OPPOSABLE THUMBS

Teachers’ Notes

Who is it for?11-14 year olds

How long will it take?This activity is designed as aone hour session

Learning outcomes: Students learn the definition of an opposable thumb, explore the variety of species withthis trait and examine the tasks primates can accomplish with the evolution of the opposable thumb.

What do you need?

  • Computer connected to a whiteboard or projector
  • Opposable Thumbs Classroom Presentation
  • Opposable Thumbs Worksheet, one copy per student team, plus the following materials per team:
  • pencil or pen
  • jar with a screw lid
  • tweezers
  • small section of a plastic straw (3” long; 7.5 cm long)
  • stopwatch (or timepiece with a seconds hand)
  • Velcro strap

Summary:

In this lesson, students explore the role of the opposable thumb in primates and what purposes it serves. Students will be introduced to a variety of species that rely on this adaptation and the different survival tasks they can accomplish because of it. Students will then challenge themselves to perform certain tasks such as unscrewing a jar lid with and without the use of their opposable thumb (by securing it with a small piece of Velcro).

Preparation guidelines:

  1. Read through these notes and prepare the Opposable Thumbs Classroom Presentation on a computer connected to a smart board.
  2. Print a copy of the Opposable Thumbs Worksheet and assemble the materials for the activity for each student team.

How to run the session:

  1. Begin by asking students if they know what an opposable thumb is and whether or not they think they have one. Ask students to brainstorm the types of tasks that having an opposable thumb allows them to do. After this discussion, lead students through the Classroom Presentation exploring more information about opposable thumbs and species that have them.

.

  1. Lead the class through the following activity steps:
  2. Divide the class into pairs or teams.
  3. Give each team: Opposable Thumbs Worksheet, pencil or pen, jar with a screw lid, tweezers, Velcro strap, a small section of a plastic straw (3” long; 7.5 cm. long), a stopwatch or timepiece with a seconds hand.
  4. Have the pairs or teams of students take turns timing each other doing the activities. Each student will have a chance to keep time and do the activity:
  5. First, the student doing the activity tries to: write their name; twist the lid off a jar; pick up a straw with tweezers.
  6. The timer writes on the worksheet the time it takes each student to do each activity with the use of their thumb.
  7. Second, the timer wraps the thumb against the fingers on the hand of the student doing the activity using the Velcro strap. The student repeats the activities.
  8. The timer writes on the worksheet the time it takes each student to do the activity without the use of their thumb.
  9. Get the students to swap roles, so that the timer becomes the participant and repeat the activity as outlined above.
  1. Assess the students results and what has been learned by:
  2. Comparing the time it takes to do the activities with and without use ofthe thumb.
  3. Listing what an opposable thumb enables humans to do.
  4. Considering how an opposable thumb could be a disadvantage.
  5. Naming species that have opposable thumbs and considering how opposable thumbs help them adapt to their habitats.
  6. Asking how tools would have to have been designed differently if humans didn’t have opposable thumbs? Think about how you would use a hammer, a pencil, etc.

1