1998 WWLPT Biology Institute:  Motion

The Effect of Surface Texture on the Stride Length of a Newt

Summary/Abstract
Instructor's Objectives
Target Age or Ability Group Audience
Teacher Instructions/Special Precautions
Materials & Equipment Needs
Background [Prior Knowledge or vocabulary necessary to complete activity]
The Student Lab
Method of Evaluation/Assessment
Extension/Reinforcement/Additional Ideas
 

Summary/Abstract  to top
 

• In       Alexander stated that the stride length of an organism would not be  effected by different surface textures.            With this background information in mine, we designed a set of experiments varying the surface texture on which a newt travelled to see if under these conditons, we could support or negate Alexander's findings.  After completion of the trials on rock, mud, sand and agar surface textures, we concluded that our data support Alexander's statement.

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Instructor's Objectives to top

• To determine the effect of surface texture on stride length.
• Evaluate the accuracy of Alexander's equation relating stride length and surface texture.

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Target Audience or Age Group  to top

• Biology students (high school)

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  Notes to the Teacher: to top

1. This lab can be used with groups of two or four students.
2. Preparation time is needed  to obtain the materials (sand, flat rock, mud, water) and to prepare the agar solution.
3. A pre-lab period is necessary to discuss locomotion, and stride length.  For students to understand newt locomotion, some discussion of the evolution of leg length and leg position in amphibians is recommended.
4. The lab activity will require a 45 minute period.
5. The stride length can not be determined in water because newts locomote differently on water than on land.  However, students should be allowed to determine this themselves through experimentation.
6. The newts do not move in a linear manner.  To facilitate linear movement, we used partitions which created narrow channels.
7. To determine stride length: measure an exact distance the newt will travel in each medium; count the number of times one leg hits the surface (same leg each time);  and calculate stride length (distance/leg hits).

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Materials & Equipment Needs to top

 Sand
 Three Newts
 Rock
 Mud
 Metric Ruler
 1.5 % Agar Solution
 Containers to hold sand, water, mud, and agar
 Stop watch
 Partition materials (cardboard, rulers)
 Dechlorinated water
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Background to top
[Prior Knowledge or Vocabulary Necessary to Complete Activity]
This activity helps students answer:
Students need to know the external characteristics of a newt and its environment.  Students should recognize that different animals have different leg positions and number of legs and how that impacts locomotion.  Students should be able to determine how stride length could be measured in an organism.
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The Student Lab to top

1. Introduction:
2. Newts have the ability to propel themselves through water by leg and tail muscle contractions.  They also are capable of walking on four limbs out of water .   In their land habitat, they encounter mud, sand, rocks and slippery organic material. An experiment was designed to determine if a Newt's stride length was affected by different surface textures.
3. Purpose:
4. Does surface texture affect stride length of a newt?


 

5. Equipment:
6.  


 Three Newts                   Dry Sand
 Rock                               Mud                              Stop watch
 1.5 % Agar Solution        Metric Ruler                  Dechlorinated water
 Partition Materials (cardboard and/or rulers)
Containers to hold sand, water, mud, and agar
 

7. Procedure:
8. 1.  Set up a definite and equal  length of  water, dry sand, mud, rock, and agar.

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Methods of Evaluation/Assessment to top

Possible Qualitative Observations:

 *Four legs with clawless toes
  *Streamlined bodies
  *Well developed head with large mouth and eyes
  *Moist, smooth skin
  *Long tail
  *Swims like eels using body muscle contractions to propel through the
   water
  *Uses limbs very seldom in swimming
   *Limbs are sprawled
  *On lands, newts use body propulsion, have several gaits
  *Very lightly colored underside, dark, speckled upper body *Four legs with clawless toes
  *Streamlined bodies
  *Well developed head with large mouth and eyes
  *Moist, smooth skin
  *Long tail
  *Swims like eels using body muscle contractions to propel through the
   water
  *Uses limbs very seldom in swimming
   *Limbs are sprawled
  *On land, newts use body propulsion, have several gaits
  *Very lightly colored underside, dark, speckled upper body

Possible Quantitative Observations:
 

Probable Conclusion:

The data indicate that surface texture does not affect stride length.  A Chi Square was done to determine the relationship between stride length and surface texture.  There is a 90% probability that surface texture does not affect stride length.
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Extension/Reinforcement/Additional Ideas to top
Questions:

1.  Determine the most ideal habitat for a newt based on surface texture.
2.  Are newts nocturnal or diurnal?
3.  Does body mass affect stride length?
4.  Do newts prefer water or land?
5.  What are the predator/prey relationships of a newt?
6.  Does the position of a newt's legs affect its stride length and/or speed?
7.  Are newts hermaphrodites?
8.  What evolutionary paths have newts followed?
9.  Do newts use gills or lungs for respiration?
10. What are some adaptations that allow newts to survive in their natural habitat?
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References Including Web Addresses to top

Amphibian breeding pond survey