210 likes | 447 Views
Variations in the Clam Species Clamys sweetus. Learning Target. I can describe how natural selection preserves favorable traits Create a new title/thread “ Clamys sweetus ” Update your table of contents. Entry Task.
E N D
Learning Target • I can describe how natural selection preserves favorable traits • Create a new title/thread “Clamyssweetus” • Update your table of contents
Entry Task • In your notebook, write 5 words or phrases that come to mind when you hear the term “Natural Selection”
Entry Task • In groups of 4, take turns sharing your lists. • Describe why you chose each word/phrase. • Choose two words/phrases to share with the class.
What is the role of natural selection in evolution? Comment on each statement. Which one do you agree with? Why?
ClamysSweetus • Read the Introduction • Descent with modification: natural selection favors some variations resulting in them becoming more common in the next generation.
ClamysSweetus • Without opening the bags, and without squeezing the clams, observe the two strains of clamyssweetus. • Answer #1,2,3 in your packet.
ClamysSweetus • Read “Observations of Clamyssweetus” p. 2 • Using Chart 1, you will be comparing pairs of clams (1 strain R and 1 strain M) to determine if one clam has a stronger shell.
ClamysSweetus • Follow Procedures 1-1 thru 1-6. • Record your results in Chart 2 (1-7) • Put your group’s results on the board.
ClamysSweetus • Using the class data, complete the Analysis section (steps 4,5,6) • Read “Setting the Scene” • Answer step 7
ClamysSweetus • Step 5: Why is it important to use class data and not just the data obtained by an individual team? Class results are more reliable because there are more trials. A larger sample size leads to increased precision and more accurate data.
ClamysSweetus • Step 6: Is there a difference in shell strength between the two varieties? Support your answer with data.
ClamysSweetus • Step 7a: The arthropod is able to crack open only relatively weak clam shells. Which variety might the arthropod seek out as it hunts for food?
ClamysSweetus • Step 7b: How might this feeding preference affect the numbers of the two varieties in this and future populations of C.sweetus?
Wrap-Up • What trait was “selected for” in this activity? • How does this activity relate to our learning target? • How do you think this learning target fits in with our chapter goal of answering the question “What are the underlying biological mechanisms of evolution?”
Exit Ticket • Complete and return the exit ticket before you leave!
ClamysSweetus Day 2 • We are going to investigate the hypothesis that shell color and hardness are related. • Follow 2-1 thru 2-3 to gather data • Put your data on the board.
ClamysSweetus Day 3 • A new color variation of ClamysSweetus has appeared – Brown • Formulate a hypothesis about the ability of brown clams to survive predation by the predatory arthropod. • Design an experiment to test your hypothesis. • This is very similar to the type of prompt you will see on the EOC! • Complete #13 and #14
ClamysSweetus Day 3 • Question:Could the presence of a few brown clams eventually lead to a population that is mostly brown clams?
ClamysSweetus Day 3 • Pocketmouse video • Does fur color influence which pocket mouse survives and which does not? • Could the pocket mouse information apply to C. sweetus? • What do you need to know to make this decision? • Video
ClamysSweetus Day 3 • Could the pocket mouse information apply to C. sweetus? • If it does, what caused the brown color to appear in the clam population? • Complete the rest of the packet.