3A
BIO
HUMAN EVOLUTION
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Important Bipedal finds
Hominin Evolution
Human Origin
Out of Africa Theory
Multiregional Theory
H. floresiensis
Cultural Evolution
The Catalyst for Culture
Cultural Periods
Lower Paleolithic
Fire
Middle Paleolithic
Art and Spirituality
Upper Paleolithic
Neolithic
Agriculture
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IMPORTANT BIPEDAL FINDS
Important “first” bipedal species finds include:
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)
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HOMININ EVOLUTION
About 7-8 m.y.a. the Hominid ancestor emerged.
This eventually branched off into Gorillas, chimps, and us.
The first solely human (hominin) ancestor may have been
Ardipithecus ramidus ~5 m.y.a., or perhaps the newly found Orrorin
tugenensis, around 6 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.
HUMAN ORIGIN
5 m.y.a.
4
3
Ardipithecus ramedus
Australopithecus anamensis
gracile
Australopithecines
A. afarensis
A. africanus
2
Paranthropus
robustus P. Boisei
1
0.5
Present
The megadonts –
vegetarians. a.k.a.
robust A.s
This represents
one possible
interpretation
of the fossil
data:
Homo
rudolfensis
H. ergaster
H. habilis
H. erectus
H. heidelbergensis
H. florensiensis H. sapiens H. neanderthalensis
Manual pg 355-58
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HUMAN ORIGIN
There are two main theories for where H. sapiens originated.
Out of Africa (replacement) Theory:
H. erectus
H. ergaster/ H. erectus migrated and
colonised many areas.
Arguments for:
Only the African type evolved into
humans, and then spread through the H. erectus H. erectus H. erectus
world replacing the others as they went.
mtDNA analysis supports the common
ancestor of all humans 170,000 y.a. in
Africa.
Extinct
H. sapiens
Extinct
All humans are genetically too similar to H. sapiens H. sapiens H. sapiens
have evolved parallel, without large
Europe Africa
Asia
gene flow between continents (unlikely).
There is little continuity of fossils outside
Africa to link H. erectus to H. sapiens.
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Multiregional:
HUMAN ORIGIN
H. erectus
H. ergaster/erectus migrated and
colonised many areas.
There was some interbreeding, but the
populations are isolated, and evolve in H. erectus H. erectus H. erectus
parallel.
Arguments for:
This results in distinct regional
differences.
H. sapiens H. sapiens H. sapiens
There is evidence of H. ergaster in
Europe
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
Asia
Some
interbreeding
Manual pg 370/1
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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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CULTURE
Culture is non-genetic adaptation, passed on within, and
between, populations. This can include:
Tools
Clothing
Shelter
Fire
Division of labour
Settlements
Agriculture and domestication
Manual pg 377/8
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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 – “the great leap forward”.
Biological evolution
Cultural evolution
Parents to offspring
Anyone to anyone else
Received at fertilization, then
doesn’t change
Constantly is developed through
lifetime
Changes are random, trial and
error – 1 trial per generation
Purposeful, cumulative, future
focused
Our cultural evolution has, in a short time, overrun the biological
evolution of our prey, predators, competitors, and most of our
parasites.
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THE CATALYST FOR CULTURE
Brain size increases to the point cultural evolution is possible.
Longer period
of learning
Better tool
making/cultural
advances
Improved food
supply
Longer period of
parental care
More post natal
brain growth
Birth at earlier stage
of development
Brain size stops increasing (stabilising selection).
The latest phase of human evolution has been entirely cultural, and
is happening at an exponential rate.
Manual pg 382
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TOOL CULTURES
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”) – the making and use of stone tools
Neolithic (“new stone age”) – agriculture, settlement, pottery
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LOWER PALAEOLITHIC
There may well have been earlier tool use – wood
and bone – but these have not survived.
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.
Acheulian tools:
These include many types of hand
axe made from a core stone. Used by
H. ergaster, H. erectus and H.
heidelbergensis.
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FIRE
H. ergaster 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.
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MIDDLE PALAEOLITHIC
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.
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H. neanderthalensis was the first hominid to arty stuff.
ART AND SPIRITUALITY
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?
Implies strong social structure and
would build group cohesion.
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.
Manual pg 383/4
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UPPER PALAEOLITHIC
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 379-81
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This is marked by the domestication of plants and animals.
NEOLITHIC
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 may 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.
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AGRICULTURE PROS AND CONS
Positives:
Negatives:
More people could be fed –
larger populations.
People more exposed to
communicable diseases.
By not having to move (being
sedentary, less nomadic)
people could specialise in
labour – developing trade.
Waste disposal.
Technology could develop, e.g.
storage, housing, pottery.
More time to develop culture,
art, language, education…
finance, politics.
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.