Here Banana! Build skills to find (and not find) what you are looking for

Question(s)

How do you prove that you find or don’t find the species you are looking for?

Overview

Students conduct this simple investigation with familiar materials to get in the groove of looking carefully for something, making a claim that they found it or did not find it, and supporting that claim with solid, bullet proof evidence. Students plan and carry out a short, sweet investigation to determine whether or not a “species” is in an “ecosystem” or not. They figure out for themselves the importance of careful observations skills.

It’s fairly easy to understand why a scientist would want information about where you find a native or invasive species. It’s a bit less intuitive to understand why a scientist would want to know where you look for, but do not find a native or invasive species.

Documenting where an invasive species has not established a population is just as important as knowing where a species actually is. This “absence data” is useful for management decisions (e.g., species x is not in this intertidal, so we may target our limited resources elsewhere; species y is not in this lake with this nice inviting boat ramp, so target resources here to keep it free of species y). Absence data also provides an important baseline measure to gauge changes over time (e.g., species z was not found here in 2009 & 2010, was first found in 2011, and appears to be expanding its population in 2012).

As a further challenge, it is far more difficult to prove that something is not there, than it is to prove that it is there. Absence data is subjective and not often reliable as it depends on the observation skills, identification skills, patience, and care taken by the scientist to look closely and rule out the species she is looking for.

Important skills built during this short, silly, easily accessible investigation will be put to use when students investigate biodiversity in a local watershed and whether they find or do not find invasive species.

Standards (MLR)

Learning Objectives

• Students practice observation skills, planning an investigation, gathering data, making claims, supporting claims with evidence, analyzing results, reflecting, and concluding their investigation.
• Students understand that reporting that they looked for something and did not find it is just as important in science (or cooking) as reporting that you looked for something and found it.

Materials

• Fruit salad with or without a slice of banana
  • 1 bowl for the whole class
  • (or) Separate bowls for small teams of students
• Spoons
• Sorting trays or bowls
• Banana identification resource (a real banana to compare to works nicely)

Time Needed

45 minutes

Activity Procedure

1. Make a fruit salad with strawberries, blueberries, pineapple, oranges, grapefruit, and one very small sliver of banana.

   Note: A hefty bag of Halloween candy or a colorful bowl of MnMs & Skittles is often more engaging (and distracting!).

2. Present your Issue Statement: I am allergic to bananas and can not eat this fruit salad if there’s a banana in it. Or something more dramatic like this: I want to serve this fruit salad to my mom tomorrow on Mother’s Day, and if there’s any banana in it it’ll spoil the whole bowl by morning and will ruin Mother’s Day! (Oh the drama.)
3. Ask your Research Question: Is there any banana in this fruit salad?
4. Ask students to come up with a prediction based on a quick glance. They can look at the salad from all angles, but can not touch or stir. Example predictions:
   • We don’t think there is any banana in this fruit salad because we looked all around and don’t see any.
   • We think there is banana in this fruit salad because we can smell it!
5. Ask students to come up with a plan/method for how they would investigate to make absolutely certain that the fruit salad either has banana or is completely banana-free.
   • Would you look at it and make a decision from a distance?
   • Would you look at it up close?
   • Would you smell it?
   • Would you feel it?
   • What tools would you use? (spoon, smaller sorting bowls, ID reference….)
   • Would you ask the person who made it?….
6. Investigate!
7. Can I eat the fruit salad? Make a claim/recommendation that is well-supported by written and visual/photo evidence. If evidence statements need a boost, consider using Prove It!, an activity that is coming up next in this Biodiversity Watershed Experience.

Reflection/Formative Assessment Ideas

Discuss as a whole class or in small teams:

1. Review the method of investigation that each team chose:
   • What worked well?
   • What you would never do again?
   • What skills and tools were critical?
2. Discuss how you would transfer what you learned from this investigation to a similar investigation looking for animals or plants outdoors in a local habitat. Plants and animals may not be as familiar to you as a banana.
   • What would you want to know ahead of time about the plant or animal before you start to look for it?
   • What resources and tools would you want to bring with you to help look for the plant or animal?

Extension Ideas

Whole class or small teams: This activity can be done as a whole class with one bowl of fruit, or in small teams each with their own bowl. With a whole class, there is opportunity to facilitate some great student-student discussion, and to model for each other best practices. With small teams, there is opportunity to emphasize the importance of a strong investigation plans – comparing methods and how methods may influence results.

Banana or no banana: This investigation works just fine both ways. Either put one slice of banana in the fruit salad, or don’t. If you use small teams, you may want to put banana in 1-2 bowls and leave the others banana-free. Take note of which bowls have the banana, though, to check for careful observation.

Have another great idea for extending this lesson? Share it with us in the comments section below.

Resources

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References

Have a solid reference for this type of learning? Tell us about it in the comments section below.