bio ch.8

  1. Natural Selection
    Individuals with one version of a trait have greater reproductive success than do individuals with a different version.
  2. 4 different mechinisms of evolution
    mutation, genetic drift, migration, natural selection (evolution is a result of natural selection).
  3. Evolution
    Change in allele frequencies in a population. Change due to natural pressures (peper moth).
  4. Population
    group of organisms of the same species living in a particular area.
  5. Natural selection (conditions)
    variation for a trait, Heritability of that trait, Differential reproductive success based on that trait(more babies). need all 3
  6. Fitness
    measure of relative amount of reproduction of an indivitual witha particular phenotype, compared to the output with alternate phenotypes.
  7. Elements to an organisms fitness
    • 1. measured relative to other genotypes or phenotypes in the poplation.
    • 2. the enviroment
    • 3. reproductive success, compared with organisms in population
    • (survival of the fittest)
  8. Adaptation
    when an organism becomes better matched to enviroment/ features that make them more fit . process of natural selection.
  9. Natureal selection can change the traits of a population in what 3 ways of selection.
    Directional, stabilizing, disrupted
  10. Directionnal selection
    ONE extreme from variation of population have higher fitness.
  11. Stabilizing selection
    individuals with intermediate phenotypes are most fit
  12. Disruptive selection
    RARE individuals with extreme phenotypes have the hightest fitness
  13. Mutation
    Alteration of base pair sequence of an individual's DNA, alteration occurs in section of DNA that codes for a particular gene. Change in DNA may change the allele. almost always cause early death or lower reproductive success.
  14. Mutagens
    mutation inducing chemicals
  15. Genetic Drift
    Random change in allele frequencies that do not influance reproductive success and population expienceses evolution
  16. Fixation
    consequence of genetic drift. occures when alleles frequency in population for a trait reches 100%. all offspring will carry that allele untill mutation occurs.
  17. Flounder Effect
    group of indeviduals that leave the exsisting population. new population will be dominated by the genetic features present in the founding members. the new population expiences evolution.
  18. Bottleneck
    surviving members of a catastrophic event that have different allele frequencies than the source population and, consequently, the new population will be dominated by the present features in the surviving members.
  19. Migration/ Gene Flow
    A group of indeviduals migrates from one population to another. Both experiance change in allele frequencies as indeviduals move in and out.
  20. Sexual Selection
    process by witch natural selection favors traits, such as ornatments or fighting behavior that gives an advantage to indaviduals of one sex in attracting matting partners.
  21. Artificial selection
    reproductive sucess is determined by humans not nature.
  22. Five Lines of Evidence Demonstraiting the occurance of evolution
    • -the fossil record
    • -biogeography
    • -comparative anatomy and embryology
    • -molecular biology
    • -laboratory and field experiments
  23. The Fossil Record
    physical evidance of organism that lived in the past
  24. Biogeography
    patterens in the geographic distribution of living organisms
  25. Comparative anatomy and Embryology
    growth, development and body structures of major groups of organisms
  26. Molecular Biology
    The examination of life at the level of individual molecules
  27. Laboratory and Field Experiments
    Implementation of the scientific method to observe and study evolutionary mechanisms
  28. Radiometric Dating
    makes it possible to determine the age of fossils. absolute and relative age
  29. Homologous Structures
    Body structures in different organisms that, although modified over time to serve different dunctions in different species, are due to inheritance from a common evolutionary ancestor.
  30. Vestigial Structures
    a structure on an animal that was once useful but lost its function over time due to evolution.( human appendix)
  31. Convergent Evolution
    process of natural selection which features of an organisms not closely related come ot resemble each other as a consequence of silimar selective forces
Card Set
bio ch.8
bio ch.8