The Human Transition

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The Human Transition

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The Human Transition. 2 million years ago. Bipedal hominids with specialized teeth and expanded brains were walking around East Africa Some made artifacts out of wood, stone, bone, and they used fire Females played active roles - PowerPoint PPT Presentation

Transcript of The Human Transition

Page 1: The Human Transition

The Human Transition

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Homo Species

Early Homo brains range from 510 to 75ocm cubed

Cranium has thinner bone and is more rounded

Face is flatter Teeth and jaws are less rugged Includes: Homo erectus, Homo

habilis, Homo heidelbergensis, Homo ergaster, Homo floresiensis

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Homo erectus

Coexisted in eastern Africa with other primate species They were here 1.8 million years ago up until 500,000

years ago Brain capacity was around 1000cm cubed Started to migrate out of Africa (went towards Russia

and China) The oldest fossil is a skeleton of a boy that is 1.7

million years old He was tall and slim, and probably hairless so that he

could sweat lots and cool off in the heat It appears as though breathing was not as advanced,

suggesting that they may not have been able to talk the way we can

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The Culture of Homo erectus

Used fire and stone tools Hard to tell if they hunted large animals...bones have been found but its

very hard to say where they came from Skull damage may suggest cannibalism Endurance running became important.

Adaptations such as these became necessary: Energetics(the flow and transformation of energy) Stabilization (how the body keeps from falling) Temperature regulation (maintaining body temp)

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Importance of Fire The transition to Homo

erectus was driven by fire

Started cooking their food which changed everything!

New diet resulted in smaller guts, bigger brains, bigger bodies, reduced body hair, and smaller teeth (since cooked food is softer)

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Homo erectus to Homo sapiens 1 proposal: Replacement Theory: Although Homo

erectus were dispersed among Africa, Asia, and Europe, only one group (in Africa) evolved into Homo sapiens. This happened 100,000-200,000 years ago Homo sapiens then travelled the globe and replaced any

Homo erectus still living They then evolved into the different races we see globally

2nd proposal: Multiregional Continental Theory: Several different migrations out of Africa by populations that looked different occurred. These migrations took place during different times using different routes. They evolved into the human species today independently

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Neandertals Continued.... Used wooden spears Drove animals off cliffs Bones of elephants and

rhinos were used for buildings

Lots of bones with torn off flesh, cuts, bite marks...not sure why....

Had light skin and red hair (DNA shows)

Lived in Europe and Western Asia

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Modern Humans

Anatomically modern human fossils have been found in Africa and Asia that are around 70,000 years old

Modern skeletal remains were found in Ethiopia that dated 160,000 years ago!

DNA evidence shows that modern humans are around 100,000-200,000 years old

So they lived at the same time as Neandretals, but in different areas.

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So What Happened to the Neandertals? There was no conquest or extermination May have evolved into anatomically

modern people, adopting stone-age culture, but this is unlikely

May have retreated and died out as modern people spread through Europe

May have interbred with migrating modern people

No one really knows...they are still debating...

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Anatomically Modern Traits of Homo sapiens sapiens

Our teeth, brow ridges, and face are smaller, evidence of less chewing stress (probably because we have awesome tools now to help )

Our brain is large, although not as large as some of our ancestors

We have a distinct chin, again possibly related to less chewing stress

Our bones are longer and thinner Our body is lankier and less

robust (probably because we don’t work as hard)

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Behaviorally Modern Traits of Homo sapiens sapiens

Symbolism (using one object or sign to mean something else)

Oldest use of symbols in in South Africa’s 70,000 year old Blombos cave, where there are dozens of stone tablets that have clearly been scratched with X’s and O’s

In Israel’s Skhul Cave, ten humans were buried 100,000 years ago and were wearing snail shell necklaces!

Complex language (communicating by stringing together messages according to complex rules, syntax, and grammar)

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Origins of Language Most anthropologists study the “Social Grooming

Theory”, as it is most supported Most primates communicate and maintain

relationships by grooming each other (picking off insects and debris from each other)

Over time, this became more complex as social group sizes increased

Larger group size is correlated to having a bigger brain!

As group size became larger, language replaced physical grooming

Language conveys more information than grooming, and can address more than one person at a time

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Evolution of Consciousness

Consciousness-is the unique human capacity for self-contemplation. (Not only do we think, but we can think about what we think)

Mithen Model-evolution of consciousness came about as the mind forged new links between previous intelligences that were isolated. There are 4 intelligences that have come about in human evolution: 1. Social intelligence (complex interpersonal primate relationships) 2. Technical intelligence (ability to make and use tools) 3. Linguistic intelligence (manage complex communication) 4. Natural history intelligence (understand cause and effect relationships)

Donald Model-evolution of consciousness came in a series of drastic changes in the mind’s way of storing and representing experiences 1. Episodic consciousness (all primates had this before Homo) 2. Mimetic consciousness (miming and simple vocalizations of the first Homos) 3. Mythic consciousness (symbol use, myths, and narratives to organize complex

and diverse ideas in the mind) 4. Theoretic consciousness (invention of objective science, rather than believing

in the supernatural, about 2000 years ago in Greece)

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Origins of Myths Myths are a way of organizing the contents of

a human’s complex mind Most are verbal, however, cave art that is

30,000 years old shows the use of myths Cave art depicts at least 4 main concepts:

1. Shamanic voyages (healers travelling the world) 2. Hunting magic (showing large herds and

vulnerable animals) 3. Myths or parables (instructing people on how to

live the “proper” way 4. Rites of passage (rituals and ceremonies that

usher people into various stages of life)

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Late Stone Age Culture Used blades, spears, and

arrows Bows and arrows have been

found that are approximately 20,000 years old

Hunted animals for their skins, not just food

Ate plant foods in addition to some meat

Used Ostrich-eggshell beads, painted animals on rocks, and made clay sculptures

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The Spread of Homo sapiens Physically and

culturally modern human beings were the first to occupy the harsh climates of Asia

Siberian fossils are between 35,000 and 20,000 years old

Alaskan and Canadian fossils are between 15,000 and 12,000 years old

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Colonizing America

There is strong support that Native Americans are of Asian decent

This is done using blood group and tooth shape evidence

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Colonizing Austrailia First colonized Austrailia

60,000 to 40,000 years ago Australia was linked to New

Guinea Migrants still would have had

to cross 30-90km of open water

They may have been connected to the widespread extinction of grass eating marsupials in Austrailia 40,000- 15,000 years ago

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