March 14

Rainfall & Bird Beak Adaptations: Natural Selection in Action 🦜🌧️

📅 Lesson Overview:
In this activity, students explored how weather patterns impact the evolution of bird beak size using a Gizmo simulation. By modeling droughts and heavy rainfall, students observed how natural selection shapes a population over time.

DUE MARCH 18 at the beginning of class. 

📝 What We Covered:

1️⃣ Darwin’s Finches & Natural Selection

• Charles Darwin observed finches on the Galápagos Islands, noting that beak shapes varied depending on food availability.

• Natural selection allows birds with the best-adapted beak sizes to survive and reproduce, passing on their traits.

2️⃣ Gizmo Simulation: How Rainfall Affects Finch Beaks

• Students ran three different climate conditions:
  ✅ Normal Rainfall (25 cm/year) – Average beak size remained stable over time.
  ✅ Drought (5 cm/year) – Large, tough seeds became the main food source, favoring larger-beaked finches.
  ✅ Heavy Rainfall (50 cm/year) – Small, soft seeds were more common, favoring small-beaked finches.

3️⃣ Data Collection & Graphing

• Tracked finch population changes and average beak size over multiple years.

• Created histograms to compare how beak depth shifted under different weather conditions.

4️⃣ Claim, Evidence, & Reasoning (CER) Analysis

• Claim: Did weather changes cause beak depth changes in the finch population?

• Evidence: Used data from graphs and tables to support claims.

• Reasoning: Explained how natural selection favors certain beak traits based on food availability.

📌 Activity Details:

✅ Gizmo Simulation – Modeled how rainfall affects beak depth over time.
✅ Data Interpretation – Used graphs and tables to track population shifts.
✅ CER Writing – Constructed explanations based on scientific data.
✅ Discussion & Reflection – Connected findings to real-world evolution and climate change.

🌍 Why This Matters:

This activity demonstrates how evolution happens in real-time. Environmental changes like droughts and floods can shape species over generations, proving that natural selection drives adaptation!

✅ Great job modeling real-world evolution! Keep thinking about how climate and food sources impact species survival. 🔬✨