How and Why Did We Become Agricultural? - PowerPoint Presentation

Slide1

How and Why Did We Become Agricultural?

Chapter 9

The Food Producing RevolutionSlide2

Era

Period

Epoch

Million

Yrs Ago

Age

Evolutionary

Milestones

Cenozoic

Quaternary

Holocene

.01

Iron

Bronze

Copper

Neolithic

Food Producing

Revolution

Mesolithic

Pleistocene

40,000-10,000

Paleolithic

Upper

Art

& symbolic expression; behaviorally modern Homo sapiens

200,000

-45,000

Middle

Blombos

carved

ochre (77,000 yrs ago)

Anatomically

Modern Homo sapiens (200,000 yrs ago)

2.5 mya-200,000

Lower

Premoderns

Homo

erectus

Homo habilis

Tertiary

Pliocene

5

million

Ardi

(4.4

mya

) Lucy (3.18

mya

)

Miocene

23 million

1

st

Apes; climate change at end; many forests become savannasSlide3

Food Producing Revolution

Neolithic Revolution

Agricultural Revolution

All 3 refer to the same process

Feder’s

Fabulous Phrasing: “The key point to remember is that this period marks a fundamental transformation of humanity as people became the managers, transformers and masters of their food resources.” (p. 347)Slide4

http://huberb.people.cofc.edu/Classroom%20Visuals/101%20Visuals/Chapter%205%20Neolithic%20Images/Map%20Early%20Domesticated%20Plants.jpgSlide5

Humans foraging

Often nomadic

Sedentism begins to take foothold if rich food resource is available

All food resources (plant and animal) are WILD

Human ability to control plants and animals is only 12,o00 years old

Before Neolithic….Slide6

Food producing revolution takes a long time

Ex. At site in Israel, people relying on wild grasses at 20,000 years ago in Upper Paleolithic

Agriculture won’t be fully developed here until 10,000 years ago

Process takes 4,000 years in N.A. and 5,000-6,000 years in Mexico

Humans Taking the Place of Nature: Artificial SelectionSlide7

From Foraging to Farming

Wild Plants and Animals

Human Intervention via Artificial Selection

Domesticated Plants and AnimalsSlide8

What we select for and what is best for plant/animal survival are not the same things.

Domestication and cultivation mean that we alter animals and plants to exhibit qualities and characteristics that work for us.

As a result, domesticated animals and cultivated plants are often not able to survive in wild…a new species has been created.

Artificial Selection Changes SpeciesSlide9

Our ancestors had been happily foraging for 6 million years

Then, between 11,000 and 2,000 years ago, agriculture developed independently among most of the world’s people.

This shift happened in just 9,000 years with different plants and animals in very different environments and was ushered in by different people.

Why did almost everyone reach this same conclusion that agriculture was the wave of the future?

Why Agriculture???Slide10

Environmental Change

Cultural Evolution

Population Growth

An Accident

A Multitude of Reasons

As always, many hypotheses…Slide11

Late Pleistocene extinction forces humans to seek new food sources

In Near East desert regions, people, plants and animals would cluster near water resource

Humans study plants and animals and figure out how to better control these precious food resources

#1 Environmental ChangeSlide12

“readiness hypothesis”

Agriculture inevitable as people become more familiar with plants—a natural progression of control over wild plants

#2 Cultural EvolutionSlide13

Mark Cohen: Food Crisis in Prehistory

Humans wouldn’t have made switch from foraging to agriculture unless they had to.

Foraging is more efficient and leaves more leisure time

Agriculture more work, but feeds more people

Prehistory population growth must have demanded switch to agriculture

#3 Population GrowthSlide14

Humans begin returning seasonally to same places or settle permanently in an area

In those areas, they continually make little changes to improve / encourage plant growth—nothing conscious

Pull useless plants

Move plants nearer their living areas

Concentrate garbage in certain areas

Plants slowly respond to these improved living conditions

Co-evolution: Plants respond to human intervention and humans continue to intervene and exploit the improved resources

#4 An AccidentSlide15

Probably no single reason that people around the world adopted agriculture between 11,000 and 2,000 years ago

Evolved for different reasons in different regions

Do see a pattern however…

Sedentism precedes (comes before) agriculture

#5 A Multitude of ReasonsSlide16

Pathway to Social Complexity

Plentiful Food Source

Agriculture

Population Growth

Sedentism

Social DifferentiationSlide17

Geography

Animals and plants in non-native areas

Size

Larger seeds

Smaller animals

Seed Morphology

Thin seed coats

Non-brittle seed attachments

Osteological Changes

Less dense bones

Population Characteristics

Humans select animals based on age and gender for different purposes

We know humans are domesticating plants and animals when we see evidence in ….Slide18

When we see evidence of plants or animals in non-native areas, we assume human control is at play

In first steps toward domestication, humans would encourage wild plants to grown in new areas

We saw this in Australia with wild yams

In some cases, moving plants might require humans to take extra steps to ensure wild plants survival in new environment like watering it

Tending to wild plants was probably the first step toward domestication

Plants / Animals in non-natural habitat = evidence of domestication

GeographySlide19

What’s best in nature ≠ what’s best for humans

In nature lots of little seeds are better

More seeds scattered means more likely to survive winter and sprout in spring

Nature also prefers seeds with different ripening times

Humans prefer larger seeds that will produce more food per seed

They aren’t leaving planting and gathering to chance

They’ll plant seed when it’s able to survive and tend seedling through to harvest

So humans will select plants in a species that have bigger seeds that ripen at same time

Larger seeds = evidence of domestication

Size in Plant SeedsSlide20

In nature larger animals of a species are more likely to survive than smaller animals of same species

Aggressiveness also advantage

Humans prefer smaller, less aggressive animals

When we find evidence of smaller animals of a species than we typically see in wild, we assume human intervention is at work.

Ex. Domesticated dogs smaller than wild wolves

In animals, smaller size = evidence of domestication

Size of AnimalsSlide21

Characteristics other than size point to plant domestication

In Nature, thick seed coats delay germination so late frosts won’t kill plants

Humans prefer early germination.

They don’t plant until weather is right. When plants sprout, early germinating plants with thinner seed coats have a head start in growing. They will be kept.

Later germinating, thick seed coated plants will be smaller because sprouted later and they will be thrown away.

Thin seed coats = evidence of domestication

Seed MorphologySlide22

Nature also prefer thick seed coats if animals help propagate

Animals eat seeds, pass through digestive tract and “excreted” –later seed will germinate in this new area

Thick seed coat helps seed survive trip through digestive tract

But thick seed coats mean humans can’t digest it unless they process first

Thinner seed coated seeds require less effort to make them digestible.

Thin seed coats = evidence of domestication

Other Thick Seed Coat DisadvantagesSlide23

In nature, Seeds firmly attach to plant until just the right time

Then attachment becomes brittle, so seed will break off easily with stiff wind and blow away to propagate for next year

Humans won’t want brittle seed attachment. When they harvest plant, they don’t want seeds to fall off. They also want to harvest seeds

Select for plants that have a non-brittle seed attachment

Non-brittle seed attachment = evidence of domestication

Morphology cont.

Non Brittle AttachmentsSlide24

Wild animals need strong, dense bones to survive

Roaming large areas

Surviving physically challenging environment

Domesticated animals live in pens and cared for by humans

Bones of domesticated species become less dense than wild counterparts

Less dense, weaker bones in animals = evidence of domestication

Osteological ChangesSlide25

When hunting, kill whatever animal is available—record shows variety of ages and sexes for animals remains

When animals domesticated, humans control population characteristics…

keep females (less aggressive) for breeding, wool, milk

Keep a couple of males for breeding

Kill and eat younger males

If bones mostly young males, assume killed from a domesticated herd rather than hunted down from wild herd

Age/Sex animal population control = evidence of domestication

Population CharacteristicsSlide26

The Near East

Mesoamerica

Africa

East Asia

Europe

North America

South America

The Road to Domestication:

Region by Region

http://huberb.people.cofc.edu/Classroom%20Visuals/101%20Visuals/Chapter%205%20Neolithic%20Images/Map%20Early%20Areas%20of%20Domestication%201103.jpgSlide27

Rich fertile lands in what is now part of Israel, Jordan, Lebanon, Syria, Turkey, Iraq and Iran

Wild cereal grasses like wheat and barley are plentiful food source in Late Pleistocene

Evidence of ground wild barley as early as 20,000 years in Israel (recovered grains from grinding stone surface)

Stone tools for grinding seeds evident at 45,000 years ago and plentiful by 20,000 years ago

14,500-11,000 years ago: climate change

More rain

Many cultures: Geometric

Kebaran

,

Mushabian

,

Zarzian

and Karim

ShahirianUpper Paleolithic/Late Pleistocene: The Near East—the Fertile CrescentSlide28

Mushabian

Simple foragers

; eat what find; not exploiting particular resource

Small sites, very mobile population

Also hunting

Kebaran

Sites larger and more complex; but no permanent houses

Spring and summer: taking advantage of wild cereals (barley and wheat) and nuts

Near East Late Pleistocene CulturesSlide29

Exploit a few rich food resources

Focusing efforts on collecting and storing a few foods leads to

sedentism

and requires

sedentism

Able to settle b/c able to feed people in that one location

Must be settled in order to tend and harvest wild plants

Know they are settled b/c see stone foundations at sites 6-30 feet in diameter

Evidence that they move plants from native site to new location (geographic range = evidence of domestication)

Necklaces of bone, teeth and shell beads in graves

Small statues of animals and people also found

Mesolithic in Near East– the

Natufian

13,000-9,800 years ago – Complex ForagingSlide30

Website for this image

huberb.people.cofc.eduSlide31

Temps drop and rain decreases between 11,000-10,000 years ago

Wild cereals not growing as well

Problem:

Natufian

population larger, sedentary and very dependent on wild grasses to feed people

Artificial selection enters picture

Natufian

must intervene and make sure cereals continue to grow when and where they want them to grow

Select and tend those wild plants that exhibit features they need: larger seeds, early germination

Neolithic in the Near East:

11,000 years ago—Climate Changes AgainSlide32

The Pathway to Domestication

What

From complex foragers

of wild cereals to early cultivators of domesticated barley, wheat, lentils and peas

When

11,000 years ago

Where

The Near East

(Israel, Jordan, Iran, Iraq)

Who

The

Natufian

What

From hunters of wild animals to keepers of sheep and goats (but killed animals all young adults, not much age variance

Why

Climate change; wild plants struggle;

Natufian

need them so intervene Slide33

Maize, beans and squash = 3 early and most important plants domesticated here

Squash = 1

st

domesticated plant

In Oaxaca, Mexico, squash seeds, rinds and stems found

– seeds larger, rinds thicker, and stems larger –all imply domestication

These changes in seeds, rinds, stems = product of seedbed selection—humans pick plants that suit their needs

Some changes result of unintentional artificial selection

Mesoamerica – 10,000-8,000 years agoSlide34

Squash first, but known for Maize

Teosinte

= wild maize

1

st

steps to domestication date to 7,000 years ago in Mexico

Teosinte

evidence found in Tabasco, but not native there—sign of domestication (geographic move—extend territory of a wild plant)

Mesoamerica and MaizeSlide35

Sunflowers domesticated 4,500 years ago in Mexico

A Side NoteSlide36

Tehuacan

Valley is the

Natufian

equivalent in Mesoamerica

Cultures become sedentary and begin long process of domestication by first tending wild plants

Process takes a long time

Cultures of the

Tehuacan

Valley –

Birthplace of Domesticated MaizeSlide37

Ajuereado

Phase 12,000-9,000 years ago

Impermanent settlements, small groups, hunting, wild plants

El

Riego

Phase 9,000-7,000 years ago

Late Pleistocene—climate drier,

Hunt less, gather wild plants more

Seasonal migrating, connecting with larger groups

Coxcatlan

Phase 7,000-5,400 years ago

Seasonal settlements continue

Abejas Phase 5,400-4,300 years ago

More sedentary; semi-permanent villages/homes1st domesticated plants in diet (squash and maize)Purron Phase 4,300-3,500 years agoPottery appears –very little other information known

Ajalpan Phase 3,500-2,850 years agoWild and domesticated foodsIrrigation canals sign of agriculture and sedentism

Tehuacan Valley CulturesSlide38

Earliest

Tehuacan

maize we find is already much different from

teosinte

We are missing a step in the archaeological record for the domestication of maize

Tehuacan

Maize Not First MaizeSlide39

Almost all the plant and animals foods we eat today were domesticated during Ancient times

Rice, wheat, potato, corn, beef, chicken, pork, turkey

Chocolate as far back as A.D. 460-480

Only

2 exceptions

Strawberries domesticated in the Middle Ages

Pecans domesticated in 1846

The Remarkable Modern Cuisine of the Ancient WorldSlide40

Issues and Debates:

How Was Domestication Accomplished?

The

Domestication of Wheat

The

rachis

of wild wheat—the area of attachment of the individual kernels of wheat—becomes quite brittle when the wheat ripens.

From

Teosinte

to Maize

Maize-like

teosinte

mutants are produced in wild populations.

But genetic evidence suggests that current diversity of maizes

originated form a single domestication “event” (perhaps as early as 9,000 years ago)Beans

People selected mutant beans with straight, limp, nonshattering pods for easier harvesting, and for more permeable varieties (Kaplan 1981).

This slide from Text PowerPointSlide41

Cereals can be a problem; don’t have all 8 necessary amino acids that all humans need

Neolithic peoples around the world compensate for these deficiencies by domesticating and adding other things to diet

lentils, beans, peas

Trivia: The protein value of every food item is calculated using which “perfect” protein source as the benchmark?

Neolithic Diet

= Fairly CompleteSlide42

Issues and

Debates:

Was Agriculture the “Worst Mistake”?

Hunter-gatherer

groups

healthier , better nutrition

and longer

life spans

than farmers.

Sedentary

communities

higher populations, close quarters—disease spreads more easily

But Natufians (food collectors) died average 1 year earlier than Food producing neighbors.

Interestingly, women’s life expectancy did not increaseLonger fertility; closer births—take toll on women Feder says institutional violence and warfare began with onset of agriculture

More people to feed; people get cranky when food runs low; easiest option = invade another territoryThis slide from Text PowerPointSlide43

Small

nomadic groups likely were largely

egalitarian

Organized based on sex and gender

Family units

Feder

stresses egalitarianism of nomadic groups – is he oversimplifying????

Rich wild food resources and

sedentism

= increase in

popultion

Lower infant mortality

More births (cereals = higher body fat = higher fertility) + cereals digestible for babies so nursing shorter times so space between babies shrinksOlder people live longer

Issues and Debates: The Roots of Social Complexity

This slide from Text PowerPointSlide44

Human population growth = “a runaway train” very hard to control

Carrying

capacity

: the maximum population an area can sustain within the context of a given subsistence system.

When hit carrying capacity, must find solution

More intensive agriculture – build canals, irrigation, farm more land

Need to organize labor leads to social complexity – someone directs and organizes the other

someones

who work

Invade another territory to acquire more land

Need to organize a fighting force leads to social

compexity

– someone orders the other

someones

to attackRoots of Social Complexity cont…Slide45

Summary

By 20,000

B.P.

, some groups had incorporated wild cereals into their diet.

Then, beginning some time after 12,000

B.P.

, villages began turning up in the archaeological record with a subsistence base that included a variety of early domesticates.

The Neolithic was not a period during which all people marched down the path to a purely agricultural mode of subsistence.

Domestication complemented foraging but did not replace it.

Only much later did agriculture and animal husbandry become the primary sources of food for most of the world’s people.

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