Bio Lecture Ch 21 vocab

  1. Natural selection
    • -a mechanism that produces changes in a species
    • -the differential survival and reproduction of individuals in a population based on variation in their traits
  2. Artificial Selection
    works on strains with certain desirable traits by animal and plant breeders
  3. Population
    a group of individuals of a single species that live and interbreed in a particular geographic area at the same time
  4. Adaption
    both the processes by which characteristics that appear to be useful to their bearers evolve (the evolutionary mechanisms that produce them) and to the characteristics themselves.
  5. Heritable trait
    a characteristic that is partly determined by the organisms genes.
  6. Alleles
    different forms of a gene that may exist at a particular locus
  7. Gene pool
    the sum of all copies of all alleles at all loci found in a population
  8. Hardy-Weinberg equalibrium
    a principle that describes a model in which allele frequencies do not change across generations and genotype frequencies can be predicted from allele frequencies
  9. Genetic drift
    random fluctuations in allele frequencies from one generations to another
  10. Gene flow
    movement of individuals into or out of a population, or reproductive contact with other populations
  11. Mutation
    any change in the nucleotide sequences of an organism's DNA
  12. Population bottleneck
    a situation in a large population passes through a period in which only a small number of individuals survive
  13. Founder effect
    the result of a population bottleneck
  14. Fitness
    the reproductive contributions of other phenotype to subsequent generations relative to the contribution of other phenotypes
  15. Stabilizing selection
    preserves the average characteristics of a population by favoring average individuals
  16. Directional selection
    changes the characteristics of a population by favoring individuals that vary in one direction from the mean of the population
  17. Disruptive selection
    changes the characteristics of a population by favoring individuals that vary in both directions from the mean in both directions
  18. Neutral allele
    an allele that does not affect the fitness of an organism
  19. Frequency-dependent selection
    a phenomenon where a polymorphism depends on its frequency in a population
  20. Clinal variation
    the gradual change in a phenotype across a geographic gradient
  21. Trade-offs
    the fitness benefits must exceed the fitness costs it imposes
Card Set
Bio Lecture Ch 21 vocab
Chapter 21, "evidence and mechanisms of evolution