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.
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
第三段和第五段提供了答案。第三段的倒数第二句中的Until…。no one will know just how many cryptic species exist.其意思就是人们目前还不知道存在多少隐蔽性物种。第五段的最后一句也说明了研究者目前对此尚未了解。
转载请注明原文地址:https://kaotiyun.com/show/XyLd777K
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
ScientistsDevelopWaysofDetectingHeartAttackGermanresearchershavecomeupwithanewgenerationofdefibrillators(除颤
ScientistsDevelopWaysofDetectingHeartAttackGermanresearchershavecomeupwithanewgenerationofdefibrillators(除颤
ScientistsDevelopWaysofDetectingHeartAttackGermanresearchershavecomeupwithanewgenerationofdefibrillators(除颤
Thedrinkingwaterhasbecamecontaminatedwithlead.
ManyChildren’sDeathsPreventable:WHOOverfivemillionchildrendieeachyearfromdisease,infectionsandaccidentsrela
Choosingatopicforresearchisimportantinthatyouwillputagreatdealoftimeandenergyintoit.Youcanresearchthet
SomeSundaynewspapersmaybelongtothesamepublishingcompanybutarenoteditedbythesamegroupofpeople.Manyboysand
HighDiveCherylSternsaimstogoboldlywherenohumanhasevergonebeforeinaballoon:40kilometersupintotheatmosph
IrradiatingFoodIrradiatingfruits,vegetables,porkandchickentokillinsectsandbacteriahasbeenapprovedbytheFood
随机试题
A.骨折延迟愈合B.血管损伤C.骨筋膜室综合征D.神经损伤E.关节僵硬腓骨头、颈骨折()
旋转阳极启动与保护装置不包括
关于碘伏,哪种说法是错误的
针灸治疗肺热伤津型痿证,可在主方的基础上加()
下列各选项中,属于民法上的孳息的有( )。
在现代纸币制度下,引起货币失衡的原因主要是()。
以下我国佛教石窟和摩崖造像中,尤以唐代造像和壁画艺术著称于世的有()。
Althoughsolutionstoaproblemareoftenthe.fruitofdirectinvestmentsintargetedresearch,themostrevolutionarysolution
AimlessnesshashardlybeentypicalofthepostwarJapanwhoseproductivityandsocialharmonyaretheenvyoftheUnitedStates
Intheearly20thcentury,fewthingsweremoreappealingthanthepromiseofscientificknowledge.Inaworldstrugglingwithr
最新回复
(
0
)