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(隐蔽的;隐藏的)species -- animals that appear identical but are genetically qui
"Hidden" Species May Be Surprisingly Common Cryptic(隐蔽的;隐藏的)species -- animals that appear identical but are genetically qui
admin
2011-01-02
49
问题
"Hidden" Species May Be Surprisingly Common
Cryptic(隐蔽的;隐藏的)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(生物多样性)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 (脱氧核糖核酸) 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 biogeographical(生物地理学的)regions.
Scientists had previously speculated that cryptic species were predominantly found in insects and reptiles(爬行动物), and were more likely to occur in tropical rather than temperate(温带的)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(分类单元)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 (非杂交繁殖的) 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(疟疾)in Europe. Ultimately, what was thought to be a single species was actually made up of six sibling(同胞,同属)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.
Do scientists know how many cryptic species exist?
选项
A、Not yet.
B、Yes, they do.
C、They will know the answer in another one or two-years.
D、They will never know the answer.
答案
A
解析
短文第三段最后一句提到“直到人们对至少一个类群的所有物种的基因信息有了深入研究,没有人能知道究竟有多少隐性物种存在。”故选A。
转载请注明原文地址:https://kaotiyun.com/show/FALd777K
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
ManyOlderDoctorsPlantoPhaseoutTheirPracticeTheresultsofanewsurveyindicatethat48percentofphysiciansbetween5
MultipleSclerosis(多发性硬化症)1.MultipleSclerosis(MS)isadiseaseinwhichthepatient’simmune(免疫的)systemattacksthecentr
AmericanDreamsThereisacommonresponsetoAmericaamongforeignwriters:theUSisalandofextremeswherethebestof
HypertensionDrugsFoundtoCutRiskofStrokeAustraliandoctorsdeclaredMondaythatacocktailofsimpleantihypertensive
ListeningtoBirdsongAmalezebrafinchchirpsawaytohimself.Suddenlyhenoticesafemalebirdnearby.Herealizesheha
AmericanDreamsThereisacommonresponsetoAmericaamongforeignwriters:theUSisalandofextremeswherethebestof
ThepowersoftheEuropeanCommissiontoregulatecompetition4ntheCommunityareincreasing.
A.milk,meat,vegetables,etc.weredeliveredB.ithaspromotedthesalesofmanykindsofcommoditiesC.anew,economicalwa
CellPhoneLetsYourSecretOutYourcellphoneholdssecretsaboutyou.Besidesthenamesand【C1】______thatyou’veprogra
Customersoftendeferpaymentforaslongaspossible.
随机试题
你在一个WindowsServer2003网络中利用DNS服务器实现名称解析服务,当我们利用DNS服务时可以实现()目的。
诊断肝豆状核变性可做的检测为()
那个不是使用环孢素的患者复诊的检查项目
按照《民事诉讼法》规定,下列不能作为自然人诉讼代理人的是()。
下列关于耕地占用税的征收管理的陈述,正确的有()。
根据车船税的有关规定,下列表述正确的有()。
下列关于酒的诗词与作者对应不正确的是()。
如果各服务对象的实际需要都相同,而社会工作者所能提供的资源和服务又非常充分,可以给予各服务对象平等的服务。如果资源不足,则可以区别对待。这采用的是处理伦理难题的什么原则?( )。
对于被判处徒刑缓刑的罪犯,由()交所在单位或者基层组织予以考察。
南齐谢赫写过一部很著名的理论著作是_______。
最新回复
(
0
)