Lecture 4 powerpoint
Agriculture • Humans shifted from huntergatherer 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 • 1. 2. 3. 4. 5. Farming changed human society forever To farm, you need fertile ground for long periods: this kept people in one spot One spotvillages Villagesstructure/rules Rulesto stable civilizations 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 Plants in the Solanaceae Food plants Psychoactive plants Ornamentals Eggplants--OW Mandrake--OW Petunias Potatoes--NW Belladonna--OW Peppers--NW Henbane--OW Tomatoes--NW Tobacco--NW 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 egglike fruit • Modern varieties have thicker, purple skin Peppers 3 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, airconditioning • 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 freezedrying; 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 Fragrance 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% Formulation Type 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 (Scrophulariace ae; 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 antitumor 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, midhigh 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 overstimulation occurs Peyote • Cactus (Cactaceae) • Used in Native Am. Ceremonies • Flower buds are most potent • Hallucinogenic • Induces nausea before ‘high’ • Compound is THC • Member of hemp family Cannabaceae • Long-term use produces brain shrinkage • Can be used to alleviate effects of chemotherapy or HIV Marijuana 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 0mg 50mg 100mg 150mg 200mg Green Tea Oolong Tea Black Tea Coffee 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 debitter 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 (50100%) • 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 nongrape 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) Textile Cotton World Production by Textile Nation 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 (Cannabac eae) • Stem tissues provide tough, durable fabric Rayon • Chemicallystraightened 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
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