Theory of Evolution

• Who was Charles Lyell?

  A geologist and Darwin's friend
• What theory did Lyell propose?

  The Theory of Uniformitarianism
• What does the Theory of Uniformitarianism state?

  The same geologic processes occur today and in the past
• Who proposed the theory of evolution via inheritance of acquired traits?

  Jean Baptiste Lamarck
• What is a common example used to illustrate Lamarck's theory?

  The evolution of the giraffe

  
• What are the main tenets of Lamarck's theory?

  1. Organisms tend to increase in size.
  2. New organs arise from new needs.
  3. Continued use develops organs; disuse leads to degeneration.
  4. Acquired traits are inheritable and accumulate over time.
• What was a major problem with Lamarck's theory?

  It was proposed before genetics was understood
• Who proposed the theory of evolution via natural selection?

  Charles Darwin and Alfred Wallace
• What is an example of the Theory of Uniformitarianism?

  The Grand Canyon forming after years of erosion
• What are the main points of the Theory of Inheritance of Acquired Characteristics?

  1. Living organisms and their limbs/apendages tend to increase in size over time.
  2. A new organ is produced when there is a need presented by the environment.
  3. If an organ is used frequently, it will continue to develop.
  4. If an organ is used infrequently, it will degenerate over time.
  5. Any changes/modifications mades to the species over time due to selection, mutations or other factors will accumulate over time and result in a new species.
• What is natural selection?

  The concept of an organism with higher fitness/adaptation to their environment surviving to reproduce and transmit their genetic information, while poorly adapted organisms and their genotype/phenotype die out over time.
• What are factors that must be in place for evolution to take place?

  1. Genetic variability...
  2. More offspring produced than can survive...
  3. Some organisms must have favorable/better adapted phenotypes than others....
  4. Differing reproduction rates due to natural selection...
• Within the environment, what can stabilize or destabilize the rate and direction of evolution?

  Biotic and abiotic factors...
• What is the reproductive rate of an organism or population referred to?

  Fecundity...
• What is evolution defined as?

  A change in allele frequency/the genetic makeup of a population over time.
• What is microevolution?


  Small-scale changes in the genetic composition of a population over time; leads to changes with the group but does not lead to speciation
• What is macroevolution?


  Major evolutionary changes that do lead to speciation..
• What are the two types of selection?

  Natural and Artificial
• What is artificial selection?

  The process of intentionally breeding non-human species with specific traits in order to produce offspring with those desired traits.
• What is an example of artificial selection?

  Farmers selectively breeding cattle that are larger to pass this desirable trait onto their offspring
• How do resistant "super-bugs" form from insecticide?

  The bugs mutating to be selected for by the insecticide. (Becoming tolerant or resistant..)
• What are the three patterns of selection?

  1. Stabilizing
  2. Directional
  3. Disruptive/Diversifying
• When does stabilizing selection occur?

  Occurs when individuals at the extremes of the range of a characteristic are consistently selected AGAINST..
• When does directional selection occur?

  Occurs when individuals at one extreme range of a characteristic are consistently selected FOR...
• When does disruptive/diversifying selection occur?

  Occurs when both extremes of a range for a characteristic are selected for and the "intermediate" condition is selected AGAINST..
• This graph shows the skew of which kind of pattern of selection?

  Directional Selection

  
• This graph shows the skew of which kind of pattern of selection?


  Stabilizing Selection

  
• This graph shows the skew of which kind of pattern of selection?


  Disruptive/Diversifying Selection

  
• What are the three criteria that population is defined by?

  1. Same species of organism..
  2. Located in the same location at the same time..
  3. Showing signs of reproduction..
• What is the Hardy-Weinberg Equilibrium?

  A theoretical condition in which a population's genotype and allele frequencies will remain unchanged over several generations..
• What are the requirements of the Hardy-Weinberg Equilibrium?

  1. No mutations..
  2. No immigration or emigration..
  3. Large population to avoid genetic drift..
  4. No natural selection..
  5. No sexual selection; random mating..
• What is the Hardy-Weinberg Equation used to calculate?

  It is used to calculate the genetic variation of a population at equilibrium.
• What is the Hardy-Weinberg Equation?

  $p^2+$$2pq+$$q^2$, where:

  • $p$ = the frequency of the A allele
  • $q$ = the frequency of the a allele
  • $p^2$= the frequency of the AA genotype
  • $q^2$= the frequency of the aa genotype
  • $2pq$ = the frequency of heterozygous (Aa) individuals
• If $p+$$q$ = 1 , what does that mean for the number of alleles in an equilibrium population?


  There are ONLY two alleles within this population..
• If $p^2+$$2pq+$$q^2$ = 1, what does that mean?


  There is ONLY one genotype within this population..
• What is genetic drift?

  Random fluctuations in the frequency of a gene in a small isolated population..
• What are the types of genetic drift?

  The founder effect and the bottleneck effect..
• When does the founder effect occur within a population?

  Occurs when a new colony is started by a few members of the original population..
• When does the bottleneck effect occur within a population?

  When a population is reduced due to a natural disaster/human activity..