/20 Bird Beaks Biology

advertisement

Biology

Ch. 6 Explore

Name __________________________

Period _______ Date _____________

Bird Beaks

/20

Purpose:

to investigate how variation in characteristics of predators affects their survival and their population across time.

Materials:

Predator ‘beaks: forceps, spoon, toothpicks, clothes pins

‘Bird food’: raisins [slugs]

Background Information:

In this lab experiment, your group will be testing out the different bird beak sizes and types to determine which one would be best suited for this environment. Charles Darwin found that in the Galapagos Archipelago, finches evolved and adapted to their environment based on how well they were equipped to consume resources there. In this lab, you will be given multiple ‘bird beaks’ and one type of food and tasked to determine which bird beak is best equipped to meet the demands of this environment.

Experimental Procedure:

1.

2.

Write a hypothesis that depicts which of the bird beaks will perform the best in the environment with ‘slugs’ and why this beak will work the best by putting your hypothesis in ‘If, then, and Because’ format.

Spread the raisins around your table and assign one person in the group to be the counter

3.

4.

5.

of how much food is consumed.

Choose one of the bird beaks to test first and assign a group member to be the tester.

Set a timer for 30 seconds and assign one member of the group to be the timer, and another group member to record the results.

When the timer presses start, the person in charge of the bird beak will collect as many of the slugs as possible in 30 seconds. Repeat this step 3 times and calculate the average.

Repeat steps 3-5 for the remaining utensils, recording the results in the data table below. 6.

Hypothesis:

Data Table:

Utensil

Forceps

Spoon

Toothpicks

Chopsticks

Clothespins

Trial 1 Trial 2 Trial 3 Average

Graph:

Create a bar graph that compares the 5 utensils used with the number of raisins that they picked up. Create an appropriate scale and label the axis (including units). Above the graph create an appropriate title that reflects the variables tested in the experiment.

Title:

Analysis Assessment:

Name:________________________

Pd:_____ Date:___________

Fill in the blanks below using complete sentences. Use the completed lab above to answer the following questions.

1. What observations do you have about the evolution of the predators and prey that you simulated with this experiment?

_______________________________________________________________________________________________

_______________________________________________________________________________________________

2. Which beak was best at capturing a particular type of food? (Think about this in terms of efficiency)

_______________________________________________________________________________________________

_______________________________________________________________________________________________

3. Considering the predator/prey relationship, make a prediction about what would happen to the predator population in this simulation after several generations. Specifically, which birds would survive to reproduce more generations, and which ones would not?

_______________________________________________________________________________________________

_______________________________________________________________________________________________

4. Make a prediction about which type of bird (utensil) would survive in the following scenarios and explain why.

a. The habitat is permanently flooded and water bugs are the main food source.

_______________________________________________________________________________________________

b. Climate change occurs causing a long-lasting drought and seeds are the main food source.

_______________________________________________________________________________________________

Read the following paragraph

:

Characteristics of a species, such as beak shape, influence what abilities to eat an organism will have. These abilities influence how likely an individual is to survive. A characteristic can change to an advantage or a disadvantage when an organisms environment or its prey changes. Individuals that are better at coping in an environment are more likely to survive and reproduce. When they reproduce, these individuals pass their advantageous characteristics on to their offspring.

5. How does variation in beaks of the predator population affect the food sources the predator can eat?

_______________________________________________________________________________________________

_______________________________________________________________________________________________

6. How might the variation be an advantage or a disadvantage to the predator?

_______________________________________________________________________________________________

_______________________________________________________________________________________________

Download