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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