Understanding Evolution: your one-stop source for information on evolution
Resource library Teaching materials Evolution 101 Support this project

Lesson summary for:
Toxin resistance in clams


Be the first to rate this resource!

To rate this resource, click a star:

Answer the security question:

3 + 5 =

This case study in the form of a set of PowerPoint slides examines the evolution of toxin resistance in clams.


Grade level:

one to two class periods

Teaching tips:
This case study is also appropriate for zoology and ecology classes. The toxin resistance is quite interesting and should be engaging to a qualified student; however, background in cell membrane physiology should be a prerequisite.

Correspondence to the Next Generation Science Standards is indicated in parentheses after each relevant concept. See our conceptual framework for details.

  • There is a fit between organisms and their environments, though not always a perfect fit.

  • An organism's features reflect its evolutionary history.

  • Some traits of organisms are not adaptive.

  • There is a fit between the form of a trait and its function, though not always a perfect fit.

  • New heritable traits can result from mutations.

  • Mutation is a random process.

  • Organisms cannot intentionally produce adaptive mutations in response to environmental influences.

  • Complex structures may be produced incrementally by the accumulation of smaller advantageous mutations.

<< Back to search results