1in250arecarriers geographicalgradientsorclines

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Unformatted text preview: erecognize gradualchangesinthefrequencyofgenotypesand phenotypesfromonegeographicalregiontoanother ExamplesfromtheAAA Physicalvariationsinanygiventraittendtooccur graduallyratherthanabruptlyovergeographicareas i.e.theyfadeinandoutwhenwelookatclinalmaps Sincephysicaltraitsareinheritedindependentlyofone another,knowingtherangeofonetraitdoesnotpredict thepresenceofothers Example:skincolor  http://www.pbs.org/race/002_SortingPeople/002_00 home.htm          SkinColor  Whatcausesvariationinskincolor? GeographyandUVR,NOTrace!! Jablonski andChaplinpredictedthatskincolorwould correlatecloselywithUVR(ultravioletradiation),basedon geographiclatitude,annualUVRexposure,andother environmentalfactors Theirpredictionscloselymatchtheactualclinal distributionofskincolorsthroughouttheworld Professor L.M. Smolich    ClinalDistributionofHairColorAmongAustralian Aborigines(aclineexistshere gradualchange) SDSU Fall 2011 4 10/23/2011 Part II: Cell Biology through Race Lecture 12: Biological Anthropology and Race Lecture Topic Anthropology 101                      TheClinalDistributionoftheBBloodAllele   DiscontinuousDistributionofRedHairinBritain (nonice,fluidgradualchangeexists  occurrence,sothereisnocline) TheClinalDistributionoftheABloodAllele Somewhatofaclineexists.About21%ofallpeoplesharetheallele.The highestfrequenciesareinsmall,unrelatedpopulations,esp.theBlackfoot IndiansofMontana(30 ­35%);AustralianAborigines(40 ­53%insome groups);andtheLapps,orSaamipeople,ofN.Scandinavia(50 ­90%).Itis apparentlyabsentamongCentralAndSouthnativeAmericans. Areasonableclineexists itishighestinCentralAsia,andlowestinthe AmericasandAustralia.Therearealsosomehighfrequencypocketsin Africa,aswell.  type only16%ofpeoplecarryit  TheClinalDistribution BloodAllele Areasonableclinecertainlyexists(usuallyresultingfromtheabsenceofbothA andBalleles).About63%ofhumansshareit.Itisverycommonaroundthe world,asyoucanseebythepercentages.ItisparticularlyhighintheAmericas, whereitnears100%.ItisalsorelativelyhighamongAustralianAboriginesandin WesternEurope(especiallywherethereareCelticancestors).Thelowest frequencyof alleleiswherethe alleleiscommon. StatementFromtheAAA Historicalresearchhasshownthattheideaof "race"hasalwayscarriedmoremeaningsthanmere physicaldifferences indeed,physicalvariationsin thehumanspecieshavenomeaningexceptthe socialonesthathumansputonthembecausewe PERCEIVEraceasbeingreal(theyaresocial constructs,constructedbypeople,andcanvaryby culture) Thus,RACEisnotabiologicalreality,butRACISM (whichisasocialandculturalconstruction)isstill veryreal.AndnotethatRACEandRACISMarevery differentfromoneanother. Professor L.M. Smolich TheEnd SDSU Fall 2011 5...
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