



by Larry Flammer This is a quick and effective way to get across to students different ways new populations can emerge, be reproductively separated from the parent population, and eventually evolve into a new species. This process, technically called Allopatry or Allopatric Speciation, is the basis for genetic drift and "bottleneck" speciation, as well as a vivid application of the point of the HardyWeinberg formula  without calculations! Preparation: Presentation (about 1015 minutes) For further discussion and clarification of speciation, especially the part played by chromosomal changes. CLICK HERE. There is also an engaging reading and worksheet on chromosomal speciation that might be helpful: The Chromosome Shuffle 
GENE FREQUENCY CHANGES DUE TO SELECTION If you like to have your students work with changes in gene and genotype frequencies due to selection, you may like this Excel spread sheet. Students can alter the fitnesses and genotype frequencies and see what happens. You can skip the handout information by clicking on each cell and seeing its formula on the formula bar. Students seem to be more at home with Excel than with algebra and delta q. This spreadsheet with instructions was kindly provided by Dr. Thomas Gregg of Miami Univ. in Oxford, OH. The PDF Instructions begins like this: John C. Bloom. Department of Computer Science, Miami University,
Oxford, OH 45056 The famous HardyWeinberg equation shows the relationship between gene frequencies and genotype frequencies in random mating populations. (pA + qa)2 = p2 AA + 2pq Aa + q2 aa This formula also serves as the starting point for understanding how different evolutionary forces, such as selection, drift, and migration bring about changes in gene and genotype frequencies. In this paper we are interested in the effects of selection on gene frequencies. 
Here's an even more graphic simulation, freely available online . PopGen Fishbowl: A Free Online Simulation Model of Microevolutionary Processes by Thomas C. Jones & Thomas F. Laughlin  in the February 2010 issue of The American Biology Teacher, pp. 100101), where you will find lots of .good suggestions for using this simulation. BTW, that issue is a goldmine of articles on teaching evolution  if you have a copy, keep it handy. This article shares a freely available online interactive simulation of natural selection, where students can change several factors, one at a time, to test the predicted effect of each one on population size and changes in gene frequency. Makes a quickandeasy investigative study. Suggestions for classroom use are included. You can take a look at the online simulation by clicking on the URL below, and then clicking there on "Population Genetics" in the left column. For directions, click there on "More Information." Clicking on PopGen Fishbowl there will take you directly to the online simulation. The model is available at http://faculty.etsu.edu/jonestc/Virtualecology.htm
and can be run in any browser with the Java 1.41 (or higher)
plugin. If you use this simulation with your class, let us know how it goes. 