3月10日最新SAT阅读考试真题火速来袭(三)

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敲黑板，划重点!这是一篇来自3月10日SAT阅读的考试真题，备考的宝宝们千万别做过这篇训练阅读的复习资料哦。

阅读本次篇章难度水平趋于正常，顺序类似于2017年8月北美出题。

阅读原文

In the spring of 1879, Hermann Lau shot two white-winged choughs,Corcorax

melanorhamphos, off their nest in Queensland, Australia. He watched asadditional

choughs continued to attend the nest, proving that a cooperativegroup shared

parental care ( 1). Since then, cooperatively breeding birds havehad a starring

role in efforts to explain the evolution of complex animalsocieties. We now know

that “helpersat-the-nest” who forgo reproduction areoften relatives of the

breeding pair. Genetic payoff is, thus, one of severaladvantages that helpers

can gain from their super? cially altruistic behavior (2). On page 1506 of this

issue, Feeney et al. ( 3) show that collective defenseagainst brood parasites

(see the ? gure) can enhance such bene? ts ofcooperation. Why do some bird

species cooperate and others do not? Globalanalyses have shown that cooperative

breeding (now known from 9% of species) isassociated with a slow pace of life

(characterized by high survival rates andlow turnover of breeding territories) (

4), monogamy (which facilitates kinselection within families) ( 5), and

unpredictable environments (such as aridzones) that might favor cooperation as a

bet-hedging strategy ( 6). But thesefactors often fail to predict the incidence

of cooperation among relatedspecies or within geographical regions ( 7). Feeney

et al.’s study is built onthe premise that brood parasitism—reproductive

cheating by species such ascuckoos and cowbirds, which exploit other birds to

raise their young—is asevere selection pressure on their hosts’ breeding

strategies. Parasitizedparents typically not only lose their current offspring

but also waste a wholebreeding season raising a demanding impostor. The best way

to avoid parasitismis to repel adult parasites from the nest. Feeney et al. show

that socialitycan be pivotal to this process. The authors begin by unfolding a

new map. Usingdata compiled by BirdLife International, they show that the global

distributionof cooperatively breeding birds overlaps strikingly with that of

broodparasites. This overlap need not re? ect a causal relationship:

The same unpredictable environments thatfavor cooperation could also favor

alternative breeding strategies such asparasitism. However, the authors go on to

show that even within geographicalregions rich in both parasites and

cooperators—Australia and southern Africa—cooperativebreeders are much more

likely than noncooperative species to be targeted bybrood parasites. To

determine the reasons for this correlation, Feeney et al.studied cooperative

breeding in superb fairy-wrens (Malurus cyaneus) inAustralia. Horsfield’s

bronze-cuckoos (Chalcites basalis) should bene? t fromtargeting larger groups of

fairy-wrens because more helpers mean faster chickgrowth. Yet, data from a

6-year field study show that in practice, cuckoosrarely experience this

advantage, because larger groups of fairywrens much moreeffectively detect and

repel egg-laying intrusions by cuckoo females,mobilizing group defenses with a

cuckoospeci? c alarm call. Thus, cooperationand parasitism could reciprocally

in? uence one another: Cooperators might bemore attractive targets because they

make better foster parents, but once

exploited by parasites, they are alsobetter able to ? ght back, helping

cooperation to persist ( 8). Feeney et al. ?nd that superior anticuckoo defenses

in larger groups account for 0.2 moreyoung ? edged per season on average than

smaller groups—a substantial boostgiven the fairy-wrens’ low annual fecundity.

These results show convincinglythat defense against brood parasites augments the

bene? ts of helping, promotingthe persistence of cooperation. But as the authors

note, they cannot revealwhat caused cooperation to evolve initially. Brood

parasitism alone cannotresolve the question of why some birds breed

cooperatively. For example,cooperative king? shers and bee-eaters are heavily

parasitized in Africa butnot in Australasia, showing that other advantages of

helping behavior are suf?cient for cooperation to persist. But we should take

parasitism seriously as animportant force in a cooperative life. Indeed, it may

provide a mechanismcontributing to the previously discovered global correlates

of cooperation (4–6). Some insight into the likely order of evolution might come

from furthercomparative predictions. For instance, if cooperation arose fi rst

as a defenseagainst parasitism, cooperators may be most prevalent among hosts

that relyheavily on repelling adult parasites, rather than on antiparasite

strategies atlater reproductive stages, such as egg or chick discrimination (

9). Incontrast, if parasites target existing cooperators because they

providesuperior care, this should be especially true of parasites whose chicks

havethe most pressing needs—for instance, those in parasitic families with

largebody size relative to their hosts or those whose chicks do not kill host

youngand therefore must share their foster parents’ care. Could there be a

similarassociation between cooperation and parasitism among other highly

socialanimals? Cooperation in mammals clearly persists irrespective of

parasitism, giventhat there are no known brood-parasitic mammals (perhaps

because it would bediffi cult for a mammal to insert live young into another’s

care). Butrepelling parasitic egg-laying intrusions is crucial to many hosts of

sociallyparasitic insects and has shaped sophisticated adaptations and

counterdefensesfor and against brute force and secrecy ( 10). It will be

fascinating toexplore how selection for antiparasitic defense has interacted

with monogamyand defensible resources as forces favoring kin-selected

cooperation ininvertebrates, touching on an active debate in evolutionary

biology. Answers tosuch comparative questions will ultimately be limited by our

knowledge ofnatural history. The work by Feeney et al. is testament to the

evolutionaryinsights enabled by careful long-term fi eld studies, together with

thecumulative legacy of those naturalists who made the unglamorous effort

torecord and publish observations of real animals in real places.

文章概述

作者：Claire N. Spottiswoode

题目：How Cooperation Defeats Cheats

本篇文章的主旨是红嘴山鸦之间的合作对于它们遭到寄生虫入侵的影响。文章中谈到，红嘴山鸦之间的合作和寄生虫的入侵是相互作用的。合作容易让它们变成寄生虫的目标，与此同时，它们之间的合作也让它们更容易对抗寄生虫。在文中，作者也阐明了群体大小对于感染寄生虫几率的影响。越小的群体，感染几率越大，越大的群体，感染几率越小。在文章的最后一段，作者表明研究的结果虽然能够说明合作对于寄生物入侵的影响，但是暂时还不能揭开红嘴山鸦最初是如何进化出合作的特性的。

考试题目

1.主旨题，问作者这篇研究的目的是什么。

2.作者文章中收集的data有什么样的作用?

3.词汇题：reflect在文中的意思。

4.词汇题：favor在文中的意思。

5.独立取证题：问那句话是文中作者提到的，群体数量对寄生物影响的证据。

6.细节题：红嘴山鸦在繁殖中的特点

7.目的题：最后一段的作用

8.图表题，问从第一个图表能得出什么关于群体大小和寄生的关系。

9.图表题，问从图表中能得出什么样的比对信息。

10.图表题，问从第二个图表中能得出什么。

以上是易伯华为宝宝们整理出来的最新SAT阅读考试真题第一篇，稍后献上3月10日考试其它阅读真题，敬请期待哦。易伯华祝备考SAT的宝宝们取得理想成绩!易伯华会一直陪在宝宝们身边，加油~