The stages of anthropogenesis

Starter

What traits make us humans?
Who are our early ancestors?

The stages of anthropogenesis

Human Biological Evolution

Learning objective

to describe the stages of anthropogenesis

Success criteria

1.Knows the main stages of anthropogenesis.
2.Describes each stage of

Terminology

Apes, homo, hominids, million years ago, modern human and apes,

Introduction…

Many different human-like species existed over the 4-8 million years since

  A. Pan troglodytes, chimpanzee, modern B. Australopithecus africanus. Australopithecus africanus,

Ardipithecus ramidus…

Fossils found in Ethiopia
Sometimes classed as an early Australopithecus.
May represent

The Australopithecines

were the earliest known pre-humans.
All of the various species lived

They mostly lived in the East African Rift Valley and in

They were all bipedal with brains slightly bigger than a chimps,

Australopithecines can be described as either gracile (slender) or robust (heavily

Australopithecus afarensis

‘Lucy’ is the best known example.
Had an ape-like face with

Sexual dimorphism with males taller than females.

Australopithecus - an ape who walked on two legs

One of the

A few years after Lucy was found, a set of footprints

Tooth rows almost parallel.
Finger bones longer than in humans and slightly

Australopithecus afarensis

Australopithecus afarensis: lived 3.2 million years ago. Stood around 1.1

Australopithecus africanus

Less ape-like than A. afarensis with a higher forehead, less

Australopithecus africanus…

Probably some sexual dimorphism but less than A. afarensis. Lived

For your notes – Gracile Australopithecines

Australopithecus afarensis: lived 3.2 million years

Robust Australopithecines

May also be classified in the genus Paranthropus.
Includes A. robustus

Robust Australopithecines

Probably fed on tough vegetation as seen by microwear pattern

A. boisei

A. robustus

For your notes:

A. robustus lived 1.3 - 2 mya, cranial capacity

Bipedalism

was the most important event in human evolution because it freed

The probable selection pressure for bipedalism was environmental change due to

Advantage of bipedalism

More energy-efficient at walking speed than knuckle walking. Also

Keeps body cool with less direct surface area exposed to the

Homo habilis

Rounded skull still with brow ridges. Some development of Broca’s

1.5 - 2.4mya in eastern Africa
Cranial volume 500 – 650cc.
1 –

Oldowan tools

Scavenging

was a way of
finding food
during times
of shortage.
Following other scavengers made

Homo erectus

1.8mya to ~300 000ya.
Cranial volume 750 – 1250cc.
No sagittal crest.

Homo erectus

Homo sapiens

Turkana boy

Note human-likeness of knees, pelvis ribcage, skull.

Used Acheulean tools such as choppers, hand axes and scrapers. May

Acheulean tools

Note how they are worked all over with many small

Homo erectus range

H. erectus learned how to use and control fire.

Fire was useful for preserving food, making it taste better and

Homo neanderthalensis

1.5 – 1.7m tall.
Sloping forehead with an occipital bun for

Receding chin. Brow ridges present.

Cranial volume 1200 – 1750cc (larger than modern humans).

Thicker limb bones, stocky build probably a cold adaptation. Large areas

Used Mousterian tools made from flint.

150 000 – 25 000ya throughout Europe.

Buried their dead with flowers, tools, food or jewellery. This suggests

Sometimes lived in caves and made stone walls and curtains. Made

Probably had a language as they had a hyoid bone.

mitDNA very different between H neanderthalensis and H sapiens suggesting H

Skeletons have been found with Neanderthal and human DNA suggesting some

Homo sapiens

Appeared about 160 000ya in Africa and spread to Asia,

They buried their dead.
Earliest humans were long limbed and gracile. 1.6

Cranial volume 1200 – 1700cc. No brow ridges, high forehead, well-developed

The expansion of the frontal lobe of the brain enabled the

Cro-Magnon man made Upper Palaeolithic tools including fish hooks, harpoons and

2 left = Middle Palaeolithic

3 right = Upper Palaeolithic

They lived in caves and shelters, made clothes, painted on cave