Human Evolution NCEA Level 3

Australopithecus

Group of extinct omnivorous bipedal hominins. Includes A. anamensis, afarensis, africanus and some others.

Biological evolution

any transfer of genetic material (DNA, chromosomes) that leads to physical change

Characteristics of Biological evolution

slow physical changes over time, limited by genetic change and natural selection

Cultural evolution

anything that is learned, not passed through DNA

Characteristics of Cultural evolution

inheritance in any direction, and is relatively faster than biological evolution

Humanoids

all humans in history, including common apes

Hominins

bipedal apes and their ancestors

Bipedalism

Walking on 2 legs. Only Australopithecus, Paranthropus and Homo genuses.

Brachiation

Swinging by arms as apes do.

Arboreal

living in trees (forest)

Broca's area

Area of brain that produces speech.

Wernicke's area

Area of brain that processes speech

Occipital Condyle

area of brain that articulates with the first vertebra

Brow ridge

Bony projection protecting eyes and reducing stress in skull and lower jaw. Prominent in early hominins.

Burin

Tool used for making holes in skins, etc.

Condyle of knee

Buttress of bone on the base of the femur. Humans have this on the outer base and apes on the inner. It prevents collapse of the knee inwards.

Cranium

Raised back of skull holding brain. bigger in humans allowing for a bigger brain

Diastema

Gap between incisors and canines to allow for space for the large canines. Humans have no diastema due to small canines.

Dryomorph

Early form of ape ancestral to both apes and humans.

Foramen magnum

hole at back of skull where the spinal cord passes through

Mesolithic

Middle Stone Age, characterized by fishing and foraging for wild grains.

Mousterian

tool culture of H.neanderthalensis, 240k-30k YA.

Mousterian tool characteristics

~150 blows to make fine stone and flint tools. rope used to attach tools to handles. sharp sophisticated weaponry could punch in animal hides.

Advantage of mousterian tools to H.neanderthalensis

Improved weaponry, could make simple clothing allowing them to move and survive in colder climates (Europe)

Neolithic

New Stone Age — age of agriculture.

Nuchal crest

where neck muscles attach. larger in apes than in humans due to quadrapedalism, so needed large neck muscles to support head and prevent drooping

Oldowan

tool culture of H.habilis 2.4M-1.6M YA.

Oldowan tool characterisitic

5-6 blows to simple stone tools used to scavenge and process meat to get bone marrow

Adavantage of Oldowan tools to H.habilis

has access to bone marrow (new food), increasing protein in diet allowing for brain growth

Palaeolithic

Old Stone Age.

Upper Palaeolithic tools

tool culture of H.sapiens

Upper Palaeolithic tool characteristics

~250 blows to make from variety of materials (bone, stone, wood, antler) -composite tools. much more sophisticated, specialised and increased range of use

Advantages of upper palaeolithic to h.sapiens

Were able to move into new environments and increase their range of diet (fish hooks in coastal environments)

Trends in tool cultures over time

tools became more refined (more blows), more specialised and sophisticated, require more materials, require improved fine motor skills

Paranthropus

Genus of vegetarian hominins includes P. aethiopicus, robustus and boisei.

Ponginae

Subfamily that contains orangutans.

Primate

Order that includes prosimians, monkeys, apes and humans.

Prognathism

having a protruding jaw. humans don't show prognanthism

Prosimian

Primitive monkey, eg lemur, loris, tarsier. Small, often solitary, nocturnal.

Quern stone

Rounded stone used for grinding grains into flour.

Sagittal crest

Bony projection on top of the cranium for attachment of chewing muscles.

Selection pressures

The environmental factors that favour certain phenotypes over others. (See the chapter on Evolution for more on this.)

Sexual dimorphism

Where the male is larger and has structural differences from the female.

Simian

Monkey-like.

Upper Palaeolithic

Culture of Homo sapiens.

Valgus angle

Carrying angle; the angle, less than 180°, between the femur and tibia. It indicates bipedalism.

Wernicke's area

Area in the brain concerned with recognition of speech.

Zygomatic arch

Bone structure on side of cheek through which the chewing muscles go.

Acheulian

Tool culture of Homo erectus and archaic H. sapiens. Pear-shaped hand axes.

Ape

Includes gorilla, orangutan, gibbon and chimpanzee. No tail, large brain; brachiating knuckle walkers.

Bipedalisim Advantages

Thermoregulation, Carrying Objects, Height, Energy Efficient

Biological Evolution

(transmission of factors inherited from parents)

Cultural Evolution

(transmission of beliefs, ideas, knowledge by learning from other members of group) Tools, Fire, Shelter, Clothing, Food-Gathering, Abstract thought, Domestication of plants and animals.

H - Feet

Arched (shock absorbing; walk longer distances). Toes face forward, longer big toe (provides thrust). Big heel bone (firm base to push against for walking/running)

A - Feet

Flat feet, big toe separate, facing outwards from foot and opposable (grasping branches and climbing trees)

H - Femur,Knee Joint, Valgus Angle

Femur hangs inward angle from hip (center of gravity between feet) Knee Joint (maintains centre of gravity) Buttresses (creates valgus angle, prevents sideways movemetn of lower leg)

A - Femur,Knee Joint, Valgus Angle

Femur hangs vertically from hip, knee joint, no buttresses or valgus angle (gives better swinging motion in branches)

HvA - Spine

H: S shape (keeps body weight above hip joints) A: Slightly curved (counterbalances downward force of organs and chest)

HvA - Chest

H: Flattened front to back, oval in cross-section (body weight brought close to spine and over centre of gravity. A: Rounded front to back, circular on cross-section (organs supported by rubs and large abdominal muscles)

HvA - Hands

H: Fully opposable thumb, straight fingers (manipulative precision grip). A: Short, opposable thumb and curved fingers (power grip and hooking)

H - Skull External

Foramen magnum at centre of base of skull (skull balances at top of spine). No brow ridges, sagittal crest or nuchal crest.

A - Skull External

Foramen magnum and back of skull, large brow ridges, sagittal crest, nuchal crest.

H - Teeth and Jaws

Smaller teeth and jaws (tools cutting up and fire softening). Enamel thicker and canines small. Jaw and tooth row more parabolic shaped.

A - Teeth and Jaws

Larger teeth and jaws, large canines (display, sexual diapmorphism) distema on upper tooth row, jaw and tooth row U shape.

H - Endocranial

Cranium volume 1400, Speacialised areas: Cerebellum (balance, swelling at back), Cerebrum (thinking skills, top surface expanded and folded), Broca's area (speech production), Wernicke's area (understanding speecha and writing) both swelling left side.

A - Endocranial

Cranium volume 450, atter on top, no specialised areas developed.

HvA - Pharynx and Larynx

H: longer P, lower L (modifies sound and tone of speech). A: shorter P, higher L (modification of tone and sound cannot occur)

HvA - Hair and Skin

H: finer and shorter hair but same number per cm3 and more sweat glands (cooling capacity for higher activity rates). A: thicker hairs, fewer sweat glands (insulation from sun, lower activity rates)

HvA - Pelvis

H: short and wide (reduces stress of upper body weight in hips, supports abdominal organs). A: tall and narrow (large surface area for leg muscle placement)

Australopithecus

A genus dating from 4-1million years ago. Also known as the southern ape. Brain size <500cc (cubic centimeters)

Homo

Genus to which humans below. Ranging from 2 million years ago (mya) to the present day. Brain size >600cc

Australopithecus afarensis

Southern ape from the afar desert. Earliest fossil 4-2.8 million years ago. Remains found in Ethiopia and Sth Tanzania. Small stature, brain size similar to chimp. Bipedal, ape-like face (elongated, pronounced brow ridges).

Small, ape-like face (elongated, pronounced brow ridges), brain size chimp, free hands, walk upright,

Features of A. afarensis

Australopithecus africanus

Lived from 3-2mya. Similar features to A. afarensis. Stature; bipedal, small brain, flatter face, large molars (plant based diet), brow ridges.

4-2.8mya

Timeline of A. Afarensis

Australopithecus robustus

2.4-1.4 mya. Larger stature & bones, more muscular. V. large molars. Small brain

2.4-1.4mya

Timeline for A. robustus

similar to A. afarensis, brain slightly larger, large molars

features of A. africanus

Large and heavily built, large bones & skull, v. large molars, small brain

features of A. robustus

Homo habilis

The 'handy man', first to use very primitive tools. Approx 2mya. East Africa. Stature; smaller teeth and jaw, human size, dominant brow ridge, sloping skull. Brain size approz 600cc

approx 2mya

Timeline for H. habilis

Smaller teeth and jaw, human size, dominant brow ridge, sloping skull, brain size approx 600cc

features of H. habilis

Homo erectus

The direct ancestors of Homo Sapiens. Approx 1mya. Migrated to other parts of africa. Less hairy, no chin, arches over eyes. Larger brain (1000cc) with more cortex allowing higher functioning. More complex tools. Teeth changed to meat eaters

brain 1000cc, less hairy, no chin, arches over eyes

features of H. erectus

Homo sapiens

Our species. Physical features: Flat high dome forehead, no arches over eyes, 1300cc brain.

Neck

Foramen magnum is more anterior/ less robust neck muscles

Spine

backward thoracic curve/ forward lumbar curve/ keeps trunk centered about the pelvis

Pelvis

basin shaped to support internal organs/ iliac blades shorter and broader/ stabilizes weight transmission

Limbs

lower limbs elongated/ thigh 20% humans, 11% gorillas

Femur

angled inward/ legs more directly under the body/ modified knee joint helps to extend it fully

Foot

enlarged and inwardly placed big toe/ longitudinal arch absorbs shock and spring to step

Teeth

reduced canine, smaller incisors

opposable thumb

when thumb can touch fore fingers, only primates have these features.

arboreal life

life in the trees, opposable thumb was important in result of this

hominoids

all apes and humans

hominid

early ancestor on human family tree

bipedalism

walking on two feet