首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Although numbers of animals in a given region may fluctuate from year to year, the fluctuations are often temporary and, over lo
Although numbers of animals in a given region may fluctuate from year to year, the fluctuations are often temporary and, over lo
admin
2019-02-01
45
问题
Although numbers of animals in a given region may fluctuate from year to year, the fluctuations are often temporary and, over long periods, trivial. Scientists have advanced three theories of population control to account for this relative constancy.
The first theory attributes a relatively constant population to periodic cli- matic catastrophes that decimate populations with such frequency as to prevent them from exceeding some particular limit. In the case of small organisms with short life cycles, climatic changes need not be catastrophic: normal seasonal changes in photoperiod(daily amount of sunlight), for example, can govern population growth. This theory— the density-independent view—asserts that climatic factors exert the same regulatory effect on population regardless of the number of individuals in a region.
A second theory argues that population growth is primarily density-de- pendent—that is, the rate of growth of a population in a region decreases as the number of animals increases. The mechanisms that manage regulation may vary. For example, as numbers in- crease, the food supply would probably diminish, which would increase mortality. In addition, as Lotka and Volterra have shown, predators can find prey more easily in high-density populations. Other regulators include physiological control mechanisms: for example, Christian and Davis have demonstrated how the crowding that results from a rise in numbers may bring about hor- monal changes in the pituitary and adrenal glands that in turn may regulate population by lowering sexual activity and inhibiting sexual maturation. There is evidence that these effects may persist for three generations in the absence of the original provocation. One challenge for density-dependent theorists is to develop models that would allow the precise prediction of the effects of crowding.
A third theory, proposed by Wynne- Edwards and termed "epideic-tic," argues that organisms have evolved a "code"in the form of social or epideic- tic behavior displays, such as winterroosting aggregations or group vocalizing; such codes provide organisms with information on population size in a region so that they can, if necessary, ex- ercise reproductive restraint. However, Wynne-Edwards’ theory, linking animal social behavior and population control, has been challenged, with some justification, by several studies.
Which of the following statements would provide the most of logical continuation of the final paragraph of the passage?
选项
A、Thus Wynne — Edwards’ theory raises serious questions about the constancy of animal population in a region.
B、Because Wynne- Edwards’ theory is able to explain more kinds of animal behavior than is the density-dependent theory, epideictic explanations of population regulation are now widely accepted.
C、The results of one study, for instance, have suggested that group vocalizing is more often used to defend territory than to provide information about population density.
D、Some of these studies have, in fact, worked out a systematic and complex code of social behavior that can regulate population size.
E、One study, for example, has demonstrated that birds are more likely to use winter-roosting aggregations than group vocalizing in order to provide information on population size.
答案
C
解析
哪个是最后一段合乎逻辑的续写?文章最后讲:Wynne一Edwards理论被一些研究攻击,接下来还会谈这个内容。W—E的观点是,有些动物的社会行为和传播行为提供关于种群数量的信息。C.正确。从一研究得出:种群呜叫与其说是提供种群数量的信息,不如讲是为了保卫地盘。否定了W—E的理论。A、B、D、E都不符上述推理。
转载请注明原文地址:https://kaotiyun.com/show/k2kO777K
本试题收录于:
GMAT VERBAL题库GMAT分类
0
GMAT VERBAL
GMAT
相关试题推荐
Muchunfriendlyfeelingtowardscomputershasbeenbasedonthefearofwidespreadunemploymentresultingfromtheirintroductio
Increasingly,overthepasttenyears,people—especiallyyoungpeople—havebecomeawareoftheneedtochangetheireatinghabit
Whatdowemeanbyasatisfactorystandardofliving?Obviously,itmustincludethebasicnecessitiesoflifesuchasfood,clo
Whatdowemeanbyasatisfactorystandardofliving?Obviously,itmustincludethebasicnecessitiesoflifesuchasfood,clo
WashingtonIrvingwasAmerica’sfirstmanofletterstobeknowninternationally.Hisworkswerereceivedenthusiasticallyboth
Alawyerfriendofminehasdevotedherselftotheserviceofhumanity.Herspecialareaiscalled,publicinterestlaw".M
Alawyerfriendofminehasdevotedherselftotheserviceofhumanity.Herspecialareaiscalled,publicinterestlaw".M
Idon’tthinkitisanyuse_________thismatteranyfurther.
Notallmemoriesaresweet.Somepeoplespendalltheirlivestryingtoforgetbadexperiences.Violenceandtrafficaccidentsc
Between1970and1980,energyconsumptionbyUnitedStatesindustrypeakedandthendeclined,sothatby1980totalindustrialu
随机试题
【背景资料】某市建筑公司承建的供电公司职工培训楼工程,地下1层,地上12层,建筑面积24000m2,钢筋混凝土框架结构,计划竣工日期为2014年8月8日。2014年4月28日,市建委有关管理部门按照《建筑施工安全检查标准》(JGJ
渴望结成紧密的个人关系、回避冲突以及建立亲切的友谊属于()
既能祛风通络,又能治经闭、乳房胀痛、乳汁不下的药是
关于钙通道阻滞剂(CCB类)药物的说法,错误的是
在城市市区噪声敏感建筑物集中区域内,禁止夜间进行产生环境噪声污染的建筑施工作业,但()除外。
下列各项关于资产处置的表述中,正确的有()。
在软件项目管理中可以使用各种图形工具来辅助决策,下面对Gantt图的描述中,不正确的是(15)
考生文件夹下存在一个数据库文件“samp3.accdb”,里面已经设计好窗体对象“fStaff"。试在此基础上按照以下要求补充窗体设计:注意:不允许修改窗体对象“fStaff”中已设置好的属性。在窗体页脚节区位置添加两个命令按钮,分别命名为“
收盘价在移动平均线之下运动,回升时未超越移动平均线,且移动平均线已由水平转为下移的趋势,是()。
It’stemptingtospendslowworkdaysthisholidayseasonshoppingforgiftsonline,butemployeesshouldthinktwice.Inarece
最新回复
(
0
)