Imagine this: on a quiet night in Hawaii, the usual symphony of chirping crickets suddenly vanishes. But it’s not just a natural lull — it’s the sound of evolution in action.
This real-life phenomenon is the centerpiece of a ready-to-use biology case study perfect for your unit on evolution, natural selection, or animal behavior. It’s built around the fascinating discovery that a mutation causing male crickets to go silent actually helped them survive and reproduce — challenging students to think deeply about how evolution works in real time.
🧬 The Story: Evolution on Fast Forward
On the island of Kauai, male field crickets once sang loudly to attract mates. But when a parasitic fly arrived that could home in on the song and kill the singer, silence became a survival strategy. A genetic mutation called flatwing rendered some males mute — and surprisingly, those males began to thrive.
Students will explore:
- How natural selection gave silent males a survival advantage
- How sexual selection typically favors song, yet flatwing males still reproduced
- Why the flatwing trait spread so rapidly through the population
This story isn’t fictional — it’s based on real, peer-reviewed research published by scientists investigating evolution as it happened.
🧪 What’s in the Lesson?
This downloadable case study includes everything you need for a powerful, standards-aligned classroom experience:
- Engaging, student-friendly reading
- Background info on cricket behavior and mating
- Reading comprehension questions
- Analysis of a real graph from the original scientific study
- Free response prompt
Related Lessons
Case Study – The Island of the Colorblind – explore human evolution, genetic drift, and population bottleneck
Mutations and Evolution in Aquatic Mammals – lessons from whales that focuses on nonsynonymous mutations
Why Can’t We Be Friends – explore isolating mechanisms, such as behavioral, temporal, and geographic
Survival of the Sneakiest – this cartoon describes the cricket’s mating behavior in a student-friendly way