HUMAN EVOLUTIONSlide 2 Important Bipedal findsSlide 3 Hominin EvolutionSlide 4 Human OriginSlide 5 Out of Africa TheorySlide 6 Multiregional TheorySlide 7 H. floresiensisSlide 8 Cultural EvolutionSlide 9 The Catalyst for CultureSlide 10 Cultural PeriodsSlide 11 Lower PaleolithicSlide 12 FireSlide 13 Middle PaleolithicSlide 14 Art and SpiritualitySlide 15 Upper PaleolithicSlide 16 NeolithicSlide 17 Agriculture

3A BIO

IMPORTANT BIPEDAL FINDSImportant “first” bipedal species finds include:

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Australopithecus africanus

- 1942 (2.5 m.y.a) “Tuang boy”

Australopithecus afarensis

- “Lucy”, 1972

- “The first family”, 1975 (3 m.y.a)

- “Laetoli footprints”, 1977 (3.75 m.y.a)

Ardipithecus ramidus

- 1995 (4.4 m.y.a)

Orrorin tugenensis

- 2001 (6 m.y.a! 1.5 my before thought)

HOMININ EVOLUTION About 5 -8 m.y.a. the Hominid ancestor emerged.

This eventually branched off into Gorillas, chimps, and us.

The first solely human (hominin) ancestor was probably Ardipithecus ramidus, around 5 m.y.a. This was followed by the Australopithecines, from 4 m.y.a. All fossils from this time have been found in Africa.

Australopithecines were bipedal. Their brains were only slightly bigger than chimps’. They (probably) didn’t use tools, except twigs (as do chimps).

Darwin's theory that bipedalism predated brain enlargement was proved to be correct. Why would this be the case?

Hands free for walking leads to them being available for tool use.

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This represents one possible

interpretation of the fossil data:

HUMAN ORIGIN Ardipithecus ramedus

Australopithecus anamensis

A. afarensis

A. africanus

Paranthropus robustus P. Boisei

Homo rudolfensis

H. ergaster

H. heidelbergensis

H. neanderthalensisH. sapiens

H. erectus

H. florensiensis

6 m.y.a.

5

4

3

2

1

0.5

Present

The megadonts – vegetarians. a.k.a.

robust A.s

gracile Australopithecines

H. habilis

Manual pg 344/5/7

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HUMAN ORIGIN Out of Africa (replacement) Theory:

H. ergaster/ H. erectus migrated and colonised many areas.

Only the African type evolved into humans, and then spread through the world replacing the others as they went.

mtDNA analysis supports the common ancestor of all humans 170,000 y.a. in Africa.

All humans are genetically too similar to have evolved parallel, without large gene flow between continents (unlikely).

There is little continuity of fossils outside Africa to link H. erectus to H. sapiens.

There are two main theories for where H. sapiens originated.

Africa AsiaEurope

H. erectus

H. erectus H. erectusH. erectus

H. sapiens ExtinctExtinct

H. sapiens H. sapiensH. sapiens

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HUMAN ORIGIN Multiregional:

H. ergaster/erectus migrated and colonised many areas.

There was some interbreeding, but the populations are isolated, and evolve in parallel.

This results in distinct regional differences.

There is evidence of H. ergaster in Europe, and some regional differences between fossils.

170,000 years is too short a time for H. sapiens to take over other populations.

mtDNA is less reliable than fossil evidence???

Africa AsiaEurope

H. erectus

H. erectus H. erectus H. erectus

H. sapiens H. sapiens H. sapiens

Some interbreeding

Manual pg 359

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H. floresiensis

H. floresiensis was discovered in late 2004 on a small Indonesian island.

The fossils date back about 13,000 years – well within human habitation of Indonesia.

The fossils found share more in common with H. erectus than H. sapiens.

A possible evolutionary pathway is shown.

Discuss if this information supports the “Multiregional” or the “Out of Africa” theory.

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CULTURAL EVOLUTION Once hands were free to make tools, our ancestors could engage in activities that required intelligence – and our brains got bigger.

As communication improved, information could be passed on by language, rather than imitation. This resulted in a massive, rapid and profound leap of cultural evolution.

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Biological evolution Cultural evolution

Our cultural evolution has, in a short time, overrun the biological evolution of our prey, predators, competitors, and most of our parasites.

Parents to offspring

Received at fertilization, then doesn’t change

Changes are random, trial and error – 1 trial per generation

Purposeful, cumulative, future focused

Constantly is developed through lifetime

Anyone to anyone else

THE CATALYST FOR CULTURE Main Menu

Brain size increases to the point cultural evolution is possible.

Brain size stops increasing (stabilising selection).

Better tool making

Improved food supply

Longer period of parental care

Birth at earlier stage of development

More post natal brain growth

Longer period of learning

The latest phase of human evolution has been entirely cultural, and is happening at an exponential rate.

CULTURAL PERIODSMain Menu

Animals use tools. How is human tool use different to them?

• Only humans use tools to make tools

• Only humans left archeological evidence of tool use (stone tools)

The cultural development has been divided into 2 stages:

Paleolithic (“old stone age”)

Neolithic (“new stone age”)

The term Mesolithic (“middle stone age”) is sometimes used for the latter stages of the Paleolithic.

LOWER PALEOLITHICThere may well have been earlier tool use – wood and bone – but these have not survived.

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Oldowan tools:

H. habilis (the “handy man”) was the first to use stone tools, about 2.5 mya. H. erectus also used this technique.

The typical tools were a hammer stone, which was used to take flakes off a core stone.

The flakes were used for skinning and cutting, the core stones for chopping, hammering, or digging.

Acheulean tools:

These include many types of hand axe made from a core stone. Used by H. erectus, H. ergaster, and H. heidelbergensis.

FIREMain Menu

H. erectus was the first to use fire 800,000 y.a. H. sapiens developed this further – using sparks from flint to start fires. This would have had huge advantages:

• The catching, returning, and cooking of meat would require better communication, and the development of a home base.

• Warmth – more survival in previously uninhabitable areas.

• Safety from animals.

• Light - more time for social interactions, as well as giving a social focus. This was probably a critical factor for further language development.

• Cooking – making food easier to chew and digest, and killing microbes on the food – better health.

MIDDLE PALEOLITHICMain Menu

Mousterian tools:

These were made between 200,000 and 40,000 y.a. by H. neanderthalensis.

They are made from the flakes, which were further shaped and had a wide variety of styles and functions. The tools were difficult to make, but could be used on spears or lances.

A Mousterian awl for punching holes in hide to make clothing.

ART AND SPIRTITUALITYMain MenuH. neanderthalensis was the first hominid to arty stuff.

They had necklaces and beads, and may have also had music (in 1995 a bone whistle was found in a cave with Neanderthal tools.

They buried the dead with flowers, clothes, beads, and red ochre. Often they were laid as sleeping and facing east-west… rituals?

They cared for people who were too infirm to survive alone. How is this significant?

Manual pg 372/3

H. sapiens – Cro-Magnons drew sweet-as cave paintings depicting animals, they made figurines of clay and also buried their dead, implying superstition and/or a rudimentary religion.

Implies strong social structure and would build group cohesion.

UPPER PALEOLITHICMain Menu

These were made by the last of the Neanderthals and H. sapiens between 40,000 and 12,000 y.a.

Includes tools for:

Making holes in hides to sew them together

Digging for plant roots

Arrow heads

Harpooning fish (from bone and antler)

The stone tools were very effective and finely worked.

Many of these tools are still used today by isolated tribes.

Manual pg 369/70

NEOLITHICMain Menu

This is marked by the domestication of plants and animals.

In other parts pastoralism developed instead. This is where tribes would follow the movements of partly domesticated animals, such as reindeer.

Domestication began with dogs (15,000 y.a.) and cats (10,000 y.a.).

Agriculture began about 10,000 y.a. as the ice age receded. Plants and naturally formed polyploids and although these would not normally reproduce, they were selected for by humans.

Goats, sheep and pigs were domesticated about 8,000 y.a.

Horses, donkeys and water buffalo about 4,000 y.a.

Most people were lactose intolerant after weaning, but a mutation in the gene allowed milk to be processed throughout the life. This would have provided an excellent source of nutrition.

The mutant gene is much rarer in Asian populations.

AGRICULTURE PROS AND CONSMain Menu

Positives:

More people could be fed – larger populations.

By not having to move (being sedentary, less nomadic) people could specialise in labour – developing trade.

Technology could develop, e.g. storage, housing, pottery.

More time to develop culture, art, language, education… finance, politics.

Negatives:

People more susceptible to communicable diseases.

Waste disposal.

Pests attracted to feed on stored food/waste.

Ownership disputes.

Many people dependent on harvest outcome.

Reliant on few crops – problems with storage and deficiency diseases.

Manual pg 366/7