15-3 Darwin Presents His Case ~Student Exploration~

*Here’s the idea… Work in groups. Participate fully. Choose who is partner one and who is partner two. Do your part. Have fun & learn the most important information about evolution.

Key Term #1 Partner 1 draws a tower of giraffes on the white board. (Yup, it really is called a tower.) You must draw at least six different giraffes. One minute Partner two laughs at giraffes. J/k  10 seconds then get over it Partner 2 really looks at the population for physical differences. Make note of physical differences in writing on the white board. Come up with at least 5.

Key Term #1 Natural Variation What partner 2 just outlined is called natural variation. Please define this term in your own words on your ½ sheet worksheet.

Key Term #2 Scenario The population of giraffes has really gone through the roof. No pun intended. Due to this incredible competition, the lowest vegetation is getting depleted. Only the tallest giraffes can access food. Partner 1 should circle those giraffes that will survive on the white board.

Key Term #2 Fitness What partner 1 just outlined is called fitness. Please define this term in your own words on your ½ sheet worksheet.

Key Term #3 Survival of the Fittest This term is often used to describe the situation in which some organisms survive while others don’t. What do you think is meant by this term? Partner 2 should write the prediction for your pair on the white board.

Key Term #3 Survival of the Fittest What do we think this means? Write a definition on the ½ sheet.

Key Term #4 What was it about the giraffes that you circled that allowed them to survive? Partner 1 should write one major physical characteristic that allowed them to survive. Please write this on the white board.

Key Term #4 Adaptation The characteristic that you described is called an adaptation. Please define adaptation on your ½ sheet of paper.

Key Term #5 In the wild, what selects in favor of the organisms that survive and selects against those that don’t? Partner 2 should write your group’s prediction on the white board.

Key Term #5 Natural Selection What you just described is called natural selection. Define this term on your half sheet.

Evidence #1 What predictions could you make about the age of fossils found at different levels of this rock layer? Partner 1 jot down a response on the white board for this one!

Evidence #1 Partner 2. Can you think of any exceptions to this? Hint: What would happen if you made a layered Jell-o dessert and then drove down a bumpy road?

Evidence #1 Define Fossil Evidence in your own words on your ½ sheet.

Evidence #2 What in the world? Don’t all of the animals to the left look alike? Well, they’re not! Partner 1, why would all of the animals at the left HAVE to look alike? This is a tricky one. Write down your answer on your white board.

Evidence #2 Define geographic distribution in your own words on your ½ sheet.

Evidence #3 Paw-Arm-Wing Wow, they really are a TON alike! Partner 2. Genetically, how could your arm be so much like the forelimb of a cat or the flipper of a whale?

Evidence #3 Define homologous structures in your own words.

Evidence #4 Check this out! http://www.pbs.org/wgbh/nova/evolution/guess-embryo.html Look at the pics to the right. Partner 1, how could you explain the similar ways in which these organisms develop? Write down an answer on the white board!

Evidence #4 Define similarities in early development in your own words.

One more thing… Partner challenge Why would a whale have a femur (upper leg bone)? Does a whale actually need a femur?