Biology Honors 2019 - 2020

Name: Block: Date: PACKET #0

Unit 0: Introduction to Biology

Learning Objectives:

Topic 1: Scientific Investigation 1. Explain the role of ignorance in scientific inquiry.2. Determine whether a question can be tested scientifically3. Given a scientific question, formulate a testable hypothesis.4. Identify independent variable, dependent variable, and controlled variables in an experimental design.5. Describe how an experiment can be designed with a control group and experimental group(s).6. Given a data table (1) determine the correct type of graph to use (2) create a graph with all important

elements e.g. title, labeled axes7. Explain how a null hypothesis is used in experimental design.

Topic 2: Ecology Connection

8. Explain the importance of bats in an ecosystem.9. Describe the white nose syndrome that affects bats, and explain how scientists are studying this

phenomenon.

Topic 3: Evolution Connection E – 1. Compare and contrast the three domains of living things. E – 2. Use a phylogenetic tree to determine evolutionary relationships and common ancestry. E – 3. Describe the contributions of Charles Darwin to the field of evolutionary biology. E – 4 Define evolution and theory. E – 5 List and explain the steps of evolution by natural selection. E – 6 Explain how artificial selection helps support Darwin’s theory of natural selection. E – 7 Define population and species (biological concept and others)

Key Terms/Concepts Hypothesis Independent variable Dependent variable

Control variable Control group Line graph

Bar graph Null hypothesis White nose syndrome

Evolution Vocabulary Archaea Bacteria Eukaryota Domain Common ancestor

Phylogenetic Tree Cladistics Evolution Natural Selection Artificial Selection

Theory Species Law Fact

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Topic 1: Scientific Investigation In-Class Activity

Science is a creative human endeavor that involves asking questions, m

aking observations, developing explanatory hypotheses, and testing those hypotheses. Biologists use science to study the phenom

ena of life, observe living systems

and organisms, ask questions, and propose explanations for those observations.

In this activity, you will review

the processes scientists use to ask and answer questions about the living w

orld. You will

also build some of the skills needed to conduct your ow

n scientific investigations.

I.A

sking Questions

Scientists use their studies of previous research or personal observations of natural phenomena as a basis for asking

questions about the underlying causes or reasons for these phenomena. For a question to be pursued by scientists, the

phenomenon m

ust be well defined, and testable. The elem

ents must be m

easureable and controllable.

1.W

hich of the following questions do you think can be answ

ered scientifically?a.

Is there a link between childhood vaccinations and autism

?b.

Can cross---pollination occur between genetically engineered turf grass and non---genetically

engineered grass?c.

Should human em

bryonic stem cells be used to treat Parkinson’s disease?

d.D

o cactus spines reduce herbivory (predation by animals)?

e.D

id the use of the herbal supplement ephedra cause the death of the 18---year old soccer player?

2.H

ow did you decide w

hich questions can be answered scientifically?

II.Developing H

ypothesesAs questions are asked, scientists attem

pt to answer them

by proposing possible explanations. These proposedexplanations are called hypotheses. A hypothesis tentatively explains som

ething observed; it proposes an answer to a

q uestion. (Note: som

e teachers require that hypotheses be stated in an “if… then…

” format. This is fine, but not

mandatory for honors bio.) A scientifically useful hypothesis m

ust be testable and falsifiable (able to be proved false).Let’s discuss an exam

ple. Question 4 above asks, “do cactus spines reduce herbivory?” A possible hypothesis could be,

“cactus spines reduce herbivory”. This could also be rephrased: “If a cactus has spines, then it will be less affected by

animal predation.” Are these falsifiable and testable? In our exam

ple, we can test by rem

oving spines from som

e cacti tosee w

hether animals still eat them

. If animals do not eat the plants, the hypothesis has been falsified. Even though the

hypothesis can be falsified, it can never be proved true. The evidence from an investigation can only provide support for

the hypothesis. Other explanations m

ust still be tested and excluded, and new evidence from

additional experiments

might falsify this hypothesis at a later date.

3.W

hich of the following statem

ents would be useful as scientific hypotheses and could be investigated using

scientific procedures? Give the reason for each answer by stating w

hether it could possibly be falsified andw

hat factors are measurable and controllable? Adapted from

: Campbell, N

eil A. et. al. Investigating Biology Lab Manual,

7 ed. 2007a.

Mole rats navigate through tunnels by orienting to the earth’s m

agnetic field

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b. Crime rates increase during the full moon.

c. Positive emotions promote long life.

d. Exposure to the pesticide endosulfan affects hormone levels in boys.

III. Designing Experiments to Test HypothesesYou must next design a test of your hypothesis that will provide unambiguous evidence to falsify or support aparticular explanation. An experiment involves defining variables, outlining a procedure, and determining controlsto be used as the experiment is performed.Read the following description of a scientific investigation of the effects of sulfur dioxide on soybean reproduction.Then answer the questions that follow.

INVESTIGATION OF THE EFFECT OF SULFUR DIOXIDE ON SOYBEAN PRODUCTION Agricultural scientists were concerned about the effect of air pollution, specifically sulfur dioxide, on soybean production in fields adjacent to coal---powered power plants. Based on initial investigations, they proposed that sulfur dioxide in high concentrations would reduce reproduction in soybeans. They designed an experiment to test this hypothesis (Figure 1.1). In this experiment, 48 soybean plants, just beginning to produce flowers, were divided into two groups: treatment and no treatment. The 24 treated plants were placed in a fumigation chamber and exposed to 0.6 ppm (parts per million) of sulfur dioxide for 4 hours to simulate power plant emissions. The no treatment plants were similarly placed in a fumigation chamber, but were exposed to filtered air for 4 hours. Following the experiment, all plants were returned to the greenhouse. When the beans matured, the number of bean pods, the number of seeds per pod, and the weight of the pods were determined for each plant.

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Figure 1.1: Experimental design for soybean experiment.

Read the description of each category of variable; then identify the variable described in the soybean investigation.

The Dependent Variable Within an experiment, one variable will be measured or counted or observed in response to experimental conditions.

4. For the soybeans, several dependent variables were measured, all of which provide information aboutreproduction. What are they?

0.6 ppm SO2

Filtered air

Untreated Treated

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The Independent Variable The scientist will choose one variable, or experimental condition, to manipulate. This variable is considered the most important variable in testing the investigator’s hypothesis. A good experiment will usually have only one independent variable.

5. What was the IV in the soybean experiment?

6. Can you suggest other variables that the investigator might have changed that would have had an effect onthe dependent variables?

7. Although other factors, such as light, temperature, and time might affect the dependent variables, only oneindependent variable is usually chosen. Why is it important to have only one independent variable?

8. Why is it acceptable to have more than one dependent variable?

The Controlled Variables Consider the variables you identified as alternative independent variables(question #6) . Although they are not part of the hypothesis being tested, they could have significant effects on the outcome of this experiment. These variables must, therefore, be kept constant during the course of the experiment. The underlying assumption in experimental design is that the selected independent variable is the one affecting the dependent variable. This is only true if all other variables are controlled.

9. What are the controlled variables in this experiment?

The Control Group When your experiment compares 2 or more groups, like the soybean experiment, it is usually helpful to have a control group. This is the group that investigators leave alone; the independent variable is not manipulated for this group. The group(s) for which the independent variable is manipulated is called experimental group(s). At the end of an experiment, we look for differences in our data between the control group and the experimental group.

10. Why is it helpful to set up a control group? Why not just add sulfur dioxide to all 48 soybean plants?

11. How is a control group different from a controlled variable?

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IV. Presenting and Analyzing Experimental ResultsOnce the data are collected, they must be organized and summarized into tables and graphs so that experimenterscan determine whether the hypothesis has been supported or falsified. Tables and graphs have two primaryfunctions. They are used (1) to help you analyze and interpret your results and (2) to enhance the clarity withwhich you present the work to a reader or viewer. Part of this clarity is that tables and graphs need to havedescriptive titles and axis labels. The title should state the effect of dependent variable on the independentvariable (y axis vs x axis). Axis labels must be precise and include the units (if applicable).

Data from the soybean experiment is presented for you below. Examine the table and graphs, and then answer the questions that follow.

Table: Effects of 4---Hour Exposure to 0.6 ppm Sulfur Dioxide on Average Seed and Pod Production in Soybeans

Treatment Number Seeds per Pod Pods per Plant

Control 24 3.26 16

SO2 24 1.96 13

Graph 1:

Graph 2:

Effect of SO2 Exposure on Seed Production in Soybean Plants

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4

3

2

1

0 Control SO2

Treatement Group

Effect of SO2 on Pod Production in Soybean Plants

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15

10

5

0 Control SO2

Treatement Group

Aver

age

Pods

per

Pla

nt

Aver

age

Seed

s pe

r Po

d

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12. Our graphed data look different from our data table. What are the benefits of presenting data in table form?What are the benefits of presenting data as a graph?

13. What limitations do tables have? What limitations do graphs have?

14. Look at graphs 1 and 2. Where do you find the independent variable on each (x--- or y--- axis)? Where is thedependent variable?

15. What parts of the experiment do the titles tell you about; IV, DV, or both? Is this true for both tables andgraphs?

Microsoft Excel or Google Sheets are helpful tools if you use them carefully! Students often create graphs from spreadsheet programs without really looking at what they’ve produced. Remember, a good graph tells your reader what the experiment was about, and what data were collected.

The graph below was formed by simply copying the entire data table into an excel spreadsheet, then creating a bar graph from the data.

Graph 3:

16. Examine the graph. How is it helpful? How is it confusing? What’s missing?

18 16 14 12 10

8 6 4 2 0

Control

SO2

Pods per plant Seeds per Pod

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17. We said earlier that graphs should (1) to help you analyze and interpret your results and (2) to enhance theclarity with which you present the work to a reader or viewer. Does Graph 3 accomplish these goals?

Line Graphs vs. Bar Graphs The two graphs you will use most frequently this year are bar graphs and line graphs. Sometimes it’s difficult to know which one to use. The type of data you have will actually determine which graph you make.

Line Graphs: Line graphs show changes in a quantity of the chosen variable and emphasize the rise and fall of values. Use a line graph to present continuous data. (Hint: look at your x---axis. If the categories are in a continuous order, you need a line graph.)

Bar Graphs: Bar graphs are used for data that represent separate or discontinuous groups, or non---numerical categories. Use a line graph to represent discrete differences between groups.

Practice Problems Answer the questions that follow each research project described below.

1. A study was conducted on the feeding preferences of slugs. Specimens were fed a variety of food sources,and data were collected on number of grams of each type of food eaten.

Food Source Food Eaten (grams) Lettuce 4.0 Mushroom 8.2 Dog food 0.0 Spinach 6.5 Apple 8.6 Peach 5.4 Orange 1.0

a. Which food source was favored most by slugs?

b. What is the dependent variable?

c. What is the independent variable?

d. What type of graph will you use? Why?

e. Give your hypothetical graph a title.

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2. Baby chickens require a constant source of food. As chickens grow, more energy is needed for dailyactivities. The following table gives the grams of food eaten by a chick over a 7---day period.

Day Food Eaten (grams)

0 0.0 1 1.0 2 3.5 3 ?? 4 8.5 5 11.0 6 ?? 7 16.5

a. What is the dependent variable?

b. What is the independent variable?

c. What type of graph will you use? Why?

Graph Title:

d. Interpolate: Use your graph (not calculations) to estimate the amount of food eaten by the chick on days 3and 6. Fill in the table with your answers.

e. Extrapolate: Predict the amount of food that will be eaten by the chick on day 8.

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3. Can we use a line graph for interpolation and extrapolation? Can we use a bar graph for interpolation andextrapolation? Explain your answer.

4. A study was made of endangered birds to see if their populations were increasing over several years inwhich a hunting ban was instituted. Scientists went out into the field every ten years and counted thenumber of whooping crane, California condor, and black swan the found in the birds’ spring feedinggrounds. Review the data table below and draw an appropriate graph with labeled lines and axes and atitle.

Year Bird Species 1950 1960 1970

Whooping Crane 24 41 78 California Condor 76 43 20 Black Swan 56 58 57

a. What is the dependent variable?

b. What is the independent variable?

c. What type of graph will you use? Why?

Graph Title:

d. By interpreting your graph, make a conclusion about the California condor population.

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Topic 2: Ecology Connection NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE

No Bats in the Belfry: The Origin of White- Nose Syndrome in Little Brown Bats by Jennifer M. Dechaine1,2 and James E. Johnson1

1Department of Biological Sciences 2Department of Science Education Central Washington University, Ellensburg, WA

Part I – The Basic Question Introduction Imagine going out for a brisk winter snowshoe and suddenly stumbling upon hundreds of bat carcasses littering the forest floor. Unfortunately, this unsettling sight has become all too common in the United States (Figure 1). White-nose syndrome (WNS), first discovered in 2006, has now spread to 20 states and has led to the deaths of over 5.5 million bats (as of January 2012). WNS is a disease caused by the fungus, Pseudogymnoascus destructans. Batsinfected with WNS develop white fuzz on their noses (Figure 2, next page) and often exhibit unnatural behavior, such as flying outside during the winter when they should be hibernating.

WNS affects at least six different bat species in the United States and quickly decimates bat populations (colony mortality is commonly greater than 90%). Scientists have predicted that if deaths continue at the current rate, several bat species will become locally extinct within 20 years. Bats provide natural pest control by eating harmful insects, such as crop pests and disease carrying insect species, and losing bat populations would have devastating consequences for the U.S. economy.

Researchers have sprung into action to study how bats become infected with and transmit P. destructans, but a key component of this research isdetermining where the fungus came from in the first place. Some have suggested that it is an invasive species from a different country while others think it is a North American fungal species that has recently become better able to cause disease. In this case study, we examine the origin of P. destructans causing WNS in North America.

Some Other Important Observations • WNS was first documented at four cave sites in New York State in 2006.

Figure 1. Many bats dead in winter from white-nose syndrome.

• The fungus can be spread among bats by direct contact or spores can be transferred between caves by humans(on clothing) or other animals.

• European strains of the fungus occur in low levels across Europe but have led to few bat deaths there.

• Bats with WNS frequently awake during hibernation, causing them to use important fat reserves, leading to death.

“No Bats in the Belfry” by Dechaine and Johnson

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NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE Questions 1. What is the basic question of this study and why is it interesting?

2. What specific testable hypotheses can you develop to explain the observations and answer the basic question of thisstudy? Write at least two alternative hypotheses.

3. What predictions about the effects of European strains of P. destructans on North American bats can you make if yourhypotheses are correct? Write at least one prediction for each of your hypotheses.

Part II – The Hypothesis As discussed in Part I, researchers had preliminary data suggesting that the pathogen causing WNS is an invasive fungal species (P. destructans) brought to North America from Europe. They had also observed that P. destructans occurs onEuropean bats but rarely causes their death.

Preliminary research also suggested that one reason that bats have been dying from WNS is that the disorder arouses them from hibernation, causing the bats to waste fat reserves flying during the winter when food is not readily available.

These observations led researchers to speculate that European P. destructans will affect North American bat hibernation atleast as severely as does North American P. destructans (Warnecke et al. 2012).

Questions 1. Explicitly state the researchers’null (H0) and alternative hypotheses (HA) for this study. (Null hypothesis. The null hypothesis,

denoted by H0, is usually the hypothesis that sample observations result purely from chance and observed difference is due to

sampling or experimental error. Alternative hypothesis. The alternative hypothesis, denoted by H1 or Ha, is the hypothesis that

sample observations are influenced by some non-random cause.)

2. Describe an experiment you could use to differentiate between these hypotheses (H0 and HA).

Figure 2. White fuzz on the muzzle of a little brown bat indicating infection by the disease.

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Part III – Experiments and Observations

NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE

In 2010, Lisa Warnecke and colleagues (2012) isolated P. destructans fungal spores from Europe and North America.They collected 54 male little brown bats (Myotis lucifugus) from the wild and divided these bats equally into threetreatment groups.

a. Group 1 was inoculated with the North American P. destructans spores (NAGd treatment).b. Group 2 was inoculated with the European P. destructans spores (EUGd treatment).c. Group 3 was inoculated using the inoculation serum with no spores (Control treatment).

All three groups were put into separate dark chambers that simulated the environmental conditions of a cave. All bats began hibernating within the first week of the study.

The researchers used infrared cameras to examine the bats’ hibernation over four consecutive intervals of 26 days each. They then used the cameras to determine the total number of times a bat was aroused from hibernation during each interval.

Questions 1. Use the graph below to predict what the results will look like if the null hypothesis is supported. The total arousal

counts in the control treatment at each interval is graphed for you (open bars). Justifiy your predictions.

2. Use the graph below to predict what the results will look like if the null hypothesis is rejected. The total arousalcounts in the control treatment at each interval is graphed for you (open bars). Justify your predictions.

“No Bats in the Belfry” by Dechaine and Johnson

Null Supported

Interval

Null Rejected

Interval

Tota

l Aro

usal

cou

nts

Tota

l Aro

usal

cou

nts

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Part IV – Results

NATIONAL CENTER FOR CASE STUDY TEACHING IN SCIENCE

Figure 3 (below) shows the real data from the study. There is no data for interval 4 bats that were exposed to the European P. destructans (gray bar) because all of the bats in that group died.

Figure 3. Changes in hibernation patterns in M. lucifugus following inoculation with North American P. destructans (NAGd), European P. destructans (EUGd), or the control serum.

Questions 1. How do your predictions compare with the experimental results? Be specific.

2. Do the results support or reject the null hypothesis?

3. If the European P. destructans is causing WNS in North America, how come European bats aren’t dying fromthe same disease?

References U.S. Fish and Wildlife Service. 2012. White-Nose Syndrome. Available at: http://whitenosesyndrome.org/. Last

accessed December 20, 2013. Warnecke, L., et al. 2012. Inoculation of bats with European Geomyces destructans supports the novel pathogen hypothesis for the origin of white-nose syndrome. PNAS Online Early Edition: http://www.pnas.org/cgi/doi/10.1073/ pnas.1200374109. Last accessed December 20, 2013.

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Credits: Title block photo by David A. Riggs (http://www.flickr.com/photos/driggs/6933593833/sizes/l/), cropped, used in accordance with CC BY- SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0/). Figure 1 photo by Kevin Wenner/Pennsylvania Game Commision (http://www. portal.state.pa.us/portal/server.pt/document/901415/white-nose_kills_hundreds_of_bats_in_lackawanna_county_pdf ). Figure 2 photo courtesy of Ryan von Linden/New York Department of Environmental Conservation, http://www.flickr.com/photos/usfwshq/5765048289/sizes/l/in/

set-72157626818845664/, used in accordance with CC BY 2.0 (http://creativecommons.org/licenses/by/2.0/deed.en).

Case copyright held by the National Center for Case Study Teaching in Science, University at Buffalo, State University of New York. Originallypublished February 6, 2014. Please see our usage guidelines, which outline our policy concerning permissible reproduction of this work.

Biology Honors

Name EVOLUTION CONNECTION 0: INTRODUCTION TO BIOLOGY

Date Block

Prelude Unit: Introduction, Evolution Connection 0: Cladistics and Evolution by Natural Selection

Learning Objectives E – 1. Compare and contrast the three domains of living things. E – 2. Use a phylogenetic tree to determine evolutionary relationships and common ancestry. E – 3. Describe the contributions of Charles Darwin to the field of evolutionary biology. E – 4 Define evolution and theory. E – 5 List and explain the steps of evolution by natural selection. E – 6 Explain how artificial selection helps support Darwin’s theory of natural selection. E – 7 Define population and species (biological concept and others)

Key Terms Archaea Bacteria Eukaryota Domain Common ancestor

Phylogenetics Cladistics Evolution Natural selection Artificial selection

Theory Hypothesis Species Law Fact

Evolution is such a broad topic that it relates to every unit in biology. In fact, it is often said that biology is difficult to understand unless you study it in the context of evolution. During each unit this year, we will discuss an “evolution connection” in which we will study an aspect of evolution that relates to our unit.

Each evolution connection will be a self-contained worksheet. This way, by the end of the year, you will have several packets that collectively represent a whole unit on evolution.

We begin our study of biology with a brief introduction to evolution. Use the online resources, along with chapter 1 of your textbook, to answer the following questions.

“Nothing in biology makes sense except in the light of evolution.”

--- Theodosius Dobzhansky

Part I: An Introduction to the Theory of Evolution

Video: What is a Species? Watch from 0:00 to 4:23. https://www.youtube.com/watch?v=9fOfFlMe6ek

1. Taxonomy is the study of:

2. What is the original scientific definition of species?

3. What problems exist with the “biological species concept”?

4. What other species definitions are there?

Video: Theory vs. Hypothesis vs. Law….. Explained! https://www.youtube.com/watch?v=lqk3TKuGNBA

5. Define the following terms. Give an example of each:Term Definition Example Fact

Hypothesis

Theory

Law

6. Why is it incorrect to say that a hypothesis is “proven”?

7. A common misconception of the general public is that science isn’t really sure about evolution and climatechange. You will frequently hear people say, “Oh, that’s just a theory”. Why do you think this confusionexists?

8. Is your answer to question #7 a fact, hypothesis, theory, or law?

9. Is Gravity a theory? Is it a law? Explain.

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Part II: Evolutionary Relationships and Cladistics http://www.ucmp.berkeley.edu/education/explorations/tours/Trex/ Begin this activity by going to the website below and selecting “Student Start” You will navigate through all 5 folders in this tutorial, beginning with folder 1.

Folder 1:

1. List some distinguishing characteristics of each of the 3 domains of living things.Domain Distinguishing Characteristics Bacteria

Archaea

Eukaryota

2. What is a common ancestor?

3. How long ago did all living things share a common ancestor?

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Folder 2: When you have examined the information in this folder, do the knowledge check questions below. (Note: these questions relate to the evolutionary tree below, which is different from the tree on the website.)

4. In the cladogram provided, label the distinct history,shared history, and common ancestor for kangaroo andhuman.

5. Which organism in the cladogram is most closely related tohumans? Explain.

Folders 3 & 4: 6. What type of information is shown in a cladogram?

7. Fill in the tables below.

8. To which animal is T. rex most closely related? (Circle one) Caiman Parrot Folder 5

9. Use the information gathered in folders 1 – 4 to make inferences about the following:

Color vision

Warm blooded

Feathers Sing to Young

Scaly skin

Melanin pigment

Amniotic egg

Few glands in skin

Hole in hip socket

3- chambered heart

4 – chambered heart

Caiman + 0 0 + + + + + 0 + 0

Parrot + + + + + + + + + 0 +

T. rex

Notice: in this typical cladogram, no information is given about relative time between evolutionary events. If the spacing between branches were different, we would call this a phylogenetic tree. Phylogenetic trees are just one specific type of cladogram.

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Cladistics and phylogeny are related fields of biology that try to map evolutionary relationships between organisms. Using cladistics, all organisms can be classified into 3 major groups, or domains. Examine the phylogenetic tree below.

10. Which two domains are most closely related to one another? Explain your answer.

11. Circle the two domains that are composed of prokaryotic organisms.

Part III: Evolution by Natural Selection

Video: “Who Was Charles Darwin?” http://www.pbs.org/wgbh/evolution/educators/teachstuds/svideos.html

12. What characteristics made Darwin especially well suited for science?

13. What did Darwin see and do on his 5---year voyage aboard the Beagle?

14. What new idea did Charles Darwin introduce to science? How did it challenge the current understanding ofbiodiversity?

We Can Observe Changing Populations Video: How Does Evolution Really Work? http://www.pbs.org/wgbh/evolution/educators/teachstuds/svideos.html

15. What are the four components of natural selection?

A.

B.

C.

D.

16. What determines an individual hummingbird’s beak length?

17. What factors in the environment might select for beak length and shape within hummingbird populations?

18. How can hummingbird DNA help Dr. Schneider determine the evolutionary history of hummingbirds?

Artificial Selection as Evidence for Natural Selection http://evolution.berkeley.edu/evolibrary/article/evo_30

19. What is artificial selection?

20. Charles Darwin was very interested in artificial selection. How might artificial selection serve as a type ofevidence that evolution occurs by natural selection?

21. Name and describe another example of organisms that have been changedby humans via artificial selection.

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