edge. took around 5 blows.

used for digging, hammering, grinding and chopping

flakes were used for cutting and skinning animals

Question 32

who created the acheulean tool

Answer 32

homo erectus

Question 33

who created the oldowan tool

Answer 33

homo habilis

Question 34

acheulean tool

Answer 34

the second tool made

larger, more symmetrical, tear shaped

flakes were either knocked off one side or both sides of the rock as well as a long running sharp edge or a sharp edge that was only at the top - giving it different purposes

more technique was required to make it, around 65 blows

the tool was long lasting

Question 35

mousterian tool

Answer 35

the third tool produced

it was more finely crafted rather than just a cobble rock with some blows.

complex worked edges which required more effort and skill to produce

Question 36

who produced the mousterian tool

Answer 36

homo neanderthalensis (neanderthals)

Question 37

upper palaeolithic tools

Answer 37

the fourth and last tool

there were 3 different shapes, ovoid, triangular, rectangular

produced through levallois method - chipping a rock until its core which was very sharp

the tool edges were as sharp as modern day metal tools

used for carving, butchering, digging for plants, making holes in hides

they were specialised and could have handles attached to it (shown through indentations)

required a lot of skill and effort.

Question 38

who created the upper palaeolithic tools

Answer 38

homo sapiens

Question 39

what species discovered fire

Answer 39

homo erectus
- fire could’ve been used by other species but there is evidence that homo erectus was the first species to be able to control it

around 800k years ago

Question 40

benefits of fire

Answer 40

• warmth at night
• light extends time, they could make tools at night
• safety from predators
• focus for social interactions (sitting around the fire)
• explore new niches
• used to harden and sharpen tools
• cooking

Question 41

evidence of fire

Answer 41

charred bones and stones

Question 42

impact of fire and diet

Answer 42

cooking food let us to make the most out of our meals. we had a more protein and nutrients rich diet, letting us grow and become smarter. leading us to evolve, create better tools, and better hunters. we spent less energy digesting food

positive feedback loop

Question 43

impact of fire and our jaw

Answer 43

cooking food made it softer, we needed less jaw muscles thus we have a smaller nuchal crest, zygomatic arch, and no sagittal crest as well as less defined brow ridge. energy was diverted to brain

Question 44

impact of fire and social interactions

Answer 44

we could sit around the fire, leading to more social interactions and cultural evolution. we could teach each other to make things as well as talk. there was more social organisation and communication (larger brocas and wernickes) it made us live together

Question 45

fire and base

Answer 45

where the fire was acted as a base. we could bring back food to the group and base through communication and live as one. fire led us to develop bases

Question 46

order of australopithecines species

Answer 46

ramidus, afarensis, africanus, paranthropus boisei

Question 47

order of the homo species

Answer 47

habilis, ergaster, erectus, heidelbergensis, neanderthals, sapiens

Question 48

impact of clothing

Answer 48

we lost body hair due to hot african environment

made from animal hide

let us explore new niches

increased our survival

spent less energy keeping us warm, which could’ve been diverted to brain growth

social wealth/identity

impacted by tool culture: knitting

hunting and camouflage better

Question 49

impact of shelters

Answer 49

proof: collection of fires, indentations, matter in a particular order

led to increased social connections, groups, storage and served as a home base

we could make more tools and store them

protection

needed planning and co-ordination to occur so demonstrates some brain development

was made through using caves, wood or other resources

Question 50

disadvantage of shelter

Answer 50

diseases more easily spread

vulnerable as we were stuck in one place

could only really utilise resources around the base

Question 51

impact of hunting

Answer 51

we went from being scavengers to predators

larger brain = better tools = hunted larger animals = got more protein = brain increased…

required communication with each other and mobility

Question 52

impact of agriculture

Answer 52

we could use animals for their wool, hide, milk, meat etc… they were also companionship

gathered plant seeds to produce barley, wheat and plants

we didn’t have to travel as far to gather resources, we were less nomadic

diet changes

led to specific tools being produced

Question 53

disadvantages/limitations of agriculture

Answer 53

animals would be inbred as the farm would be small (leading to fixed alleles and low genetic diversity)

we could only really eat what we grew

food poisoning

Question 54

impact of speech

Answer 54

started off with basic gestures and sounds with special meanings, such as calls and grunts. this is shown in primates

more complex language = better co-ordination = better tool making = better hunting in groups = better diet = larger brain

the development of speech is due to broca and wernickes area

social hierarchy, alliances, talking to each other, teaching

teaching is paramount of cultural evolution

Question 55

ardipithecus ramidus

Answer 55

the oldest species

arboreal, tree dwelling, hand grasping toe

very short

possibly bipedal but more adjusted to tree life. shown by its torso

small brain, meaning it ate lots of vegetation and had little protein

no sexual dismorphism, male and females had similar teeth

big canines = aggressive display

omnivores = ate small animals such as insects. shown by teeth and prognathism

Question 56

australopithecus afarensis

Answer 56

2nd oldest species

likely to be the first bipedal ancestor

lived in a forest and semi-savana

it lasted extremely long, meaning it had good adaptions and/or little competition

children grew up early, less parental guidance and socialisation. this meant the environment was safe, there was abundant resources and increased reproduction

high survival as it was well adapted for ground and tree life

Question 57

australopithecus afarensis body

Answer 57

small canine teeth = less aggressive

bipedal, regularly upright. shown through slightly different changes in everything. ex. foramen magnum slightly more centred

had ape and human characteristics. the face was more ape-like whilst the body was more human-like, showing the effects of its diet and bipedalism

it was GRACILE - meaning not robust

Question 58

australopithecus afarensis cultural evolution

Answer 58

no articulated speech, thus small wernickes and brocas area

hung out in groups, bones were found together

did not use tools, it had a small brain

possibly scavenged for small animals