考研英语真题带学第二期D2（碧果）.pdf

碧果考研

“破茧”计划考研英语真题带学

第2期

Day2

Text1

Itisawisefatherthatknowshisownchild,buttodayamancanboosthispaternal

(fatherly)wisdom–oratleastconfirmthathe’sthekid’sdad.Allheneedstodoisshellout

$30forapaternitytestingkit(PTK)athislocaldrugstore–andanother$120togetthe

results.

Morethan60,000peoplehavepurchasedthePTKssincetheyfirstbecameavailable

withoutprescriptionslastyear,accordingtoDougFogg,chiefoperatingofficerofIdentigene,

whichmakestheover-the-counterkits.MorethantwodozencompaniessellDNAtests

directlytothepublic,ranginginpricefromafewhundreddollarstomorethan$2,500.

Amongthemostpopular:paternityandkinshiptesting,whichadoptedchildrencanuse

tofindtheirbiologicalrelativesandfamiliescanusetotrackdownkidsputupfor

adoption.DNAtestingisalsothelatestrageamongpassionategenealogists–andsupports

businessesthatoffertosearchforafamily’sgeographicroots.

Mosttestsrequirecollectingcellsbyswabbingsalivainthemouthandsendingittothe

companyfortesting.AlltestsrequireapotentialcandidatewithwhomtocompareDNA.

Butsomeobserversareskeptical.“There’sakindoffalseprecisionbeinghawkedby

peopleclaimingtheyaredoingancestrytesting,”saysTroyDuster,aNewYorkUniversity

sociologist.Henotesthateachindividualhasmanyancestors–numberinginthehundreds

justafewcenturiesback.Yetmostancestrytestingonlyconsidersasinglelineage,eitherthe

Ychromosomeinheritedthroughmeninafather’slineormitochondrialDNA,whichis

passeddownonlyfrommothers.ThisDNAcanrevealgeneticinformationaboutonlyoneor

twoancestors,eventhough,forexample,justthreegenerationsbackpeoplealsohavesix

othergreat-grandparentsor,fourgenerationsback,14other