Anthropology 2

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Three key developments of fossil primates

-The first primate
-Origins of higher primates (Anthropoids)
-Origins and evolution of the major anthropoid groups (monkeys, apes, humans)

Arboreal Hypothesis

Proposition that primates' unique suite of traits is an adaptation to living in trees
- Accounts for grasping and feet, binocular vision and greater intelligence

Visual Predation Hypothesis

Primate's unique traits arose as adaptations to preying on insects and small animals
- Explains the visual adaptations, intelligence and grasping, it does not address why primates eat fruit

Angiosperm Radiation Hypothesis

certain primate traits occurred in response to the availability of fruit and flowers following the spread of angiosperms.
-Original primate adaptation was about access to fruit, not insects

Plesiadapiforms

-65-55 mya
- probably not primates
- Lack postorbital bar and convergent eye orbits, opposable thumbs, and had highly specialiezed teeth

Characteristics of fossil primates

- opposable thumbs
- Nails instead of claws
- Stereoscopic vision/binocular vision
- reduced smell
- General dentition
- Big brain

Euprimates

-Appeared in Eocene (55 mya)
- most agreed upon for earliest primates
- have clear primate characteristc

Types of Euprimates

Adapids and Omomyids

Adapids

- Flat and vertical incisors
- Pronounced sexual dimorphism
- Short foot bones

Omomyids

- Large, projecting central lower incisors, small canines and variation of other teeth
- Short skull with narrow snout and large eye orbits

Basal Anthropoids

Eosimas and Biretia
Fossils contain characteristics expected in anthropoid ancestor

Eosimas

First true anthropoid - 42 mya - Calcaneus

Biretia

Beginning of higher primates - 37 mya - Bicuspid lower premolar

Ancestors of euprimates

Plesiadapiforms unlikely
Carpolestes simpsoni is a possiblity

First in genus "Homo"

Homo habilis, 2.5 - 1.8 MYA

H. habilis found in...

Tanzania, Ethiopia, Kenya, South Africa

4 Characteristics of H. habilis

1. Reduction in chewing complex
2. Larger brain (650 cc)
3. Still relatively short arms with shorter legs length
4. Relied on stone tools

After H. habilis came...

Homo erectus, 1.8 - 300,000 ybp

4 Characteristics of H. erectus

1. short arms and long legs
2. must taller - increase in body size
3. Increased brain size (900 cc)
4. Variation: Robust and gracile

Earliest fossil evidence of H. erectus in Asia

1.7 MYA

Asian Homo erectus characteristics (5)

1. Smaller face and jaw
2. less pronounced brow ridge
3. long legs and short arms
4. increasing brain size
5. decreasing teeth size

What's special about Homo erectus in China?

Zhoukoudian - excavations revealed the first controlled use of fire.

Cooking food makes it easier to chew leading to further reduced reliance on large teeth

Earliest fossils of H. erectus in Europe

80,000 ybp

Gran Dolina

Animal and hominid bones that had been cut and purposely broken

Atapuerca 3

Skull appears more modern than other members of Homo erectus

H. erectus characteristics

1. Increase in body size
2. Taller than H. habilis (males 33% and females 37% taller)
3. Due to access to meat (protein)
4. Acheulian tool complex (more advanced)

Taphonomy

The study of deposition of plant or animal remains and the environmental conditions affecting their preservation

Fossils

The remains of organisms that have been wholly/partially transformed into rock

Minerals in bones (calcium and phosphorus) are replaces the rock-forming minerals (iron and silica)

Geologic Timescale

3 Eras:

Paleozoic: 545-245 MYA
Mesozoic: 245-65 MYA
Conozoic: 65-0 MYA

Holocene: 10 KYA-Present

Pangaea

Teh original continent from which all continents derive: Platetectonics

Law of Superposition

Principle states that the lower stratum is older and the strata above are younger

Relative Dating

Determines only if something is older or younger than something else

Methods of Relative Dating

Chemical Dating
Fluorine Dating
Biostratographic (Faunal) Dating
Index Fossil
Cultural Dating

Chemical Dating

Methods that use predictable chemical changes that occur over time

Fluorine Dating

Bones that have been in the ground for long periods of time will have absorbed more fluorine than bones that have been in the ground a shorter period of time

Biostratographic Dating

Dating method that uses the association of fossils in specific stratigraphic layers to determine each layers approximate age

Index Fossil

Like finding audio cassette - pretty good idea what date range./time period it's from

Cultural Dating

Dating a site based on the association of material culture

Absolute Dating

Assign a numerical date (calendrical)

Dendrochronology; definition and limitations

Counting the number of tree rings in a wood sample

Limitations:
Only works with certain trees
Wood does not always preserve
Not every culture uses wood
Wood can be recycles/reused at a site

Radiocarbon Dating (Carbon 14) Definition and limitations

Measures the ratio of Carbon 12 to Carbon 14 present in a sample to provide an absolute date

Half-life of 5,730 Years

Limitationss:
Only works on organic material
Preservation
Only works on samples 500-50,000 years old

Radiopotassium Dating definition and limitations

AKA Potassium-Argon dating
Measures the ratio of Potassium 40 to Argon 40 to provide an absolute date
Half-life is 1.3 Billion Years

Limitations:
Only works on non-organic materials (rock)
Can only date deposits older than 200,000 years old

Dryopithecids

Early Anthropoid in Europe 13 MYA

Sharp, tusk=like canines
Teeth had simple chewing surfaces
larger brains
longer forelimbs
long, grasping hands and feet

Sivapithecids

Early Anthropoid in Asia - 12-8 8 MAY

Thick enameled teeth and robust jaw
Similar to living orangutans

First Primates - when and where did they appear and what were they?

Euprimates 55 MYA

Adapids and Omomyids

Western NA, Europe, Africa

Which species evolved into Old World Monkeys

Victoriapithecus

Hominid

Earliest Characteristics:
Bipedal locomotion
non-honing Chewing

Bipedal

1st defining characteristic of hominids.

5 Characteristics of bipedalism:
Foramen Magnum is directly beneath the skull
Pelvis is shorter front to back
Long legs in comparison to body size and arm length
Double arch in the foot
the big toe is not opposable

Non-honing Chewing

chewing in both hominids and non-human primates is aided by masticatory muscles

Doesn't sharpen the back of the canine toth

Darwin hypothesis for hominid origin

bipedalism freed hands for carrying weapons required to hunt and kill food

large brain was required for making tools
humans relied on tools and didn't need large canines

it is now known that tool use and the increase in brain size occurred well after the reduction of canines in hominids

Rodman and McHenry Hominid Hypothesis

bipedalism developed in response to fragmented forests

Lovejoy's hominid hypothesis

If mothers had increased access to food, they would be able to care for more than one infant at a time

Sexual dimorphism

Occurs in populations where there is competition for mates

little sexual dimorphism between male an female hominids indicates that little competition was taking place

emphasis was placed on cooperation, not competition

Pros and Cons of bipedalism

Pros:
More efficient to cover long distances
ease of transporting goods
freeing of hands
increased view of landscape

Cons:
Exposure to predators
Burden on circulatory system
leg/foot injuries drastically reduces survival chances
Reduced birth canal in pelvis - more iin Homo genus

Order of hominid species - oldest to youngest

Pre-Australopithecines
Australopithecines

Pre-Australopithecines - species and time periods

Sahelanthropus Tchadensis: 7-6 MYA - found in the Djurab desert in Chad, large brow-ridge, 350 cc brain size, bipedal, non-honing canine chewing complex
Orrorin Tugenensis: 6 MYA - fossils consisted of femurs that suggested bipedalism, hand phalanx had arboreal characteristics, non-honing canines
Ardipithecus Kadabba: 5.8-4.4 MYA
Ardipithecus Ramidus: 5.8-4.4 MYA - thin emamel, femur and pelvis indicate bipedalism, curved foot phalanges reflect some arboreal activity

Australopithecines

4-1 MYA
small brain
small canines
large premolars and molars

Australopithecines species, characteristics and date ranges

Australopithecus anamensis: 4 MYA - large canines, parallel teeth rows
Australopithecus afarensis: 3.6-3.0 MYA - best known, femur indicates bipedalism, face below the nose projects, larger canines than later hominids, curved phalanges suggest arboreal locomotion - "Lucy"
Australopithecus garhi: 2.5 MYA - small brain 450 cc, projecting face below nose, human-like ratio of arm length to leg length, ancestral to Homo genus, first stone tools 2-2.5 MYA.

Oldest stone tools?

Oldowan tool complex with Australopithecus garhi.

Java Man

First known fossils found of Homo erectus

Turkana Boy

Most complete skeleton of Homo erectus found.

Which hominid was the first to leave Africa?

Homo erectus - 1.8 MYA

What tool complex did Homo erectus use and what is the dominant tool?

Acheulian complex, hand axe

Modern Homo Sapien characteristics and Archaic Homo Sapien Characteristics.

Modern Homo sapiens:
High, vertical forehead
Round and tall skull
Small browridge (Neanderthals are exception)
Small Face
Small teeth
Projecting chin
Gracile/thin bones

Archaic Homo sapien Characteristics:
Longer, lower skull
Longer browridges
Bigger, more projecting face
Projecting occiptal bones
larger teeth
no chin
Robust//thick bones

Out of Africa Hypothesis

Homo sapiens first evolved in Africa, then spread out into Asia and Europe, replacing the archaic Homo sapiens populations

Multiregional continuity hypothesis

sates that the transition to modern H. sapiens took place regionally, without replacement of existing archaic H. sapiens

When did Archaic H. sapiens appear in Africa? Asia? Europe?

Africa: 350,00-200,000 ybp
Asia and Europe: 350,000-130,000 ybp

When did Modern H. sapiens appear in Africa? Asia? Europe? North America?

Africa: 160,000 ybp
Asia and Europe: 130,000 ybp
North America: 15,000 ybp

Neantertal Characteristics and dates

130,000 - 24,000 ybp
large nasal opening
projecting face
an occipital bun
long, low skull
large front teeth with heavy wear
Short an stocky arms and legs
Large brain, some larger than modern humans
large intraorbital foramen
Short, wide body truck
short limbs (bergmann-allen rules)

Tool complex of Neandertals

Mousterian tool technology: Lovallins flaking technique

Early modern H. sapiens appearance in Africa, Asia, Europe

Africa: 200K-26K YBP
Asia: 90-18K ybp
Europe: 35-6K ypb

What tools did earliest inhabitants of North America use?

fluted point technology

Domestication - Three characterists

Lesection of large seeds
Selection for softer shells or husks
Selection for tough rachus

Neolithic period

10,000 ybp - Plant domestication began.

Why did domestication occur?

More suitable climate
population pressure

Where did agriculture first appear?

Mesopotamia

China domesticated plants

rice, foxnut

Eastern North American domesticated plants

sunflower, goosefoot

Central Mexican domesticated plants

Bottle Gourd, corn

Andes/south American domesticated plants

Potatoes, sweet potatoes and manioc

Indian domesticated plant

millet

new Guinean domesticated plant

banana

Mesopotamian domesticated plants

wheat, einkorn, barley

Sub-Saharan African domesticated plants:

Yams, sorghum

Malocclusion

a misalignment of teeth and/or incorrect relation between the teeth of the two dental arches

Osteoarthritis

chronic breakdown of cartilage in the joints

Cribra Orbitalia

A symptom of iron deficiency anemia in which the bone of the upper eye sockets takes on a spongy appearance.

Enamel Hypoplasia

caused by any condition that inhibits enamel formation, may cause small pits or grooves at different levels in crown

5 Agricultural Trade-offs

1. Population Growth - leads to competition for resources and warfare.
2. Environmental Degradation - erosion, soil depletion
3. Infectious Disease - Periosteal reaction - stimulates new bone growth - syphillis
4. Dental Caries or Cavities increase dtramatically
5. Nutritional Stress - iron deficiency causing anemia

How did agriculture effect people's health?

Health worsened

Laetoli

Site where bipedal footprints were found in Africa.

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