Friday, May 29, 2015 HOMEWORK: Finish Snakes packet (Doc#12) OBJECTIVE: I will be able to create models that show the change in a species over time, multiple generations, offspring and final version of a species DO NOW: What happened to the head size of the red bellied snakes? Why?

Share your initial models with your group members. What can you do to make your model better? How does it fit the model criteria? (Make changes in red ) Why the head size of the Australian Red-Bellied Black Snakes has changed since 1935?

Evaluating 2 Models: Model A & B Next you will discuss 2 models in class. For each model, discuss this question in pairs, and then write your answer individually.

MODEL A Write answers, class discussion

MODEL B Key: Snakes with varying head sizes Poisonous toad Shows snakes that die from eating poisonous toads 1, 2, 3… Steps Write answers, class discussion

Evaluating Two Models Which evidence contradicts Model A? Why does it contradict it? Which evidence is not included in Model B? Give reasons for your answer.

Share your initial models with your group members. What can you do to make your model better? How does it fit the model criteria? (Make changes in red ) Why the head size of the Australian Red-Bellied Black Snakes has changed since 1935?

Model C Now look at Model C, and complete an arrows diagram for the evidence and the model you selected. In groups, discuss each evidence and which rating and arrows are best. Ask each other questions; give lots of reasons; listen to and think about each person’s ideas. After discussing each evidence, individually write your rating and arrows on the diagram. Be prepared to explain to the class each of your arrows. (pg 6) Then individually write your answers to Questions 1 and 2.

MODEL C (Same key as Model B)

Model C Discuss how good model C is, and why. Compare it and contrast your initial model to Model C.

Arrows Diagram Evidence GoodnessMODEL C Evidence 1 Snakes often die when they eat poisonous toads. Evidence 2 The spread of poisonous toads in Australia from 1935 to Evidence 3 Snakes in areas with poisonous toads have smaller heads than snakes in areas without poisonous toads. Evidence 4 Sydney Zoo Newsletter reports 6 new baby snakes born. Evidence 5 Head size in Red-Bellied Black Snakes is a genetically inherited trait. Evidence 6 The head size of adult Red-Bellied Black Snakes does not ever decrease or 1 1 or 2 2

Arrows Diagram 1. What arrow did you draw between Evidence 3 and Model C? Write your reasons for your arrow choice. 2. What arrow did you draw between Evidence 5 and Model C? Write your reasons for your arrow choice.