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NAME_______________________________________________________________________________HOUR___________

WHAT IS ADAPTATION? Adaptation:___________________________________________________________________________________________

_________________________________________________________________________________________________________ Extinct: _______________________________________________________________________________________________

Polar bears live unprotected in sub-zero weather. You cannot. Neither can most organisms.

Polar bears are “built” for the bitter cold. They have a thick layer of fat and dense fur.Some animals live comfortably in other climates. The camel, for example, is suited to live in the hot, dry desert. Alligators are suited to live in hot, humid marshes.

An ______________________________ must be well suited to its environment in order to survive. It must be able to tolerate the climate. It must also be able to get food, protect itself from enemies, and reproduce. An organism that is well suited to its environment is said to be _________________________ to its environment.

Earth is about ______________________________ years old. Life has existed here for more than _______________________________ years. Fossil records tell us that Earth has been constantly changing. So have its life forms.

Many species that lived in the past have died out. They are ___________________________. These organisms could not adapt to their changing environments.

Adaptation does not only apply to animals. It applies to plants and protists as well. For example, a cactus can grow in the hot, dry desert. An oak tree, on the other hand, grows well in a cooler, moister environment.

How does adaptation take place? There are many theories. The most accepted one is the ________________________________________________________.

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THEORY OF NATURAL SELECTION

1. Organisms produce more offspring than the environment can support. Some must die to allow proper balance of life to continue. Which ones will die?

2. Overproduction leads to a struggle. All the organisms compete for food, water, and the other necessities of life. Only those organisms that are well suited to their surroundings survive. The rest die.

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3. Organisms of the same species are very similar. But they do have _________________________ differences. These differences are important in the “struggle for survival.” For example, extra speed can mean the difference between life and death. A fast antelope may escape an attacking tiger. A slower neighbor may become the tiger’s next meal.

4. The most adapted organisms survive and reproduce. They, in turn, pass their favorable traits to their offspring. The offspring are then more likely to survive.

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UNDERSTANDING THE THEORY OF NATURAL SELECTION

Study the diagrams. Then answer the questions.

1. Did all ancient giraffes have long necks?

____________________________

2. ___________________________ - necked giraffes Long, Short

were better able to reach food far offthe ground.

3. ___________________________ - necked giraffes Long, Short

were better suited to the environment.

4. The ___________________________ - necked Long, Short

giraffes died out.

5. Which giraffes survived and reproduced?

a. The ___________________________ - necked Long, Short

giraffes.

b. What important adaptation did the surviving giraffes pass on to theiroffspring?__________________________________________

6. All giraffes living today are

___________________________ - necked Long, Short

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ADAPTATION

The woodpecker is well adapted to dig insects out of trees.

Birds have feathers and lightweight bones. They are well adapted for flight.

Can you think of a better way to escape an attacker? Fly away and live to fly another day.

The streamline shape of fish allows them to move quickly through the water.

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Some organisms adapt by looking like other organisms.For example, the monarch butterfly (top) is “bad tasting.”

The viceroy butterfly (bottom) does not bad taste.Hunting birds do not know this and are fooled by the lookalike butterfly. So they stay away from both species.

Some organisms blend in with their surroundings. This makes it difficult for other organisms to see them…

See how this toad blends in with its surroundings? It is almost invisible.

The polar bear and the snowy owl blendin with the white arctic snow.

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HUMAN ADAPTATION

An important human adaptation in the thumb. How important is the thumb? More important that you may realize…

Try this:Tape your right thumb (if you are right-handed) to your next finger. Then try to do these tasks…

1. Fasten (or unfasten) a button2. Pick up a book3. Turn a doorknob4. Hold an object as you would a hammer5. Turn a screwdriver

How important is the thumb? You answer the question!Do you think civilization would be as advanced if people did not have thumbs? Explain.___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

COMPLETING SENTENCES

changingshape uplimited number

favorableadaptedhelp

not surviveorganismsship out

very differentreproduce

1. An organism that is suited to its environment is said to be ________________________ to its

surroundings.

2. Earth is always ________________________.

3. As the earth changes, the ________________________ that live on it also change.

4. An organism that does not change as its environment changes may ________________________.

5. A favorable environment can support only a ________________________ of organisms.

6. Organisms belonging to the same species can be ________________________.

7. Some individual differences ________________________ an organism survive.

8. Organisms that adapt to their environment may ________________________ and pass their

________________________ traits on to their offspring.

9. Using Navy terms, as far as adaptation is concerned, “you either ________________________ or

________________________.

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NATURAL SELECTION

1. What are some difference you have noticed in the size and shape of dogs in your neighborhood?

2. Do their differences make them better at some things, but not well-suited for others?

3. What would happen if the world suddenly changed, so the only thing that dogs could eat was deer and there was absolutely no way for a dog to eat if it wasn’t big or strong enough to each and kill a deer?

Most likely, smaller dogs would die off, and the bigger ones would survive and reproduce. After a while, instead of a population of dogs of all sizes, most of the dogs in the population would be big dogs.

Next, think about the mice shown below. Describe what is happening in figures 1-3.

Living things that are well adapted to their environment survive and reproduce. Those that are not well adapted don’t survive and reproduce. An ________________________ is any characteristic that increases ________________________, which is defined as the ability to survive and reproduce. What are some characteristics of animals or plants that affect their fitness?

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Below are descriptions of four female mice that live in a beach are which is mostly tan sand with scattered plants. Color of fur Brown Tan Tan and Brown CreamAge at death 2 months 8 months 4 months 2 months# pups produced by each female

0 11 3 0

Running speed 8m/min 6m/min 7m/min 5m/min

4. According to the definition given for fitness, which mouse would biologist consider the fittest? Explain why this mouse would be the fittest.

5. If a mouse’s fur color is generally similar to its mother’s color, what color fur would be most common among the pups?

A more complete definition of fitness is the ability to survive and produce offspring who can also survive and reproduce. Below are descriptions of four male lions. Name George Dewayne Spot TyroneAge at death 13 years 16 years 12 years 10 years# cubs fathered 19 25 20 20# cubs surviving to adulthood 15 14 14 19Size 10 feet 8.5 feet 9 feet 9 feet6. According to this definition of fitness, which lion would biologists consider the “fittest”?

Explain why.

Suppose that Tyrone had genes that he passed on to his cubs that helped his cubs to resist infections, so they were more likely to survive to adulthood. These genes would be more common in the next generation, since more of the cubs with these genes would survive to reproduce. A characteristic that is influenced by genes and passed from parents to offspring is called ________________________.

Over many generations, heritable adaptive characteristics become more common in a population. This process is called _________________________________________________________________. Evolution by natural selection takes place over ____________________________________ generations.

Evolution by natural selection leads to adaptation within a population. The term evolution by natural selection does not refer to individuals changing, only to changes in the frequency of adaptive characteristics in the population as a whole. For example, for the mice that lived in the beach area with tan sand, none of the mice had a change in the color of their fur; however, due to natural selection, tan fur was more common for the pups that for the mother mice.

In summary, a heritable characteristic that helps an animal or plant to have more offspring, which survive to reproduce, will tend to become more common in a population as a result of evolution by natural selection.

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7. Explain why a characteristic, which helps an animal to live longer, will generally tend to become more common in the population as a result of evolution by natural selection.

8. Not all characteristics that contribute to longer life become more common in the population. Some characteristics contribute to long life, but not more offspring. For example, a female cat, which is sterile and cannot have any offspring, may live longer because she will not experience the biological stresses of repeated pregnancies. Explain why a characteristic like this which contributes to a long lie, but with few or no offspring, would not become more common as a result of evolution by natural selection.

Below is a series of pictures representing changes in a population of cacti over many generations.

9. Why could a deer be more likely to eat the cactus that the right cactus?

10. In figure 3, the right cactus has flowers, but the cactus that has been eaten by the deer is too damaged to make flowers. Figure 4, shows the situation several months later. What has happened? Do you think that evolution by natural selection is occurring in this cactus population? Explain why or why not.

11. “Survival of the fittest” is a common expression. What do you think most people mean by this expression? How would you explain this expression to help someone understand how natural selection actually functions?

12. What characteristics of humans do you think helped them survive and reproduce during the hundreds of thousands of years when they were hunter-gathers?

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EVOLUTION OF AN ORIGAMI BIRD

INTRODUCTION:The Origami Bird (Avis papyrus) lives in dry regions of North America. Only those birds that can successfully fly the long distances between the sparsely spaced oases will be able to live long enough to breed successfully. In this lab you will breed several generations of Origami Birds and observe the effect of various phenotypes on the evolutionary success of these animals.

PROCEDURE:1. Prepare “ancestral” bird (see teacher’s example):

Cut two strips of paper, each 2 cm x 20 cm.Loop one strip of paper with a 1 cm overlap and tape. Repeat.Tape each loop 3 cm from the edge of the straw.

2. Breed offspring. Each Origami Bird has three offspring.a. The first egg has no mutations. It is a clone of the parent.

To save time you may substitute the parent when testing this chick, rather than building a duplicate.

b. The other two chicks have mutations.For each chick, flip you coin and throw your die then record the results of the mutation based on the table below. Then build each offspring.

MUTATION TABLE The coin flip determines where the mutation occurs:

on the anterior or posterior end of the animal.o Heads = anterior (front) mutationo Tails = posterior (back) mutation

The die throw determines how the mutations affect the wing.o 1 = The wing position moves 1 cm toward the end of the strawo 2 = The wing position moves 1 cm toward the middle of the strawo 3 = the circumference of the wing increases 1 cmo 4 = the circumference of the wing decreases 1 cmo 5 = the circumference of the wing increases 2 cmo 6 = the circumference of the wing decreases 2 cm

3. Test the birds. Release the birds with a gentle, overhand pitch. It is important to release the birds as uniformly as possible. Test each bird at least three times.

4. The most successful bird is the one that can fly the farthest. Record the dimensions of the most successful bird on the data table.

5. The most successful bird survives to be the only parent of the next generation. Continue to breed, test, and record data for at least 6 generations.(Gain extra points for doing 8 generations)

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FIRST GENERATION:Parent Information: (Ancestral Bird)

Head ring is _________ cm from end, and __________ cm in circumference

Tail ring is ___________ cm from end, and __________ cm in circumference

Offspring Information:

A. (Same as parent)

B. Head ring is _________ cm from end, and __________ cm in circumference


C. Head ring is _________ cm from end, and __________ cm in circumference


SECOND GENERATION:Parent Information: (The most successful from generation #1)




A. (Same as parent)





THIRD GENERATION:Parent Information: (The most successful from generation #2)




A. (Same as parent)





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FOURTH GENERATION:Parent Information: (The most successful from generation #3)




A. (Same as parent)





FIFTH GENERATION:Parent Information: (The most successful from generation #4)




A. (Same as parent)





SIXTH GENERATION:Parent Information: (The most successful from generation #5)




A. (Same as parent)





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*SEVENTH GENERATION: extra credit*Parent Information: (The most successful from generation #6)




A. (Same as parent)





*EIGTH GENERATION: extra credit*Parent Information: (The most successful from generation #7)




A. (Same as parent)





RESULTS: Record the dimensions of the most successful bird of the final group:



CONCLUSION: Answer the questions.1. Did your selection process result in better flying birds?

2. Describe two aspects of this lab that model evolution of biological organisms.

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3. Your bird has a different ancestral history than your neighboring groups’. Compare your bird with your neighbors’ and describe and similarities or differences.

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