资源描述：
《考研英语阅读练习》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、重庆森博国际教育沙坪坝三峡广场新华书店旁立海大厦25楼考研英语阅读练习Itisawisefatherthatknowshisownchild,buttodayamancanboosthispaternal(fatherly)wisdom—oratleastconfirmthathe’sthekid’sdad.Allheneedstodoisshellour$30forpaternitytestingkit(PTK)athislocaldrugstore—andanother$120togettheres
2、ults.Morethan60,000peoplehavepurchasedthePTKssincetheyfirstbecomeavailablewithoutprescriptionslastyears,accordingtoDougFog,chiefoperatingofficerofIdentigene,whichmakestheover-the-counterkits.MorethantwodozencompaniessellDNAtestsdirectlytothepublic,rangin
3、ginpricefromafewhundreddollarstomorethan$2500.Amongthemostpopular:paternityandkinshiptesting,whichadoptedchildrencanusetofindtheirbiologicalrelativesandfamiliescanusetotrackdownkidsputupforadoption.DNAtestingisalsothelatestrageamongpassionategenealogists
4、-andsupportsbusinessesthatoffertosearchforafamily’sgeographicroots.Mosttestsrequirecollectingcellsbyswabbingsalivainthemouthandsendingittothecompanyfortesting.AlltestsrequireapotentialcandidatewithwhomtocompareDNA.Butsomeobserversareskeptical,“Thereisaki
5、ndoffalseprecisionbeinghawkedbypeopleclaimingtheyaredoingancestrytesting,”saysTreyDuster,aNewYorkUniversitysociologist.Henotesthateach5重庆森博国际教育沙坪坝三峡广场新华书店旁立海大厦25楼individualhasmanyancestors-numberinginthehundredsjustafewcenturiesback.Yetmostancestrytestin
6、gonlyconsidersasinglelineage,eithertheYchromosomeinheritedthroughmeninafather’slineormitochondrialDNA,whichapasseddownonlyfrommothers.ThisDNAcanrevealgeneticinformationaboutonlyoneortwoancestors,eventhough,forexample,justthreegenerationsbackpeoplealsohav
7、esixothergreat-grandparentsor,fourgenerationsback,14othergreat-great-grandparents.Criticsalsoarguethatcommercialgenetictestingisonlyasgoodasthereferencecollectionstowhichasampleiscompared.Databasesusedbysomecompaniesdon’trelyondatacollectedsystematically
8、butratherlumptogetherinformationfromdifferentresearchprojects.ThismeansthataDNAdatabasemayhavealotofdatafromsomeregionsandnotothers,soaperson’stestresultsmaydifferdependingonthecompanythatprocessestheresults.Inaddition,the
