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ANNOUNCEMENTS Open lab tomorrow (11-1) and Thursday (11-12) Final exam is Monday May 9 @ 10:10 – 12:00 Inaugural Speaker: Eugenie Scott, NCSE 4 :00 in NULH “ Evolution and Creationism”. Allison Kupar. Plant Domestication. Humans on earth for ~2 million years
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ANNOUNCEMENTS Open lab tomorrow (11-1) and Thursday (11-12) Final exam is Monday May 9 @ 10:10 – 12:00 Inaugural Speaker: Eugenie Scott, NCSE 4:00 in NULH “Evolution and Creationism” Allison Kupar
Plant Domestication Humans on earth for ~2 million years - hunted and gathered plant and animal foods Earliest domestications ~8000 - 12,000 years ago - in areas of abundant wild food resources How and why did agriculture happen then?
Plant Domestication Proposed explanations for the timing of agriculture 1. accidental people saw seeds germinating in trash-heaps, caught on 2. cultural inevitableby-product of more settled way of life 3. ecological new conditions (ex. drought) made agriculture necessary
Plant Domestication • How does domestication happen? • Cultivation/management of wild populations • “Unconscious” selection through propagation • Conscious propagation of plants with desired traits • Now, hybridization, polyploidization, transgenics...
Plant Domestication • How does domestication happen? • Cultivation/management of wild populations • “Unconscious” selection through propagation • Conscious propagation of plants with desired traits • Now, hybridization, polyploidization, transgenics... Alternative perspective: the plants are using us!
Wild Rice - managed but not propagated
Maize - modifed by selection for “domestication” traits
Changes at just a few major genes cause most of the differences between maize and teosinte
Maize - further selection for increased yield etc. Teosinte Change in kernel number & size over 1500 years
Later in domestication: hybridization to introduce novel variation Example: wheat
What changes during domestication? Traits directly related to human consumption - seeds: oil content, protein content, size, number - fruits: sugar content, oil content, size - leaves: tenderness, flavor - shoots: tenderness, flavor
Traits changed by artificial selection Brassica oleracea
What changes during domestication? • Traits related to agricultural yield selection for: • annual habit (crop every year) • lack of seed dormancy • self-compatibility (assured seed production) • sturdiness to withstand cultivation/harvesting • drought tolerance • storage • uniformity
Transgenics: a brief history 1952-1970: Structure, replication mechanism, and protein-defining code of DNA were solved. 1972 - 1st recombinant DNA molecules made 1973 - Amplification of recombinant DNA in E. coli 1975 - Asilomar Conference set standards for regulation of recombinant DNA technology 1985 - PCR technology published 1989 - Human Genome Project begun 1993 - FlavrSavr tomatoes (1st GMO food) in stores
What is recombinant DNA technology? • once a major concern, now routine • essential to modern biology • medically useful - e.g. insulin
What are some common GM crops? Round-Up (herbicide) tolerant soybeans etc.
What are some common GM crops? Bt (Bacillus thuringensis) corn, cotton etc. not-Bt Bt (corn-borer resistant)
What are concerns with GM crops? • Evolution of resistance (Bt corn) • Introgression into wild relatives (corn, canola) • Direct impacts on non-GM relatives (salmon) • Introgression into non-GM crops (corn) • Human health impacts? • General extension of agribusiness hegemony • Loss of locally-adapted/diverse crop races • Loss of sustainable farming practices
South America • potato (Solanaceae) • tomato (Solanaceae) • tomatillo (Solananceae) • pepper (Solanaceae) • pumpkin (Cucurbitaceae) • cassava (Euphorbiaceae!) • chocolate (Sterculiaceae) Theobroma cacao w/ fruits
Central/North America • beans (Fabaceae) • peanut (Fabaceae) • chayote (Cucurbitaceae) • hot peppers (Solanaceae) • maize/corn (Poaceae) • wild rice (Poaceae) • sweet potato (Convolvulaceae) • avocado (Lauraceae) Ipomaea flowers and sweet potatoes
Malaysia • mungbeans (Fabaceae) • blackeyed peas (Fabaceae) • eggplant (Solanaceae) • taro (Araceae) • yam (Dioscoriaceae) Dioscorea flowers and yams
Mediterranean • peas (Fabaceae) • beets (Chenopodicaceae) • cabbage (Brassicaceae) • turnip (Brassicaceae) • lettuce (Asteraceae) • artichoke (Asteraceae) • celery (Apiaceae) • parsnip (Apiaceae) • asparagus (Liliaceae)
Central Asia (North India, Afghanistan) • peas (Fabaceae) • mungbeans (Fabaceae) • mustard (Brassicaceae) • onion (Liliaceae) • garlic (Liliaceae) • spinach (Chenopodiaceae) • carrot (Apiaceae) • apples (Rosaceae) • apricots (Rosaceae)
China/SE Asia • soy bean (Fabaceae) • Chinese cabbage (Brassicacae) • radish (Brassicaceae) • cucumber (Cucurbitaceae) • Chinese yam (Dioscoriaceae) • rice (Poaceae) • peach (Rosaceae) • tea (Theaceae)
Ethiopia/East Africa • cowpeas (Fabaceae) • okra (Malvaceae) • millet (Poaceae) • coffee (Rubiaceae) okra flower and fruit
Middle East (Turkey, Jordan, Iran) • lentils (Fabaceae) • lupine (Fabaceae) • barley (Poaceae) • wheat (Poaceae)