Grade level
Asking questions (for science) and defining problems (for engineering)
Developing and using models
LS4.C: Adaptation
ESS2.D: Weather and Climate
Students are presented with the puzzling phenomenon of the darkling beetle from the Namib Desert. The Namib Desert expects only 5 to 85 millimeters of water each year. In order to survive, the beetle has to use multiple adaptations to collect and take in water. Students are not yet told about the different mechanisms, but they are introduced to pictures and a video of the beetles so that they can observe them first hand. The beetles find water in seeds blown into their ecosystem, in the food they eat, and by catching water vapor droplets from the fog on their backs, using a special collection adaptation. This adaptation has a hydrophobic region that pushes water toward a hydrophilic region that helps the water vapor form into liquid water that the beetle can drink.
Students were asked to create an initial model of how they believe the beetle collects water to drink. They were asked to include different ways they think the beetle might get their water and survive in one of the hottest and driest places on Earth.
Student models generally showed thinking about biotic/abiotic interactions as well as the role of adaptations to help the beetle find and drink water. Samples A-E each indicate the abiotic factor of the sand acting as a ‘sponge’ and soaking up any water that is present in the system. This abiotic factor then interacts with the biotic, the beetle, who digs into the sand to access the water when needed. Samples B-D indicate increased attention to animal adaptations, particularly how the legs are used to dig into the sand and how the antennae might be used to locate the water underneath the sand. Samples A-D indicate that students are thinking only about liquid water in the environment, but Sample E references the fog (water vapor) that accumulates underneath the sand and can be accessed by the beetle digging.
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