E-Science: Exploring the Scientific Method

Greetings E-Science folks!

Welcome to Biology Now! This posting will present information for you, the budding scientist, to learn how to investigate scientific phenomenon. In class and in your readings, you were introduced to the scientific method. Now, you will get another chance to learn more about how science is done.

In the following activity, you will be working with a partner participating in a computer simulation activity. One partner will run the simulation, while the other reads along and makes notes when necessary. You are both responsible for discussing the activity and answering the questions together. You will be turning in one answer set for your working partnership. Be sure BOTH your names are on the answer sheet!

Click on this ClassZone link and scroll down to Chapter 2. Click on 'How Might You Investigate Scientific Phenomenon?'

There are 9 steps to this assignment, HOWEVER, you are only to do the first 8! Read each step carefully, view the animations and answer the questions. These are to be done on a separate sheet of paper. If you are feeling particularly inspired, you are welcome to complete step 9. This last step would be considered an EXTRA-CREDIT assignment and you are given an extra 2 days to complete it.

Biology - Evolution

Greetings Biology Students!

Lately, we've been studying evolution at Ann Sobrato High. Several assignments feature interactive web activities designed to guide student inquiry regarding natural selection.

• Click on the link 'Fish with Fingers' to view the QuickTime movie that accompanies the Fossil Record - Evidence for Evolution activity (see below for worksheet). Students view the movie and answer a series of reflective questions given on the activity handout.
  
• Click on the links 'Homologous Structures' and 'Evidence for Evolution' to view webs to help find answers to questions asked in the Fossil Record - Evidence for Evolution activity.
• Click on the link 'Flashy Fish' to view the interactive web experiment which explores the relationship between natural selection and sexual selection in wild guppy populations.

Evidence for Evolution: Fossil Record
Tetrapod Limbs – Homologous Structures
If you want to see concrete evidence of evolution, look no further than your hand or your foot. Five fingers, five toes. There's nothing magical about the number, yet five digits at the end of their limbs is a motif that runs through all the animals with four limbs, called tetrapods. Even when there are fewer than five digits in the adult animal -- as in horses' hooves and the wings of bats and birds -- it turns out that they develop from an embryonic five-digit stage.

Please read ALL the instructions before proceeding!

With your partner, view the Quicktime Video: Fish with Fingers.

Click on the VIEW button to watch the video.

Discuss and answer the following questions:

1. What did old theories say about the evolution of land-dwelling animals, and why was paleontologist Jenny Clack dissatisfied with these explanations?
2. What evidence did Clack find to disprove old theories?
3. What explanation of the evolution of land animals can Clack give based on current fossil evidence?
   

Click on the Evidence for Evolution link and examine the limb structures of various animals. Discuss with your partner the following questions.

Write your answers in your own words on a separate sheet of paper! Use drawings to provide evidence of your thinking. You may also refer to your Biology text, pages 401-411 to help you in your understanding and in answering the questions. In addition, you will want to check out the websites provided in the links to the right.

1. What are the similarities and differences among the four limbs shown?
2. How would scientists explain why these very different species all have limbs with five digits?
3. What is the difference between a homologous structure and an analogous structure? Name some examples of each.
4. What is a vestigial organ or structure?