meili 发表于 2022-10-18 19:39:56

考研英语阅读综合辅导之生物学类02

<p>  阅读综合辅导  [生物学类]  题目序号  题型归类  第1题  细节推导题型  第2题  写作手法题型  第3题  审题定位与中心主旨题型  第4题  词汇题型  第5题  审题定位题型  <span word="Flatfish">Flatfish</span>, <span word="such">such</span> <span word="as">as</span> <span word="the">the</span> <span word="flounder">flounder</span>, <span word="are">are</span> <span word="among">among</span> <span word="the">the</span> <span word="few">few</span> <span word="vertebrates">vertebrates</span> <span word="thatlack">thatlack</span> <span word="approximate">approximate</span> <span word="bilateral">bilateral</span> <span word="symmetry">symmetry</span> . <span word="Most">Most</span> <span word="striking">striking</span> <span word="among">among</span> <span word="the">the</span> <span word="manyasymmetries">manyasymmetries</span> <span word="evident">evident</span> <span word="in">in</span> <span word="an">an</span> <span word="adult">adult</span> <span word="flatfish">flatfish</span> <span word="is">is</span> <span word="eye">eye</span> <span word="placement">placement</span>: <span word="before">before</span> <span word="maturity">maturity</span> <span word="oneeye">oneeye</span> <span word="migrates">migrates</span>, <span word="so">so</span> <span word="that">that</span> <span word="in">in</span> <span word="an">an</span> <span word="adult">adult</span> <span word="flatfish">flatfish</span> <span word="both">both</span> <span word="eyes">eyes</span> <span word="are">are</span> <span word="on">on</span> <span word="the">the</span> <span word="same">same</span> <span word="side">side</span> <span word="ofthe">ofthe</span> <span word="head">head</span>. <span word="While">While</span> <span word="in">in</span> <span word="most">most</span> <span word="species">species</span> <span word="with">with</span> <span word="asymmetries">asymmetries</span> <span word="virtually">virtually</span> <span word="all">all</span> <span word="adults">adults</span> <span word="share">share</span> <span word="thesame">thesame</span> <span word="asymmetry">asymmetry</span>, <span word="members">members</span> <span word="of">of</span> <span word="the">the</span> <span word="starry">starry</span> <span word="flounder">flounder</span> <span word="species">species</span> <span word="can">can</span> <span word="be">be</span> <span word="either">either</span> <span word="left">left</span>-<span word="eyed">eyed</span> <span word="or">or</span> <span word="right">right</span>-<span word="eyed">eyed</span>. <span word="In">In</span> <span word="the">the</span> <span word="waters">waters</span> <span word="between">between</span> <span word="theUnited">theUnited</span> <span word="States">States</span> <span word="and">and</span> <span word="Japan">Japan</span>, <span word="the">the</span> <span word="starry">starry</span> <span word="flounder">flounder</span> <span word="populations">populations</span> <span word="vary">vary</span> <span word="from">from</span> <span word="about">about</span> 50<span word="percent">percent</span> <span word="left">left</span>-<span word="eyed">eyed</span> <span word="off">off</span> <span word="the">the</span> <span word="United">United</span> <span word="States">States</span> <span word="West">West</span> <span word="Coast">Coast</span>, <span word="through">through</span> <span word="about">about</span> 70 <span word="percentleft">percentleft</span>-<span word="eyed">eyed</span> <span word="halfway">halfway</span> <span word="between">between</span> <span word="the">the</span> <span word="United">United</span> <span word="States">States</span> <span word="and">and</span> <span word="Japan">Japan</span>, <span word="to">to</span> <span word="nearly">nearly</span> 100 <span word="percentleft">percentleft</span>-<span word="eyed">eyed</span> <span word="off">off</span> <span word="the">the</span> <span word="Japanese">Japanese</span> <span word="coast">coast</span>.  <span word="Biologists">Biologists</span> <span word="call">call</span> <span word="this">this</span> <span word="kind">kind</span> <span word="of">of</span> <span word="gradual">gradual</span> <span word="variation">variation</span> <span word="over">over</span> <span word="a">a</span> <span word="certaingeographic">certaingeographic</span> <span word="range">range</span> <span word="a">a</span> <span word="cline">cline</span> <span word="and">and</span> <span word="interpret">interpret</span> <span word="clines">clines</span> <span word="as">as</span> <span word="strong">strong</span> <span word="indications">indications</span> <span word="that">that</span> <span word="the">the</span> <span word="variation">variation</span> <span word="isadaptive">isadaptive</span>, <span word="a">a</span> <span word="response">response</span> <span word="to">to</span> <span word="environmental">environmental</span> <span word="differences">differences</span>. <span word="For">For</span> <span word="the">the</span> <span word="starry">starry</span> <span word="flounder">flounder</span> <span word="thisinterpretation">thisinterpretation</span> <span word="implies">implies</span> <span word="that">that</span> <span word="a">a</span> <span word="geometric">geometric</span> <span word="difference">difference</span> <span word="is">is</span> <span word="adaptive">adaptive</span>, <span word="that">that</span> <span word="left">left</span>-<span word="eyedness">eyedness</span> <span word="in">in</span> <span word="the">the</span> <span word="Japanesestarry">Japanesestarry</span> <span word="flounder">flounder</span> <span word="has">has</span> <span word="been">been</span> <span word="selected">selected</span> <span word="for">for</span>, <span word="which">which</span> <span word="provokes">provokes</span> <span word="a">a</span> <span word="perplexing">perplexing</span> <span word="question">question</span>:<span word="what">what</span> <span word="is">is</span> <span word="the">the</span> <span word="selective">selective</span> <span word="advantage">advantage</span> <span word="in">in</span> <span word="having">having</span> <span word="both">both</span> <span word="eyes">eyes</span> <span word="on">on</span> <span word="one">one</span> <span word="side">side</span> <span word="rather">rather</span> <span word="than">than</span> <span word="onthe">onthe</span> <span word="other">other</span>?  <span word="The">The</span> <span word="ease">ease</span> <span word="with">with</span> <span word="which">which</span> <span word="a">a</span> <span word="fish">fish</span> <span word="can">can</span> <span word="reverse">reverse</span> <span word="the">the</span> <span word="effect">effect</span> <span word="of">of</span> <span word="the">the</span> <span word="sidednessof">sidednessof</span> <span word="its">its</span> <span word="eye">eye</span> <span word="asymmetry">asymmetry</span> <span word="simply">simply</span> <span word="by">by</span> <span word="turning">turning</span> <span word="around">around</span> <span word="has">has</span> <span word="caused">caused</span> <span word="biologists">biologists</span> <span word="to">to</span> <span word="studyinternal">studyinternal</span> <span word="anatomy">anatomy</span>, <span word="especially">especially</span> <span word="the">the</span> <span word="optic">optic</span> <span word="nerves">nerves</span>, <span word="for">for</span> <span word="the">the</span> <span word="answer">answer</span>. <span word="In">In</span> <span word="all">all</span> <span word="flatfishthe">flatfishthe</span> <span word="optic">optic</span> <span word="nerves">nerves</span> <span word="cross">cross</span>, <span word="so">so</span> <span word="that">that</span> <span word="the">the</span> <span word="right">right</span> <span word="optic">optic</span> <span word="nerve">nerve</span> <span word="is">is</span> <span word="joined">joined</span> <span word="to">to</span> <span word="the">the</span> <span word="brains">brains</span> <span word="left">left</span> <span word="sideand">sideand</span> <span word="vice">vice</span> <span word="versa">versa</span>. <span word="This">This</span> <span word="crossing">crossing</span> <span word="introduces">introduces</span> <span word="an">an</span> <span word="asymmetry">asymmetry</span>, <span word="as">as</span> <span word="one">one</span> <span word="optic">optic</span> <span word="nerve">nerve</span> <span word="mustcross">mustcross</span> <span word="above">above</span> <span word="or">or</span> <span word="below">below</span> <span word="the">the</span> <span word="other">other</span>. <span word="G">G</span>. <span word="H">H</span>. <span word="Parker">Parker</span> <span word="reasoned">reasoned</span> <span word="that">that</span> <span word="if">if</span>, <span word="for">for</span> <span word="example">example</span>, <span word="aflatfishs">aflatfishs</span> <span word="left">left</span> <span word="eye">eye</span> <span word="migrated">migrated</span> <span word="when">when</span> <span word="the">the</span> <span word="right">right</span> <span word="optic">optic</span> <span word="nerve">nerve</span> <span word="was">was</span> <span word="on">on</span> <span word="top">top</span>, <span word="therewould">therewould</span> <span word="be">be</span> <span word="a">a</span> <span word="twisting">twisting</span> <span word="of">of</span> <span word="nerves">nerves</span>, <span word="which">which</span> <span word="might">might</span> <span word="be">be</span> <span word="mechanically">mechanically</span> <span word="disadvantageous">disadvantageous</span>. <span word="Forstarry">Forstarry</span> <span word="flounders">flounders</span>, <span word="then">then</span>, <span word="the">the</span> <span word="left">left</span>-<span word="eyed">eyed</span> <span word="variety">variety</span> <span word="would">would</span> <span word="be">be</span> <span word="selected">selected</span> <span word="against">against</span>, <span word="sincein">sincein</span> <span word="a">a</span> <span word="starry">starry</span> <span word="flounder">flounder</span> <span word="the">the</span> <span word="left">left</span> <span word="optic">optic</span> <span word="nerve">nerve</span> <span word="is">is</span> <span word="uppermost">uppermost</span>.  <span word="The">The</span> <span word="problem">problem</span> <span word="with">with</span> <span word="the">the</span> <span word="above">above</span> <span word="explanation">explanation</span> <span word="is">is</span> <span word="that">that</span> <span word="the">the</span> <span word="Japanese">Japanese</span> <span word="starryflounder">starryflounder</span> <span word="population">population</span> <span word="is">is</span> <span word="almost">almost</span> <span word="exclusively">exclusively</span> <span word="left">left</span>-<span word="eyed">eyed</span>, <span word="and">and</span> <span word="natural">natural</span> <span word="selectionnever">selectionnever</span> <span word="promotes">promotes</span> <span word="a">a</span> <span word="purely">purely</span> <span word="less">less</span> <span word="advantageous">advantageous</span> <span word="variation">variation</span>. <span word="As">As</span> <span word="other">other</span> <span word="explanationsproved">explanationsproved</span> <span word="equally">equally</span> <span word="untenable">untenable</span>, <span word="biologists">biologists</span> <span word="concluded">concluded</span> <span word="that">that</span> <span word="there">there</span> <span word="is">is</span> <span word="no">no</span> <span word="importantadaptive">importantadaptive</span> <span word="difference">difference</span> <span word="between">between</span> <span word="left">left</span>-<span word="eyedness">eyedness</span> <span word="and">and</span> <span word="right">right</span>-<span word="eyedness">eyedness</span>, <span word="and">and</span> <span word="that">that</span> <span word="the">the</span> <span word="twocharacteristics">twocharacteristics</span> <span word="are">are</span> <span word="genetically">genetically</span> <span word="associated">associated</span> <span word="with">with</span> <span word="some">some</span> <span word="other">other</span> <span word="adaptivelysignificant">adaptivelysignificant</span> <span word="characteristic">characteristic</span>. <span word="This">This</span> <span word="situation">situation</span> <span word="is">is</span> <span word="one">one</span> <span word="commonly">commonly</span> <span word="encountered">encountered</span> <span word="byevolutionary">byevolutionary</span> <span word="biologists">biologists</span>, <span word="who">who</span> <span word="must">must</span> <span word="often">often</span> <span word="decide">decide</span> <span word="whether">whether</span> <span word="a">a</span> <span word="characteristic">characteristic</span> <span word="isadaptive">isadaptive</span> <span word="or">or</span> <span word="selectively">selectively</span> <span word="neutral">neutral</span>. <span word="As">As</span> <span word="for">for</span> <span word="the">the</span> <span word="left">left</span>-<span word="eyed">eyed</span> <span word="and">and</span> <span word="right">right</span>-<span word="eyed">eyed</span> <span word="flatfish">flatfish</span>,<span word="their">their</span> <span word="difference">difference</span>, <span word="however">however</span> <span word="striking">striking</span>, <span word="appears">appears</span> <span word="to">to</span> <span word="be">be</span> <span word="an">an</span> <span word="evolutionary">evolutionary</span> <span word="red">red</span> <span word="herring">herring</span>.  1.<span word="According">According</span> <span word="to">to</span> <span word="the">the</span> <span word="text">text</span>, <span word="starry">starry</span> <span word="flounder">flounder</span> <span word="differ">differ</span> <span word="form">form</span> <span word="most">most</span> <span word="other">other</span> <span word="species">species</span> <span word="offlatfish">offlatfish</span> <span word="in">in</span> <span word="that">that</span> <span word="starry">starry</span> <span word="flounder">flounder</span>  [<span word="A">A</span>] <span word="are">are</span> <span word="not">not</span> <span word="basically">basically</span> <span word="bilaterally">bilaterally</span> <span word="symmetric">symmetric</span>.  [<span word="B">B</span>] <span word="do">do</span> <span word="not">not</span> <span word="become">become</span> <span word="asymmetric">asymmetric</span> <span word="until">until</span> <span word="adulthood">adulthood</span>.  [<span word="C">C</span>] <span word="do">do</span> <span word="not">not</span> <span word="all">all</span> <span word="share">share</span> <span word="the">the</span> <span word="same">same</span> <span word="asymmetry">asymmetry</span>.  [<span word="D">D</span>] <span word="have">have</span> <span word="both">both</span> <span word="eyes">eyes</span> <span word="on">on</span> <span word="the">the</span> <span word="same">same</span> <span word="side">side</span> <span word="of">of</span> <span word="the">the</span> <span word="head">head</span>.  2.<span word="Which">Which</span> <span word="of">of</span> <span word="the">the</span> <span word="following">following</span> <span word="best">best</span> <span word="describes">describes</span> <span word="the">the</span> <span word="organization">organization</span> <span word="of">of</span> <span word="the">the</span> <span word="text">text</span> <span word="as">as</span> <span word="awhole">awhole</span>?  [<span word="A">A</span>] <span word="A">A</span> <span word="phenomenon">phenomenon</span> <span word="is">is</span> <span word="described">described</span> <span word="and">and</span> <span word="an">an</span> <span word="interpretation">interpretation</span> <span word="presented">presented</span> <span word="and">and</span> <span word="rejected">rejected</span>.  [<span word="B">B</span>] <span word="A">A</span> <span word="generalization">generalization</span> <span word="is">is</span> <span word="made">made</span> <span word="and">and</span> <span word="supporting">supporting</span> <span word="evidence">evidence</span> <span word="is">is</span> <span word="supplied">supplied</span> <span word="and">and</span> <span word="weighed">weighed</span>.  [<span word="C">C</span>] <span word="A">A</span> <span word="contradiction">contradiction</span> <span word="is">is</span> <span word="noted">noted</span> <span word="and">and</span> <span word="a">a</span> <span word="resolution">resolution</span> <span word="is">is</span> <span word="suggested">suggested</span> <span word="and">and</span> <span word="then">then</span> <span word="modified">modified</span>.  [<span word="D">D</span>] <span word="A">A</span> <span word="series">series</span> <span word="of">of</span> <span word="observations">observations</span> <span word="is">is</span> <span word="presented">presented</span> <span word="and">and</span> <span word="explained">explained</span> <span word="in">in</span> <span word="terms">terms</span> <span word="of">of</span> <span word="thedominant">thedominant</span> <span word="theory">theory</span>.  3.<span word="The">The</span> <span word="text">text</span> <span word="supplies">supplies</span> <span word="information">information</span> <span word="for">for</span> <span word="answering">answering</span> <span word="which">which</span> <span word="of">of</span> <span word="the">the</span> <span word="following">following</span> <span word="questions">questions</span>?  [<span word="A">A</span>] <span word="Why">Why</span> <span word="are">are</span> <span word="Japanese">Japanese</span> <span word="starry">starry</span> <span word="flounder">flounder</span> <span word="mostly">mostly</span> <span word="left">left</span>-<span word="eyed">eyed</span>?  [<span word="B">B</span>] <span word="Why">Why</span> <span word="should">should</span> <span word="the">the</span> <span word="eye">eye</span>-<span word="sidedness">sidedness</span> <span word="in">in</span> <span word="starry">starry</span> <span word="flounder">flounder</span> <span word="be">be</span> <span word="considered">considered</span> <span word="selectivelyneutral">selectivelyneutral</span>?  [<span word="C">C</span>] <span word="Why">Why</span> <span word="have">have</span> <span word="biologists">biologists</span> <span word="recently">recently</span> <span word="become">become</span> <span word="interested">interested</span> <span word="in">in</span> <span word="whether">whether</span> <span word="a">a</span> <span word="characteristicis">characteristicis</span> <span word="adaptive">adaptive</span> <span word="or">or</span> <span word="selectively">selectively</span> <span word="neutral">neutral</span>?  [<span word="D">D</span>] <span word="How">How</span> <span word="do">do</span> <span word="the">the</span> <span word="eyes">eyes</span> <span word="in">in</span> <span word="flatfish">flatfish</span> <span word="migrate">migrate</span>?  4.<span word="Which">Which</span> <span word="of">of</span> <span word="the">the</span> <span word="following">following</span> <span word="is">is</span> <span word="most">most</span> <span word="clearly">clearly</span> <span word="similar">similar</span> <span word="to">to</span> <span word="a">a</span> <span word="cline">cline</span> <span word="as">as</span> <span word="it">it</span> <span word="is">is</span> <span word="describedin">describedin</span> <span word="the">the</span> <span word="second">second</span> <span word="paragraph">paragraph</span> <span word="of">of</span> <span word="the">the</span> <span word="text">text</span>?  [<span word="A">A</span>] <span word="A">A</span> <span word="vegetable">vegetable</span> <span word="market">market</span> <span word="in">in</span> <span word="which">which</span> <span word="the">the</span> <span word="various">various</span> <span word="items">items</span> <span word="are">are</span> <span word="grouped">grouped</span> <span word="according">according</span> <span word="toplace">toplace</span> <span word="of">of</span> <span word="origin">origin</span>.  [<span word="B">B</span>] <span word="A">A</span> <span word="wheat">wheat</span> <span word="field">field</span> <span word="in">in</span> <span word="which">which</span> <span word="different">different</span> <span word="varieties">varieties</span> <span word="of">of</span> <span word="wheat">wheat</span> <span word="are">are</span> <span word="planted">planted</span> <span word="to">to</span> <span word="yield">yield</span> <span word="acrop">acrop</span> <span word="that">that</span> <span word="will">will</span> <span word="bring">bring</span> <span word="the">the</span> <span word="maximum">maximum</span> <span word="profit">profit</span>.  [<span word="C">C</span>] <span word="A">A</span> <span word="flower">flower</span> <span word="stall">stall</span> <span word="in">in</span> <span word="which">which</span> <span word="the">the</span> <span word="various">various</span> <span word="species">species</span> <span word="of">of</span> <span word="flowers">flowers</span> <span word="are">are</span> <span word="arrangedaccording">arrangedaccording</span> <span word="to">to</span> <span word="their">their</span> <span word="price">price</span>.  [<span word="D">D</span>] <span word="A">A</span> <span word="housing">housing</span> <span word="development">development</span> <span word="in">in</span> <span word="which">which</span> <span word="the">the</span> <span word="length">length</span> <span word="of">of</span> <span word="the">the</span> <span word="front">front</span> <span word="struts">struts</span> <span word="supportingthe">supportingthe</span> <span word="porch">porch</span> <span word="of">of</span> <span word="each">each</span> <span word="house">house</span> <span word="increases">increases</span> <span word="as">as</span> <span word="houses">houses</span> <span word="are">are</span> <span word="built">built</span> <span word="up">up</span> <span word="the">the</span> <span word="hill">hill</span>.  5.<span word="Which">Which</span> <span word="of">of</span> <span word="the">the</span> <span word="following">following</span> <span word="phrases">phrases</span> <span word="from">from</span> <span word="the">the</span> <span word="text">text</span> <span word="best">best</span> <span word="expresses">expresses</span> <span word="the">the</span> <span word="authors">authors</span> <span word="conclusionabout">conclusionabout</span> <span word="the">the</span> <span word="meaning">meaning</span> <span word="of">of</span> <span word="the">the</span> <span word="difference">difference</span> <span word="between">between</span> <span word="left">left</span>-<span word="eyed">eyed</span> <span word="and">and</span> <span word="right">right</span>-<span word="eyed">eyed</span> <span word="flatfish">flatfish</span>?  [<span word="A">A</span>] <span word="Most">Most</span> <span word="striking">striking</span>  [<span word="B">B</span>] <span word="variation">variation</span> <span word="is">is</span> <span word="adaptive">adaptive</span>  [<span word="C">C</span>] <span word="mechanically">mechanically</span> <span word="disadvantageous">disadvantageous</span>  [<span word="D">D</span>] <span word="evolutionary">evolutionary</span> <span word="red">red</span> <span word="herring">herring</span>  [答案与考点解析]  1.【答案】<span word="C">C</span>  【考点解析】这是一道细节推导题。根据本题题干中的<span word="most">most</span> <span word="other">other</span> <span word="species">species</span>可以把本题的答案信息来源确定在第一段的第三句,从第三句的主从句中可以归纳推导出本题的正确答案<span word="C">C</span>。本句中的<span word="while">while</span>一词的含义是虽然、尽管,用来表达事物之间的对照对比。考生在解题时一定要首先学会审题定位的基本功。  2.【答案】<span word="A">A</span>  【考点解析】这是一道文章具体写作手法题。这是一道比较难的题型,需要考生对文章的叙述结构有深刻的理解。本文第一段介绍了一种现象,第二段和第三段是生物学家对这种现象的解释,第四段是本文作者对生物学家的解释提出否定。可见本题的正确选项是<span word="A">A</span>。考生在解题时一定要注意文章的发展脉络。  3.【答案】<span word="B">B</span>  【考点解析】本题是一道审题定位题型。本题的题干没有具体给出寻找答案信息的任何线索。在这种情况下考生一定要牢记原文作者的主要意图。具体来说,本文作者的主要意图是要否定一些生物学家对某种生物现象的解释。相关的内容出现在原文第四段的首句。如果考生能够认识到原文第四段首句在全文中的重要性,就找到了破解本题的方法,再把第三段的尾句和第四段的第二、三句通读并且仔细理解就会找出本题的正确答案<span word="B">B</span>。当然这是一道比较难的题目,需要考生良好的答题素质。希望考生在迷失答题思路的时候,一定要多想一想从原文的中心主旨句和每段的段首句设法破解难题。  4.【答案】<span word="D">D</span>  【考点解析】这是一道词汇理解题。根据原文中的<span word="cline">cline</span>一词可迅速把本题的答案信息确定在第二段第一句。第二段第一句中的<span word="gradual">gradual</span>、<span word="geographic">geographic</span>、<span word="adaptive">adaptive</span>和<span word="environmental">environmental</span> <span word="differences">differences</span>等词提供了本题的正确答案<span word="D">D</span>。考生在阅读原文回答问题时,一定要学会识读原文中的相关重要词语。  5.【答案】<span word="D">D</span>  【考点解析】这是一道审题定位题。根据题干中的<span word="the">the</span> <span word="authors">authors</span> <span word="conclusion">conclusion</span>可将本题的答案信息迅速确定在尾段,确切地说就是尾段的最后一句。考生一定要清楚原文作者的结论一般会出现在全文的尾段。本题的正确答案应该是涉及到尾段的选项<span word="D">D</span>。  [参考译文]  鲆鱼,例如比目鱼,是少数左右两侧不太对称的脊椎动物之一(左右两侧对称指的是身体中线左右两边的结构为镜象反射)。在成年的比目鱼所具有的众多明显的不对称现象中,最令人震惊的是它的眼睛的位置:在成熟以前,一只眼睛会移动,结果是成年比目鱼的两只眼睛都移动到头部的同一侧。在大多数非对称的物种中,成年个体的非对称性看起来都是相同的,但星形比目鱼种的成员则既可以是眼在左侧的(两只眼都在头部的左侧),也可以是眼在右侧的。在美国和日本之间的水域中,星形比目鱼的群体组成不断变化,在美国西海岸附近,50%是眼在左侧的,在美国和日本之间的中间位置,70%是眼在左侧的,而到了靠近日本海岸的地方,则几乎百分之百都是眼在左侧的了。  生物学家将这种在特定地理区域范围内的逐渐变化称为渐变群,并针对渐变群解释说,它强烈地表明这种变化是适应性的,是对环境差异所作出的反应。对于星形比目鱼来说,这种说法暗示形状上的差异(同左右两侧对称的鱼相比)是适应性的,日本的星形比目鱼之所以眼在左侧,是选择的结果,但这又引起了一个令人困惑的问题:两只眼睛都在一侧比两只眼睛分在两侧具有什么选择性的优势呢?  鱼只要简单地转个身,就可以使它的眼睛在一侧的不对称性所带来的影响逆转,这是非常容易的,所以生物学家只好去研究内部解剖学,特别是研究视觉神经,以寻求答案。在所有的比目鱼中,视觉神经都是交叉的,右边的视觉神经连接到大脑的左半部,左边的视觉神经连接到大脑的右半部。这种交叉会引起不对称性,因为一条视觉神经必须会在另一条视觉神经的上面,要不就在下面。<span word="GH">GH</span>帕克对此解释说,举例来说,如果一条比目鱼的右视觉神经在上面而左眼发生了移动,那么两条视觉神经就会扭曲纠缠在一起,这在结构上可能是不利的。于是对于星形比目鱼来说,就不应该选择眼在左侧,因为在星形比目鱼中,左侧的视觉神经是在上面的。  上面这种解释的问题是日本的星形比目鱼种群几乎全是眼在左侧的,而大自然的选择则从不推动完全没有有利条件的种属发展。由于其它的解释被证明同样也是站不住脚的,所以生物学家得出了结论,认为眼是在左侧还是在右侧并没有什么重要的适应性差异,这两种特征在遗传上与别的一些有意义的适应性特征相关。研究进化的生物学家经常会遇到这样的情况,他们经常必须判断一个特征究竟是适应性的,还是在选择上中性的。对于眼在左侧的比目鱼和眼在右侧的比目鱼来说,它们的差异虽然很惊人,但这似乎是进化过程中的一个分散人们注意力的不相干的现象。</p>
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