BIO220H1 Lecture 18: Lecture 18 Development of Agriculture

• School: UTSG
• Department: Biology
• Course: BIO220H1
• Professor: Doug Thomson

Document Summary

Lecture 18 bio220 development of agriculture: some basic ecology of food. Selection attractiveness = > dispersal: seeds, tubers: energy storage organs. Artificial selection on native plants: grasses: wheat, rice, maize, barley, key innovations, non shattering seed heads (plant evolution, amylase evolution (human evolution, legumes, fruits. Irrigation channels: fishing by net (mass technology, domestication of agricultural animals and lactose tolerance evolution, plow replaced digging sticks. Intrinsic growth performance of crops: limited areas suitable for growth, edaphic factors: soil moisture, fertility, soil exhaustion, buildup of insects, disease. Leaching of soils: when rainwater, snowmelt percolate downward through soil, dissolving ions carry down to water tables, out of reach to plant roots. Ions dissolved depend on temperature, ph: ancient soils heavily leeched. Prairie plants ~ perennials with immense root systems: enrich soil with organic matter. Legumes enrich soil with n: form root nodules: bacteria capture inert n2 soluble, reactive form.