How Do Species Adapt to Different Environments?

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1 Objectives Introduction Period Name Other members of lab team How Do Species Adapt to Different Environments? Organisms have traits that help them to survive in different habitats. Fish can live in water because they have gills and fins. Birds have wings and lightweight bones, so they can fly. Some plants have tiny "claws" that enable them to cling to such surfaces as rocks and walls. Everywhere you look, organisms seem to be well suited to their particular set of environmental factors. How are these helpful characteristics acquired? Suppose the climate changes. Can whole populations of organisms acquire new characteristics to enable them to be successful under the conditions, or must they move to avoid extinction? 1. To discover ways in which species change over time to become adapted to certain environments. 2. To propose a mechanism for those changes. Materials One piece of different patterned fabric Fabric number 10 vials, each containing 100 paper chips of a single color graph paper Procedure 1. In this lab, you will try to discover what happens to the characteristics of organisms within a population that is subjected to predation over a number of generations. Ideas from this lab may help you answer the question, "How do species adapt to environments?" Work in groups of 3 or To do this lab, you will play the role of a population of birds known as Gooney birdicus (gooney birds). Gooney birds feed on a species of mouse known as Microtus coloriferii (colorful mice). The role of the colorful mice will be played by the paper chops. Gooney birds are very hungry and always capture the first mouse they see. After the capture, they always take their prey to their nest (the small container) before they return to hunt more. 3. Begin by spreading a piece of fabric on your table. This represents a natural habitat. 4. Take 10 "mice" from each of the 10 vials. 5. Spread the 100 mice at random throughout the habitat. 1

2 Repeat steps 6, 7 and 8 for a total of three rounds 6. At the teacher's signal, begin capturing mice and placing into your nest one at a time. Your group should capture a total of 75 mice (25 mice should remain in the habitat). One person should record, and 3 should capture 25 mice each. 7. Remove the surviving mice from the habitat to the counting sheet. Count and record the number of mice of each color left. 8. Have the 25 survivors reproduce by adding three paper chips of the same color for each of the survivors. This new population of mice consists of 25 first-generation mice and 75 second generation mice for a total of 100 mice. Fill in your results on the table marked Results of Predation. 9. After your third round of predation and reproduction, make a bar graph showing the number of each color of mice left. (See an example on the next page - note that the numbers of mice total USE YOUR OWN NUMBERS, NOT THE EXAMPLE OR ANOTHER TEAM S RESULTS) 10. a) Select one member of your group to put their graph on your table next to your habitat fabric. Go from table to table and on the back page of this lab (on the back of the data chart), describe each habitat (identified by fabric number) and what the results were. Briefly describe how those results compared to the habitat (comparing colors, patterns, etc.) Try and explain, What patterns are revealed by the graphs? Write your answers to 10 a on the back page b) How can the results of your graph be explained? 11. Answer the following questions about your results: a. What colors of prey were eaten in the greatest numbers in your habitat? b. How does their color compare to that of their habitat? c. Why didn t you let the mice you picked up (when you were a Goony Bird ) to reproduce? d. Did each color of mouse do equally well in each habitat? Why or why not? e. What might happen if the mice where all the same color at the start? f. What might happen if the mice produced less that 3 offspring? g. What might happen to the mouse population if no more mice were eaten? h. What might happen if mouse color were not passed from parent to offspring? 2

3 Study Questions 1. During the 1920 s, a population of spotted crabs was know to inhabit the white sandy beaches near a volcano on one of the Hawaiian Islands. The spotted crabs were observed to feed off plants that were cast up on the beaches by ocean waves. Occasionally, seagulls were observed capturing and eating some of the crabs. When first observed, about 90% of the crabs were white with a few small black spots on their claws. About 8% were white with many black spots, while the remaining 2% were almost completely black. In 1930, the volcano erupted, sending a lava flow across the beach and out into the water. The lava cooled and blocked the ocean currents that had deposited the white sands on the beach. Black sands from other currents began to accumulate on the beach until the beach was completely covered with black sand. By the 1950 s, nearly 95% of the spotted crab population was composed of crabs that were completely black. About 4% were white with many black spots, and 1% were white. Use the theory of natural selection to explain the change of the most frequent color of the spotted crabs from white to black. Define biotic potential, limiting factors, variation, and heredity. 2. Would natural selection in a population over time occur A) more rapidly, B) less rapidly, or C) not at all if... a. No inheritable variation existed in the species (they were all the same)? b. No changes occurred in the environment? c. Conditions of life were unlimited (no competition)? d. Biotic potential a species was relatively low? 3. How is the process of natural selection similar to and different from artificial selection? 3

4 Number of mice Example of bar graph (use your own results and colors, though!!!) Total Mice Left red blue green yellow purple orange whit e black cream brown Color of mice 4

5 Results of Predation Color of Mice Survivors after round one) Babies from round one times 3) Total mice going into round 2 (Babies + Mice left) Survivors after round two) Babies from round two times 3) Total mice going into round three (Babies + Mice left) Graph last column Survivors after round three) Babies from round three times 3) Total mice left at end of three rounds Babies + Mice left) Total mice left: expected/actual 25/ 75/ 100/ 25/ 75/ 100/ 25/ 75/ 100/ These numbers are what you should end up with after each round 5

6 10 a Select one member of your group to put their graph on your table next to your habitat fabric. Go from table to table and on the back page of this lab (on the back of the data chart), describe each habitat (identified by fabric number) and what the results were. Briefly describe how those results compared to the habitat (comparing colors, patterns, etc.) Try and explain, What patterns are revealed by the graphs? List each habitat by number and write your description and results next to the habitat number. 6