IE 116 1st Edition Lecture 5Outline of Last Lecture Origins of Agriculture and spreading- 8 theories of how Ag originatedo Discovery, Crowding, (co)Evolution, Extension, Alcohol, Religion, No One Theory, and Chance along with food stress- 3 theories of how Ag spreado Demographics, Disease resistance, and Cultural and Technological developments- Thanks to humans, only best is chosenOutline of Current Lecture I. Domesticationa. Definition Anthropogenic EvolutionII. Types of Domesticationa. Typesb. How Domestication occursIII. Selection and Diversitya. Definitions and UnderstandingsCurrent LectureI. Domesticationa. Definitions- Progenitors are the biological differences between modern crops and their wild ancestorspecies. - Domestication is an anthropogenic evolution of a wild species to one that cannot survive without human assistance. Anthropogenic: - Corn – Originally small, shatterable, and bushy for survival.- Now – Moved to large seeds, fixed, stalks, suited for mechanized agriculture. Evolution: - A change in trait frequency over time.II. Types of Domesticationa. Types- Primary: domesticated in the same area it grows naturally. (Wheat, Barley, Peas, Maize)- Secondary: Transported UNINTENTIONALLY, then domesticated. (Rye, oats)- Trans-domestication: INTENTIONALLY transported and domesticated. (Tomatoes)b. How domestication occurs- Utilized: Little pressure or competition, grows naturally with no/little help. (Blueberries)- Cultivated: Naturally poisonous, cultivated to be edible. (Almonds)- Semi-domesticated: nutritionally complete, little help, chosen to be grown. (Quinoa) - Fully domesticated: different than original, can’t survive without humans. (Corn)III. Selection and Diversitya. Definitions and Understandings- Diversityo Needs multiple versions of traits1. Mutations -> change certain traits2. Recombination -> Mixed parental traits3. Migration -> Introduces new traits into a population- Selectiono Puts pressure and acts on diversity1. Humans select for specific traits2. May result in loss of diversity- Diversity is a prerequisite for evolution. With very few exceptions, diversity exists in all species.o Selection changes levels of diversity. Bottle-necks and results in loss of population Less diversity and makes it harder to select for a trait in an emergency.- For example: The banana. One kind left. No seeds. Dying out.- We could quite possible lose bananas.IMPORTANT Domestication Syndrome / Patternso The traits that were selected for domestication are considered the “domestication syndrome” Example: 1 Pick the seeds from largest flower head, or 2 pick seeds from the largest fruit, or 3 the prettiest
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