Objective: Students will explain how the traits expressed by members of a population can change naturally over time.

Sponge: Two long-haired dogs (dad: Ll, mom: LL) reproduce and have puppies.  Use a Punnett square to show the possibility of them having long or short-haired puppies.

Anticipatory Set: Complete “Response Sheet: Natural Selection;” using Think-Ink-Pair-Share

After partner share, discuss as a class & share ideas

Guided Practice: Read “Successful Variations” (Daybook p. 73) on giraffes; highlight sentences describing survival advantage on student copy

-Discuss how student answers compare AND have them make corrections as needed

-Q: What are other examples of organisms and selective pressure?

Independent Practice:

- Students will diagram an example of a population being affected  by selective pressure (ex: a wolf pack culling caribou from a herd)

Making Meaning:

-Discuss student diagrams: what did you diagram?  How does selective pressure affect these organisms?

-Discuss Mid-Summative Exam 8 #7: APPLY knowledge of genetics to explain how populations respond to selective pressure

Closure: Complete #8 on Mid-Summative Exam – addresses peppered moth scenario (Why is variation in a population important?)

Homework: "Bikini Bottom Genetics" due Friday