Evolutionary Biology

Evolutionary biology is the subfield of biology that studies the evolutionary processes—including natural selection, genetic drift, and mutation—that have produced the diversity of life on Earth. It seeks to explain the history of life, from the origin of species (speciation) and the adaptation of organisms to their environments, to the shared ancestry that connects all living things. By integrating evidence from genetics, paleontology, and ecology, evolutionary biology provides the foundational, unifying framework for all of modern biology, explaining how life changes and diversifies over time.

1. Foundations of Evolutionary Thought
   1. Pre-Darwinian Ideas
      1. Essentialism and the Great Chain of Being
         1. Concept of Fixed Species
         2. Hierarchical Classification of Life
         3. Aristotelian Influence
      2. Early Ideas of Change
         1. Lamarckism
            1. Inheritance of Acquired Characteristics
            2. Use and Disuse Theory
            3. Environmental Influence on Traits
         2. Erasmus Darwin's Contributions
         3. Buffon's Ideas on Species Change
         4. Cuvier's Catastrophism
      3. Contributions from Geology
         1. Uniformitarianism
            1. James Hutton's Principles
            2. Charles Lyell's Influence
         2. Deep Time and Earth's Age
         3. Stratigraphic Principles
         4. Fossil Evidence for Change
         5. Extinction Events
      4. Contributions from Economics and Demographics
         1. Malthusian Principles
         2. Population Growth and Resource Limitation
         3. Competition for Resources
   2. Darwin's and Wallace's Contributions
      1. The Voyage of the Beagle
         1. Observations in the Galápagos Islands
            1. Finch Diversity
            2. Tortoise Variations
            3. Marine Iguana Adaptations
         2. Biogeographical Patterns
         3. Fossil Discoveries in South America
         4. Geological Observations
      2. Development of the Theory of Natural Selection
         1. Formulation of Key Principles
         2. Artificial Selection as Analogy
            1. Pigeon Breeding
            2. Agricultural Examples
         3. Influence of Malthus
         4. Notebooks and Early Sketches
      3. Alfred Russel Wallace and Independent Discovery
         1. Wallace's Fieldwork in Southeast Asia
         2. The Ternate Essay
         3. Correspondence with Darwin
         4. Joint Presentation to the Linnean Society
      4. "On the Origin of Species"
         1. Structure and Arguments of the Book
         2. Evidence Presented
         3. Reception and Controversy
         4. Subsequent Editions and Revisions
         5. Impact on Scientific Thought
   3. The Modern Synthesis
      1. Integrating Genetics with Natural Selection
         1. Rediscovery of Mendelian Genetics
         2. Reconciliation of Continuous and Discrete Variation
         3. Biometrical School vs. Mendelians
      2. Key Figures and Contributions
         1. Ronald Fisher
            1. Mathematical Population Genetics
            2. Fundamental Theorem of Natural Selection
         2. J.B.S. Haldane
            1. Selection Coefficients
            2. Linkage and Selection
         3. Sewall Wright
            1. Genetic Drift
            2. Shifting Balance Theory
         4. Theodosius Dobzhansky
            1. Genetics and the Origin of Species
         5. Ernst Mayr
            1. Biological Species Concept
            2. Geographic Speciation
         6. George Gaylord Simpson
            1. Paleontological Evidence
         7. G. Ledyard Stebbins
            1. Plant Evolution
      3. Population Genetics as a Foundation
         1. Hardy-Weinberg Equilibrium
         2. Mathematical Models of Evolution
         3. Genetic Structure of Populations
         4. Quantitative Genetics