Biology - Human evolution

Brachiation

Movement by swinging beneth brunches with two arms

Binocular/stereoscopic

Two forward-facing eyes that give overlapping vision

Plantigrade

Walking on the whole bottom of the foot

Opposability

The ability of the thumb to touch the fingertips of the same hand

Mosaic

Combination of features

Arboreal

Living in trees

Bipedalism advantages

See further, Hands freed up, throwing things for hunting, look larger/more dominant, more efficient over long distance walking

Bipedal

Using two limbs/feet for locomation (walking/transport)

Quadrupedal

Using 4 limbs for locomotion - knuckle walking (chimps, gorillas)

Bipedalism disadvantages

S shaped spine, birth more painful - large headed babies, prone to falling and foot/leg injuries, takes time to learn to walk

what is the spinal trend?

C to S shaped

What is the pelvis trend?

Went from long and narrow to short and wide/broad (bowl shaped) - this occurred as a trade off between efficient bipedal movement and large brain size

Did the valgus angle increase or decrease?

Increase - to increase stability as the knees were bought closer together under the COG

Where did the Foramen magnum shift?

Shifted from the rear base of skull to the centre base of skull

What is the feet trends?

Big toe became aligned with other toes, short toes, big toe = provides trust, arch feet to absorb shock and more efficienct for walking long distances

arm to leg ratio

Arms went from being longer than legs to legs being relatively longer than arms

Is bipedalism more efficient than quadrupedal locomotion? Why/Why not?

Yes - freed up hands allowed us to carry out activities that gave us advantages, saving energy

What are three theories behind bipedalism?

1. Postural - reaching for food, balance

2. Provision - freed up hands

3. Savannah - early hominins who settled on ground became increasingly bipedal

What was the trend in the skull shape?

Flat top - rounded top, robust - gracile, sloping - flat face

What are three areas on the skull that got smaller

Brow ridges, saggital crest, Nuchal crest

Did the brain size increase or decrease?

Increase - mordern humans now have much larger brains

Trends in the jaw

Smaller jaw as diet changed due to natural selection - higher quaility food, softer, less energy required

What was the trend for teeth?

U to V shaped

Natural selection

The process by which organisms with favourable traits are selected for by environmental selection pressures, making them more likely to survive and reproduce, passing these traits onto their offspring.

Which part of the brain is for understanding speech/comprehension?

Wernickes

Which part of the brain is for production of speech?

Broccas

In the brain, what does broccas control?

The jaw, tongue, lips, and vocal cords

As selection pressures drove the increase in brain size and development, what order does fossils show these changes?

1. Bipedalism

2. Dental changes

3. Larger brain developments

What is the fingers trend?

They become shorter and straighter

What was the trend in the thumb?

Went from semi-opposable to fully opposable

What are the two types of grips?

1. Power grip

2. Precision grip

What is "Lucys” scientific name?

Australopithecus afarensis

What is the scientific name for the “Handy man”? and what was he the first to do?

Homo habilis - first to use tools

What is the scientific for the “Pecking man/Java Man”?

Homo erectus

What is the scientific name for the “Cave men”

Homo neanderthalensis/Neandertal

Who left Africa first?

Homo erectus

What are the two dispersal models?

1. Out of Africa/replacement theory

2. Multiregional model

What model is this?

Out of Africa theory

What model is this?

Multiregional theory

Which theory is mainly supported by genetic evidence and why?

OOA model - mtDNA, Y chromosomes, African population has the highest genetic diversity, suggesting humans originated from Africa

Which theory is mainly supported by fossil evidence and why?

MR - transitional fossils were found in many places, showing the gradual change physically across the 3 different species (H. erectus, Neanderthal, H. sapiens

Who has Neandertal DNA today?

All non-Africans, telling us that having the same amount tells us interbreeding occurred before the population diverged

What are features all modern hominins share?

Big brain, light/gracile skeletons, evolved in Africa

What are features that demonstrate differences between individuals?

Nose shape, skin colour, hair colour, eye colour - regional differences due to mutations

Cultural evolution

The passing on of learned behaviours, beliefs, customs and ideas in a group that is passed on (non genetic basis)

Biological evolution

Biological evolution is the change in inherited characteristics of a population over generations

What is the lower palaeolithic tool first used by H. Habilis (“Handy man”)?

Oldowan tool culture

What is the lower palaeolithic tool first used by H. erectus?

Acheulian tool culture

What is the middle palaeolithic tool first used by Neanderthals?

Mousterian tool culture

What is the upper palaeolithic tool first used by H. sapiens

Upper palaeolithic tool culture

Who first used fire?

H. erectus

What was fire first used for?

Light, cooking, warmth, keeping predators away, hunting

Who first made forms of art?

H. sapiens