7.1 Resources - Darwin and Natural Selection 

Instructions for ch 13 text activity: 

1) The first "term" listed - use the textbook to do a written summary

2) Use an alternate source of summarize item number 2 

- Depict or diagram one of the two terms 

- Due Monday (3/2) 

Preview

Natural Selection - A story. 

Now that we have heard several examples of natural selection in action (Darwin's finches, twitching lizards, elephants tusks, Galapagos Marine Iguanas)   - you now must find an example of your own. 

Do some research to an example of natural selection that is unique. Your job is to do a write-up similar to what you used for your elephant or iguana example. YOUR WRITE UP IS NOT THE EXPLANATION OF NATURAL SELECTION BUT THE INTRODUCTION PORTION. (See example to the right) 

Evolution in Action:

Natural Selection and Elephant Tusks

 

History: African Elephants have long been sought after by hunters that are illegally poaching large adults for the ivory in their tusks. Experts from the Wildlife Conservation Society believe that there are around 25,000 elephants poached each year despite a poaching ban that came in the 80s. In 1930, biologists noticed that about 1% of wild elephant populations were born with a “tuskless” allele and would not grow tusks during adulthood.

 

The Situation: Today, in some populations, 38% or more of African Elephants are born without tusks. Poachers are much less interested in the “tuskless” variety due to absence of the valuable ivory from the tusks.

 

The Question: Explain how NATURAL SELECTION would have caused this obvious change in the “tuskless” variety of elephants in Africa. In your response, include how elephants show variation, which trait is beneficial and why, and how the beneficial trait becomes common over time.

Introduction to Evolution Activity 

- Use the PowerPoint to the right(and your topic guide - divide the backside in half and record on the left hand side) and record 

- 3 things you already knew about evolution 

- 3 things you did not know 

- 2 questions you have

Evolution in a Big City

- On the back of your topic guide, answer the following questions: 

1) What are the organisms being studied in this study?

2) What are three differences between the city and country mice? 

3) What tool is being used in this study that Charles Darwin didn't have during his lifetime?