ch 24

  1. This is the study of gene and genotypes in a population.
    population genetics
  2. Is a group of individuals of the same species, members of a given population can interbreed.
  3. all of tthe alleles for every gene in a givem population.
    gene pool
  4. refers to the phenomenon that a trait displays variation within a population.
  5. A gene that commonly exists as two or more alleles in a population is a
    polymorphic gene
  6. exists predominantly as a single allele in a population. Also, when 99% or more of the alleles of a given gene are identicalin a population.
    monomorphic gene
  7. A polymorphism may involve various types of changes such as a deletion of a significant region of the gene, a duplication of a region, or a change in a single nucleotide. This last phenomenon is called
    Single-nucleotide polymorphism
  8. Allele frequency formula
    #of cpies of a spcific Allele in pop/Tot # of alleles for that gene in POP.
  9. Genotype frequency formula
    # of individuals w/ a particular genotype in a pop/tot # of individuals in a pop.
  10. What is the Hardy-Weinberg formula?
  11. The Hardy-Weinberd formula can only work when a population is in Equalibrium or stable. How is that possible? (5 ways)
    No new mutations, No Natural selection, large population fo alleles do not change due to random chance, no migration, and random mating occurs
  12. is used to describe changes in a population’s gene pool, such as changes in allele frequencies, from generation to generation.
  13. is the process in which beneficial traits that are heritable become more common in successive generations.
    Natural selection
  14. is the likelihood of an individual contributing fertile offspring to the next generation
    Reproductive success
  15. is the relative likelihood that a genotype will contribute to the gene pool of the next generation as compared with other genotypes.
  16. The average reproductive success of members of a population is called
    mean fitness of the population
  17. individuals at one extreme of a phenotypic range have greater reproductive success in a particular environment.
    Directional selection
  18. Type of natural selection that favors the survival of individuals with intermediate phenotypes and slects agains those with extremem phenotypes.
    Stabilizing selection
  19. favors the survival of two or more different genotypes that produce different phenotypes.
    Diversifying selection
  20. is a type of natural selection that maintains genetic diversity in a population. Over many generations, balancing selection can create a situation known as a balanced polymorphism, in which two or more alleles are kept in balance and therefore are maintained in a population over many generations.
    Balancing selection
  21. is a second way that natural selection can produce a balanced polymorphism. In this pattern of natural selection, the fitness of a genotype decreases when its frequency becomes higher. In other words, rare individuals have a higher fitness, and common individuals have a lower fitness.
    Negative frequency-dependent selection
  22. is directed at certain traits of sexually reproducing species that make it more likely for individuals to find or choose a mate and/or engage in successful mating.
    sexual selection
  23. members of one sex directly compete with each other for the opportunity to mate with individuals of the opposite sex
    Intrasexual selection
  24. namely, mate choice. This type of sexual selection often results in showy characteristics in males
    intersexual selectiong
  25. which refers to changes in allele frequencies due to random chance
    genetic drift
  26. A population can be reduced dramatically in size by events such as earthquakes, floods, drought, and human destruction of habitat. These occurrences may eliminate most members of the population without regard to their genetic composition. When allele frequencies of the resulting population change due to genetic drift, this is called
    bottleneck effect
  27. This occurs when a small group of individuals separates from a larger population and establishes a colony in a new location.
    founder effect
  28. most genetic variation is due to the accumulation of neutral mutations that have attained high frequencies in a population via genetic drift.
    Neutral theory of evolution
  29. This movement of alleles into or out of a population, called
    gene flow
  30. which means that individuals choose their mates irrespective of their genotypes or phenotypes. In many species, including human populations, this condition is violated. Such
    Nonrandom mating
Card Set
ch 24
exam 1