Big Ideas From Gizmo Activities
Birdbeak Gizmo • Organisms ADAPT to their environment over time; the most fit organisms survive to mate. • During normal rainfall, most birds will have average sized beaks. • During droughts, the surviving birds will have larger beaks, and there are fewer birds. • During plentiful rainfall, average beak size is favored, but the environment can support more birds (population size).
Food Chain Gizmo • The sun is the source of all energy on earth. • There are lower numbers of organisms at higher trophic levels (“up” on the pyramid) because it takes more prey than predators (the predators need their “next meal”). • When disrupted (excess rain or drought, fire, hurricane, etc.) a system will work to reach equilibrium.
EXTRA! • Initially, a disruption in any level (diseased rabbit, diseased grass, etc.) will have effects on all trophic levels until equilibrium can be reached. • When making a food chain, the arrow points FROM the prey TO the predator. • Food webs are complicated food chains. • Only 10% of energy is passed on each level of a food chain.