natural selection and adaptations what’s up with that bird?
TRANSCRIPT
Natural Selection and Adaptations
What’s up with that bird?
Vocabulary
•Adaptation•Natural Selection•Mutation
1.Scientists believe that the Earth and its inhabitants have changed a great deal over time.
-They have observed species’ fossil records and have noticedchanges over time.
-Organisms tend to adapt or change over time.
2. Adaptation- a change in an organism that helps it live and reproduce successfully in its environment.
-these adaptations can be physical or behaviorallong neck or stripes
Reproduction, protection,or finding food
http://www.lawrencehallofscience.org/kidsite/portfolio/build-a-fish/
3. One scientist that observed these kinds of differences in plantsand animals of the same species is Charles Darwin.
In 1831 Darwin sailed on board the SS Beagle from his home in England to a small island group off the coast of Ecuador
4. Darwin traveled to the Galapagos islands where he saw plants and animals that differed from those on other islands and the mainland.
Examples: tortoiseslong neck versus short neck
Live in dry climates with cacti Live in damp area with abundant plant life
5. Darwin also found different types of finches (birds). He noticeddifferent beak shapes and sizes from one island to the next.Woodpecker finch
Vegetarian finch
Large ground finch
Cactus finch
There are at least 13 species of finches, each with a different niche. All are said to have come from the same ancestral species, which only got to the islands about 2 million years ago. This is known as adaptive radiation-where one species quickly changes or adapts to fill in the “empty” ecospace.
6. When most plants and animalsreproduce, they usually produce moreoffspring than can survive.
Example: salmon-lay 1000’s of eggs, but not all will hatch. Of those that do
hatch, only a fraction will survive disease and avoid fish eating predators.
Only a small % of these survivors will make it to adulthood, with only a few being able to reproduce successfully.
7. From one generation to the next there are always variations. These genetic variations are passed down.
8. A change in genetic material is calleda mutation. Some mutations make theindividual better able to survive.
http://phet.colorado.edu/en/simulation/natural-selection -run now version
Camouflage an adaptation or a mutation?
Time: late 18th/early 19th century Place: Pre-industrial EnglandSubject: Biston betularia or the peppered mothBefore industry-trees had gray trunks-gray moths blended in better.
-Moths will rest during the day
After industry developed-treetrunks turned black due to thepollution from factories-black moth was then able to blend in
After many, many generations of this, most moths were then black.In this case coloration is
considered to be an adaptation.
-Black moth coloration considered a mutation
Moths
Peppered Moth Simulation• Objectives: Describe the importance of coloration in avoiding predation
Relate environmental change to changes in organisms (adaptation)Explain how natural selection causes populations to change
• Materials:
Sheet of white paper Clock or Watch with Second HandNewspaper 30 newspaper circles (made with hole punch)Forceps 30 white circles (made with hole punch)Colored Pencils
• Purpose: In this lab, you will simulate how predators locate prey in different environments. You will analyze how color affects and organism's ability to survive in certain environments.
Starting PopulationNumber Picked up
Trial Back
groundNewspaper
White WhiteNewspaper
1 white 30 30
2 white 30 30
3Newspaper
30 30
4Newspaper
30 30
Peppered Moth Simulation Copy this data table into your lab notebook
Introduction: Industrial Melanism is a term used to describe the adaptation of a population in response to pollution. One example of rapid Industrial Melanism occurred in populations of peppered moths in the area of Manchester, England from 1845 to 1890. Before the industrial revolution, the trunks of the trees in the forest around Manchester were light grayish-green due to the presence of lichens. Most of the peppered moths in the area were light colored with dark spots. As the industrial revolution progressed, the tree trunks became covered with soot and turned dark. Over a period of 45 years, the dark variety of the peppered moth became more common.
Procedure:1. Place a sheet of white paper on the table and have one person spread 30 white circles and 30
newspaper circles over the surface while the other person (or “predator”) isn’t looking (eyes closed).
2. The "predator" will then use forceps/tweezers to pick up as many of the circles as he/she can in 30 seconds.
3. Without putting the circles back between trials, repeat with white circles on a newspaper background, newspaper circles on a white background, and newspaper circles on a newspaper background. Record your data in the chart.
Starting PopulationNumber Picked up
Trial Back
groundNewspaper
White WhiteNewspaper
1 white 30 30
2 white 30 30
3Newspaper
30 30
4Newspaper
30 30
Peppered Moth Simulation
Analysis 1.What did the experiment show about how prey are selected by predators?
2. What moth coloration is the best adaptation for a dark (newspaper) background? How do you know?3. What would you expect the next generation of moths to look like after trial 1? What about the next generation after trial 3? 4. How does the simulation model natural selection?
5. Imagine a second mutation (clear or colored circles) caused a third population to arise, what affect do you think it might have on the other two populations of moths?
5. Examine the table and construct a graph. Plot the years of the study on the X-axis, and the number of moths captured on the Y axis. You should have 2 lines on your graph - one for light moths, and one for dark moths.
6. Explain in your own words what the graph shows. 7. Describe a situation where this type of selection might occur.
Year# of Light Moths
Captured# of Dark Moths
Captured
2 537 112
3 484 198
4 392 210
5 246 281
6 225 337
7 193 412
8 147 503
9 84 550
10 56 599
Use the ½ sheet of graph paper
3rd Period
Only
9. If this organism is able to survive and reproduce, the mutation is passed on to future generations. This is called selective breedinghttp://www.pbs.org/wgbh/nova/evolution/evolution-action.html
Example: Terriers bred to show certain characteristics
10. This idea led to the Darwin’s theory on Natural Selection.
11. Natural Selection: the process by which organisms that are best suited to their environment survive and reproduce. Example: small marine iguana on
an island with a thin layer of algal growth
http://media.nclive.org/authvid.phtml?vid=203&ctime=6 Voyage to the Galapagos video and questions (~60 minutes)
Who wants to live a million years?
http://science.discovery.com/interactives/literacy/darwin/darwin.html
Introduction. Scene - On a distant planet there exists 5 species of a creature called a Woolybooger. Each Woolybooger is similar except their mouth has variations. All woolyboogers eat beans. Some woolyboogers have a clothespin mouth (look at how to use the clothespin to pick up beans). Some woolyboogers have a tweezer mouth (as demonstrated), some have a needle mouth (as demonstrated). One year a new species of woolybooger was discovered, this woolybooger was called the Spoon-Mouthed Woolybooger (as demonstrated).
Each of you will play the part of a woolybooger on this planet. The spoon-mouth wooly booger is rare, so only two of you will get to be this type of woolybooger.
Survival of the Woolybooger
• Overview - Students will model natural selection by using various utensils to "capture food"
• Materials:
3 bags of beans (northern or lima) 10 tweezers
10 trays 10 clothespins
10 plastic spoons 10 rounded toothpicks
•At this point, I will pass out the utensils and give each group a tray with beans. The entire group will share bean trays but each person should have their own utensil.
•There is no "cheating", you must use your utensil in the way they are intended to be used (as I demonstrated).
•We will do several rounds. Each trial will require your Woolybooger to gain at least 20 beans. If 20 beans are not acquired during the time period, your Woolybooger has died.
•We will start with 1 minute.
Discussion Questions:1.What happens to animals that cannot compete as well withother animals in the wild?
2. Can you think of any real-life examples of the woolybooger, where one species has a definite advantage over another?
3. Sometimes animals that are introduced into an area that they never lived in before, out-compete and endanger resident species, why do you think this happens?
4. If only one species is considered the "fittest", why do we still have so many variations among species. Why do some birds have very long pointy beaks, while other birds have short flat beaks?
5. How do you think diseases can affect natural selection?
Darwin’s FinchesAdaptation occurs in an ecosystem so that species can better survive in their habitat. Sometimes these adaptations cause competition between species allowing one species to thrive while the other dies out.
A good example of this type of adaptation occurs on the Galapagos Islands with thefinches that inhabit the area. Each species of finch has a specific body weight, beak shape and eating habits that allows them toavoid competing for food with the otherfinches.
Birds of a beak activityIn this activity you represent finches with four different beak types. You may only use your beak to gather food to put in your “stomach”.
First, we will try to determine what kind of food your beak type would like best. You’ll try each of the different food types one at a time and then record the amounts in lab notebook data table.
Finch type Number of finches
Popcorn Marbles Beans Blocks Paperclips Toothpicks
Large Binder
Medium Binder
Small Binder
Spoon
Table 1Record the total number of each food item in
your “stomach”
1. You will need to have an area that is approximately 2 feet by 2 feet (one desk top).2. Each person in the group will have a different type of beak. 3. Scatter the contents of one cup of “food” into the marked territory (this is your island).4. When the teacher announces, you will have 2 minutes to gather as much food as you can. 5.The food has to make it to and stay in your stomach in order to count. Once in your stomach no one can take it from you.
Second, a mixture of food will be placed on your table and you have to see how many of the different beaks survive. You do this by adding up the number of calories you get (use the chart below) and comparing that to the number of calories you need to live.
Calories each food is worth:
Marbles – 50 caloriesBeans - 20 caloriesPaper clips – 15 caloriesToothpicks – 10 caloriesBlocks –30 caloriesPopcorn - 10 calories
Calories each finch needs to live:
Large binder clip- 300 caloriesSpoon- 250 caloriesMedium binder clips- 150Small binder clips- 100
Table 2Record the number of each food item you
collect from the food mixture. At the end, calculate the caloric intake of each beak. Did your finch survive? Finch type Popcorn Marbles Beans Blocks Paperclips Toothpicks Calories Did You Live?
Large Binder
Medium Binder
Small Binder
Spoon
Birds of a Beak Conclusion Questions
• From situation 1, which beak was best adapted? Which was least adapted?
• Which food item could be eliminated and not effect the population of finches?
• From situation 2, if food was in low supply-which food item could your finch survive off of?
Evolution LabIn this lab, you will use a computer simulation to track a population of organisms as they evolve. You will take data on the number and varieties of the organisms and graph them to show change over time and determine how two factors: MUTATION RATE and SELECTION STRENGTH affect how populations evolve.
Instructions1. Go to www.biologyinmotion.com and click on the link that says "evolution lab"2. Read the introduction and the contents to learn about the imaginary creatures you will be studying and how to operate the simulator. You may also want to look at the help link.3. Open the simulator and practice using the controls before you go on to the real simulation. Be sure to "reset" the simulator when you're finished practicing.
http://biologyinmotion.com/evol/index.html
Simulation A - The purpose of this simulation is to determine how the mutation rate affects the evolution of your population. You will need to run 4 trials with varying settings for mutation rate. Fill out the Data Table and create a graph using the graphing program at . You will have 4 lines on your graph. The X-axis will be cycles, and the Y will be mean phenotype.
Simulation B - The purpose of this simulation is to determine how selection strength affects the evolution of your population. Run three trials with the selection strength at 0, and three trials with the selection strength at varying ranges. (See data table)Fill out the data table and create a graph for simulation B.
Graphing Program located at: http://www.nces.ed.gov/nceskids/graphing
Blank Data Tables (doc)
AnalysisAnswer the following questions on a separate page, title this page "Evolution Simulation" and make sure your name is on it. You can even type it in Word if you like.1.Describe how the simulation models natural selection (and evolution).
2. Explain HOW the mutation rate affects the evolution of your populations. --> Explain WHY the mutation rate affects the evolution of your populations.
3. Explain HOW altering the selection rate affects the evolution of your populations. (You may want to include an explanation of what "selection strength" means.) --> Explain WHY altering the selection rate affects the evolution of your populations.
At the end of this web activity, you will have turned in the following documents:•Data tables •2 Graphs •Analysis Questions Credits: Special thanks to Leif Saul, author of Biology in Motion and the creator of the Evolution Lab.