Namib Desert Beetle
Water is necessary for all life to live, but in some places, water is scarce. Living things have evolved various behaviors and adaptations that allow them to take advantage of the chemical properties of water. Understanding the different states and properties of water helps explain how living things collect water in unique ways.
This storyline investigates the interesting phenomenon at the intersection of the biotic and abiotic as it looks at the behavior of the Namib beetle, raising the question for students, “How do beetles survive in the driest place on earth?
The storyline begins by looking at a video of darkling beetles in the Namib desert. Students watch their curious behavior and after observing live darkling beetles, draw a model that illustrates how they think the beetle gathers water for survival.
Students then start to look at different concepts necessary to explain this phenomenon. They start with principles from earth science, exploring how sunlight hits earth differently and at different angles based on geography, causing different climates. Students then build on their understanding of the sun and the energy it brings to earth by investigating how energy from the sun in the form of heat transforms water from solid to liquid and liquid to gas.
After exploring the states of water, students then learn about the chemical structure of water and how the polar nature of water affects how some materials and surfaces attract or repel water. Specifically, students look at the hydrophobic and hydrophilic surfaces on a beetle and how they interact with water. Students use the principles from this exploration to transfer their knowledge to an engineering design challenge in which they try to design systems for collecting water.
As students return to their original models to explain how a beetle can survive in drought conditions, students also transfer their knowledge of water and materials to other living creatures.
