Biology

Heredity: Adaptation

Lesson Plan

State Standards:

Reproduction and Heredity, Grades 7-8, #7-9, p. 52; Evolution and Biodiversity Grades 7-8, #10-12 p. 52

Essential Question:

How do organisms adapt to an environment in order to survive and ultimately reproduce offspring?

Lesson Question:

Do individual organisms adapt to their environment, or does adaptation take place gradually through subsequent generations?

Introduction:

Traits which help organisms survive will then, in turn, be passed on to their offspring. Traits are carried on genes. But how is it that organisms survive in the wild long enough to pass on their traits? We'll look at one way organisms adapt and survive, so that future generations can survive: protective camouflage.

Task:

How is it that organisms survive in the wild? After an initial discussion, we will watch a video on camouflage in the animal kingdom. Then, we will cut out paper moths, and color them in to blend with plainly visible surfaces in the classroom to avoid detection by the students in subsequent classes. What can we learn from our moths about how camouflage works? How does this trait become an adaptation that helps future generations survive?

Lesson Experiences:

Class 1
Boys and girls, today we will look at ways animals survive in the wild despite predators lurking around them and wanting to eat them. How do you think they survive? Let's discuss for 10 to 12 minutes and see what answers you produce.


Now we will watch a short video on ways in which animals survive. Some of this may be familiar to you, and some new to you. Try and remember what is new to you, so that you can share it with us after the video ends.

Peppered Moth Evolution

YouTube:  Peppered Moth Evolution

What did you learn? Let's discuss for 10 minutes.


Now, let's work with an example of the organism studied in the video: the moth.

To do this, we will create our own moths and see if they survive.


moth image Draw the outline of a small moth no larger than 5cm x 5cm. Then, color it in. You should try and have it blend in with a surface inside the classroom, such as a wall, floor, or cabinet. When you are finished with it, cut it out and place a little tape or putty on the back so it will stick to the surface, which you drew it to match. Remember where you put it. (This will take about 25 minutes).

Your fellow students in the next class will try and find as many as possible. You will be given the same opportunity during the first class tomorrow morning. We will see which class can find the most paper moths.


Well done! Tomorrow we will see how many of your paper moths were discovered, and how many avoided detection.

Class 2

Good morning, boys and girls. You may recall that yesterday we were exploring the question, "How do animals survive in the wild despite the enemies that are lurking about ready to kill them and eat them?” You cut out paper moths, which you had colored in. Now locate the spot where you affixed a moth, and tell us whether it is still there or has it been found. If it was not discovered, please leave it where you placed it. We'll do this for about 10 minutes.

Now, let's look at how many were found, and how many are still where you left them. We will tally the results. The moths that your classmates in another room did not find are like the ones in the wild that survive. These will more likely have a chance to mate and bear offspring. We'll do this for about 10 minutes.

During the remaining time in class, let's explore how other species have adapted through time. Some mimic their surroundings because of changes in the species from one generation to the next, while in others species, organisms have evolved differently by changing their own color or patterns to match their surroundings more completely like a praying mantis or the cuttlefish in this video. (25 minutes)



"Evolution of Camouflage"

Nova Evolution of Camouflage

The Cuttlefish's Amazing Camoflage

When this is done, we'll discuss protective camouflage and how it protects an organism. Do individual organisms adapt to their environment, or does adaptation take place gradually through subsequent generations? How does our moth example show the answer?

Conclusion:

The moths that mimic their surroundings have a better chance of surviving and passing on their genes to their offspring, than those that do not. This shows us one way organisms adapt and survive to pass on their genes, so that their future generations can survive: protective camouflage.

Assessments:

You will be able to....

Strong

Good

Adequate

Inadequate

Weighting

Draw a moth

Moth is drawn carefully,
and blends will with the surface
on which it was attached

Moth is drawn, and blends in
somewhat with the surface
on which it was attached

Moth is drawn poorly, and
barely resembles the surface
on which it was attached

The noth was not finished, and does not blend with the surface on which it is attached.

10%

Understand adaptations

Understands that adaptations take place through generations, and not in the individual organism, and can explain it.

Understands that adaptations take place through generations.

Has a sense that good traits are passed on.

Unable to comprehend that adaptations take place in a species over time, and not in the individual.

30%

Understand Genes

Understands that genes are contributed by both parents in sexual reproduction on the chromosomes

Has a basic sense of gene transfer from parent to offspring

Knows that genes are inherited from both parents in sexual reproduction, bud has no understanding of how

Does not grasp the concept of gene transfer or of how genes are responsible for inherited traits

30%

Understand Natural Selection

Clear grasp of how well adapted organisms are able to carry on and reproduce

Basic understanding of why some organisms survive to reproduce, while others do not

Limited understanding of how natural selection works

No understanding of how natural selection works.

30%

Resources:

PBS Teachers Domain "Nowhere to Hide" interactive

PBS Teachers Domain "Masters of Disguise"

PBS Teachers Domain "Evolution of Camouflage"

"Evolution of the Peppered Moth" -- YouTube


"Peppered Moth -- Wired Science"

The Evolution Game from Recerca en Acció

Arkive video Images of Life on Earth

Cuttlefish Camo example

Classroom supplies:

 

Teacher Notes:

This lesson assumes that the students have already covered genetics, and the transfer of traits on genes during sexual reproduction and the development of the organism from the humble zygote to a complete adult. Students will be introduced to the idea that traits which help offspring survive will then, in turn, be passed on to their offspring. Students will be reminded that during the lessons that traits are carried on genes.

 

Image credits:

Red moth image from Wikimedia Commons

Otodonta dromedarius03 by Kulac, from Wikimedia Commons