amnh logo

Milstein Family Hall of Ocean Life Educator's Guide: Activity


Evolution


Natural selection plays a large role in the evolution of a species. The following activity demonstrates this concept.


What you need: What you do:
  1. Randomly place 20 squares of newspaper and 20 squares of white paper on a white paper background on the floor. (This is your hypothetical original population.) Explain to students that the newspaper and white paper pieces represent two different coloration patterns found in the same species.
  2. Ask students to use tweezers to pick up as many pieces of paper as they can in 10 seconds. Students will pick up more newspaper than white paper (because the newspaper is more visible against the white background).
  3. Explain that the remaining pieces of paper are the "breeding pairs." For each pair of paper squares that are left, add one more square of the same kind.
  4. Have students continue picking up squares with tweezers for 10 seconds. Over different turns (which represent generations), a trend will arise in the growing number of white squares.
  5. Track the results on a graph, and explain that this is a model of natural selection. Just as the white squares become greater in number, members of a population of a species with certain characteristics become dominant.
  6. Perform the experiment again, this time using a newspaper background instead of a white background.