Peanut Variation Lab
Adapted from: C. Massengale

Variation is the fuel for Natural Selection. Without a variation of a trait within a population there can be no change....

When there is a variation of traits within a population, it is likely that some variations will be more helpful in surviving.


You will investigate two variations among peanuts

      1. length of shell
      2. number of seeds per shell.  


50 peanuts in shells,   metric ruler,   pencil, data table,  graph paper


    1. Count out 50 peanuts in their shells.

    2. Use a metric ruler to measure the length of each shell in millimeters.  Put a check mark in Table 1 in the space indicating the length of the shell.

    3. Open the shell and count the number of seeds inside.  Put a check mark in Table 2 in the space next to the number of seeds that you counted. 

    4. Repeat steps 1 - 3 for the other 49 peanuts.

    5. Set up two bar graphs using the headings from each table
      as the axes for each graph.

    6. Plot a bar graph from the data in each table.









  1. What is the most common length of the shells you measured?

  2. What was the most common number of seeds in the peanut shells that you opened?

  3. What might happen if each shell contained fewer than normal seeds and why?

  4. What might happen if each shell contained more than the normal number of seeds and why?

  5. Was there a relationship between the most common length of shells and the number of seeds they contained? Explain your answer.

  6. Write 1-2 paragraphs explaining how shell length and seed number in peanuts illustrates natural selection within this species.