Neutral Evolution: Genetic Drift
Lecture DescriptionPrinciples of Evolution, Ecology and Behavior (EEB 122) Neutral evolution occurs when genes do not experience natural selection because they have no effect on reproductive success. Neutrality arises when mutations in an organism's genotype cause no change in its phenotype, or when changes in the genotype bring about changes in the phenotype that do not affect reproductive success. Because neutral genes do not change in any particular direction over time and simply "drift," thanks in part to the randomness of meiosis, they can be used as a sort of molecular clock to determine common ancestors or places in the phylogenetic tree of life. 00:00 - Chapter 1. Introduction 04:56 - Chapter 2. Genes and Amino Acid Changes Not Reflected in Phenotypes 14:29 - Chapter 3. Neutral Evolution in the History of Life 20:38 - Chapter 4. Mechanisms of Neutral or Random Evolution 35:28 - Chapter 5. The Molecular Clock of Neutral Evolution Complete course materials are available at the Open Yale Courses website: http://open.yale.edu/courses This course was recorded in Spring 2009.
The Nature of Evolution: Selection, Inheritance, and History – Basic Transmission Genetics – Adaptive Evolution: Natural Selection – Neutral Evolution: Genetic Drift – How Selection Changes the Genetic Composition of Population – The Origin and Maintenance of Genetic Variation – The Importance of Development in Evolution – The Expression of Variation: Reaction Norms – The Evolution of Sex – Genomic Conflict – Life History Evolution – Sex Allocation – Sexual Selection – Species and Speciation – Phylogeny and Systematics – Comparative Methods: Trees, Maps, and Traits – Key Events in Evolution – Major Events in the Geological Theatre – The Fossil Record and Life’s History – Coevolution – Evolutionary Medicine – The Impact of Evolutionary Thought on the Social Sciences – The Logic of Science – Climate and the Distribution of Life on Earth – Interactions with the Physical Environment – Population Growth: Density Effects – Interspecific Competition – Ecological Communities – Island Biogeography and Invasive Species – Energy and Matter in Ecosystems – Why So Many Species? The Factors Affecting Biodiversity – Economic Decisions for the Foraging Individual – Evolutionary Game Theory: Fighting and Contests – Mating Systems and Parental Care – Alternative Breeding Strategies – Selfishness and Altruism