Name______Hour___

VARIATION LAB

HOW PATTERNS OF VARIATION RELATE TO EVOLUTION

Definitions:

Adaptation

Selection Pressure

Variation

Purpose: In this lab, you will investigate patterns in nature (variation) and how they relate to the survival of a species. You will also practice graphing and analyzing data.

Procedure:

HANDS: Using a meter stick measure your hand spread apart from thumb to little finger in centimeters. Record class data table and graph on graph paper.

MEAL WORMS: Obtain 5 mealworms in a petri dish. Using a metric ruler, measure in millimeters. Record class data table and graph on graph paper.

PEANUTS: Obtain 5 peanuts in a shell. Crack them open and measure the inside nut (cotyledon) in millimeters. Record class data in data table and graph on graph paper.

DATA:

Each set of data should be recorded in a data table. Below is an example of one.

hand size (cm) / 15 / 16 / 17 / 18 / 19 / 20 / 21 / 22 / 23 / 24 / 25 / 26 / 27 / 28
number of students

Each set of data should be graphed using a line graph. The graph should be done on graph paper, and be labeled as to what it is. Note: The vertical axis is used for the number of students (dependent variable) and the horizontal axis is used for what you are measuring (independent variable).

QUESTIONS: Answer on a separate page along with your definitions, stapled to the graph paper.

1.  Looking at each of the graphs, what effect does sample size have on the shape of the graph and the validity of the information?

2.  For mealworms and peanuts, name a selection pressures that might act upon that organism in its natural environment

3.  Looking at each of the graphs, list an advantage and disadvantage for each organism having that size and helping survive in it’s environment.

4.  For mealworms and peanuts, make up a new selection pressure (not mentioned above) and explain using your graphs what affect it will have on the population of that organism.

5.  Having made the observations above and having graphed them, what general statement can you make about the gene pool for each of the populations you studied?

CONCLUSION: Write a conclusion explaining this statement.

How patterns of variation relate to evolution.