Teacher’s Resource Guide.…Teacher’s Resource Guide to A Teacher’s Resource Guide to...

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Teacher’s Resource Guide

Transcript of Teacher’s Resource Guide.…Teacher’s Resource Guide to A Teacher’s Resource Guide to...

Teacher’s Resource Guide

Teacher’s Resource Guide to

A Teacher’s Resource Guide to Galapagos was cre-ated by the National Science TeachersAssociation, Special Publications, 1840 WilsonBlvd., Arlington, VA 22201-3000, with fundinggenerously provided by the National ScienceFoundation and the Smithsonian Institution.

This material copyright © 2000 SmithsonianInstitution and Imax Ltd. All rights reserved.IMAX® and AN IMAX EXPERIENCE® are registered trademarks of Imax Corporation.

WRITER: Richard Benz, Wickliffe High School,Wickliffe, OH

EDITOR: Erin Miller, National Science TeachersAssociation

DIRECTOR OF SPECIAL PUBLICATIONS:Shirley Watt Ireton, National Science TeachersAssociation

SCIENCE AND CURRICULUM ADVISORS:Dr. Carole Baldwin, Smithsonian Institution,Washington, DC

Sue Cassidy, Bishop McNamara High School,Forestville, MD

Dr. Robert Hoffmann, Smithsonian Institution,Washington, DC

Sue Mander, Imax Ltd., Toronto, Canada

Laura McKie, Smithsonian Institution,Washington, DC

Dr. David Pawson, Smithsonian Institution,Washington, DC

Sharon Radford, Paideia School, Atlanta, GA

Dr. Irwin Slesnick, Western WashingtonUniversity, Bellingham, WA

Dr. John Weld, Oklahoma State University,Stillwater, OK

Dr. Don Wilson, Smithsonian Institution,Washington, DC

Sponsored by America Online Inc., theSmithsonian Institution and Imax Ltd. present inassociation with the National Science Foundation,a Mandalay Media Arts production Galapagos.

EXECUTIVE PRODUCERS: Laurence P.O’Reilly, Andrew Gellis, Peter Guber, Barry Clark

PRODUCERS/DIRECTORS: Al Giddings andDavid Clark

WRITERS: Barry Clark and David Clark

DIRECTOR OF UNDERWATERPHOTOGRAPHY: Al Giddings

DIRECTORS OF TOPSIDE PHOTOGRAPHY:Reed Smoot and Andrew Kitzanuk

NARRATOR: Kenneth Branagh

MUSIC COMPOSER AND PRODUCER:Mark Isham

2 TEACHER’S RESOURCE GUIDE TO GALAPAGOS

Acknowledgments

Table of ContentsIntroduction for Teachers . . . . . . . . . . . . . . . . . . 3

Film Synopsis . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Pre-Screening Discussion . . . . . . . . . . . . . . . . . 3

Where in the World? . . . . . . . . . . . . . . . . . . . . . 4

Adventuring in the Archipelago . . . . . . . . . . . 5

Adventuring in Your Own Backyard . . . . . . . . 8

How Did Life Get to the Galápagos? . . . . . . . . 10

Current Events in the Ocean . . . . . . . . . . . . . 11

Hot Side Hot, Cool Side Cool . . . . . . . . . . . . . 16

Modern-Day Darwins . . . . . . . . . . . . . . . . . . . 19

Why Do Species Change? . . . . . . . . . . . . . . . . . 21

Biodiversity of the Galápagos . . . . . . . . . . . . 22

Galápagos Adaptations . . . . . . . . . . . . . . . . . 26

Natural Selection: The “How” of Evolution . 29

Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Introduction for teachersThis Teacher’s Resource Guide is intended as aclassroom supplement for middle-school grades,and is consistent with the National ScienceEducation Standards. Designed in conjunctionwith the IMAX® film Galapagos, this guide pro-vides background information to the teacher onthe subjects of Galápagos geography, geology,ecology, and evolution. Use the Guide to plan forpost-viewing discussions and activities. The mate-rial is intended for flexible use, and teachers maymodify and duplicate the copyrighted materials tosuit their students’ needs. We especially recom-mend for photocopying the pages marked“student section.” These activities may be modi-fied for elementary students.

Film SynopsisFollow Smithsonian marine biologist Dr. CaroleBaldwin as she retraces the steps of evolutionarypioneer Charles Darwin on his epic voyage to theGalápagos Islands. With the help of modern tech-nology, students experience the spectacle andabundance of wildlife both on land and beneaththe waters of the islands. The age-old powers ofobservation, combined with cameras, scuba gear,submersibles, and robot arms, allow today’s scien-tists to extend their research to an undersea worldthat was far beyond the reach of Darwin when hevisited the islands more than 160 years ago.

Students observe the variety of life—from families of sea lions and schools of sharks totrudging tortoises and impish iguanas—thatdemonstrates how the Galápagos’ island geogra-phy and isolation from the mainland contributesto the evolution of species found nowhere elseon Earth.

Pre-Screening DiscussionBefore visiting the film, familiarize your studentswith Darwin’s role as the first person to publishthe theory that new species originated from otherspecies through evolution driven by natural selec-tion (see the Resources section for further readingsuggestions). Darwin’s ideas were prompted by histrip to the Galápagos, which makes these islandsan important landmark in scientific history.

The first section of this teacher’s guide, “Where inthe World?” can be used either as pre-screeningor post-screening activities. As pre-visit exercises,they introduce students to the location of theislands and the importance of observation to thescientific process. This allows them to betterunderstand the work performed by the scientistsin the film.

A pre-visit discussion of some of the unusual ani-mals shown in the film will stimulate yourstudents’ interest. Visit the Galapagos Web site athttp://pubs.nsta.org/galapagos/ for pictures andinformation about some of these creatures, andinstruct your students to look for them in the film.This Web site also provides details on how theactivities meet the National Science EducationStandards.

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Resources

4 TEACHER’S RESOURCE GUIDE TO GALAPAGOS

Where In the World?

So, where in the world are these islands thatDarwin described as “A little world within itself”?

The Galápagos Archipelago, or island group, con-sists of 13 large islands, six smaller islands, and agreat number of small volcanic islets or “rocca.”These islands in the eastern Pacific Ocean areapproximately 960 km (600 miles) west of main-land Ecuador in South America, situated alongthe Equator. They lie almost directly south ofChicago, Illinois, in the United States. The geo-

graphic position and isolation of the Galápagosare the key to the island group’s natural history.To understand why the Galápagos Archipelago isrenowned as a laboratory of evolution and adap-tation, we must understand a little about therelationship of life forms to location. Your stu-dents will learn how absolute location of theislands compares with relative location, and dis-cover how isolated the Galápagos Islands arefrom the rest of the world.

Aboard the HMS Beagle, Darwin traveled westfrom the coast of South America in 1835, andarrived off the coast of San Cristóbal onSeptember 17.

“In the morning we landed on San CristóbalIsland which, like the others, rises with a tameand rounded outline, broken here and there byscattered hillocks, the remains of former craters.”

The Beagle explored the Galápagos Islands fromSeptember 15 through October 20, 1835. Duringthis time Darwin landed on at least six of thelarger islands, starting at San Cristóbal and end-

ing at Pinta Island. The Beagle left theGalápagos and sailed toward Tahiti onOctober 20.

This archipelago consists of ten principal islands, of which five exceed the others in size. They are situatedunder the Equator, and between five and six hundred miles west … of the coast of America. They are all

formed of volcanic rocks...Considering that these islands are placed directly under the equator, the climate isfar from being excessively hot; this seems chiefly caused by the singularly low temperature of the surround-

ing water, brought here by the great southern Polar current. (Darwin, 1845)

At the time Darwin wrote his journal, he referred to theislands by their English names. Because the islands are a

part of Ecuador, we have changed Darwin’s quotes toreflect the modern, Spanish names, and

to avoid further confusion, we updatedthe spelling of certain words.

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Adventuringin the ArchipelagoTeacher Section

ObjectiveTo learn basic mapping skills and understand thedifference between absolute and relative location.

Materials• globe

• map of your country

• local map with latitude and longitude

• copies of maps on the inside-front and inside-back covers

• copies of pages 6–7

• string

• pencil

Locate the Galápagos Islands on a globe, andmeasure the distance to the coast of Ecuadorusing a piece of string. Now take that same pieceof string and place one end on your hometown,and find a city that is the same distance from youas the Galápagos are from the mainland. Askyour students how they think animals and plantslocated in that city would get to yours. Imaginethe two cities are separated by water, and informyour students that these plants and animals don’tswim! This will be dealt with later in the teacher’sguide, but it will get your students thinking aboutthe problems of colonizing a far-off island.

Now, using a map of your country, ask your stu-dents to describe their hometown’s location inrelative terms compared to the other city identifiedabove. Next have your students find the absolutelocation of their hometown and other familiarlocations on a map that shows latitude and longi-tude. After students are comfortable with absoluteand relative location of familiar landmarks, askthem to describe their location in relation to theGalápagos Islands. Finally, describe the position of

the Galápagos in relation to mainland Ecuador(see map on the inside back cover).

After completing this exercise, students shouldknow where the Galápagos Islands are located,and they should understand their position in bothabsolute and relative terms.

In this activity the students will follow Darwin’sGalápagos adventures by locating some of hislanding sites in the archipelago. Make copies ofthe Galápagos Islands map from the inside frontcover and of Darwin’s quotes on pages 6–7, anddistribute to each student. Each site will be intro-duced by a short quote from Darwin’s journals orfrom The Voyage of the Beagle. The absolute posi-tions (latitude and longitude) are listed after eachquote. The students should read the quote, notethe absolute position and find the site on the mapof the Galápagos Islands. When they find the sitethey should mark it with a small dot and list thedate from the quote. (As an added element, stu-dents can calculate the mileage between stops,and add that to the map.) When all the sites havebeen located the students should “connect thedots” of Darwin’s voyage around the Galápagos.As a final evaluation of this activity, the studentscan discuss this part of Darwin’s journey or createa journal as though they had accompaniedDarwin on this part of the trip.

Suppose you live in Milwaukee, Wisconsin. You couldchoose Washington, DC as your comparison city, the same

distance on your piece of string. Your students woulddescribe Milwaukee as being approximately 1,600 kilome-ters northwest of Washington or 200 km almost due northof Chicago. These are relative locations. The absolute loca-tion of Milwaukee is approximately Latitude 48° N, 88° W.

6 TEACHER’S RESOURCE GUIDE TO GALAPAGOS

Now that you know where the Galápagos Islandsare located, you are going to travel around thisisland group and get a feeling for what CharlesDarwin found when he visited more than 160years ago. Darwin, aboard the HMS Beagle, trav-eled west from the coast of South America inSeptember 1835, and arrived off the coast of SanCristóbal Island on September 17.

Here are some quotes from Darwin’s journal.Darwin’s absolute position (defined by latitude

and longitude) follows each quote. On the mapyour teacher has given you, make a small dot forthe location of each quote, and write the date ofthe quote next to it.

After you have made a dot for each quote, play“connect the dots” starting with the first one, andconnect them in order. You will see the approxi-mate route Darwin took during his five weeks ofexploration in the Galápagos Islands more than160 years ago!

Adventuring in theArchipelago

Student Section

September 17, 1835

In the morning we landedon San Cristóbal Island, which, like theothers, rises with a tame and roundedoutline, broken here and there by scat-tered hillocks, the remains of formercraters. Nothing could be less invitingthan the first appearance. A broken fieldof black basaltic lava, thrown into themost rugged waves, and crossed by greatfissures, is everywhere covered by stunted,sunburned brushwood, which shows littlesigns of life.

Location: 0º50’ S, 89º30’ W

September 23, 1835

The Beagle proceeded toFloreana Island. This archipelago haslong been frequented, first by the bucca-neers, and latterly by whalers, but it isonly within the last six years, that asmall colony has been established here.The inhabitants are between two andthree hundred in number; they are nearlyall people of color, who have been ban-ished for political crimes from theRepublic of the Ecuador, of which Quitois the capital.

Location: 1º15’ S, 90º20’ W

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Adventuring in the Archipelago

September 29, 1835

We doubled the south-west extremity of Isabela Island, and thenext day were nearly becalmed betweenit and Fernandina Island. Both are cov-ered with immense deluges of blacknaked lava, which have flowed eitherover the rims of the great caldrons, likepitch over the rim of a pot in which ithas been boiled, or have burst forth fromsmaller orifices on the flanks; in theirdescent they have spread over miles ofthe sea-coast. On both of these islands,eruptions are known to have taken place;and in Isabela, we saw a small jet ofsmoke curling from the summit of one ofthe great craters.

Location: 0º20’ S, 91º15’ S

October 8, 1835

We arrived at SantiagoIsland. Mr. Bynoe, myself, and our ser-vants were left here for a week, withprovisions and a tent, whilst the Beaglewent for water. We found here a party ofSpaniards, who had been sent from

Floreana Island to dry fish, and to salttortoise-meat.

Location: 0º10’ S, 90º50’ W

October 18, 1835

Finished survey of Isabela Island

Location: 0º10’ N, 91º10’ W

October 19, 1835

To Pinta Island.

Location: 0º30’ N, 90º40’ W

October 19, 1835

Darwin and Wolf Islands

Location: 1º30’ N, 92º0’ W

October 20, 1835

Headed for Tahiti

Location: 17º37’ N, 149º27’ W(off the map)

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ObjectiveTo understand the importance of careful observa-tion, and make a permanent record of theseobservations.

Materials• Notebook or diary, used just for this project.

Can be spiral bound or a binder; but somethingto which students can add pages is best.

Keeping a journal is a crucial part of any field-work. Explorers and scientists keep journals oftheir investigations and adventures. Scientistskeep journals to provide a permanent record ofwhat they witness in the natural world—like adiary of nature. When scientists look back atpages from weeks gone by, they will know theexact day when they saw a particular animal orother natural phenomena. If you keep a journalof your observations in the same area for severalyears, you will begin to notice patterns; eventu-ally you’ll be able to predict when certainanimals will return to the area or when particularplants will bloom.

“This volume contains, in the form of a Journal, ahistory of our voyage, and a sketch of those obser-vations in Natural History and Geology,”

Thus begins Darwin’s The Voyage Of the Beagle.Throughout his life Darwin kept many volumes ofjournals from his observations and studies ofnature. He carried a small notebook wherever hewent, and later transferred his notes to the masterjournal that was kept on board the Beagle.

To understand the importance of recording obser-vations, ask students to keep their own“fieldwork” journal. This activity can be limited totheir study of evolution, or can be continuedthroughout the year. Students can observe andmake entries in any kind of notebook, but a hard-cover binder or a permanently bound notebookmay help them to take this assignment seriouslyand encourage them to continue making journalentries after this activity is over.

You can structure this activity in a number ofways: One option is to direct where your studentsobserve, e.g. in their own backyard or at a schoolsite. Or, ask them to record their journey to andfrom school for a few days. Another alternative isto localize their observations to a small modelecosystem in a jar. Students can add a smallamount of gravel, pond water, aquarium plants,and a snail to a one-quart jar, seal it, and place itin low light. They can start an “AquaticEcosystem” journal as though they were natural-ists who discovered this habitat while on theirown “voyage” of discovery. Encourage the stu-dents to draw pictures or “field sketches”whenever possible, to help illustrate and adddetail to their observations. These observationscan be discussed with the rest of the class atweekly intervals to help encourage continued par-ticipation.

Adventuring in Your Own BackyardTeacher Section

9TEACHER’S RESOURCE GUIDE TO GALAPAGOS

Thus begins The Voyage Of the Beagle. Throughouthis life Darwin kept many volumes of journalsfrom his observations and studies of nature. LikeDarwin, you are a field scientist studying a newlydiscovered habitat. To help you remember whatyou observe, you will keep a journal. Scientistskeep journals of their projects, and they do it for areason: journals are invaluable for keeping trackof, and making sense of, their work.

In your journal you will share your observationsabout a particular environment you are investigat-ing. You will observe nature and ask why or howabout the things you see. Why is the male cardi-nal a bright red, but the female a dull brown?Why doesn’t a cactus need a lot of water com-pared to most plants? How can the ant carry apiece of bread several times its size? What, why,how, and where are the overriding questions thatscientists ask. You need to think about the thingsyou observe, and your journal is the place torecord your observations, questions, andhypotheses.

On your first day, write a detailed description of theplace you are focusing upon. Use all of yoursenses—what does it look like, how does it smell,what sounds can you hear? Make sure to includewhere your place is located (in both absolute andrelative terms, if possible). For all subsequententries, make sure to list each day’s date and thetime you visited. See if you can find a centraltheme or idea, such as encountering a bird’s nestand then recording the changes with each observa-

tion. Make sure to record each day while yourthoughts are fresh. Your teacher will help directyour observations and your journal writing activity.

Charles Darwin kept a journal throughout his life.Much of what we know about the GalápagosIslands of the eighteenth and nineteenth centuriescame from journals kept by explorers like Darwin.Dr. Carole Baldwin, from the Galapagos film, kepta journal of her entire trip. Dr. Baldwin is amarine biologist at the Smithsonian Institution.Here is one of her journal entries:

February 12, 1999, Cabo Douglas, Fernandina

Arrived here late yesterday morning and immediatelysaw hundreds of marine iguanas in the water androcks covered with bright green algae. Also,there are a lot of sea turtles in the water,blue-footed boobies on the rock ledges, andsea lions. Got to see the blue-footed boobydoing its sky-pointing mating dance. Thebeak points upwards, the tail pointsupwards, and each foot is alternately liftedhigh off the ground. You absolutely cannotlook at this and not laugh! I get the same feelingfrom watching marine iguanas basking on rocks andspitting salt crystals. Nature can certainly be humor-ous... (Dr. Carole Baldwin, 1999)

Remember, to be a good scientist you must becurious and you must observe the world aroundyou—and you must record what you see in yourfield journal.

Adventuring in Your Own Backyard

Student SectionThis volume contains, in the form of a Journal, a history of our voyage, and a sketch of those

observations in Natural History and Geology. (Darwin, 1845)

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The Galápagos are a series of volcanoes arrangedin a pattern with two major axes that run in aneast-northeast and north-northwest direction.These volcanoes result from a “hot spot” fixeddeep in Earth’s interior.

The oldest Galápagos Islands formed several mil-lion years ago and they also have the greatestdiversity of plants and animals. The young west-ern islands of Isabela and Fernandina are activevolcanoes and thus are still forming.

The distinctive plants and animals throughout thearchipelago are a direct result of this unusualcombination of recent volcanic formation andvast distance from another land mass.

A volcanic island newly built above sea levelwould be bare, rugged, and largely sterile. Howdid the plants and animals arrive and what condi-tions would they need to survive? To answer this,we must investigate the wind patterns and oceancurrents to find the mode of transportation for thepioneering plants and animals that came from themainland and colonized the Galápagos Islands.

The Galápagos lie in a crossroads of wind andocean currents that bring both cool (temperate-zone) and warm (tropical) water to the islands.Ocean currents brought an abundance of marinelife that populated the islands’ coastal waters.Wind currents brought birds, which fed on the richmarine life. Vegetation came in the form of seedsdropped by birds, or on “rafts” of soil and plants.

The unusual cross-section of life on the Galápagosincludes temperate-zone organisms, like the sealion, and tropical organisms, like the butterfly fish.This mix is made possible by the converging cur-rents and wind patterns. Although the Galápagosare unique because many of the plants and ani-mals that have evolved there (and nowhere else),the islands are not unique in terms of the processof evolution. Evolution exists wherever life formsare found. Changes that occur on isolated islandsare sometimes easier to “see,” but similar changesoccur continuously throughout the living world.

I scarcely hesitate to affirm, that there must be in the whole archipelago at least two thousand craters—Nothing could be less inviting than the first appearance. (Darwin, 1845)

Hot spots are concentrations of heat deep below theEarth’s crust that produce plumes of hot rock, which

work their way upward to form volcanoes. As plate tec-tonics slowly move the crust over thousands and

millions of years, a new volcano forms directly over thehot spot, and older extinct volcanoes form a chain ofislands. At times, nearby volcanoes coalesce to make a

multi-volcano island, such as Isabela.

Scientists think land rafts—mats of logs androot masses washed out from flooding

rivers—are one way in which many of the ter-restrial animals arrived at the Galápagos. In

October 1995, 15 iguanas arrived on the east-ern shore of the Caribbean island Anguilla.

The group, including a pregnant female, trav-eled more than 320 km from the distant

island of Guadeloupe on a land raft. Beforethis event there were no iguanas on the

island, but they survived and reproduced,forming a new population.

How Did Life Getto the Galapagos?

11TEACHER’S RESOURCE GUIDE TO GALAPAGOS

ObjectiveTo investigate how landforms and wind affectocean surface currents, and how this relates tothe ways in which life arrived to the Galápagos.

MaterialsFor each student team:

• map of the eastern Pacific

• baking pan or clear plastic shoebox

• non-permanent marker

• modeling clay

• colored pencils

• black permanent marker

• food coloring

• towels or rags for cleanup

For each student:

• plastic drinking straw with a flexible elbow

Currents—large scale movements of water—occurthroughout the ocean in both the surface and thesubsurface layers. Wind moving over water dragssurface water along its path, creating surface cur-rents. A map showing prevailing wind directioncorrelates with a map showing surface currents inthe major ocean basins (compare maps on pages12 and 14). This activity allows students to simu-late the flow of the Humboldt Current in thePacific Ocean and experiment with how land for-mations and variations in wind direction canaffect ocean currents. It is important, however, tolead students to the understanding that many fac-tors determine current formation in the ocean andthat this model presents just one of them. Currentformation is an extremely complex aspect ofoceanography.

The prevailing winds in the Pacific are called the“trade winds.” (As an extra activity, you may wantto have your students investigate how thesewinds became known as the trade winds.) Thetrade winds that move air over the South Pacificfrom the southeast toward the northwest arecalled South Easterlies. Near the Galápagos,these winds move up along the coast of Peru andthen out towards the Galápagos. This wind pat-tern moves the ocean waters in the samedirection forming the Humboldt Current.

As the surface water current moves along theSouth American coast, off-shore winds push itwestward allowing cooler, deeper water to cometo the surface and to the Galápagos Islands. Inaddition, the South Equatorial Current moveswarm water from the Panama Current directlyfrom the coast of Ecuador west to the Galápagos(see page 12).

This movement of surface water away from thecoast, bringing cold subsurface waters to the sur-face is a process known as “upwelling.” This cold,nutrient-rich, upwelled water supports an abun-dance of sea life along the coast of South Americaand the Galápagos Islands. Biologists have dis-covered that many marine species are unusuallydense in the Galápagos waters. They theorize thatthis is because of the nutrient-enriched water thatfirst provides food to enormous numbers of micro-scopic life forms. These life forms then becomefood for small crustaceans and fish, which in turnbecome food for larger organisms. Because theincreased nutrients in the water bolster the entirefood chain, the area can support more life of allsizes. In the Galápagos, therefore, some predatorspecies, such as hammerhead sharks or barracu-das, appear in large schools—a behavior that isseldom seen anywhere else in the world.

Current Eventsin the OceanTeacher Section

12 TEACHER’S RESOURCE GUIDE TO GALAPAGOS

Sailors have known for centuries that ocean cur-rents—large scale movements of water—canspeed up or slow down a ship, just as airplanepilots know that it takes longer to fly from NewYork to California than the reverse, because of thejet stream. In modern times, scientists have dis-covered that ocean currents have major effects onweather patterns and on the ecology of the oceanand nearby land masses. One type of current iscalled a surface current, which, as you might have

guessed, flows across the surface of the oceanalmost like a river flows across dry land. However,a surface current lacks the solid banks of a riverto direct its flow. As a result, the direction of asurface current may change when the wind blow-ing across it shifts, when it encounters warmer orcolder water, or when it nears land. This activitywill show how surface currents are affected by thedirection of the wind.

Current Eventsin the Ocean

Student Section

NorthAmerica

SouthAmerica

N

Australia

13TEACHER’S RESOURCE GUIDE TO GALAPAGOS

With your team:

1. Using a map of the eastern Pacific provided byyour teacher, draw an outline of the westerncoast of North and South America near theright side of the pan or plastic shoebox with acrayon or non-permanent marker.

2. Following the pattern, place ridges of modelingclay along the bottom of the pan to containthe “ocean.” Press the clay firmly to the pan orplastic box and smooth the gaps between theclay and the pan. It is important to create awater-tight seal to prevent “oceanic” leaks.

3. Create some island masses about 3cm west ofSouth America at the position of the equator.This will represent the Galápagos Islands.

4. Fill the ocean area of your model with water.Wait for the water to settle.

5. Bend the straw at the elbow. Write your nameon the short end of the straw with the perma-nent marker. This will identify your straw andremind you which end of the straw to pointtoward the water. Do not put the short end ofthe straw with your name on it into yourmouth.

6. Try not to touch the pan or plastic box as youdo the following:

• Hold your straw so that the short end is par-allel to the ocean surface.

• Point your straw from the lower tip of SouthAmerica toward the equator.

• Have your partner place one or two drops offood coloring in the water near the end ofyour straw.

• As soon as the food coloring is in the waterblow gently through the straw and observethe patterns of ocean currents that the windproduces.

7. Repeat step 6 a few more times to develop asense of the relationship between wind direc-tion, landmass configuration and currentpatterns. You may need to get clean water if the“ocean” becomes too dark from food coloring.

8. Repeat step 6 once more, but this time blowgently along the coast of Central Americatowards South America (from north to south).This action represents the Panama Currentthat brings warmer water to the northernGalápagos Islands.

9. Describe the relationship between wind andocean currents. How do variables, such as winddirection, wind speed, land formations, etc.,seem to be related to ocean current patterns?

Current events in the ocean

14 TEACHER’S RESOURCE GUIDE TO GALAPAGOS

Current events in the ocean

North

Am

erica

SouthA

merica

N

Australia

15TEACHER’S RESOURCE GUIDE TO GALAPAGOS

Current events in the ocean

Hum

bold

tCurrent

N

16 TEACHER’S RESOURCE GUIDE TO GALAPAGOS

ObjectivesTo understand how cold and warm ocean cur-rents interact, and the effect they have on nearbyland masses

MaterialsFor each student team:

• clear plastic shoebox or small aquarium

• 250 ml beaker

• 2 small paper drinking cups

• water

• food coloring

• 2 straight pins or push pins

• ice

• paper

• pens or pencils

This activity will help your students visualizewhat happens when liquids of different densitiesmeet. Warm ocean water is less dense than coldand the two will not readily mix. As the coldHumboldt Current flows up the South Americancoast it tends to keep the warm Panama currentfrom reaching the Galápagos. Eventually, thewarm (lighter) water pushes over the colder(heavier) water, still not mixing with it. When thishappens, the warm water reaches the northernislands and brings warm water species with it.

There are tropical species of fishes in the northernislands of Darwin and Wolf that don’t occur any-where else.

In Part A, as the colored, cold water leaves thecup, it sinks to the bottom. Students should beable to see waves and currents that form as thewarm and cold water meet. The food coloringshould stay in the lower half of the container. InPart B the warm water will tend to float on top ofthe cold water in the container. See the illustra-tions on pages 17–18 for guidance.

Instead of handing out pages 17–18, you maywish to divide your class into teams, and provideeach with a set of the above materials. Have themdevise a method for observing the effects of whenwarm and cool currents meet. You can have eachteam prepare a report of its procedure and find-ings to the rest of the class.

Hot Side Hot,Cool Side CoolTeacher Section

17TEACHER’S RESOURCE GUIDE TO GALAPAGOS

Darwin described the cold waters at the Earth’shottest latitude in 1845. Why do ocean currentsbring cold waters to regions that are at the equa-tor? Why don’t warm waters mix with these coldwater currents? What happens when cold watermeets warm water? The climate of a regiondepends upon the movement of cold and warmwater in its surrounding oceans. This activity willhelp you explore what happens when cold waterand warm water meet.

Most people know that hot air rises—just watchthe flight of a hot air balloon or feel the tempera-ture rise as you climb the stairs on a warmsummer day. Why does warm air rise above cold?Warm air is less dense than cold air and thereforefloats above the heavier cold air in a room. Is thisalso true with water? Let’s investigate.

1. Fill the plastic shoebox or aquarium with luke-warm water—be sure to keep the water levelbelow the height of the paper cup (e.g., if youhave a cup that is 8 cm tall, be sure to onlyput 6.5 cm of water in the box).

2. Place two ice cubes in a 250 ml beaker, andadd cool tap water. Add three or four drops offood coloring to the ice water in the beaker.

3. Wait a couple of minutes for the colored waterin the beaker to cool down.

4. With one of your pins, punch a hole in theside of the paper cup about 2–3 cm from thebottom. Repeat with the other pin on the otherside. Leave the pins in the cup; as they will actas temporary plugs (see illustration below).

Considering that these islands are placed directly under the equator, the climate is far from being excessivelyhot; this seems chiefly caused by the singularly low temperature of the surrounding water, brought here by

the great southern Polar current. (Darwin, 1845)

Hot Side Hot, Cool Side CoolStudent Section

18 TEACHER’S RESOURCE GUIDE TO GALAPAGOS

5. Next, fill the cup with the colored ice waterwell above the level of the pins, and place thecup into the water-filled shoebox. Put the cupall the way to one side of the container, andwait for the water to become still.

6. Carefully remove the pins. Plan your proce-dure before you try it. As much as possible, trynot to disrupt the water in the container. If nowater leaves the cup, you may have to makethe pin holes a little larger.

7. Describe what you observed when the cold,colored water entered the warm water in thecontainer. In which direction did the coldwater flow? What happened when the coloredwater hit the bottom of the container?

Now repeat the whole process, this time usingcool water in the shoebox and warm water andfood coloring in the plastic cup.

Write up the results of your experiments, andexplain what might happen when the coldHumboldt Current meets the warm PanamaCurrent near the Galápagos Islands.

HOT SIDE HOT, COOL SIDE COOL

19TEACHER’S RESOURCE GUIDE TO GALAPAGOS

ObjectiveTo create model experiments to see how seedsmay have traveled from the mainland to theislands and still survive to germinate into plants.

MaterialsThese will vary depending on student creativity:

• various seeds (any seeds that are fast growing,or easy to obtain, such as radish seeds, beans,sunflower seeds, grass seeds, etc.)

• container to hold salt water

• tap water

• ocean water—if not available, then use a solu-tion of 35g table salt (NaCl) per liter of water.(“Instant ocean mix” is sometimes available in pet supply stores.)

• planting containers (pots, trays, etc.)

• sterile (seedless) potting soil, purchased froma garden store

• materials to make simulated bird feet (straws, cotton swabs, tooth picks, other…)

During the years following Darwin’s voyage onthe Beagle, he worked on many projects relatingto his observations. One topic that particularlyfascinated him was how plants could have colo-nized the newly formed and relatively barrenvolcanic islands. Darwin conducted a series ofexperiments about seed dispersal to remoteoceanic islands. In one experiment, Darwin foundthat out of 87 types of seeds, 64 germinated evenafter 28 days immersed in salt water, yet few sur-vived immersion after 137 days.

In other experiments, Darwin investigated thepossibility that seeds from the mainland were car-ried to the islands in mud stuck to the feet ofbirds that made their way to island landing sites.In one example, Darwin saved mud washed fromthe feet of a duck, and germinated 53 plants.

Can your students devise a series of experimentsto find out if seeds could survive the long salt-water journey in currents from mainland SouthAmerica? One way might be to vary the timeseeds can last in salt water, yet still be able to ger-minate. What about seeds found in the mud stickto the feet of birds? One possible experiment is tomix seeds in potting soil and then have studentsdevise model “bird feet.” Students can “walk”their model feet through the soil and try to har-vest seeds from the attached mud.

Below are some questions students may ask dur-ing the course of their investigation. If studentsare having problems designing experiments, con-sider using some of these prompts:

• What seeds should we use?

• How long should we put the seeds in the“ocean?”

• How do we make model birds’ feet?

• How will my model bird “walk” in the mud?

• Where should we plant the seeds?

• How should we plant the seeds?

• How should we care for our newly plantedseeds?

These discovery activities will help studentsunderstand the possible means of transport ofplants that colonized the Galápagos Islands.

Modern-Day DarwinsTeacher Section

20 TEACHER’S RESOURCE GUIDE TO GALAPAGOS

After his trip to the Galápagos, Darwin wonderedhow plants got to the islands? Were they carriedthere by the ocean currents that travel from thecoast of South America to the islands? Can seedsthat fall into the ocean even survive the saltwater?Could birds have brought seeds to the island andif so, how?

In the 1850s Darwin conducted experiments totest both these hypotheses. Can you become a“modern-day” Darwin? Invent experiments to testwhether seeds could travel ocean currents andsurvive the salt-water to take root on the distantbarren islands. Create an experiment to test ifbirds may have carried seeds to the islands in themud on their feet. Darwin collected birds from hisown yard and washed mud off their feet and thenput the mud in a container to see if any plantssprouted. Simulate Darwin’s experiment, butdon’t capture a flock of birds and wash their feet!

With your team:

1. Develop a hypothesis about how plants mighthave colonized the Galápagos Islands.

2. Design an experiment that will show underwhat circumstances plants could have colo-nized the Galápagos. Show your experimentalplan to your instructor for approval.

3. Conduct your experiment. Don’t forget to keepdetailed records of everything you do andobserve, just as Darwin did during his experi-ments. Collect and record all your dataincluding weights, measurements, or counts,as necessary.

4. Analyze the results of your experiment when itis over, and discuss them with your classmates.

5. Draw your conclusions. Have you come upwith evidence to support how the barrenGalápagos were populated by plants?

Modern-Day DarwinsStudent Section

21TEACHER’S RESOURCE GUIDE TO GALAPAGOS

We have studied the isolation of the Galápagosand the unusual conditions that exist because oftheir position at the crossroads of various currents.But what caused the “different set of beings” thatDarwin wrote about? How and why did the speciesthat initially arrived from the mainland eventuallychange? The Galápagos were a “blank slate” whenfounder individuals arrived, thus there were manyenvironmental niches available. We know thatplants and animals adapted and changed to filldifferent niches, but we haven’t explained howthey did this. The answer is the crux of evolution:adaptation and natural selection.

In this section we will investigate the biodiversity ofthe Galápagos Islands, and how natural selectionof organisms led to their adaptation to these envi-ronments. An adaptation is a feature of an organismthat enables it to survive and reproduce as wellas, or better than other members of the species, or other species that don’t have that feature.

Random genetic changes occur in species fromgeneration to generation. While one change mayallow an individual to find food more easily,another change may make an individual morelikely to be spotted by a predator. The individualswith the disadvantageous changes are less likelyto survive and less likely to reproduce; the disad-vantageous features are therefore less likely to bepassed on. This is “survival of the fittest,” anotherterm for natural selection.

Natural selection is the idea that there are manymore organisms born than survive; that these

organisms vary from one individual to another;and those individuals whose variations happen tobe better suited for their environment will surviveand are likely to produce more offspring. AlthoughDarwin did not understand the mechanisms ofthis variation at the time he wrote Origin of theSpecies, he understood the importance of thisvariability on the survival of the species. We nowknow that the mechanism is genetic variability ofoffspring due to mutation and the recombinationof genes.

If organisms that have adapted to a new nichecannot or do not reproduce with members of theoriginal population, then a new species with avery different lifestyle will have formed or“evolved.” A good example of this can be seenwith the Galápagos land and marine iguanas,which evolved from one common ancestralspecies that diverged into two separate species,each able to exploit a different niche and habitat.The marine iguana feeds on abundant greenalgae, while the land iguana specializes in grassand terrestrial plants, especially the large prickly-pear cactus.

By far the most remarkable feature in … this archipelago … is that the different islands… are inhabited bya different set of beings … I never dreamed that islands, about fifty or sixty miles apart, and most of them in

sight of each other, … would have been differently [colonized] (Darwin, 1845)

“Fittest” does not necessarily mean the biggest and thestrongest. For example, a bird with a small beak is better

able to use small seeds than a bird with a huge beakdesigned for opening large seeds. This may be advanta-

geous if the habitat has more small seeds than large ones.

Why DoSpecies Change?

22 TEACHER’S RESOURCE GUIDE TO GALAPAGOS

ObjectivesTo understand how climate and water cyclesaffect the local environment, and form hypothesesabout the effects of climate change on ecologicalzones and the species that inhabit them.

MaterialsFor each student:

• student copies of page 23, “Vegetative Zones ofa Galápagos Island”

• student copies of pages 24–25, “Plant Species ofthe Galápagos”

• pencils

Remind your students of the location and the vol-canic origin of the Galápagos Islands, and askhow a volcanic island newly built above sea levellooks (bare, rugged, and largely sterile). We’vealso discussed how vegetation arrived on theisland, probably from seeds that were eitherblown, floated, or transported by animals fromthe mainland.

So, what conditions do plants need to grow? Allplants need moisture, nourishment, and mostneed light, but plants vary greatly in their individ-ual requirements. What growing conditions existin the Galápagos? Soil is thin and relativelydevoid of nutrients; rainfall is scant during mostof the year, although there are better growing con-ditions in the highlands because of the increasedmoisture. So, given this information, ask studentswhether they would expect to find a wide varietyof plants to be able to survive in these islands.

Review the water cycle with your students to helpthem understand how moisture is an intrinsic partof the environment, then distribute page 23.Explain that in the Galápagos, rain is infrequent,but rising moist air cools, resulting in misty pre-cipitation high on the windward side of the islandmountains. Just as with animals, different types ofplant life adapt to different niches on a volcanicisland. Plants are the basis of every terrestrialfood chain, and this activity describes the depen-dence of vegetation on climatic conditions. Theamount of biodiversity depends on the range ofenvironments; the greater the range, the largervariety of plants, and thus a greater variety of ani-mals that depend on the vegetation.

Next distribute student copies of pages 23–25;give students time to read the material. Usingpages 24–25 as a guide, ask the students to markon the island in which zones each of these plantsappears.

Discuss the changes that might occur in eachregion during exceptionally dry weather or excep-tionally warm, wet weather, as in an El Niño year.What factors seem to be most important in deter-mining the type of vegetation in each zone? (Theamount and type of moisture available.) Theisland shown on page 23 is more than 900 meters(2,953 feet) high. If it were only 500 meters (1,644feet), what kind of vegetation would grow in itstop zone (humid area plants)?

Biodiversityof the GalapagosTeacher Section

23TEACHER’S RESOURCE GUIDE TO GALAPAGOS

vegetative zones OF a Galapagos island

Sedge/FernZone

Miconia Zone

Scalesia/TransitionalZone

Arid ZoneCoastalZone

Intertidal Zone

(Elevation)

900M

700M

450M

300M

0M

(not to scale)

SOUTH NORTH

PrevailingWind

24 TEACHER’S RESOURCE GUIDE TO GALAPAGOS

Plant species OF THE Galapagos

SEDGE/FERNS—Ninety different species grow inthe islands, some as large as 3 m tall (almost 10ft). They reproduce by spores, which can travelgreat distances. They grow in the Scalesia andMiconia Zones.

SCALESIA—This is the

tallest memberof the daisy family.

Trees with white flowersgrow up to 15 m (49 ft).

Scalesia thrives in dense rainforest settings. It is thedominant plant in theScalesia Zone.

MICONIA—This flowering shrub grows from 2–5 m tall (6.5–16 ft). Its green leaves turn red-orange during the dry season. Clusters offlowers grow at the tips of the branches. Its fruitis a blue-black berry. It is the dominant plant inthe Miconia Zone.

MOSSES—There are also about 90 species ofmoss in the Galápagos. They are found in allhumid zones, but predominantly in the ScalesiaZone.

LIVERWORTS—About 110 species of liverwortsoccur in the islands. They are found predomi-nantly in the Miconia Zone.

Highlands: Humid Area Plants

(Grow in Sedge/Fern, Miconia, andScalesia/Transitional Zones)

25TEACHER’S RESOURCE GUIDE TO GALAPAGOS

Plant species OF THE Galapagos

PRICKLY PEARCACTUS—Thiscactus grows upto 12 m (39 ft)

with a thick trunk,flat pads, spines,yellow flowers andgreenish fruit.

LAVA CACTUS—This is a short; thick cactusonly about 12 cm (5 in.) high. Each branch iscovered with many spines, and lasts only a fewyears. Its flowers open before dawn, and shrivelby 7 or 8 a.m.

CANDELABRACACTUS—This species grows toabout 7 m high (23 ft).Its branches look likeorgan pipes or like thearms of a giantcandelabra.

MANGROVE—Several species of floweringmangrove shrubs and trees grow at water’s edge.Their branches may reach as high as 25 m (82 ft).Mangroves are able to resist salt, conserve water,and absorb oxygen from the air. Their roots are

shallow but spread out over a wide distance. Mangroves send out prop roots from their branches to helpanchor the plant. The tangle of their roots gives shelter to many small fish and marine animals.

Mangrove Zone: Salt Resistant Plants

GALAPAGOSTOMATO—This varietyof tomato is a small plantwith spear-shaped leavesand small yellow or redfruit. Its seeds haveevolved a thick coat toresist salt and drying.They usually sprout onlyafter passing through theintestines of a tortoise ora mockingbird.

Arid Zone: Dry Area Plants

26 TEACHER’S RESOURCE GUIDE TO GALAPAGOS

ObjectiveTo observe differences between closely relatedspecies, form hypotheses about their differencesand their relationship to Galápagos environment.

MaterialsFor each student:

• copies of pages 27–28

• pens

• paper

How have isolation and the diverse environmentsof the islands given rise to the unusual features ofGalápagos animals? This activity will enable stu-dents to give examples of features from closelyrelated species. The organisms of the Galápagosare in an area that is harsh in many ways, butwhich also offers some advantages. Because ofthe upwelling of cool, nutrient-rich waters, there isa greater abundance of food than is normallyfound in tropical waters. Temperatures on landtend to be cooler than elsewhere in the tropicsbecause of the cool water. And until recently, theGalápagos’s natural isolation prevented mostpredators from establishing significant numbers.These elements had an impact on the first speciesthat first came to the islands. Over time, theyadapted through natural selection to survive inthese unusual conditions.

Direct students to work in pairs and distributecopies of pages 27–28. The paired drawingsdepict individuals of the same sex and size.Instruct students to compare the drawings care-fully and to list any differences they notice, nomatter how small. Even a tiny piece of data mayturn out to be important.

When done, ask the students to brainstorm aboutwhy each of these closely related animals hasevolved in such different ways. How do theseadaptations allow each organism to thrive in itsparticular niche? Many Galápagos animals haveadapted through natural selection to fit previouslyunoccupied niches, so they may look very differ-ent from species found elsewhere in the world—oreven in a different niche right next door!

GalapagosAdaptationsTeacher Section

Niche—the ecological role of an organismin a community, especially in regard to

food consumption

MARINE IGUANA LAND IGUANA

Coastal zone Arid zoneLong claws Short claws Short snout Long, pointed snout Dark color Light color Large bumps on head Small bumps on head

SADDLEBACK DOMEDTORTOISE TORTOISE

Transition zone (drier) Scalesia zone (wetter)Highly arched Low, rounded

shell opening shell openingLong neck Short neckLong legs Short legs

GILBERT’S GOBY BLUE-BANDED GOBY

8–9 bars 3–5 barsWhite bars Blue bars

with dark edgesSmaller (to 4.5 cm) Larger (to 6 cm)21–22 fin rays 22–26 fin rays

in dorsal fin in dorsal fin

27TEACHER’S RESOURCE GUIDE TO GALAPAGOS

Galapagos adaptations

LAND IGUANA (ABOVE)—A large relative of the South American and Caribbean terrestrialiguanas, it has a round tail, a pointed nose and is brownish-red in color on top, yellow-orangeunderneath. It eats grass and terrestrial plants,especially the large prickly-pear cactus.

Remember, species don’t “choose” to adapt tofit an environment or to avoid a predator. Thedifferences between individuals are random—just like you are different than your parents or

siblings—and it is those individuals whoseadaptations make them better able to survive

who are likely to produce more offspring.

MARINE IGUANA (BELOW)—The only marineiguana in the world, it has a flat tail, a somewhatsquare nose, dark coloration, and partiallywebbed feet. The dark coloration allows youngiguanas to be camouflaged by the dark lava onwhich on which they live, and enables them toabsorb more heat from the sun.

28 TEACHER’S RESOURCE GUIDE TO GALAPAGOS

Galapagos adaptations

SADDLEBACK TORTOISE—One of major groupsof giant tortoises in the Galápagos, the shell

(carapace) is arched in the front and thetortoise has very long legs, a longsnout, and a long neck that allow it toreach for its food high above theground. The saddleback type ofGalápagos tortoise has been found onthe dry areas of Española, Pinzon,

Pinta, and Fernandina islands.

BLUE-BANDED GOBY—This fish is found fromsouthern California to Ecuador, includingGalápagos and Cocos Islands. It is bright redchanging to orange near its tail, and it has a pairof narrow blue bars on its head and 3–5 similarbars on its body. This species is often found nearbrightly-colored purple sea urchins. It is largerthan the Gilbert’s Goby—up to 6 cm long—andhas a long dorsal fin.

GILBERT’S GOBY—This fish is found only in theGalápagos Islands. It has a pinkish-orange headand a purplish brown body with 8–9 dark-edgedwhite bars. This fish is often found near light-col-ored sponges—its light coloring and white barsmay help the fish camouflage with the sponges. It is a small fish, up to 4.5 cm long, and has asmall dorsal fin.

DOMED TORTOISE—One ofmajor groups of giant tortoises inthe Galápagos, it has a roundedshell, blunt snout, and a shorterneck. The dome-shaped tortoiseis found on islands with rich vegeta-tion like Santa Cruz and Isabela. Thetortoise is larger, heavier, and the roundedshape of the shell allows it to move throughthe thick vegetation more easily than the saddle-back tortoise.

29TEACHER’S RESOURCE GUIDE TO GALAPAGOS

ObjectiveTo understand the principles behind adaptation andnatural selection, as they relate to predator/preyrelationships.

MaterialsFor each group:

• 50 cm square piece of patterned fabric or wrap-ping paper; the pattern can simulate a naturalenvironment, such as a floral, leaf, or fruit print,and should have several colors and be of intricatedesign. Try to have multiple patterns so everygroup does not have the same.

• zip-type sandwich bag containing 120 paper dots(e.g., remnants from a hole punch), 20 each of sixdifferent colors (including black and white). Ifpossible, cut dots out of the same material as the“habitat” to make sure the colors blend in. Thisbag should be labeled “beginning population.”

• six sandwich bags each containing spare dots of aspecific color. (You can have bags for each group,or communal bags.)

• paper

• pencils

For teacher:

• stopwatch or a wristwatch that displays seconds

We have investigated biodiversity and adaptationsin the Galápagos. Now we will investigate the “how”of adaptation, that is, natural selection. The follow-ing is an activity that will help students understandnatural selection as a result of predator/prey rela-tionships. In fact, in the Galápagos, there are fewernatural predators than on the mainland so naturalselection happened without much predator pressure.In the Galápagos, “survival of the fittest” refers to aspecies that makes best use of an environmentalniche—either adapting to an unoccupied niche, oroutcompeting another species for the same niche.

However, this activity will provide students with afun way to learn about some of the mechanismsbehind “survival of the fittest” by simulating apredator-prey relationship and investigating howthis type of selection pressure can influence evolu-tion.

The “prey” will consist of paper dots spread on apiece of patterned paper or cloth, and the predatorswill be students in each lab group. Divide the classinto teams of three or four, with one studentassigned as the team “manager.” Each team shouldhave one piece of cloth and one “beginning popula-tion” bag. Have the “predators” close their eyeswhile the manager spreads the “beginning popula-tion” dots randomly on the fabric.

When all the teams are ready, begin timing for 30seconds as the “predators” search for dots (you canvary the time length according to student level). Atthe end of that period, students should count thenumber and color of remaining dots, and have themanager record the number of each colored dotthat “survived” to reproduce. Add three new dots ofthe same color for each dot that survived. Repeatthese steps for as many “generations” as you like.Have the students graph the survival results of eachgeneration in a bar graph, and answer the questionson their sheets. Students should be able to under-stand that dots that are easily seen on the cloth arequickly “eaten” by the predators and dots that aredifficult to see “survive,” and “reproduce.”

Variations in the results from different groups canbe compared with real life variations: different kindsof predators (more eager students); competitionamong predators (students who fight over theirdots); or different habitats (a more complex fabricpattern may have more “niches” where colored dotscan hide).

NaturalSelection:the “How” of EvolutionTeacher Section

30 TEACHER’S RESOURCE GUIDE TO GALAPAGOS

NaturalSelection:the “How” of Evolution

Student Section1. Once assigned to a team, gather the materials

from your teacher and decide who will be themanager and who will be the predators.

2. Examine the paper dots in the “beginning pop-ulation” bag. There are 120 dots in six colors:each color represents a species; each dot anindividual.

3. The manager spreads out the patterned clothor paper to represent an island environment.All the predators should close their eyes, asthe manager spreads out the dots from the“beginning population” bag across the pattern.

4. When all the groups are ready, the teacher willtime 30 seconds during which the predatorsshould open their eyes, and start picking updots. Wait for the teacher’s signal before youopen your eyes!

5. After the teacher calls time, stop hunting andcarefully collect all of the dots that remain onthe fabric and sort them by color. The man-agers are responsible for recording the numberand color remaining.

6. For every dot that “survived,” add three dotsof the same color from the extra-dot bags.

7. Continue this same process, recording the dataat the end of each round. Then graph theresults according to your teacher’s instructions.

8. Write a summary report about how naturalselection works based on your experiencehere. Be sure to include information on:

• Which colors of paper dots, if any, survivedbetter than others during the first round?What about after several generations?

• What might be the reason that predators didnot select these colors as often as they didother colors?

• What effect did capturing a particular colordot have on the numbers of that color in thefollowing generations?

• Why might different groups have had differ-ent results?

31TEACHER’S RESOURCE GUIDE TO GALAPAGOS

GLOSSARYAbsolute location—on a map or globe, expressed as theintersection of lines of latitude and longitude.

Adapt—gradual change in response to environmental conditions.

Adaptation—feature of an organism that enhances survivaland reproductive success.

Archipelago—a group of islands sharing common physicaland location characteristics.

Biodiversity—biological diversity in an environment as indi-cated by numbers of different species of plants and animals.

Competition—rivalry between organisms for food, shelter, orcontrol of a territory. Competition occurs both within thesame species and among different species.

Coordinates—the latitude and longitude numbers thatexpress location (in degrees north or south and east or west)as a point on a map or globe.

Current—the part of a fluid body moving continuously in asingle direction.

Ecosystem—a community of plants and animals that func-tion as an interrelated unit in nature.

Elevation—in maps, the altitude above sea level. Elevationprovides a more objective measurement than height, which isaltitude above the surrounding area.

Endemic species—native to a region; not introduced ormerely resident.

Equator—an imaginary circle around the middle of the earthhalfway between the North and South Poles, at 0 degreesLatitude.

Evolution—change in lineages of populations between gen-erations.

Fault—a fracture in the crust of the Earth along which move-ment can be determined.

Germination—the development of a sprout or young plantfrom a seed that has been moistened.

Habitat—the environmental conditions of the place in whichan organism lives.

Humboldt Current—also known as the Peru CoastalCurrent, cold-water current that flows counter-clockwise inthe southern Pacific, going north along the west coast ofSouth America to the Galapagos.

Hypothesis—a trial solution suggested for a scientific prob-lem, subject to testing.

Island—a tract of land completely surrounded by water.

Journal—a record of events, observations, and thoughts writ-ten as they are experienced.

Latitude—the angular distance (in degrees) north and southof the equator.

Lava tubes—a cave or tunnel formed when the lava flowsurface cools, forms a crust, and the molten interior continuesto flow.

Longitude—the angular distance (in degrees) east and westof the prime meridian.

Natural selection—process by which individuals in a popu-lation that are best adapted to the environment increase innumber relative to less well-adapted forms, over a number ofgenerations.

Naturalist—a person who studies natural objects and organ-isms along with their evolution, origins, description, andinterrelationships.

Niche—the ecological role of an organism in a communityespecially in regard to food consumption.

Panama Current—warm-water current that flows fromCentral America to the Galápagos.

Plate tectonics—the concept that the Earth’s surface isbroken into large, rigid plates that move slowly but relent-lessly, relative to each other, experiencing major unrest attheir margins.

Population—a group of individuals of the same species thatoccupy the same geographic region, interbreed, and produceviable offspring.

Prevailing—something that is in effect most often at the pre-sent time.

Prime Meridian—an imaginary line that runs from theNorth Pole to the South Pole and is known as zero longitude.

Relative location—the comparison of one location toanother in terms of a reference point or an area.

Scale—the ratio between map distance and real Earth dis-tance; for example, 1 centimeter represents 1 kilometer, or 1inch represents 1 mile. Scale will vary from map to map.

South Easterlies—winds that move air from the southeasttoward the northwest, south of the equator.

South Equatorial Current—equatorial current that flowswesterly along and south of the Equator.

Species—a population of similar organisms that are capableof interbreeding (in the wild) and producing viable offspring,but do not interbreed with any other populations.

Theory—a hypothesis that relates and organizes much of theknowledge in a science and has been tested with successmany times, until it has been accepted.

Trade wind—a wind blowing almost constantly in one direc-tion, either south (called Easterlies) or north (calledWesterlies) of the equator.

Undercurrent—a current that flows under other currents,usually in a different direction.

Upwelling—the flow of cold, deep water to the surface of awater body. This cold, nutrient-rich, upwelled water supportsan abundance of sea life.

32 TEACHER’S RESOURCE GUIDE TO GALAPAGOS

RESOURCESTeaching Material:Ecology and Evolution: Islands of ChangeBy the National Science Teachers Association

Although evolution happens everywhere, theGalápagos Islands are considered a “living laboratory”because their volcanic origin, geographic isolation,sharply-defined ecozones, and relatively small numberof species allows scientists and visitors alike to see theongoing effects of the evolutionary process. Using theGalápagos as a case study, these activities and investi-gations explore geology, ecology, and evolutionarytheory at the middle level. Available: April 2000. Toorder, contact NSTA, 1840 Wilson Blvd., Arlington, VA22201-3000, 800-722-6782. Http://www.nsta.org/

Family Guide:Discover Galapagos: A Family Adventure ExploringEvolution and BiodiversityBy the Institute for Learning Innovation

Color photos, games, activities, and science informa-tion bring biodiversity and evolution to life in theGalápagos family guide, a resource kit developed forfamilies to explore the concepts highlighted in the film.Check your local museum or Imax theater shop foravailability, or contact the National Museum ofNatural History Shop, Smithsonian Institution,Washington, DC 20560-0951, 202-357-1537.

CD-ROM:Galápagos—The CD-ROM EncyclopediaBy Luis Die, Jonathan Green, Macarena Green, andRichard Polatty

More than 540 photos, more than 400 species descrip-tions, animations, and videos; there are clickable mapsof the islands. A portion of the proceeds from the pur-chase of this CD-ROM goes to the Charles DarwinFoundation. To order, call 800-242-4775 x 15961 orvisit http://www.naturalist.net/cdrom/.

Books:Boyce, Barry. A Traveler’s Guide to the GalapagosIslands. Aptos California: Galapagos Travel, 1998.

Darwin, Charles. Voyage of the Beagle. London: JohnMurray, 1845.

Darwin, Charles. On the Origin of the Species. London:John Murray, 1859.

Jackson, Michael H. Galápagos: A Natural History.Calgary: University of Calgary Press, 1993.

De Roy, Tui, Spectacular Galapagos: Exploring anExtraordinary World. Berkeley, California: Publishers’Group West, 1999.

Weiner, Jonathan. Beak of the Finch: A Story ofEvolution in Our Time. New York: Knopf, 1994.

Web sites:Supplement to Teachers Resource Guide to GalapagosBy National Science Teachers Associationhttp://pubs.nsta.org/galapagos/

GalapagosBy Imax Ltd.http://www.imax.com/galapagos/

National Museum of Natural Historyhttp://www.mnh.si.edu/nmnhweb.html

Voyage of the BeagleBy The Biology Placehttp://www.biology.com/visitors/ae/voyage/introduction.html

Virtual GalápagosBy TerraQuesthttp://www.terraquest.com/galapagos/

Explore Galápagos By Discovery Channel Schoolhttp://www.discoveryschool.com/schoolfeatures/featurestories/galapagos/index.html

The Galápagos: Pressures on ParadiseBy World Wildlife Fundhttp://www.wwf.org/galapagos/

GalapagosBy Charles Darwin Foundation, Charles DarwinResearch Station, Galapagos Conservation Trusthttp://www.galapagos.org/

GalápagosBy Naturalist Nethttp://www.naturalist.net/

Global Volcanism ProgramBy National Museum of Natural Historyhttp://www.volcano.si.edu/gvp/

Galápagos Volcano TourBy Volcano Worldhttp://volcano.und.nodak.edu/vwdocs/volc_tour/galapagos/gal_pgs.html

Enter Evolution: History and TheoryBy University of California, Berkeleyhttp://www.ucmp.berkeley.edu/history/evolution.html

For more information, go to America OnlineKeyword: Galapagos

This film is totally the work of theproducers and may not necessarilyreflect the opinions of the funders.

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