Biology

 

ladybugs

Variation in ladybugs. Photo credit: readingevolution.com/evolution.html

 

Intro to Natural Selection

Grade Level: 7

Lesson Plan

State Standards:

10. Give examples of ways in which genetic variation and environmental factors are causes of evolution and the diversity of organisms.

Essential Question:

Lesson Question:

Introduction:

Have you heard of the phrase "survival of the fittest"? Are organisms that are the "fittest", the "best"? In biology, what does it mean for an organism to be "fit"?

Over the next couple of days, we will explore what it means for an organism to be "fit". Through examples, we will look at factors that affect how likely an organism is to survive and reproduce. Ultimately, these factors affect the chararcteristics of future generations of organisms of the species. This phenomenon is known as "natural selection".

In the end, you and a partner will present your own example of natural selection using Prezi.

Task:

Your ultimate task is to create a presentation using prezi.com that will do two things:
1. describe what natural selection is and how it works
2. give an example of natural selection

In order to accomplish this task, you will first explore what natural selection is using an interactive game and by watching two videos. Then you will learn new vocabulary using quizlet.com. After our work together (in class and homework), you will be prepared to plan and create your presentation.

Lesson Experiences:

Process (include all steps of the lesson procedure):

Day One: (50 min)
1. As a "Do Now", think about the phrase "survival of the fittest". What do you think it means? Write your thoughts in your notebook.
2. Log in to the computer and go to the following website.
http://sciencenetlinks.com/media/filer/2011/10/07/evolution.swf
Before you play the game, click on the "How to Play" button and read the text. Then click on the "back" button. Play the game and then write your answers to the questions in your notebook. Lastly, click on the "Learn More" button and read the text.


Check your answers with a partner if you are waiting for people to finish.
3. We will review the answers as a class.
4. Working in your assigned group, write a definition for the following terms:


All members of the group should take a turn and contribute his/her ideas.
One member is the "recorder" and will post your groups' answers to the class wiki site / or on an overhead (as technology allows).
One member will be the "reporter" and will share aloud the responses to the post.
5. We will discuss the answers and agree on official definitions.
6. Your homework tonight is to watch the following two videos and write a brief explanation for how natural selection is happening in each video.

a. Peppered Moth video (video)

b. Rock Pocket Mouse (just watch the first 3:10 min of video)

Choose the first video for the mouse.
(just watch the first 3:10 min of video)

Day Two: (50 min)
1. "Do Now" :
a. Take out your homework and leave it on your desk.
b. Use the following vocab set on quizlet.com to learn the new vocab words. Use the "flashcard" mode and then test yourself using the "learn" mode.

Study these flashcards

c. If you finish this, discuss your answers to the homework with your partner.

2. We will now discuss the two examples of natural selection from the homework as a class.

3. Describe the following components of natural selection in your own words. Write your answers in your notebook.
a. variation
b. overproduction
c. competition - List three things that organisms might compete for.

4. So far, we have talked about examples of natural selection acting on visible traits. However, there are many traits that you cannot see that affect an organism's likelihood to survive and reproduce. Watch the following video about an example of natural selection on a trait that we can not see with our own eyes.
video: why evolution matters now
Answer the following questions about the video in your notebook.
Describe the example of natural selection.
What problem does this type of natural selection pose for humans?
Have you heard about this problem before? What are your thoughts about it?

5. Homework (2 parts)-

Homework Part 1: Choose an organism and list 3 traits and possible variations of those traits for organisms of the same species.
For example, let's say I chose the peppered moth. The color of the peppered moth's wings is one trait and variations of that trait are black or peppered (white with black spots). A second trait is the wingspan of the moths. Variations in wingspan could be measured using a ruler. A third trait could be length of the moth's body or antenna length (variations in either trait could be measured.)
Note: you may not choose the peppered moth or the rock pocket mouse.

If you are having trouble with ideas, you may want to check out one of the following websites:
A to Z animals
Google Images - Variation within a species
Google Images - Plants

Homework Part 2:
Go back to the quizlet words from class. Review the words and then click on the "Test" button and take the quiz.

Day Three: (50 min)

Your task today is to design a presentation on prezi.com with your partner about natural selection.

1. Read through the description of "What you should include in your prezi".
2. Review your homework with your partner.
3. Decide if either one of your homework examples might be developed for use in Part II of the Prezi. If not, choose another species and trait for your presentation.
4. Brainstorm! Think about / research the content for your prezi first.
5. Talk about what you want your prezi to look like.
6. Now you may begin designing your prezi.
prezi.com
What you should include in your prezi. (See rubric below in assessments section.)

Part I. Include and explain the following terms in your prezi:
natural selection
trait
variation
overproduction
competition
"survival of the fittest"

Part II. Give an example of natural selection.
Choose one trait of one specific species.
Include at least one image of the species. The image must have a photo credit.
Describe the environment where this species lives (habitat).
Explain how a particular environmental factor in this habitat can affect the likelihood of the variations to survive and reproduce.
If the environment remains unchanged and you were to return to it after 50 more generations of offspring, what would you expect organisms to look like with respect to this particular trait?
Describe one possible change in the environment that could affect the natural selection process of this trait.

Conclusion:

You should now be able to explain what natural selection is and describe three components of natural selection. You should also be able to give at least one example of how variation and environmental factors can cause natural selection.

Look at the diagram below.
Each circle represents an organism (of the same species). In the top row, there is one circle. It is connected by lines to the three circles in the second row. Those three circles represent the offspring of the circle in the top row. The red X through a circle means that the organism died.
You should be able to explain this diagram using the terms natural selection, variation, and competition.

chart

To learn more about the history of natural selection (who discovered it and how), watch the following video.

Assessments:

1. Homework from Day One - descriptions of the video examples of natural selection
2. Homework from Day Two - example of natural selection
3. Homework from Day Two - quiz on quizlet.com
4. Prezi presentation from Day Three - see the assessment rubric below
Informal assessments on Days One and Two = participation in class discussion

Assessment Rubric
for Prezi presentation

rubric

Resources:

Resources:
Students need:
pens/pencils
notebook
computers with internet access
access to a class website or wiki

Web resources:
1. ladybug photo
2. Nowhere to Hide interactive game =
3. Peppered moth video =
4. Rock Pocket mouse video =
5. http://quizlet.com/
6. Why Evolution Matters Now =
7. A to Z Animals website
10. http://prezi.com/
11. natural selection diagram =
12. video on Darwin

Teacher Notes:

Depending on timing:
Part I content (the 6 terms) in the prezi could be omitted.
Students could present prezi's to the class or post prezi's to class website. Homework could be to view 2-3 other prezi's on the website and make comments.
Additional resources:
6-8 Teachers' Lounge on evolution.berkeley.edu website
Grants' research on finch beak size on Daphne Major (text)