Natural Selection Lab

Problem:  To what extent does coloration affect survival rate in white, red, and natural colored beans?
To what extent do food gathering "adaptations" (spoon, knife, or fork) predict survival of lab participants?

Research:  What were Charles Darwin's 5 ideas about evolution?






Hypotheses:  H1: coloration of beans:

H1: food gathering adapations:


Materials: Red Beans, Natural Colored Beans, and White Beans; Plastic knives, forks, and spoons; Dixie cups

Procedure: 1) Find a plot of grass that is approximately 30 ft by 30 ft. The instructor scatters 100 natural beans, 100 red beans, and 100 white beans randomly over the plot while the students face away from the plot.
2) All students should be given a single plastic knife, fork, or spoon (approximately even numbers to begin with). The number of students with each type of utensil should be entered in data table 2.
3) Students should "forage" for beans on the plot and use only their utensil to pick the bean up, stand up, and put it in the cup (they cannot put beans in the cup except in the standing position).
4) After several minutes, the instructor stops students from foraging. The students count their beans and line up in the order of the number of beans they have collected.
5) The 5 students with the lowest bean count "die" and hand in their utensil. The 5 top bean collectors have the priviledge of reproducing by coming to the instructor to get another utensil like theirs. They then hand it to one of the "dead" students who become foragers again with a new utensil. Enter the new count of students with each tool in data table 2 for "year 2".
6) Count the number of each type of bean that the students gathered and enter them in data table 1 row B. Do the calculations for row C, D, & E. The instructor should gather the correct number of offspring (row D) to scatter for the next round.
7) Steps 3 through 6 should be repeated and the numbers calculated to project what the new population would be for year 3. You do not need to do the last sentence of step 6.
8) Graph the data results making a line graph with 3 colors of pencils. Please use a scale that will spread your graph over 2/3 of the way up the vertical axis and over the x axis.

Data Table 1:

White Beans

Red Beans

Natural Beans

A)  population # to begin year 1




B) # found after 5 min of foraging

C)  # left in the field (A-B)

D)  # of offspring (Cx2)

E)  # of year 2 population (D+C)

G) # found after 5 min of foraging

H) # left in the field (E-G)

I)  # of offspring (Hx2)

J)# of year 3 population (H+I)

Data Table 2:

# Knives
# Forks
# Spoons
Year 1
Year 2
Year 3


Line Graph of Showing the
Effects of Coloration on Survival
(graph lines A, E, J)



Legend (color of lines
used for each bean):





Line Graph Showing the
Effects of Tool Type on Survival



Legend (color of lines
used for each tool type):




Conclusion Questions:

1)  What was the most successful color of bean?  Why?

2)  What was the least successful color of bean?  Why?

3)  Give 2 examples of natural populations this may be occurring in for organisms that you have seen in your yard or on school property.  Explain why the ones you observed were successful.

4)  Which of the collecting tools (adaptations) were the most and least successful? Why?

5) Give 2 examples of what these "tools" might represent in real predator populations.

6) Was Darwin in error with any of his 5 ideas on how evolution occurs?  Explain.

7) What affect does coloration and tool type have on survival rates of organisms?