Texas Science Teacher Resource Hub

Different species in the same environment usually have very different body parts because they have different jobs. In a Texas pond, the frog has webbed feet to swim, the heron has long legs to wade, and the fish has fins. Same pond, three different ways to move through water. Each one works for that particular species' lifestyle. There's no one-size-fits-all body for any environment.

Plants have lots of structures that help them survive. A cactus has spines (to discourage animals from eating it) and a thick stem (to store water). A tree has deep roots (to reach water and stay anchored) and broad leaves (to capture sunlight). Water lilies have wide, flat leaves that float on the pond surface to catch sunlight without getting submerged. Plants can't move, so their structures have to do all the work.

Many structures do more than one thing at once. A turtle's shell protects it from predators AND helps it regulate body temperature AND houses internal organs. A frog's long tongue catches food AND helps it sense the environment. A heron's beak is used for catching fish, but also for grooming feathers and building nests. When kids analyze a structure, they should think about all the jobs it might be doing, not just one.

Many species share environments without one pushing out the other because they have different roles, eat different food, and use different parts of the habitat. The frog and the turtle both live in the same pond, but the frog mostly eats insects while the turtle eats plants and small water creatures. The heron lives in the same pond but spends most of its time wading on the edges. Each species fits a different role in the shared environment.