INTERPRETING EVIDENCE: An Approach to Teaching HUMAN EVOLUTION in the Classroom

8/14/2019 INTERPRETING EVIDENCE: An Approach to Teaching HUMAN EVOLUTION in the Classroom

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Interpreting Evidence: An Approach to Teaching Human Evolution in the ClassroomAuthor(s): Jeremy DeSilvaSource: The American Biology Teacher, Vol. 66, No. 4 (Apr., 2004), pp. 257-260+262-267Published by: University of California Presson behalf of the National Association of Biology TeachersStable URL: http://www.jstor.org/stable/4451668.

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INTERPRETING EVIDEN EAnApproachoTeaching U M N V O I U T I inthe Classroom

JEREMYDESILVA

?erhapshe besttopic eachers anuse toexempli-fy the natureof science is paleoanthropology,he studyof human evolution through the fossil record.Scienceeducators have an opportunity to tackle How do weknow? questions by examining evidences of our pastand accuratelydefining the terms hypothesis, fact,theory, nd belief. heycan use recent discoveries odemonstrate hat science is a self-correctingmechanismof understanding the world. By examining differenthypotheses, they can encourage he skepticism,debate,and challenge o authorityon which science thrives.

Often, teaching human evolution is a struggle.Teachers anbe derailed nto philosophical discussionsinappropriaten a science class.They can fall victim to a

curriculum design that leaves evolution to the end ofthe year, forcing them to squeeze four billion years of lifeinto the last two weeks of June. Even schools addressingbiological evolution may fail to teach the evolutionaryhistory of the mammals sitting in front of them.

In this article, we present an updated approach toteaching human evolution, and a model for explainingwhat science is and how it is done.

What Is the Problem?There may be no other scientific exploration that

elicits more passion, skepticism, and debate thanhuman origins. Paleoanthropologist Meave Leakeywrites, All people are innately curious and seek toknow why and how they came to be. (Leakey, 2003).

Since Charles Darwin published On the Origin ofSpecies in 1859, paleoanthropologists have been

JEREMYDESILVAs an educator at the Boston Museum of Scienceand in the Department of Anthropology at Boston University,Boston,MA 02215; e-mail: [email protected].

INTERPRETINGVIDENCE57

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searching for fossil evidence of our past, and fiercelydebating hypotheses for human ancestry.Many popu-lar ideas have come and gone, and some of the mostenthusiasticallyendorsed hypotheses have witheredinlight of new evidence.Just in the last two years, newlydiscovered fossil hominids have forced paleoanthro-pologists to reanalyzethe evolution of bipedalism inour ancestors (Shipman, 2002), and to reevaluatethemorphology and timing of the last common ancestorwith chimpanzees(Brunet, 2002; Wood, 2002).But, textbooks often do not communicate theexcitement and debate generated by new discoveries.The typical, inear representationsof our evolutionaryhistoryare not onlyincorrect, heyareboring.Alles andStevensonhaverecentlyremarkedon this problem n aphenomenal article Teaching uman evolution oundin the May,2003 issue of TheAmericanBiologyTeacher.Using the model we proposein thispaper,studentswillhave an opportunity to explore a science with morequestions than answers,without having to memorize

oversimplified ersions of humanancestry.Unfortunately,onfusionoverthe discoveries hem-selves preventsmany teachers from everreachingthispoint with theirstudents.To start,the names assigned-tonew fossils are often confusing to teachers and mis-understoodby students.

Lumpers & SplittersCurrently, here are two modes of thought in cate-gorizinghuman ancestors: he lumpers, who tend togroup fossils into relatively ew species, and the split-

ters, who use measurable differencesas evidence forprolificspeciation n ourpast.Eachuses the samemeas-urements,and the same fossils,but interpret he resultsdifferently.Tim White, Professor of IntegrativeBiologyat theUniversityof California,Berkeley, ses the variation hatexists within a species today to understand the fossilrecord(Figure 1). This strategyhas landed him withinthe lumper ategory.

Rightnow, there is oversplittinggoing on by mod-ern people inferringtoo many fossil species based onthe differences hey see betweenfossils,when the samedifferencesare seen amongskulls from a singlemodernspecies, for example, chimpanzees, or gorillas, orhumans, aysDr.White. This s a good indication hatnaming manyof the newer fossils as different pecies isnot warranted. White, 2003a)Regardednow as a splitter, an Tattersall,Curatorof the AnthropologyDivision of the AmericanMuseumof NaturalHistory n New York,s influencedby his firstresearch nterest,lemurs. Fifty species of lemur resideon the island of Madagascar, nd by looking only at

their skeletons,one may be hardpressed to findenoughmeasurabledifferences o distinguishall 50 species. Furcolor, ovulatory cycles, behaviorpatterns, communica-tion methods, and genetics do not fossilize. Therefore,even the slightest difference in skeletal morphologymight constitute evidence for a new species. Tattersallstudied lemur taxonomyfor many years and now seesthe samediversityn the human fossil record(Figure2).The lemurs had told me a tale of diversity;andlooking at the human fossil record, which [has] been

steadily expanding ... taught me the same thing abouthominids, Tattersallwrote in Monkey in the Mirror(2002).Tim White, a lumper, ooks at the fossil record andsees variationwithin a few species. Ian Tattersall, split-ter,sees diversityandrecognizesmany different pecies.To highlight the difference, consider the followingexample. One million years from now, would a futurepaleontologistbe able to tell that a 7'2 basketballplay-

er like Shaquille O'Neal was a member of the samespecies as a 5'2 actorlike Danny DeVito?This is thechallenge to a paleoanthropologist;trying to decidewhether a new fossil discoveryrepresentsa new species,or a variantof an alreadyrecognizedanimal.

for Figures1-3The letters indicate where the fossil was found:

AL - AfarLocality, EthiopiaBAR - Baringo district, KenyaBOU-VP - Bouri Vertebrate Paleontology,

EthiopiaER - East (Lake) Rudolf, KenyaKNM - Kenya National Museum (where fossil

is on display)KP - Kanapoi, KenyaKT - Koro Toro, ChadOH - Olduvai Hominid, TanzaniaSK - Swartkrans, South AfricaSts - Sterkfontein type site, South AfricaTM - Toros-Menalla,ChadWT - West (Lake) Turkana, Kenya

The number of the fossil found at that site follows:For instance, KNM-ER 3733 was the 3,733 speci-men found in East Rudolf. It is at the Kenya NationalMuseum.

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0 | ~~~*Cro-MagnonH.apiens *Laerrassie| *Herto | *Shanidar H.neanderthalensis*Bodo_ \ | ~~*Peking

I ~~~ManH. rectus*Daka erectus A.boisei

15000 Early A.robustus *KNMERergaster *KNM-ER *KNM-ERH4063733 1813 Homo *SK 8 ~~~~~~*OH

2~~~~~~~~~~FJT - mChild Aar-*NW|*BOU-VP 12/130 | A.afri- 1KNMW~VP12/1 0 1~~*Sts 17000

A.garhi 0- _ c sAustralopithecus.4. - -_ aethiopicus

a) *A.L. 44-2*A.L. 88-1(Lucy)O *KT 2/H1,KNM-WT A. afarensis4

4| *KNM-KP| Australopithecus29281 anamensis*ARA-VP/129 IAr. amidusramidus

5M 11/171 Ardipithecus*ALA-VP ramidus*BAR1000'00 2/11 kadabba(Millenium Man)

6 P ?Orrorin |tugenensis*TM266-01-260-1(Toumai)

Sahelanthropustchadensis7 _ __ __ __ -__-__-__-__-__-__-Tim White's Family Tree. Dr.TimhitesaprofessorfIntegrativeiologyt heUniversityfCaliforniatBerkeley.is iscoveriesnEthiopiancludeossilsfArdipithecusamidus,ustralopithecusfarensis,ustralopithecusarhi, omorectus,ndHomoapiens.otehatDr.Whiteroupshe ameossil ominidsntoewerpeciesnd as muchmoreinearelationshiphanDr.Tattersall.




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0 E*CroMagnonH. apiens *La errassie H.neanderthalensis*Herto ISaida .nadrhlniH.heidel- *Bodo -bergensis *PekingMan

H. nte-1 cessor *Gran|oina| H. rectusPboisei

*KNM-WTKNM 715000 R P robustus *NEERNM *KNM-ER KME*NMR147 3733 - 1813 Homo *S 8406|2 Homo- habilis *OHergaster

K.ru4o1fensis COU-VP2/130 hild A.afri- 1700ftft ~I *Sts| I A.garhi canus Paranthropusu^) | I -o _ ~ aethiopicusa)~~~~~~~~~~~~~~~~~~~~0

31 ,I|*AL4442'.- *KT2/H1 *A.L.288-11KNenTh A.bahreg li Lucy) A.afarensisIA ~~40000

O Kenyanthropus'pl4Watyops AKNM-KPustralopithecus

L29281 anamensisAr.amidus| \ | ~~~~~~~~~~~~~~~~*ARA-VP/129 |AeaiuV 1/129 ramidus

|*AME-VP| 11/1711ArdipithecusI*ALA_VPaiuI*BAR1000'00 21 kadabba(Milleniuman) kdb6 > Orrorin

tugenensis*TM266-01-260-1| l (Toumai)

Sahelanthropus| ~~~~~~~~~~~~tchadensis7 - - - - - - - - - - - - - - - - - - - _-Ian Tattersall's Family Tree. Dr.lIanattersallsCuratorf he DivisionfAnthropologyt heAmericanuseumof Naturalistory.is esearchnteress include ominidvolution,nd hebiologynd volutionf heLemursfMadagascar.

continued on page 262260 THEMERICANIOLOGYEACHER,OLUME6,NO.,APRIL004



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InterpretingEvidencecontinuedrompage260

For a teacher, t is significantlymore valuable toexplain to students why scientists disagree over thespeciesdesignationof aparticular ossil,thanto confusethemwith the names themselves.Takeforexamplethefollowingsituation.Skull 1470

In August of 1972, Kenyanfossil hunter BernardNgeneo uneartheda 1.9 million-year-oldkull, knowntechnicallyas KNM-ER 470, from the easternshoreofLake Turkana (Schwartz & Tattersall, 2003).PaleontologistRichardLeakeypublishedhis analysisofthisfind n NatureLeakey, 973)and aftermuch debate,Skull 1470 was assignedto the alreadyknown species,Homo habilis. Citing differences in cranial capacity(1470'scranialcapacitys 775 cc, while otherH. habilisskulls are in the 550 cc range) and dental pattern,RussiananthropologistValeriiAlexeevpulled 1470fromH. habilisand renamed t HomorudolfensisJohanson,1996). In 2001, MeaveLeakeydiscovereda 3.5 million-year-old skull in Kenya that she has designatedKenyanthropus latyops (flat-faced man of Kenya).Similarities n face morphology suggest that 1470'sspecies (H. rudolfensis)maybe a distant descendantofthe newly named K. platyops Figure3) (Lieberman,2001). This has led some paleontologiststo rename1470,Kenyanthropusudolfensis. thersevensuggest hatSkull 1470 retainsenough primitive haracteristicso beconsideredAustralopithecusudolfensisWood,2002).So,what is 1470? Somestillsayit is a Homohabilis.Somesayit is a Homorudolfensis. ndnow,some call ita Kenyanthropusudolfensis,or even Australopithecusrudolfensis. his can be confusing to teachersand stu-dents alike.Ultimatelyhough,the names do not matter.The creature hat died and left what we call 1470 livedapproximately .9 millionyearsago.No one argues hatfact.Whether 1470 was a habilisor a rudolfensishouldnot be the focusin a classroom.As Tim Whitesuggests,Whyconfuseyour students with this?Get them ontorelationships,ot names. White,2003a)UnderstandingHominidRelationships

Many hominid species once existed. But, today,only one remains-us. How did this happen?Again, tdepends on whom you ask.Tim White,Ian Tattersall, nd MeaveLeakey'sphy-logenies, or family trees, all differ,even though their

interpretationsare based on the same measurements,using the same equipment, the same units, and thesame well-aged ossils.These phylogeniesareworkinghypotheses, designed to be tested and scrutinized,while flexible enough to be changed when new evi-dence is found. For students, the lesson from thesefamily reesshouldnot be the lines themselves,but whyscientistsdrawthe relationships hey do, andwhy theydisagree.Too often, the public and our students think thatconflictinghypothesesunderminethe validityof a sci-entific principle.Too often,we fail to educateour stu-dents that science is rooted in doubt-that challenge,skepticism,and debateareexcitingcornerstonesof sci-entific thought.We fail to educateour studentsthatsci-ence is drivenby questions,not answers.The scientificarguments urroundinghumanevolutionare ntellectu-ally stimulating nddemonstrate ow scientistsdevelophypotheses from availableevidence. Next, we will out-line a numberof activities hat teacherscan employinteachinghuman evolution o theirstudents.Mostof theinformationneeded to execute these activities s avail-able at the Boston Museum of Science Web site:www.mos.org/evolution.

Activity1.Where Do You Draw theLines?Print he three amilyreespresentedn thispaperorgoto theMuseum f ScienceWeb iteanddownloadthe family rees here.Print hem ontransparencyilm

if possible)andpresent hemas handoutso yourstu-dents.Now,examine ach ndetail.Ofthe thousandsffossils hathavebeenunearthed,9 were hosen o rep-resent arlyhumans.Theseare he greatestits. Whatdifferencesoyounoticeabout hese nterpretationsfthe fossilrecord?Comparehe family rees (overlaythem f usingtransparencyilm),paying areful tten-tion to whereTattersall,eakey, nd Whitediffer, ndwhere heyagree.Thesephylogenies reup-to-dates of July,2003(seethewww.mos.org/evolutionebsiteforthe mostcurrent hylogeneticrees)and areconsiderably ore

accurate ndinterestinghan the traditionalextbookmodel.They llustrate lternativenterpretationsf thehuman ossilrecord, teachingmethodconspicuouslyabsent rommostscience extbooks.Examine he Whitemodel versusthe Tattersallmodel.Whitedeals trictly ith heknown ossil ecordand does not speculatethe existence of undiscoveredhominid species. He also dismisses recent suggestionsthat the human family ree s shapedmore like a bush.

262 THE MERICANIOLOGYEACHER,OLUME6,NO. , APRIL004



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O | ~~~Cro-HMagnonH.sapiens *L|ersi0 Hertgno~| *H p FShanida1 H neanderthalensisH.heidel- Z7]bergensis i* 1okd

ManL*GranDolina H.erectus*Daka

P.boisei

15000 Probustus *KNM|ER*KNM- *KNM-ER401470118132 _ Homo habilisergaster

*BOU-VP2/130 Child A.fi *KNM-WTIK.udolfensis *Sts A. afri- 17000A.garhi canus Paranthropus

,r} 3 aethiopicus


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Observationsegardinghe bushy ature f theearliesthominidfamilyreefall ntothecategoryof X-files aleontology pure peculation-basedon preconception-butncheckedyfossildata).Present ata indicate hat thehominidfamilyreewas neverparticularly bushy, r speciose n thenormalmammalianense,despite ecent laimsto the contrary.

(T. White, ThePrimateFossilRecord, 003.)Tattersall'sree,however, s particularly bushy. Herecognizes five additional species, and two genera,Kenyanthropus,nd Paranthropus,hich White incorpo-rates into Australopithecus.lso, Tattersallsuggests amore indirect relationship between currently recog-nized hominids.

No hominid fossil species that we know are likelyto be the direct ancestorsof any other known species,Tattersall xplains. Infact, recognizingancestors s aproblem since they have to be primitive n all respectsrelative o their descendents. Tattersall, 003).

Recognizing he uncertainly f their nterpretations,both Ian Tattersalland Tim White use dotted lines,instead of solid lines, in theirfamily rees.

MeaveLeakey akes this caution a step further,anddoes not even use lines. She draws circlesaroundrelat-ed species.Thespecies enclosed in the ellipses are those thatshare features that appear to link them. I do suggestrelationships,but I do not give such detailed relation-ships as those who draw inesbecauseIbelieve the linesimply that we know more about how things are relatedthan we actuallydo. She continues, Wewill neverknow exactlyhow any species relatesto anotherunless,by some amazing good fortune,we are ever able toextractDNAfrom these fossils. Leakey,2003)

Activity 2. Why Do You Draw the Line?Now, encourage your students to examine thesephylogenies using real, measured evidence. They willlearn the skills of inquiry, skepticism,and evidence-basedunderstandingof a scientificconcept.Scientific upply companies ike Carolinaand BoneClones have model hominid skulls-reproductions ofactual inds.But, fyou do not have the resources opur-chasethese skulls,you canprint ife-sizedpicturesfromthe Internet(see referencesection for URLs), or pur-chase FromLucy o Language Johanson,1996), which

e A S y CS S i i BeAm

1-800-558-9595 4 wwvweNASCO.coms J o i z L4kV JVL1A,~~~~~~~~~U,C&~~~~~~~~~~~~Ce

ZbA1-0-5899 ow,,,wweNSCOco

264 THE MERICANIOLOGYEACHER,OlUME6,NO.,APRIll2004



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has hundreds of life-sized photographs of fossilhominids. Referencednformationaboutparticular os-sils is also availableon the Boston Museumof ScienceWeb site.Students examiningtheir fossilized ancestorsmayconsiderwhich criteria hey would use to hypothesizerelatedness.Perhaps they could look at the changing

size of the skull diameterovertime,or the angleof theface, molar size, browridge, r presenceor absenceof asagittalcrest(see Website forguidance n takingthesemeasurements).They may begin to understand hatalltraitsdo not necessarilyevolve n step, or at a constantrate.Studentsmayalsorecognize hat certaincharacter-istics may be informativewhen hypothesizingrelation-ships and may use these data to construct their ownphylogenetic rees.Compare heirdifferentphylogeniesto those of White, Tattersall,and Leakey;encouragedebateand Howdo you know? questions.There s noanswerkey to this activity.Rather, he objectiveof thisexercise is to empower students to know that theirhypotheses, if supported by evidence, are legitimate.Students may even leave your class with an under-standingthatchallenge s healthyand necessaryto sci-ence.Activity 3. How Do We Know What WeKnow? Questions

Using models of hominiddiscoveries,or the photo-graphssuggested n thepreviousactivity, ncourage hestudents to explore the specimens in more detail.Perhaps he students could workin groups researchingone of these questionsandpresenttheirfindingsto theclass. Activities3 and4 are also excellentopportunitiesto integratescience writinginto your curriculum.Wesuggestsix differentquestionsthat canbe addressedbyyourstudents.* Did more hanone kindof hominid iveat thesametime?We arecurrently he only type of human onthe planet, but has it always been this way?Careful xaminationof the dates and morpholo-gies of skulls KNM-ER 06 and KNM-ER 733provide nsight nto this question.* Canwe tell whether hominid s male or female?Scientistsapplywhat they know about animalstoday to those that no longer exist. Have yourstudents examine he famousLucyskeleton (A.L.288-1), or the Black Skull (KNM-WT17000).What evidence helps scientists hypothesize thesex of these individuals?* How do scientistsknow how old these ndividualswerewhen they died?How do we know that theTaungChildwas, in fact, a child and not a chim-

panzee?How do we know thatKNM-ER 813 isan adult?How do we know Kabwe ived to be anold individual?* When did the last common ancestor betweenhumans nd theAfrican peslive?Whatdid it looklike? Discoveries in just the last few years ofSahelanthropus, rrorin, ndArdipithecushow a

fascinatingmorphologicalamalgamation f apeand hominid-like raits. Students will recognizethat becausewe share a common ancestorwiththe Africanapes,when dealingwith fossils fromthis time period (the late Miocene),it becomesexceedingly difficult to distinguish between agorilla ancestor, chimpanzee ancestor, and ahominid. Students can also investigate howgeneticcomparisonsand paleontologicaldiscov-eries inform this multidisciplinarynvestigationof humanorigins.* Wheredid ourgenusevolve?Encourage he stu-

dents to examineallfinds dated1.8millionyearsand older. Where were they all discovered?Students can then hypothesizewhen hominidsfirst left Africaand perhapseven engagein theOut of Africaversus MultiregionalEvolutiondebate. How would we test whether humansevolved in Africa and spread worldwide, leftAfrica n one migrationor many, or whether weevolved independently in different parts ofAfrica,Asia,andEurope?* Who were the Neanderthals? Compare aNeanderthalskull to an anatomicallymodern

human skull. What differencesdo you notice?Competing hypotheses argue whether ourspeciesmayhave nterbredwithNeanderthals rnot. How might DNAhelp inform us about therelationship between modern humans andNeanderthals?Activity 4. Incorporating New Discoveries

In the last three years, fossils that representSahelanthropus,rrorin,Kenyanthropus,ndArdipithecuswereadded to the humanfamily ree.The oldest Homosapienswas unearthedin Ethiopia (White, 2003c). Aremarkable et of skulls, possibly representinga newspecies of early Homo,was discoveredin the formerSovietRepublicof Georgia Vekua,2002). And a fossilfromOlduvaiGorge n Tanzaniamay shed light on the1470 puzzle mentioned earlier in this article(Blumenschine, 2003). Teachers have a wonderfulopportunityto teach theirstudents the very natureofscience by presenting the latest fossil discoveriesandfollowingthe scientificdebate that ensues. You mightobtain the primary ournalarticlesof recentdiscoveries,




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foundoften in Nature rScience, nd haveyourstudentscomparethese peer-reviewedpapers to newspaperorscience magazineaccounts of new fossils.Understandthatthe interpretation f new discoveries s alwayscon-troversialand informedskepticism s necessaryto thescientificprocess. Consider he followingexample:New to Leakey'sphylogeny n 2001 was KNM-WT40000, the defining fossil, or type specimen, ofKenyanthropus latyops. An ellipse connecting40000 with 1470 implies the relationshipbetweenthose two skulls mentioned earlier n the article.Tattersall'sphylogeny reflects an agreementwiththis interpretation. imWhite'sdoes not.

I havenowseen theoriginal platyops ndIfind that t is mostprobably crushed faren-sis cranium ndneither newspeciesnoranewgenus,Whitesaid.I amlookingforwardto therecovery fadditional ndistortedfos-silsof thisagefromKenya hatmightallowus todetermine hetherDr.Leakeys rightorwrongn her nterpretation.

(T.White, Personalcorrespondence,2003)Leakeyadds

... I appreciatehatscience dvances ytestingpreviousheories nd thatthemoreoutrageousand unscientificheories ften eneratemoreintensive esearchyothers o prove rdis-prove hese heories. hey rethususeful ngeneratingndstimulatingfurtheresearch.na sense,by makingKenyanthropusnewgenus,we weredoingustthatandpresentingan interpretationfourobservationshatwasperhaps eadingmorento theevidencehantheevidenceustified.

(M.Leakey,Personalcorrespondence,2003)We havepresentedthreedistinctfamilytrees fromthreewell-respected cientistsstudying human origins.There s littledisagreement bout heages of these fossilsandwhether heybelong n thehominid amily, utinter-pretations f speciesdesignation revariedandquestionsregardingwhich,if any, species areancestral o modern

humansremain.Thesequestionscan only be answeredwith moreevidence.Failureo impressuponstudents hemethodbywhichwe understand urpastandtheuncer-tainties hat still remainundermines hescience tself.There s an excitingargumentn paleoanthropologyright now, one that allows informed students to get tothe very heart of science. Everyyear this argumentevolves, with new fossil discoveries provoking morequestions than answers.As of the submission of thispaper, reports of a partial skeleton of Ardipithecus;

anotherskull fromDmanisi,Georgia; 2 additional os-sils fromOrrorin, nd severalmore unclassifiedfossilsfromSouthAfricaall awaitpublicationand interpreta-tion. With these discoveriesnearing publication,thephylogeniespresented in this paper may be obsoletewithin the year.Such is the natureof science, so staytuned, and keep those family reesupdated.

AcknowledgmentsI am gratefulto Drs. MeaveLeakey, an Tattersall,and Tim White for their contributionsto this paper.Their work is an inspirationto all bipedal primates.Additional thanks to Lucy Kirshner, Erin Henry,Michael Schiess, Bruce DeSilva, Gail Jennes, RandyMoore,andthreeanonymousreviewers ortheir nsight-ful contentand editorial uggestions.

Web Site Addresseswww.mos.org/evolution

The activities uggested n this articleareavailableonline at the BostonMuseumof ScienceWebsite.www.becominghuman.ororg

Multi-media ite fromInstituteof HumanOrigins.www. mc.maricopa. edu/anthropology/hominidiourneyZindex.html

Mesa Community College Department ofAnthropology.Excellentphotos.www.mnh.si.edu/anthro/humanorigins/index.htmAmericanMuseumof NaturalHistorysite.

www.talkorigins.org/faqs/homs/specimen.htmlAnalysisof individual ossils.Excellentphotos.

www.msu.edu/~heslipst/contents/ANP440/index.htmMichiganStateUniversity ite. Wellorganizedwithusefulphotographsandfossildescriptions.

ReferencesAlles, D.L. & Stevenson, J.C. (2003). Teaching human evolu-tion. AmericanBiologyTeacher, 5(5), 333-339.Blumenschine, Rj. et al. (2003). Late Pliocene Homo andhominid land use fromWestern Olduvai Gorge,Tanzania.Science,299(February 21), 1217-1221.Brunet, M., et al. (2002). A new hominid from the upperMiocene of Chad, Central Africa.Nature,418(Julyl1), 145-151.

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Darwin, C. (1859). On the Originof Speciesby Means ofNatural Selection. London: Murray.

Gibbons,A. (2002). In searchof the first hominids.Science,295(5558), 1214-1219.Haile-Selassie,Y., Suwa, G.,White,T. (2004). LateMioceneteeth from MiddleAwash,Ethiopia,and EarlyHominiddental evolution.Science, 03, 1503-1505.Johanson, D. & Edgar, B. (1996). From Lucy to Language.New York:Simon& SchusterEditions.Leakey,M.(2003). Personalcorrespondence.Leakey, R.E. (1973). Evidence for an advanced Plio-Pleistocene hominid from east Rudolf, Kenya.Nature,242, 447-50.Lieberman,D. (2001). Another face in our family tree.Nature, 10(6827),419-420.Schwartz,J.H. & Tattersall, . (2003). The Human FossilRecord.New York:Wiley-Liss.Shipman,P. (2002). Hunting the first hominid. American

Scientist,90(1), 25-27.Tattersall, 1. (2002). Monkey in the Mirror. New York:Harcourt, nc.Tattersall,. (2003). Personalcorrespondence.Vekua,A. et al. (2002). A new skull of early Homofrom

Dmanisi, Georgia. Science,297(July 5), 85-89.White,T.(2003a). Personalcorrespondence.White,T. (2003b). EarliestHominids.In WalterHartwig's,

The Primate Fossil Record (pp. 407-417). Cambridge:CambridgeUniversityPress.White, T.,Asfaw,B., DeGusta,D., Gilbert,H., Richards,G.,Suwa,G.,Howell,F.C. 2003). PleistoceneHomo apiensfrom MiddleAwash, Ethiopia.Nature,423 (June 12),742-747.

Wood,B. (2002). Humanorigins: ife at the top of the tree.Treeof LifeSymposium.New York:American Museum ofNaturalHistory.

BREAKING NEWSIn March2004, Tim White's team of paleoanthro-pologists announced the discovery of 5.8 million-year-oldhominid teeth in Ethiopia.As a result, itarguesthatArdipithecusamidus adabbas its ownseparate species: Ardipithecus kadabba.Additionally, he authors suggest that the earliestknown hominid fossils Ardipithecus, rrorin,andSahelanthropusmay belong to a single genus:ArdipithecusHaile-Selassie, 004).

Free, New ResourcesFor Teaching GeneticsOn National DNA DayApril 30, 2004National DNA Day commemorates hecompletion of the HumanGenomeProject nApril 2003 and the discoveryof DNA's doublehelix a half centuryago. The National HumanGenome Research Institute (NHGRI)seeks tohelp you inspirethe next generationof scientistsworking to understand he humangenomesequenceand use it to benefit humanhealth.

James D. Watson, eft, and FrancisCollins,right,atApril2003 DNA Day event.

CelebrateNational DNA Day withyourstudentsby using these free resources available athttp://www.genome.gov/DNAday/3 GeneticEducationModules orTeachersK ExploringOur MolecularSelves,AnOnlineMultimediaEducationKitX HumanGeneticVariationCurriculum

SupplementM GeneticsMentorshipNetwork3 OnlineVideosand Webcasts

Updates on National DNA Daywill be available athttp //www.genome.gov/DNAday


Documents

INTERPRETING EVIDENCE: An Approach to Teaching HUMAN EVOLUTION in the Classroom