Eras of Plant Improvement Domestication The Green Revolution Genetic Modification

Continuous Improvements in Agriculture The distant past (thousands of years ago) Crop plant domestication The recent past (past 100 years) Hybrid seeds/intentional breeding  The "Green Revolution" Now and into the future (past 25 years) Advances in breeding Genetic modification technologies 

Phase 1: Domestication More than 10,000 years ago until approximately 1900 Humans transitioned from hunter-gatherer lifestyle with improvements in agriculture  Development of human civilizations is correlated with the development of agriculture Major crops were domesticated approximately 5,000 – 15,000 years ago Domestication: cultivating or taming organisms to accentuate traits that are considered desirable for humans Physical appearance Behavioral characteristic  Individual size  Selecting for physical traits modified the genetic makeup of the plant

Phase 2: The Green Revolution 1960s - 1980s Important advancements: High-yielding grain varieties (rice, wheat) "semi-dwarf" varieties: shorter plants that waste less energy on growing stems for height  Disease-resistance  Dramatically increased crop yields for the same acreage of land  Able to grow more food without using more land 

Phase 3: Genetic Modification 1980s – present  Advances in science and genetic understanding have led to technologies that allow scientists to directly modify the genetic make up of species to exhibit a trait of interest Can use genes from that species or another First crops released in 1995 Herbicide and insect resistant – reduces pesticide needs, increases yield  Rapidly adopted by farmers – increased farmer profits  Primary crops: cotton, soybean, corn, canola, cotton, alfalfa, papaya  Lots of possibilities for potential improvements (GMOs)