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
"Hidden" Species May Be Surprisingly Common Cryptic species animals that appear identical but are genetically quite distant—
"Hidden" Species May Be Surprisingly Common Cryptic species animals that appear identical but are genetically quite distant—
admin
2011-01-02
48
问题
"Hidden" Species May Be Surprisingly Common
Cryptic species animals that appear identical but are genetically quite distant—may be much more widespread than previously thought. The findings could have major implications in areas ranging from biodiversity estimates and wildlife management, to our understanding of infectious diseases and evolution.
Reports of cryptic species have increased dramatically over the past two decades with the advent of relatively inexpensive DNA sequencing technology. Markus Pfenninger and Klaus Schwenk, of the Goethe-Universitat, in Frankfurt, Germany, analyzed all known data on cryptic animal species and discovered that they are found in equal proportions throughout all major branches of the animal kingdom and occur in equal numbers in all biogeographieal regions.
Scientists had previously speculated that cryptic species were predominantly found in insects and reptiles, and were more likely to occur in tropical rather than temperate regions. "Species that are seemingly widespread and abundant could in reality be many different cryptic species that have low populations and are highly endangered. " Says Pfenninger. Until the genetic information of all species in at least one taxon is thoroughly studied, no one will know just how many cryptic species exist. "It could be as high as 30%. " Pfenninger says.
"I’m extremely surprised by their results. " Says Alex Smith of the University of Guelph in Ontario, Canada. "It’s a call to arms to keep doing the broad kind of genetic studies that we are doing. "
Sampling as many individuals as possible, scientists hope to complete work on all fish and birds in another 5 to 10 years. Once either of these taxonomic groups is completed, Pfenninger says researchers will be able to decide how many cryptic species exist throughout the animal kingdom.
Examples of cryptic species include the African elephant. A 2001 study found the elephants were actually two genetically distinct, non-interbreeding species, the African bush elephant and the African elephant. The species are currently listed as vulnerable and threatened, respectively, by the World Conservation Union (WCU).
The reclassifications are more than an academic exercise. They define populations that have evolved independently of each other and whose genetic differences can have significant consequences. In the early 1900s misidentification of mosquito species based on morphology confused attempts to control malaria in Europe. Ultimately, what was thought to be a single species was actually made up of six sibling species, only three of which transmitted the disease. "The basic unit in biology is always the species, and you have to know what you are dealing with. " Pfenninger says. Much previous research is now no longer used, he says, because it is not clear what species was being studied.
Which of the following about the African bush elephant and the African elephant is true?
选项
A、The WCU are interbreeding those elephants.
B、They are interbreeding species.
C、They are two genetically distant species.
D、They depend on each other for survival.
答案
C
解析
答案在第六段中。该段举了非洲大象为例,说明什么是cryptic species。第六段的句子“A 2001 study found the elephants were actually two genetically distinct,non-inter-breeding species”是选择C的依据。选项A不对,the WCU并没有杂交繁殖这两种象。选项B不对,短文说这两类象是非杂交物种。选项D的内容短文中找不到。
转载请注明原文地址:https://kaotiyun.com/show/HyLd777K
本试题收录于:
职称英语理工类A级题库职称英语分类
0
职称英语理工类A级
职称英语
相关试题推荐
Common-coldSenseYoucan’tbeatit,butyoudon’thavetojoinit.Maybeitgotthename"commoncold"becauseit’smoreco
Around45%oftheUK’scarbondioxideemissionscomefromtheenergypeopleuseeveryday—athomeandwhentheytravel.Inord
EarBreakthroughNewresearchpublishedinthejournalCurrentBiologyhasaddedsignificantlytounderstandingofhowthee
MobilePhonesMobilephonesshouldcarryalabeliftheyprovedtobeadangeroussourceofradiation,accordingtoRobertBell,
MobilePhonesMobilephonesshouldcarryalabeliftheyprovedtobeadangeroussourceofradiation,accordingtoRobertBell,
SomeSundaynewspapersmaybelongtothesamepublishingcompanybutarenoteditedbythesamegroupofpeople.Bookstallsonl
ALEDLightingIsNotMatureBLEDLightingWillReplaceTraditionalLightingCAlmostEverythingCouldBetheMainLight
HighDiveCherylSternsaimstogoboldlywherenohumanhasevergonebeforeinaballoon:40kilometersupintotheatmosph
IrradiatingFoodIrradiatingfruits,vegetables,porkandchickentokillinsectsandbacteriahasbeenapprovedbytheFood
TheFoodScandalWidensAsthescopeofthefoodscandalwidensinTaiwan—morethan200firmsand500productshavebeeninv
随机试题
(2020年青岛)在西方教育思想史上,被称为“里程碑著作”的有()
简述8086/8088的寄存器。
导致急性肾衰的原因庆大霉素对肾脏损伤的部位
见证取样检测是指在监理单位或建设单位监督下,南施工单位有关人员现场取样,并送至()所进行的检测。
_______是指根据物资的包装、外形、性质特点、重量和数量,结合季节和气候情况,以及储存时间的长短,将物资按一定的规律码成各种形状的货垛。
团队的有效性要素构成有()。
“意识在任何时候都只能是被意识到了的存在,而人们的存在就是他们的现实生活过程。”这表明
if语句的基本形式是:if(表达式)语句,以下关于“表达式”值的叙述中正确的是()。
在考生文件夹下,打开文档wordl.docx,按照要求完成下列操作并以该文件名(wordl.docx)保存文档。【文档开始】最低生活保障标准再次调高本报讯经北京市政府批准,本市城市居民最低生活保障标准再次调整,由家庭月人均收入280元增加到285元。
Forthispart,youareallowed30minutestowriteajobapplicationletter.Youshouldwriteatleast150wordsbutnomoretha
最新回复
(
0
)