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
66
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.
People are confused in their attempts to control malaria in Europe in the early 1900s, because scientists ______.
选项
A、identified only one mosquito species instead of six species
B、thought only three mosquito species transmitted disease
C、thought there was only one mosquito species
D、did not know what species was being studied
答案
A
解析
短文最后一段告诉我们,由于对蚊子种类不了解,20世纪初期疟病曾肆虐欧洲,最终,科学家才了解到坟子这一物种不是由一个种类而是由六个种类组成。所以应该选择A。
转载请注明原文地址:https://kaotiyun.com/show/TyLd777K
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
DNAFingerprintingDNAisthegeneticmaterialfoundwithinthecellnucleiofalllivingthings.Inmammals(哺乳动物)thestrand
FermiProblemOnaMondaymorninginJuly,theworld’sfirstatombombexplodedinNewMexicodesert.Fortysecondslater,t
DuringtheApril28earthquake,thewholeEnglandwasleftwithoutpower.Itwasreportedthatoneladyhadgotherheadandne
Theimmensechangeofthecityastonishedeverymemberoftheconference.
SingingAlarmsCouldSavetheBlindIfyoucannotsee,youmaynotbeabletofindyourwayoutofaburningbuilding--andtha
ALEDLightingIsNotMatureBLEDLightingWillReplaceTraditionalLightingCAlmostEverythingCouldBetheMainLight
ALEDLightingIsNotMatureBLEDLightingWillReplaceTraditionalLightingCAlmostEverythingCouldBetheMainLight
Wehavetothinkverycarefullybeforewetakeanyaction,becauseit’saveryserioussituationwehaveencountered.
Theseareourmotivesfordoingit.
Theseareourmotivesfordoingit.
随机试题
A.丙氨酸和谷氨酰胺B.谷氨酸和丙氨酸C.瓜氨酸和精氨酸D.半胱氨酸和瓜氨酸E.组氨酸和赖氨酸氨在肝中合成尿素的主要中间物质
男性,42岁,患扩张型心肌病3年,检查:心界向左下扩大。心脏听诊:下列哪一种情况不可能出现
庆大霉素无治疗价值的感染是:
增溶剂是高分子化合物,助溶剂是低分子化合物。()
甲公司是一家服装企业,在营销的过程中,一直打着“男人的衣柜”这个口号,根据以上信息可以判断,该公司采用市场定位的方法是()。
进行心理评估的途径或手段有()。
案例一:林老师是某初中的生物老师,正在给初一(2)班上《两栖动物的特点》一课。本课的教学目的是让学生了解两栖类动物青蛙的特点,林老师还精心准备了青蛙标本、三张挂图和视频材料。在上课前,标本和挂图就吸引了许多学生的围观。上课时,他先给学生展示了青蛙
下列命题不正确的是().
Hehadanincreasinglyuneasyfeelingabouthisanswertothequestion.
Duringthetraditionalweddingceremony,thebridalcouplepromiseeachotherlifelongdevotion.Yet,aboutoneoutoffourAmer
最新回复
(
0
)