EVOLUTION QUESTION - 1986			L. PETERSON/AP BIOLOGY

	Describe the process of speciation. Include in your discussion the 
	factors that may contribute to the maintenance of genetic isolation.
 

  
  STANDARDS:
  
  DESCRIBE PROCESS                 (max. 9 points)
  __Definition of speciation
  __Differences in populations
  __Barriers occur (various kinds)
  __Barriers prevent inbreeding
  __Mutations responsible for differences
  __Differences (variations) result in populations
  __Genetic drift occurs in small populations
  __Founder effect (populations markedly different from parents)
  __Differential selection pressures (environmental)
  __Adaptive radiation, divergence
  __Hardy-Weinberg Assumptions 
     (how population size, random mating affects speciation )
  __Polyploidy (related to speciation)
  __Allopolyploidy (two different species)
  __Sympatry
  __Allopatry
  
  MAINTENANCE OF GENETIC ISOLATION      (max. 9 points)
  __Mechanical isolation (structural, prevents mating)
  __Seasonal isolation (different mating seasons)
  __Habitat isolation (don't encounter each other)
  __Behavioral isolation (courtship, mating behaviors differ, songs, etc.)
  __Gamete isolation (gametes can't live in reproductive tract of other species)
  __Hybrid sterility (vigorous, infertile hybrids)
  __Hybrid elimination (hybrids fertile, not competitive)
  __Hybrid weakness (weak, malformed hybrids, die young)
  __Developmental incompatibility (embryo-parent)
  
     [Maximum for examples in either section - 2 additional points]