Chapter 16

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  1. Population genetics
    The study of evolution from a genetic point of view
  2. Microevolution
    Evolution at the genetic level; defined as a change in the collective genetic material of a population
  3. Bell Curve
    on a graph of the frequency of some variable, a curve that first rises and then falls, thus forming a bell-shaped curve
  4. Gene Pool
    describes the total genetic information available in a population
  5. allele frequency
    the proportion of gene copies in a population that is a given allele, expressed as a precentage
  6. Phenotype frequency
    Equal to the number of individuals with a particular phenotype divided by the total number of individuals in the population
  7. Hardy-Weinberg principle
    states that the frequency of alleles in a population does not change over generations unless outside forces act on the population
  8. Immigration
    The movement of individuals into a population
  9. Emigration
    The movement of indivduals out of a population
  10. Gene Flow
    the process of genes moving from one population to another
  11. Genetic drift
    phenomenon by which allele frequencies in a population change as a result of random events or chance
  12. Sexual selection
    When females tend to choose the males they mate with based on certain traits
  13. Stabilizing selection
    individuals with the average form of a trait have the highest fitness
  14. Disruptive selection
    individuals with either extreme variation of a trait hoave grater fitness than individuals with the average form of the trait
  15. Directional Selection
    individuals that display a more extreme form of a trait have a greater fitness than individuals with an average form of the trait
  16. Speciation
    the process of species formation, results in closely related species
  17. Morphology
    The internal and external structure and appearance of an organism, chief criterion for classifying it as a species
  18. biological species concept
    states that a species is a population of organisms that can be successfully interbreed but cannot breed with other groups
  19. Geographic isolation
    the physical separation of members of a population
  20. Allopatric Speciation
    Occurs when species arise as a result of a geographic isolation
  21. Reproductive isolation
    happens from barriers to successful breeding between population groups in the same area
  22. Prezygotic isolation
    • occurs before fertilization
    • also called premating isolation
  23. Postzygotic isolation
    • Occurs after fertilization
    • also called postmating isolation
  24. Sympatric speciation
    occurs when two subpopulations become reproductively isolated within the same geographic area
  25. Gradualism
    The idea that speciation occurs at a regular, gradual rate
  26. Punctuated equilibrium
    a model of evolution in which short periods of drastic change in species, including mass extinctions and rapid speciation, are separated by long periods of little or no change
Card Set:
Chapter 16
2012-02-16 00:57:43
Biology Honors

Population Genetics and Speculation
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