Part Three III › Division I I › Section 312 312

The Origin of Life and the Evolution of Living Things

Subject Outline

AStages in the emergence of life
- 1Hypotheses about the origin of life
- 2Steps in the production of chemical precursors of life
  - aFormation of the Earth's primitive reducing atmosphere
  - bProduction of simple organic molecules
  - cProduction of long-chain molecules consisting of repeating units
  - dOrigin of the genetic code
- 3The earliest living systems
  - aEvolution of enzymatic reaction chains
  - bOrigin of procaryotic and eucaryotic cells
  - cEvolution of photosynthesis
- 4The antiquity of life: evidence of biological activity in the geological record [see also 242 and 243]
BThe theory of evolution
- 1The history of evolutionary theory
  - aLamarck's contribution
  - bDarwin's theory of natural selection
  - cMendel's theory of heredity
  - dThe synthetic theory of evolution
  - eMolecular and genetic studies
- 2The evidence for evolution
  - aThe fossil record of gradual change
  - bStructural similarities (homologies) of different species
  - cVestiges of ancestral forms in embryonic development
  - dMolecular clues to evolutionary history
CThe process of evolution
- 1Genetic variation through gene or chromosomal mutation
- 2Changes in gene frequencies within a population through gene mutation, gene migration, and genetic drift
- 3Natural selection
  - aAdaptation and fitness
  - bAspects of the process of natural selection; coloration; mimicry; polymorphism
  - cNatural selection in the process of genetic change
  - dTypes of selection: stabilizing, directional, diversifying, sexual, and kin
DThe origin of species and the process of speciation
- 1The distinctiveness of species
- 2The criterion of reproductive isolation
- 3The properties of species
- 4Modes of speciation (e.g geographic speciation, adaptive radiation, quantum speciation)
- 5Genetic differentiation during speciation
- 6Patterns and rates of species evolution
  - aThe topology (or configuration) of phylogenies
  - bThe rate of morphological change: gradual or punctuational evolution
  - cMolecular evolution