Bio1151 Chapter 23 9
  1. A               is a localized group of individuals of a species.
     
  2. Natural selection acts on individuals, but                evolve, based on variations that are inherited over generations.

     
  3. As a population evolves, its heritable variation is reflected in change of           and             frequencies.
     
  4. A non-evolving population reaches the                   equilibrium due to Mendelian                of alleles.
     
  5. At Hardy-Weinberg equilibrium, the distribution of 2            p and q in a population can be modeled by two equations.
     
  6. Natural populations may           if conditions deviate from the Hardy-Weinberg model.
     
    • Genetic          in small populations tends to           genetic variation. In very small populations the                effect can contribute to severe loss of genetic diversity.


       
    • Gene         from the movement of individuals or gametes between populations can affect allele frequencies and tends to           genetic differences between populations.
       
    •             is the basis for natural selection, and results in unequal reproduction of alleles.
       
    • Sexually reproductive organisms often exhibit              mating behaviors such as                selection and                selection.

       
    • Natural selection is the major mechanism that drives adaptive             .



       
      Causes of Evolutionary Change: