Evolution of a DNA Sequence Over Time

Abstract

One of the basic requirements of evolution is variation in a population upon which selection can act.  One of the sources of variation is mutation in DNA.  These changes may or may not be reflected in the ensuing amino acid sequence of a protein.  This exercise explores the additive effects of mutation on an amino acid sequence over several generations.  The activity is also useful in that it addresses several of the components of Darwin’s theory of evolution through natural selection.  There are three separate activities, one regarding sequence change over time, one regarding selective pressure on sequences, and one regarding divergence over time.
 

Intended Audience
 

5-8
9-12 X

 


Learning Objectives


By completing this activity, the student will be able to:

  1. Understand that variation in a sequence can be generated through mutation.
  2. See that successive rounds of mutation lead to further variation in a sequence.
  3. Recognize that sequences that are most closely related in a temporal sense will share the highest degree of similarity.
  4. Become familiar with the degeneracy in the amino acid code and how it may mask underlying changes in the DNA sequence.
  5. Be able to use clustering programs to perform an analysis of similarity.
  6. Recognize sequence similarity in organisms may indicate underlying evolutionary relatedness.

Necessary Student Background

Learner should be familiar with Darwin’s theory of evolution by natural selection.  Students should also understand that DNA is the hereditary and informational molecule and that information for the synthesis of proteins is encoded in the DNA.

Keywords

Theory, evolution, natural selection, artificial selection, extant, extinct, neutral mutation, silent mutation, codon, CLUSTAL, dendrogram

User Comments

 
“I have used part of this lab exercise in one of my non-major science classes and the results were very good.” Michael J. Hanophy Ph.D.
St. Joseph's College, Brooklyn, NY.

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Evolution of a DNA Sequence Over Time (25 pages)

 

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