Chapter 19 Lecture Enrichment Ideas


  • Describe how each of the conditions of the Hardy-Weinberg equilibrium retards evolution.
  • Provide examples of directional selection, stabilizing selection, and disruptive selection¾ consider very tall and very short humans, different breeds of dogs, etc.
  • Discuss why adaptive radiation should be prevalent when there is no competition for an environmental habitat, as after the death of the dinosaurs or when finches arrived on the Galpagos Islands.
  • Consider why premating isolating mechanisms are more efficient than postmating isolating mechanisms in reproductive isolation leading to speciation and why Mayr predicted that postmating isolation would occur before premating isolation in geographic isolation and speciation.
  • Discuss why allopatric speciation would be more likely than sympatric speciation.


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