"We wear these oxygen helmets so we can't introduce our bacteria into an ancient atmosphere." - Travis, "A Sound of Thunder."
Although Ray Bradbury's "A Sound of Thunder" primarily focuses on how nature can be thrown into chaos if an organism is removed (i.e. a mouse, a butterfly), it does hint at the opposite possibility: that nature can also be massively disrupted by the addition of an organism (i.e. the sterilization of the suits and the use of oxygen helmets). Therefore, this lesson explores - through two key unit terms, "niche" and "invasive species" - whether Time Safari, Inc.'s "chaos theory," in its additive form, exists in reality. For a kinesthetic, interactive introduction to "niche," a beach-ball baseball game mimicked how species exhibit specific roles in a habitat (just like baseball players: short stop, third base, catcher, pitcher, etc) and how, when two species have the same position, competition leads to a less effective play. Students' exposure to the aquatic biome emerged only through teacher modeling of the "nesting cup" food chain activity in a prior lesson. Therefore, an online site dedicated to spotlighting marine invaders and their effect on their non-native oceanic region provided a competitive exploration of the previously overlooked biome. With a concluding class poll at the end of class as motivation, students were challenged to find the "worst" invader (i.e. Who creates the most "chaos" when added?).
Baseball Game Analogy: Basics NICHE As an introductory, kinesthetic activity to a key vocabulary word, "niche," we had six student volunteers come to the front of the room, and the teacher assigned to a position in baseball: batter, catcher, pitcher, first baseman, second baseman, third baseman. Armed with a beach ball, the students stood on makeshift floor markers that resembled the diamond of a baseball field. The teacher narrated a play-by-play, requiring the students to mimic how they would handle the situation (i.e. "Batter hits lowball to third base and third baseman throws to first" = Batter rolls beach ball to third and third baseman student throws the ball to first while batter runs). We discussed what happened in terms of how well the situation was handled. Launching off the role-playing, we discussed an organism's "niche" by reading the associated section in textbook chapter, "4-2: What Shapes an Ecosystem?" Just like each player on a baseball team has a specific role to play to keep the game running smoothly, every organism has a unique role in its habitat. A niche includes the biological conditions in which an organism lives, like when and how it reproduces, the type of food an organism eats, how it obtains this food,and which other species use the organism as food. It also involves the physical conditions, like the temperature range an organism needs to survive. |
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Baseball Game Analogy: Key Concept TWO SPECIES, ONE NICHE No two species can share the same niche in the same habitat, so - back to our baseball analogy - what do you think happens when we add a second third baseman? How would the addition affect the player's ability to maintain a smooth game? What would happen at third base? We made our predictions, got another student volunteer to stand by third, and ran through the same play. What happened? Competition at third that sent the game into dysfunctional chaos. This hypothetical addition lead into our look at invasive species through the brief associated section in textbook chapter "6-3: Biodiversity." |
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"A Sound of Thunder" + Textbook + Video: Invasive Species Cause/Effect T-CHART To supplement and bring to life the brief description the textbook provides on invasive species, we watched an animated video clip that explains the concept through monster Frank - a voracious city-dweller - monster Oliver - a picky eater on a faraway island. The video is provided to the left. Then, using three sources of information, we filled in a T-Chart for the causes and effects of invasive species:
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Niche: the full range of physical and biological conditions in which an organism lives and the way in which it uses those conditions. An organism's unique role in its habitat.
Invasive Species: a species (plant or animal) introduced to a nonnative region that negatively affects the ecosystems they invade economically, environmentally, and/or ecologically.
Chaos Theory: Given a very small difference in initial conditions, the same system will behave – after a very short time – totally differently. Therefore, due to extreme sensitivity in a system, a seemingly insignificant event can spur a chain of events with unpredictable outcomes.
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Student Choice - Online Exploration: Aquatic Invasive Species Since we overlooked the marine biome in our food chain-based study of terrestrial biomes, we navigated an online website dedicated to spotlighting aquatic invasive species in four main ocean regions: the Atlantic, the Pacific, the Gulf, and the Great Lakes. Go to "Nab the Aquatic Invader!" available at the link below, click on one of the colored regions on the homepage's map, select "Meet the Suspects" - the first file folder on the left side of the screen - and pick which invasive species you'd like to learn more about! Each of the four regions provides ten (10) species. You'll notice that some permeate more than one area, while others are unique to an area. Feel free to explore the lists for each region before selecting one to read. Once you've decided on a species, be prepared to share your findings in a group of four. Map Color Key:
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Small Group Sharing Class Poll: The "Worst" Invader Once we finished exploring the website and interacting with some of its features - some of the invasive "suspects" even gave an oral report! - we split into groups of four to talk about the species we chose. After hearing each other's chosen invasive species, each group chose the one that they believed to be the "worst" invasive species (which, interestingly, also makes it the most successful invasive species!). Which has the largest, most irreversible effect on its infiltrated habitats? After picking, each group shared their top choice to the class and provided a brief rationale. With permission from the student creator, the teacher projected the graphic organizer for each group's choice as a visual during the brief oral synopsis. After hearing each group's top pick, the class voted which was the "worst," submitting their vote on a slip of paper before they left class. The "worst" invasive species will be announced next class! |