lab

Introduction

In this lab I will learn on the subject of the characteristics of primates. Specifically, I will study pentadactylism, opposable thumbs, quadrupedalism, as well as bipedalism.

Procedure

Exercise 1: Opposable Thumb

1. I picked up the tape to prepare both of my hands so that my thumbs are no longer opposable by taping each thumb either to the side or your hand.

2. With both opposable thumbs immobilized, I will perform all of the tasks listed in Data Table 1.

3. When I have completed all tasks with the opposable thumbs immobilized, I removed the

tape from both of my hands.

4. Using both of my opposable thumbs, I re-performed each task in Data Table 1. (As each task is performed I placed a check mark in one of the columns to the right. If the task was easier with the opposable thumb, place a check mark in the “With Opposable Thumb” column. If the task was easier to perform with the opposable thumb immobilized, place a check mark in the “Without Opposable Thumb” column. If the opposable thumb did not have any impact on my ability to perform the task, place a check mark in the “Opposable thumb did not impact ability to perform task” column).

5. Lastly, when all tasks have been completed and Data Table 1 has been filled in, I clean up all items.

Exercise 2: Bipedalism versus Quadrupedalism

1. I located an area with open space.

2. I arranged my body so that it is in a quadruped stance. (as in Figure 6).

3. Next, I moved around the area in the quadruped stance, with my hands and feet on the ground. As I moved, I observed how moving becomes more difficult or less difficult as a quadruped.

4. After I had finished moving in a quadruped stance, I stood up and stretched out my hands,

arms, feet, and legs.

5. Lastly, I walked around the area on both feet in a biped stance, as I normally would.

Primate Characteristics

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Lab Report Assistant

This document is not meant to be a substitute for a formal laboratory report. The Lab Report Assistant is simply a summary of the experiment’s questions, diagrams if needed, and data tables that should be addressed in a formal lab report. The intent is to facilitate students’ writing of lab reports by providing this information in an editable file which can be sent to an instructor.

Exercise 1: Opposable Thumb

Observations

Data Table 1: Tasks with and without opposable thumb.
Tasks:	Place a  under one column for each task:
	With opposable thumb	Without opposable thumb	Opposable thumb did not impact ability to perform task
Pick up a piece of clothing			
Pick up a book or magazine	
Turn book or magazine pages one at a time	
Pick up a pen or pencil			
Write your name on a sheet of paper	
Peel a banana (optional)	
Remove the cap from a marker or bottle			
Place the cap on a marker or bottle			
Untie shoelaces		
Tie shoelaces	

Experiment

Primate Characteristics

241

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Questions

A. How many tasks were more difficult to perform without an opposable thumb? How many tasks were easier to perform with an opposable thumb? How many tasks were not impacted by the use of an opposable thumb?

B. Which task was the most difficult to perform with your opposable thumbs immobilized? Specifically, what about this task was challenging, and how was it easier to perform with the use of your opposable thumbs?

C. Was dexterity or grasping ability most impacted when your opposable thumbs were immobilized? Explain your answer.

D. Many primates have opposability in their big toe in addition to their thumbs. How do you think your daily life would be impacted if Homo sapiens had opposability in their big toes?

Exercise 2: Bipedalism versus Quadrupedalism

Questions

A. What were the difficulties you experienced in moving as a quadruped? Specifically, what muscles were uncomfortable?

B. What everyday tasks do you think would become more challenging if Homo sapiens were full- time quadrupeds instead of full-time bipeds? Explain your answers.

C. What movements or tasks do you think would become easier and less challenging if Homo sapiens were full-time quadrupeds instead of full-time bipeds? Explain your answers.

Laboratory Summary

What have you learned from doing this laboratory that you did not know before you began it?

References