Origin of Species: Starting the Story with DNA

 

Tested Studies in Laboratory Teaching, 2011, Volume 32

Robert B. Ketcham

Abstract

This activity starts with a pop bead model of DNA, although the model is presented to students initially not as DNA but as necklaces worn by members of a tribe of humans. Students manipulate the necklaces according to customs of the tribe and discover the simple story of where new species come from: populations split and the resultant daughter populations diverge due to mutation. In our labs we connect the necklace model to a specific example of diversity by analyzing a phylogeny of great apes. The necklaces can also be used to teach about the specificity of restriction enzymes and how these enzymes allow us to distinguish different sources of DNA.

Keywords:  evolution, molecular clock, origin of species, speciation, phylogeny, biological diversity, common ancestor, restriction enzyme

Dalhousie University (2010)