agriculture humans shifted from hunter- gatherer to farmer about 12,000 yrs ago happened almost...

Agriculture• Humans shifted

from hunter-gatherer to farmer about 12,000 yrs ago

• Happened almost simultaneously around the world; three major centers were around the Middle East (‘fertile crescent’), Eastern China, and India

Impact of farming• Farming changed human society

forever

1. To farm, you need fertile ground for long periods: this kept people in one spot

2. One spotvillages

3. Villagesstructure/rules

4. Rulesto stable civilizations

5. Stable civilizationsadvancements

Domestication

•Stability allowed long-term domestication of plants & animals•Domestication occurred by selective breeding; all modern crops derived from wild relatives (same with cows, chickens, etc.)•Domestication not easy—but produces more in long run

Top Agricultural Crop Families

• Grass family (Poaceae)—rice, wheat, corn, etc.

• Tomato family (Solanaceae)—tomatos, potatoes, peppers, eggplants

• Bean family (Fabaceae)—soybeans, peas, beans

• Cabbage family (Brassicaceae)—cabbage, mustard, turnips, broccoli

• Melon family (Cucurbitaceae)—watermelon, honeydews, squash, zucchini

• Carrot family (Apiaceae)—carrots, celery, parsnips, cilantro

Poaceae—Grass family

• Named for genus Poa• Crops called cereal crops (Greek god of

agriculture was Ceres)• Monocots• Old family name: Graminae (=grains)• Of the total food produced by the World's

top 30 crops (based on dry matter), about 23.4% comes from wheat, followed by maize (21.5%) and rice (16.5%) (Harlan, 1995).

Poaceae• ~70% of farmland dedicated to this

group

• 9,000 species worldwide

• 35 species domesticated, 5 important today

• Only 1 from New World—which one?

Rice

Corn

Wheat

Sorghum, Millet

Sugar Cane

Oats, Rye

Grass vegetative structure

• Fibrous roots

• Leaves wrap around stem

• Produces clones (tillers) from runners (stolons) or from rhizomes

Grass reproductive structure• Highly modified

flower—no sepals, no petals

• Protective leaves (glumes) around flower stem base

• Closer to each flower, 2 more protective leaves: lemmas, paleas

• 1 carpel, 2 stigma lobes, 3 stamens

Grass seeds:• As seed matures, fuses completely to ovary wall=caryopsis (kernel)

• Ovary wall + seed coat = bran

• Interior to seed coat is oil-rich layer called aleurone layer

• Lots of endosperm• 1-cotyledon =

monocot

Grass domestication:

• Synchronicity

• Tiller elimination

• Height (reduced lodging & matting)

• Shattering reduction

• Easier threshing

Bean family (Fabaceae)

• 2nd to grasses in economic importance

• Major crops: soybeans, peanuts, beans, peas, alfalfa, clover, chickpeas, lentils

• Old family name = Leguminosae because fruit type is legume

• 1-carpel flowers with many seeds; dehiscent at maturity

Fabaceae• Rhizobium bacteria form symbiotic relationships with roots• Produce nodules

Cucurbitaceae: melon family

• Cucumbers, melons, squashes, zucchini, gourds, pumpkins, loofahs

• Fruit typepepo

• Some medicinal uses: Chinese abortions & compound tricosanthin slows HIV

Apiaceae: carrot family• Carrots,

parsnips, celery • Herbs: chervil,

angelica, dill, caraway, coriander, cumin, fennel, parsely, aniseed, cilantro, rhubarb

• Old name: Umbelliferae

Solanaceae:Family of Paradox

Eggplants--OW

Potatoes--NW

Peppers--NW

Tomatoes--NW

Food plants

Mandrake--OW

Belladonna--OW

Henbane--OW

Tobacco--NW

Psychoactive plants

Petunias

Ornamentals

Plants in the Solanaceae

Alkaloids of Solanaceae plants:

• Atropine from belladonna

Nicotine

• 2 species: Nicotiana rusticum & N. tabacum

Other common alkaloids:

• Scopolamine—used for motion sickness

• Mandragorine—1st date-rape drug

• Hyoscyamine—hallucinogenic

Eggplants

• Native to India• Domesticated

about 3,000 yrs ago

• Original plants produced egg-like fruit

• Modern varieties have thicker, purple skin

Peppers3 main species, each with many varieties:

Capsicum annuum

Capsicum frutescens

Capsicum chinense

The name “Capsicum” could arise from the Latin capsa (box) or the Greek kapto (to bite).

Why are peppers so hot?•produce the alkaloid capsaicin, chemically similar to vanillin in vanilla orchids

•capsaicin is the main ingredient in pepper sprays

•humans can detect capsaicin in 8 parts per billion!!

•all the capsaicin is located in the tissue that connects the pepper seed to the ovary wall of the flower:

*The hottest pepper recorded was a Habanero.

Pure Capsaicin measures 16,000,000 Scoville units.

Pepper Facts:

• first appear in cave deposits in Mexico about 7000 BC

• a second, independent origin in South America by 5000 BC

• first European encounter: Columbus in 1494

• spread from Europe to Hungary (paprika) & to India, where peppers became naturalized

• spread from Mexico to Louisiana & Texas in the 1850s after the Mexican-American war

Little known pepper anecdotes:

• Carib Indians’ usage: POW’s

• Aztec usage: punishment, air-conditioning

• Incan usage: gas warfare

• Paprika, Szent-Gyorgyi, and the Nobel Prize

Tomatos: wolf-peaches• Lycopersicon

esculentum=‘wolf-peach tasty’

• Domesticated in Central America

• Nahuatl tribes called them ‘tomatl’

• First record in Europe is 1544 in Italy

• Called ‘love apples’ to boost sales

• Not eaten for centuries in Europe because it looked like local toxic cousins

• Ketchup finally popularized in early 1900s, salsa in the 1980s

Potatoes• Domesticated in

mountains of Argentina• Good crop for area—cool,

moist, underground• Tuber=modified stem• Biennial crops• ‘eyes’ = axillary buds• Native name ‘batatas’• Natives first to discover

the process of freeze-drying; used potatoes

Potatoes & history

• Irish potato famine—1840s—killed 1-6 million people—caused by potato fungus Phytophthora

• Russians used potatoes as fermentation sourcevodka

Asteraceae: sunflower family• Composite/head

flowers• Old name

Compositae• Egyptians

domesticated by 5000BC!

• Columbus carried to New World

• Crops: lettuce, endive, chicory, artichoke, sunflower seeds/oil

Liliaceae: lily family

• Crops: onions, garlic, leeks, chives

• Domesticated by Egyptians 6000BC—garlic & onions used for mummification & perfumes

Cabbage family: Brassicaceae

• Crops: cabbage, broccoli, cauliflower, turnips, kale, collards, mustard, brussel sprouts, rutabagas

Spices

• Phoenicians (2000BC-1000BC) cornered market on spice trade from India to Spain

• Arabs took over spice trade to Europe 500AD-1000AD

• Spices more valued than gold, silver, diamonds

• Value of spices started European exploration ~1100AD

• European food rather tasteless, also meat rotted so spices covered up rotten part

Spices: Mint family• Spearmint,

sage, basil, rosemary, thyme, oregano, peppermint, marjoram

Spices: myrtle family (Myrtaceae)

• Cloves, allspice

Spices: Saffron (Iridaceae)• Saffron is world’s

most expensive spice

• Saffron=stigma lobes of purple crocus

• 1 oz costs $36

Spices: ginger family• Turmeric, cardamom, ginger

• Family Zingiberaceae (tropical)

Spices: Cinnamon• Family Lauraceae

• Cinnamon is bark of cinnamon tree

Spices: Licorice• Licorice comes from bean

family, Fabaceae

• So does tamarind

Perfumes• The basic ingredients are

odorants (=volatile oils) that can be extracted

• Extracted with organic solvents, alcohols, steam, pressing oils, or heating with alcohol

• Many compounds used in perfumes are synthesized

• Blending of fragrances is an art and producing a new scent can cost $2-$3 million, mostly for advertising

Formulation TypeFragrance or Essential Oil

Perfume Diluent

Perfume 20% to 30% 70% to 80%

Cologne 15% to 20% 80% to 85%

Eau de Cologne 12% to 17% 83% to 88%

Eau de Toilette 5% to 10% 90% to 95%

Aftershave 2% to 5% 95% to 98%

Vegetable Oils

• Canola AKA rapeseed (Brassicaceae)

• Corn (Poaceae)

• Peanut (Fabaceae)

• Olive (Oleaceae)

• Palm (Arecaceae)

• Coconut (Areaceae)

• Safflower (Asteraceae)

Medicinal Plants• Plant/plant compounds used to treat/cure

disease/illnesses• Long history of human-plant use for this• Usually accidental discovery of value• ¼ to ½ modern medicines derived from plants• Herbalists use strong plant solutions;

homeopaths use very dilute solutions• Most rainforest species will disappear before

we can determine their medicinal value

Yams: Dioscorea• Family

Dioscoreaceae

• Produce diosgenin, precursor compound for birth control pills

Foxgloves• =Digitalis

(Scrophulariaceae; snapdragon family)

• Compound named digitalis

• Stabilizes arrythmia

• 1st use in 1790s

Poppies: Papaveraceae• Carpel produces latex

(milky juice) that contains opioids

• Domesticated by Sumerians 3500BC

• China-Great Britain fought several wars over mandated poppy production

Cinchona tree• Produces quinine,

an anti-malarial compound

• Native to South America

• Member of Rubiaceae, the coffee family

Willows• Salicaceae

• Bark/leaves contain salicylic acid, which, in mammals, converts to acetylsalicylic acid or aspirin

• Bayer patented aspirin in 1899

Periwinkles

• Produce anti-tumor compounds vinblastine, vincristine

• Apocynaceae (dogbane family)

Psychoactive plants

• Plant with compounds that affect mainly the central nervous system

• Usually causes hallucinations, delusions, visions, etc.

• Can be fatal

Coca• Cocacocaine, an

alkaloid• Bushes; tropical, mid-

high altitude• Member of

Erythroxylaceae• Natives chew leaves

to prevent altitude sickness

• Present in early versions of Coca-cola

• Stimulant effect

How cocaine works:

• Normally: norepinephrine (neurotransmitter) is released from axon of one neuron & stimulates a nearby neuron

• Cocaine prevents the reuptake (recycling) of norepinephrine, so over-stimulation occurs

Peyote• Cactus

(Cactaceae)

• Used in Native Am. Ceremonies

• Flower buds are most potent

• Hallucinogenic

• Induces nausea before ‘high’

Marijuana• Compound is

THC• Member of

hemp family Cannabaceae

• Long-term use produces brain shrinkage

• Can be used to alleviate effects of chemotherapy or HIV

Opium/Heroin• Heroinbrain

opiate receptors dopamine release=pleasure

• 4-5 hour ‘high’

• Pain is blocked

• Body adapts, requires more & more

Nicotine

• Tobacco in Solanaceae

• Nicotine=alkaloid

• Also a dopamine releaser

• Also addictive

LSD• Lysergic acid

• 2 natural sources: several morning glory species & a fungus (ergot)

• Morning-glories: ¼ seed can be fatal

• Ergot: Salem witch trials?

Stimulating Beverages

• Usually served hot

• Usually have caffeine or other stimulant

• Several major: coffee, chocolate, tea, kola for example

Green Tea

Oolong Tea

Black Tea

Coffee

0mg 50mg 100mg 150mg 200mg

Amounts of caffeine per 5 ounces of beverage.

Tea• Camellia sinensis

(camellia from China)• Theaceae• Shrubby; after Opium

Wars, Brits took tea to India (now #1 grower)

• 2 types: green & black; difference in how leaves are harvested

• Green tea: leaves picked, shredded, allowed to dry

• Black tea: leaves picked, sometimes shredded, wetted to allow fermentation, then dried

Chocolate• Theobroma cacao

(Sterculiaceae)• =cocoa (not coca!)• Central American tree• Theobroma=food of the

gods• Flowers arise from outer

cortex cells, not from axillary buds

• Chocolate compounds come from fermentation of seed sheaths

Chocolate• Stimulant in chocolate

is theobromine, chemically almost identical to caffeine

• Very bitter alkaloid• Fermentation changes

to usable produce• Labor-intensive

industry• White chocolate has

no chocolate in it

Coffee• Native to

Ethiopia (Africa)• Exported by

Arabs to rest of world for 1000 years

• Dipped seeds in boiling water to prevent others from growing

Coffee• Genus Coffea in

family Rubiaceae• 3 species used:

– C. arabica ~90% of world’s coffee

– C. canephora ~9%– C. liberica ~1%

• Coffee ‘bean’ not a true bean but 2 seeds per fruit

Coffee’s history

• 1720s: coffee seeds/plants stolen from Paris botanical garden & transported to Caribbean

• From several trees to thousands in a few decades

• Then transported to Brazil, Colombia, Venezuela

• Brazil now #1 grower• Coffee more valuable than oil

Coffee processing• ‘beans’ picked green• Transported to

coasts; roasted on site

• Bagged and shipped to grocery stores

• Decaf coffee made by steaming or organic solvents

• Instant coffee

Alcoholic Beverages

• Alcohol=ethanol (not methanol; methanol is poisonous)

• 2 types: fermented & distilled• Alcohol derived from Arabic al kuhul

because they invented distillation process• Proof = double the % of ethanol:

– 100 proof = 50% ethanol– 190 proof = 95% ethanol

Fermented vs. Distilled• Fermented: beers,

wines• Distilled: uses

fermented solutions & steam to concentrate % ethanol

• Fermented uses fungus Saccharomyces to turn glucose into ethanol as a byproduct

• ~50% of sugars get made into ethanol

Fermented: Beer

• Beers start as fermented grains

• Usually barley, rye, or wheat (sometimes corn)

• Malting=sprouting grain used

• Hops (marijuana family) used to de-bitter beer

• Beers (by law) usually 3.5%-8%

Fermented: Wine

• Wines start as fruits (grapes usually), not seeds

• Grape wine usually red or white; white wine has skins removed; red keeps skins

• Usually 4-8% ethanol

Other fermented:

• Sake—rice beer, not wine

• Pulque—agave-based (yucca relative)

• Chicha—corn-based

Distillation Process• Ethanol boils at

83C, water at 100C

• As ethanol evaporates, leaves water behind

• Fumes are concentrated

Distilled: Whiskeys• 3 types: scotch,

bourbon, rye

• Scotch: malted barley

• Bourbon: malted corn (only American whiskey)

• Rye: malted rye

Distilled: Vodka• Potatoes used as starch

source

• Usually 100-200 proof (50-100%)

• Can almost run car on high proof vodka

• Tasteless, odorless

Distilled: Rum

• Uses sugar cane sap as sugar source

Distilled: Gin

• Flavored with juniper cones (‘berries’)

• Gin & tonic favorite drink of British because in India, gin covered the bitter taste of quinine (anti-malarial drug)

Distilled: Tequila

• Made from sap of yucca-relative

Brandy/Liqueurs

•A fortified wine

•Wine+ethanol

•Usually based on non-grape wine; ex. Blackberry, elderberry

Textiles

• Early cultures used animal skins• About 15,000 yrs ago (maybe as much

as 40,000) we see woven clothes• Cloth ‘fiber’=cellulose, not a botanical

fiber• Commonly derived from seed hairs

(cotton), stems (linens), or lignified leaf fibers (“hard” ex. Agave)

World Production by TextileTextile NationCotton China, US

Flax (linens) China, France

Hemp China, Romania (outlawed by the U.S.)

Jute India

Sisal Brazil

Cotton• Gossypium sp. in family

Malvaceae• Cotton ‘fibers’ derived from

single epidermal cells of seed coat

• History: as British withdrew after Rev. War, took sugar supplies; U.S. needed fast economic boost

• 1790s—Eli Whitney invents cotton gin—begins period of massive slavery

• 1791—400 bales produced; 1800-30,000 bales produced

Whitney’s cotton gin

Modern Cotton Gin

Flax• Linum sp. in

Linaceae

• Stem tissues provide strong fabric=linen

• Superior to cotton, but more expensive to make

Hemp

• Marijuana family (Cannabaceae)

• Stem tissues provide tough, durable fabric

Rayon• Chemically-

straightened cotton ‘fibers’

• Doesn’t wrinkle as easily

• Invented as a cheap alternative to silk

Dyes• Probably used

originally to dye skin

• Common dyes:– Henna (brown)– Indigo (blue)—color of

royalty before purple was discovered

– Saffron (yellow)– Nettles (green)

Genetically Modified Crops• Non-plant genes

incorporated • Ex. Golden rice—

has extra copies of Vitamin A genes

• Ex. Bt corn (Morningstar Corn)-contain natural insecticide genes from Bacillus thuringiensis

The downside:

• Unknown and unpredictable effects

• Ex. Bt corn genes have now shown up in the ancient varieties still grown in northern Mexico

• Ex. Monarchs may be damaged by contact with pollen containing Bt genes