Key Idea.
Section 1
A New Mystery (Sticklebacks)
Scientists are studying Stickleback fish in lakes. Some of these fish have heavy "armor plates" (Full Armor), while others have very few (Low Armor).
Fossil data and modern observations show a rapid change: in some lakes, the population shifted from mostly Fully Armored to mostly Low Armor in a very short time. We must use our Natural Selection model to explain why.
Section 2
Analyzing the Environment
To explain the shift, we must look at the environmental pressures.
In the ocean, large fish try to eat sticklebacks, so armor is adaptive. But in these specific lakes, the predators are different (e.g., dragonfly larvae). We need to determine if "Low Armor" provides a survival advantage in this specific lake environment.
Expand to review the lesson summary and core properties.
Section 1
A New Mystery (Sticklebacks)
Scientists are studying Stickleback fish in lakes. Some of these fish have heavy "armor plates" (Full Armor), while others have very few (Low Armor).
Fossil data and modern observations show a rapid change: in some lakes, the population shifted from mostly Fully Armored to mostly Low Armor in a very short time. We must use our Natural Selection model to explain why.
Section 2
Analyzing the Environment
To explain the shift, we must look at the environmental pressures.
In the ocean, large fish try to eat sticklebacks, so armor is adaptive. But in these specific lakes, the predators are different (e.g., dragonfly larvae). We need to determine if "Low Armor" provides a survival advantage in this specific lake environment.