Bio ch 23

The flashcards below were created by user acandrew on FreezingBlue Flashcards.

  1. Microevolution
    evolution on the smllest scale as change in the allele frequency over generations
  2. Genetic Variation
    Differences among individuals in the composition on their genes or other DNA segments
  3. Average heterozygosity
    The average percentage of loci that are heterozygous
  4. Geographic variation
    Differences in the genetic composition of separate population
  5. Cline
    A graded change in a character along a geographic axis
  6. Population
    A group of individuals of the same species that live in the same area and interbreed, producing fertile offspring
  7. Gene pool
    Consists of all copies of every type of allele at every locus in all members of the population
  8. Hardy-weinberg principle
    The gene pool of a population that is not evolving
  9. Genetic drift
    Chance events that cause allele frequencies to fluctuate unpredictably from one generation to the next, especially in small populations
  10. Founder effect
    When a few individuals become isolated from a large population, this small group may establish a new population whose gene pool differs from the source population
  11. Bottleneck effect
    A sudden change in the environment, such as a fire or flood, may drastically reduce the population size
  12. Gene flow
    The transfer of allele into or out of a population due to the movement of fertile individual or their gametes
  13. Relative fitness
    The contribution an individual makes to the gene pool of the next generation relative to the contribution of other individuals
  14. Directional selection
    When conditions favor individuals exhibiting one extreme of a phenotypic range, thereby shifting a population's frequency curve in one direction or the other
  15. Disruptive selection
    When conditions favor individuals at both extremes of the phenotypic range over individuals with intermediate phenotypes
  16. Stabilizing selection
    Acts against both extreme phenotypes and favors intermediate variants
  17. Sexual selection
    A form of selection in which individuals with certain inherited characteristics are more likely than other individauls to obtain mates
  18. Sexual dimorphism
    A difference between two sexes in secondary sexual characteristics
  19. Intrasexual selection
    Selection within the same sex, individuals of the same sex compete directly for mates of the opposite sex
  20. Intersexual selection
    Mate choice, individuals of one sex are choosy in selecting their mates from the other sex
  21. Neutral variation
    Difference in DNA sequence that do not confer a selective advantage or disadvantage
  22. Balancing selection
    When natural selection maintains two or more forms in a population
  23. Heterozygote advantage
    Individuals who are heterozygous at a particular locus have greater fitness than do both kinds of homozygous
  24. Frequency -dependent selection
    The fitness of a phenotype depends on how common it is in the population
Card Set:
Bio ch 23
2012-04-22 01:09:11

Show Answers: