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Questions | Answers
  1. proteins
  2. Gene: a specific section of DNA that contains the code for producing a protein.
  3. Alleles: different versions of a gene.
  4. Gene Pool: all of the alleles (types and proportions) of all the genes in a population.
  5. Evolution: genetic change in a population (or change in a population's gene pool).
  6. Mechanisms of evolution
    1. Mutation: random change in the nucleotide sequence in DNA due to copying errors or the effects of chemicals/radiation. Mutation is the ultimate source of new alleles and genes.
    2. Migration (Gene Flow): the movement of alleles between populations as a result of movement of individuals from one population to another.
    3. Chance (Genetic Drift): a change in allele frequencies in a population due to chance (differences in reproductive success not due to genetic makeup of individuals like in natural selection). Genetic drift does not lead to adaptation, and its effects are stronger on smaller populations.
    4. Natural Selection: change in allele frequencies in a population due to differential reproductive success among the members of the population. This is the only mechanism that leads to adaptive changes in the population's gene pool.
  7. Natural Selection Flow Chart:
    1. Mutation and Recombination produces Genetic Variability in a population
    2. Environmental Selection Pressures act on the population creating...
    3. Differential Survival and Differential Reproduction which leads back to...
    4. Mutation and Recombination to create a potentially changed gene pool.
  8. Types of evolution
    1. Divergent Evolution: different populations within a species become genetically different due to experiencing different selection pressures. Example: White-tailed deer tend to be larger in the north than in the south.
    2. Convergent Evolution: different species come to look/behave similarly due to experiencing similar selection pressures. Example: sharks (fish) and dolphins (mammals) look similar.
    3. Coevolution: interacting species act as selection pressures on each other due to their interactions. Example: as prey get faster, predators tend to get faster.
  9. Definitions
    1. Bottleneck Effect: a large portion of the population dies off; survivors only possess a subset of the original genetic diversity.
    2. Founder Effect: a small subset of the population becomes isolated from the rest of the population.