Download Modeling Natural Selection Lab: Procedure

Modeling Natural Selection Lab: Procedure
DO NOT eat the experimental M&Ms. Many people may have touched them and they are not clean!
Please show good sportsmanship during this lab. You may encourage and give advice to members of your
team but do not tease or be unpleasant to anyone on any team. You may discuss strategy, and you should
focus on ONE GOAL ONLY: being the FASTEST team to finish the task each time!
Materials: towel, plastic cup, bag of M&Ms (60 total, 10 of each color), tweezers, pencil, and paper,
sunglasses
Procedure, part A: Set-up
1. Read the procedure and observe the experimental set-up. If you are not clear about any step, ask
questions before we begin!
2. On the paper provided, draw a quick diagram of the experimental set-up.
5. Working in groups of 4-5 people as assigned by your teacher, clear the table except for lab
materials.
Procedure, part B: Experimentation
6. Scatter the 60 M&Ms randomly across the towel “environment”.
7. At your teacher’s signal, put on your sunglasses.
8. Using the tweezers ONLY, a group member will grab ONE M&M and drop in into the cup as
quickly as possible.
8. The group member will then pass the tweezers to the next person, who will grab one M&M and
drop it into the cup.
NOTE: You can use any technique with the tweezers and M&Ms, but you may NOT move the
terrain (towel), move the cup OR touch the M&Ms with anything other than the tweezers.
9. Going from person to person, without skipping people, continue until half of the M&Ms have
been “captured” (30 M&Ms).
10. You are competing against the other student groups to see who can finish the fastest. As soon
as the 30th M&M is captured, raise you hands so your teacher can record your rank.
11. When all groups have finished, count the “surviving” M&Ms (those that are still on the towel)
by color – do not record the number yet!
12. Now the M&Ms will “reproduce” to form the next generation. For each surviving M&M on the
towel, add one “offspring” of the same color. (Use your “captured” M&Ms to be “offspring” first. If you
need more of a color, get extras from your teacher.)
13. Record the number of M&Ms of each color in your data table. If you have done this correctly,
the total will always be 60. Notify your teacher right away if you have made an error.
14. Repeat from step 6 as directed by your teacher.
15. Clean up your materials. Be sure to put 10 M&Ms of each color back into the starting bag for
the next class.
NOTE: Prizes may be awarded for the fastest team of “predators”. If you cheat, you will be
disqualified!
Names__________________________________________________________________ Section________
Modeling Natural Selection Lab: Write-up and Discussion
Made a labeled diagram of the experimental set-up here (include your towel color):
DATA COLLECTION:
Number of M&Ms by color
Generation
Number
Red
Orange
Yellow
Green
Blue
Brown
1
10
10
10
10
10
10
2
3
4
5
6
Total
number of
M&Ms
60
DATA PROCESSING (find a helpful way to present your data that clearly shows what happened over time)
DISCUSSION SECTION:
1. In this experiment there are two examples of competition and selection: the student teams of “predators”
and the M&M “prey”. In the table below are 5 key points of the Darwin-Wallace theory of natural
selection.

Explain specifically how the M&M “prey” AND the “predator” teams demonstrate or do not
demonstrate EACH point.
Key Point of Natural Selection
1. Heritable variation exists within
a species.
2. There is competition for limited
resources within a species.
3. More offspring are born than
can survive to reproduce.
4. Some variations are more
helpful than others in the struggle
to get resources, survive and
reproduce.
5. Helpful variations will become
more common over time,
eventually replacing the less
helpful variations.
M&M “Prey” Model
Student “Predator” Model
2. Over time, natural selection can lead to change in a population (evolution).

Did evolution seem to occur in your population of M&Ms?
Explain.

Did population change happen “naturally”, or did your group strategize about which color
M&Ms to select (artificial selection)? “Natural Selection” / Artificial Selection / Both
Explain.

If you strategized about color selection, what was your strategy and why?

Were there any factors other than color that seemed important in M&M survival, such as
proximity to the cup? If so, what were they?
YES
/
NO
3. Humans show biological (genetic) evolution. However, humans also learn and pass their ideas to each
other and the new generation. This is called cultural evolution.

To what extent did your “predator” team use cultural evolution to improve your cooperation
and use of the tweezers?

How important was “genetic” variation (sunglass strength, etc.) compared to “cultural”
evolution (way of holding and passing tweezers, etc.)?

Using examples, discuss the importance of genetic evolution and cultural evolution to the
human species right now? Is the balance the same for people everywhere, or does it depend
on circumstances? Explain.