英语翻译Intheearly1960sWiltChamberlainwasoneofonlythreeplayersintheNationalBasketballAssociation(NBA)listedatoversevenfeet.Ifhehadplayedlastseason,however,hewouldhavebeenoneof42.Thebodiesplayingmajorprofession
英语翻译
Intheearly1960sWiltChamberlainwasoneofonlythreeplayersintheNationalBasketballAssociation(NBA)listedatoversevenfeet.Ifhehadplayedlastseason,however,hewouldhavebeenoneof42.Thebodiesplayingmajorprofessionalsportshavechangeddramaticallyovertheyears,andmanagershavebeenmorethanwillingtoadjustteamuniformstofitthegrowingnumbersofbigger,longerframes.
Thetrendinsports,though,maybeobscuringanunrecognizedreality:Americanshavegenerallystoppedgrowing.Thoughtypicallyabouttwoinchestallernowthan140yearsago,today'speople-especiallythoseborntofamilieswhohavelivedintheU.S.formanygenerations-apparentlyreachedtheirlimitintheearly1960s.Andtheyaren'tlikelytogetanytaller."Inthegeneralpopulationtoday,atthisgenetic,environmentallevel,we'veprettymuchgoneasfaraswecango,"saysanthropologistWilliamCameronChumleaofWrightStateUniversity.InthecaseofNBAplayers,theirincreaseinheightappearstoresultfromtheincreasinglycommonpracticeofrecruitingplayersfromallovertheworld.
Growth,whichrarelycontinuesbeyondtheageof20,demandscaloriesandnutrients-notably,protein-tofeedexpandingtissues.Atthestartofthe20thcentury,under?nutritionandchildhoodinfectionsgotintheway.Butasdietandhealthimproved,childrenandadolescentshave,onaverage,increasedinheightbyaboutaninchandahalfevery20years,apatternknownastheseculartrendinheight.YetaccordingtotheCentersforDiseaseControlandPrevention,averageheight-5′9〃formen,5′4〃forwomen-hasn'treallychangedsince1960.
Geneticallyspeaking,thereareadvantagestoavoidingsubstantialheight.Duringchildbirth,largerbabieshavemoredifficultypassingthroughthebirthcanal.Moreover,eventhoughhumanshavebeenuprightformillionsofyears,ourfeetandbackcontinuetostrugglewithbipedalpostureandcannoteasilywithstandrepeatedstrainimposedbyoversizelimbs."Therearesomerealconstraintsthataresetbythegeneticarchitectureoftheindividualorganism,"saysanthropologistWilliamLeonardofNorthwesternUniversity.
Geneticmaximumscanchange,butdon'texpectthistohappensoon.ClaireC.Gordon,senioran