2024年6月3日发(作者：)

2000-1Text2

1-Beingamanhasalwaysbeendangerous.

Thereareabout105malesbornforevery100females,butthisratiodropstonearbalanceattheageof

maturity,andamong70-year-oldstherearetwiceasmanywomenasmen.

Butthegreatuniversalofmalemortalityisbeingchanged.

Now,boybabiessurvivealmostaswellasgirlsdo.

Thismeansthat,forthefirsttime,therewillbeanexcessofboysinthosecrucialyearswhentheyare

searchingforamate.

Moreimportant,anotherchancefornaturalselectionhasbeenremoved.

Fiftyyearsago,thechanceofababy(particularlyaboybaby)survivingdependedonitsweight.

Akilogramtoolightortooheavymeantalmostcertaindeath.

Todayitmakesalmostnodifference.

Sincemuchofthevariationisduetogenes,onemoreagentofevolutionhasgone.

2-Thereisanotherwaytocommitevolutionarysuicide:stayalive,buthavefewerchildren.

Fewpeopleareasfertileasinthepast.

Exceptinsomereligiouscommunities,veryfewwomenhave15children.

Nowadaysthenumberofbirths,liketheageofdeath,hasbecomeaverage.

Mostofushaveroughlythesamenumberofoffspring.

Again,differencesbetweenpeopleandtheopportunityfornaturalselectiontotakeadvantageofithave

diminished.

Indiashowswhatishappening.

Thecountryofferswealthforafewinthegreatcitiesandpovertyfortheremainingtribalpeoples.

Thegrandmediocrityoftoday-everyonebeingthesameinsurvivalandnumberofoffspring-meansthat

naturalselectionhaslost80%ofitspowerinupper-middle-classIndiacomparedtothetribes.

3-Forus,thismeansthatevolutionisover;thebiologicalUtopiahasarrived.

Strangely,ithasinvolvedlittlephysicalchange.

Nootherspeciesfillssomanyplacesinnature.

Butinthepass100,000years-eventhepass100years-ourliveshavebeentransformedbutourbodies

havenot.

Wedidnotevolve,becausemachinesandsocietydiditforus.

Darwinhadaphrasetodescribethoseignorantofevolution:they“lookatanorganicbeingasasavage

looksataship,asatsomethingwhollybeyondhiscomprehension.”

Nodoubtwewillremembera20thcenturywayoflifebeyondcomprehensionforitsugliness.

ButhoweveramazedourdescendantsmaybeathowfarfromUtopiawewere,theywilllookjustlikeus.

edtobethedangerinbeingamanaccordingtothefirstparagraph?

[A]Alackofmates.

[B]Afiercecompetition.

[C]Alowersurvivalrate.

[D]Adefectivegene.

estheexampleofIndiaillustrate?

[A]Wealthypeopletendtohavefewerchildrenthanpoorpeople.

[B]Naturalselectionhardlyworksamongtherichandthepoor.

[C]Themiddleclasspopulationis80%smallerthanthatofthetribes.

[D]Indiaisoneofthecountrieswithaveryhighbirthrate.

horarguesthatourbodieshavestoppedevolvingbecause________.

[A]lifehasbeenimprovedbytechnologicaladvance

[B]thenumberoffemalebabieshasbeendeclining

[C]ourspecieshasreachedthehigheststageofevolution

[D]thedifferencebetweenwealthandpovertyisdisappearing

fthefollowingwouldbethebesttitleforthepassage?

[A]SexRatioChangesinHumanEvolution

[B]WaysofContinuingMan’sEvolution

[C]TheEvolutionaryFutureofNature

[D]HumanEvolutionGoingNowhere