gre考试阅读真题解析（陈虎平版）
<p> <span word="Immediately">Immediately</span> <span word="relevant">relevant</span> <span word="to">to</span> <span word="game">game</span> <span word="theory">theory</span> <span word="are">are</span> <span word="the">the</span> <span word="sex">sex</span> <span word="ratios">ratios</span> <span word="in">in</span> <span word="certain">certain</span> <span word="parasitic">parasitic</span> <span word="wasp">wasp</span> <span word="species">species</span> <span word="that">that</span> <span word="have">have</span> <span word="a">a</span> <span word="large">large</span> <span word="excess">excess</span> <span word="of">of</span> <span word="females">females</span>. <span word="In">In</span> <span word="these">these</span> <span word="species">species</span>, <span word="fertilized">fertilized</span> <span word="eggs">eggs</span> <span word="develop">develop</span> <span word="into">into</span> <span word="females">females</span> <span word="and">and</span> <span word="unfertilized">unfertilized</span> <span word="eggs">eggs</span> <span word="into">into</span> <span word="males">males</span>. <span word="A">A</span> <span word="female">female</span> <span word="stores">stores</span> <span word="sperm">sperm</span> <span word="and">and</span> <span word="can">can</span> <span word="determine">determine</span> <span word="the">the</span> <span word="sex">sex</span> <span word="of">of</span> <span word="each">each</span> <span word="egg">egg</span> <span word="she">she</span> <span word="lays">lays</span> <span word="by">by</span> <span word="fertilizing">fertilizing</span> <span word="it">it</span> <span word="or">or</span> <span word="leaving">leaving</span> <span word="it">it</span> <span word="unfertilized">unfertilized</span>. <span word="By">By</span> <span word="Fishers">Fishers</span> <span word="genetic">genetic</span> <span word="argument">argument</span> <span word="that">that</span> <span word="the">the</span> <span word="sex">sex</span> <span word="ratio">ratio</span> <span word="will">will</span> <span word="be">be</span> <span word="favored">favored</span> <span word="which">which</span> <span word="maximizes">maximizes</span> <span word="the">the</span> <span word="number">number</span> <span word="of">of</span> <span word="descendants">descendants</span> <span word="an">an</span> <span word="individual">individual</span> <span word="will">will</span> <span word="have">have</span> <span word="and">and</span> <span word="hence">hence</span> <span word="the">the</span> <span word="number">number</span> <span word="of">of</span> <span word="gene">gene</span> <span word="copies">copies</span> <span word="transmitted">transmitted</span>, <span word="it">it</span> <span word="should">should</span> <span word="pay">pay</span> <span word="a">a</span> <span word="female">female</span> <span word="to">to</span> <span word="produce">produce</span> <span word="equal">equal</span> <span word="numbers">numbers</span> <span word="of">of</span> <span word="sons">sons</span> <span word="and">and</span> <span word="daughters">daughters</span>. <span word="Hamilton">Hamilton</span>, <span word="noting">noting</span> <span word="that">that</span> <span word="the">the</span> <span word="eggs">eggs</span> <span word="develop">develop</span> <span word="within">within</span> <span word="their">their</span> <span word="hostthe">hostthe</span> <span word="larva">larva</span> <span word="of">of</span> <span word="another">another</span> <span word="insectand">insectand</span> <span word="that">that</span> <span word="the">the</span> <span word="newly">newly</span> <span word="emerged">emerged</span> <span word="adult">adult</span> <span word="wasps">wasps</span> <span word="mate">mate</span> <span word="immediately">immediately</span> <span word="and">and</span> <span word="disperse">disperse</span>, <span word="offered">offered</span> <span word="a">a</span> <span word="remarkably">remarkably</span> <span word="cogent">cogent</span> <span word="analysis">analysis</span>. <span word="Since">Since</span> <span word="only">only</span> <span word="one">one</span> <span word="female">female</span> <span word="usually">usually</span> <span word="lays">lays</span> <span word="eggs">eggs</span> <span word="in">in</span> <span word="a">a</span> <span word="given">given</span> <span word="larva">larva</span>, <span word="it">it</span> <span word="would">would</span> <span word="pay">pay</span> <span word="her">her</span> <span word="to">to</span> <span word="produce">produce</span> <span word="one">one</span> <span word="male">male</span> <span word="only">only</span>, <span word="because">because</span> <span word="this">this</span> <span word="one">one</span> <span word="male">male</span> <span word="could">could</span> <span word="fertilize">fertilize</span> <span word="all">all</span> <span word="his">his</span> <span word="sisters">sisters</span> <span word="on">on</span> <span word="emergence">emergence</span>. <span word="Like">Like</span> <span word="Fisher">Fisher</span>, <span word="Hamilton">Hamilton</span> <span word="looked">looked</span> <span word="for">for</span> <span word="an">an</span> <span word="evolutionarily">evolutionarily</span> <span word="stable">stable</span> <span word="strategy">strategy</span>, <span word="but">but</span> <span word="he">he</span> <span word="went">went</span> <span word="a">a</span> <span word="step">step</span> <span word="further">further</span> <span word="in">in</span> <span word="recognizing">recognizing</span> <span word="that">that</span> <span word="he">he</span> <span word="was">was</span> <span word="looking">looking</span> <span word="for">for</span> <span word="a">a</span> <span word="strategy">strategy</span>.</p><p> 与博弈理论更为直接相关的是某些寄生性黄蜂种类的性别比例，雌性黄蜂占有绝对的过量。在这些种类的黄蜂身上，受精卵发展成为雌性黄蜂，未受精卵发展成为雄性黄蜂。雌性黄蜂能储存精子，并对她所产的每一个卵，通过使其受精或不让其受精，从而决定其性别。按照菲希尔的论点，生物体所会择取的是那样一种性别比例，那种性别比例能在最大程度上增加一个个体所能拥有的后代数量，并因此能在最大程度上增加所传递到后代身上去的基因复制品的数量，对于雌性黄蜂来说，繁殖同等数量的雄性后代和雌性后代仍不乏益处。汉密尔顿注意到，蜂卵是在其寄主另一只昆虫的幼虫体内成熟发展的，并且刚刚自卵中育出的成年黄蜂随即进行交配，然后积各奔东西，提供了一种极为严谨的分析。既然一般而言只有一只雌性黄蜂在一特定的幼虫体内产卵，对她来说，只需要繁殖一只雄性黄蜂便获益匪浅，因为这一只雄性黄蜂可以将其同胞的雌性黄蜂在自卵中育出之际皆予授精。如同菲希尔一样，汉密尔顿也意欲寻觅一种在生物进化上的稳定策略，但他更深入了一步，因为他认识到他的研究正是为了去寻找一种生物体的进化策略。</p>
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