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‘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 Frailkfurt,Germany,analyzed all known data on cryptic animal species and discovered that they are found in equal pmponions throughout all major branches 0f the animal kingdom and occur in equal numbers in all biogeographical 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 aU fish and birds in another 5 to 10 years. Once either of these taxonomic groups is completed,Pfenninger says researchers will able t0 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. 第 36 题 Which of the following about the significance of the research on cryptic species is NOT true?
A.
The results of the research can help the development of many other research areas.
B.
The results of the research can help the development of biodiversity estimates.
C.
The results of the research can help our understanding of infectious disease evolution.
D.
The results of the research can help our understanding of“survival of the fittest.”
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【单选题】要在平滑曲线转折点和直线转折点之间进行转换,可以使用 __________- prefix="o" ns="urn:schemas-microsoft-com:office:office" ?xml:namespace>
A.
添加锚点
B.
删除锚点
C.
转换点
D.
自由钢笔
【单选题】追求崇高的理想需要坚定的信念。坚定社会主义信念的根本途径是( )
A.
大胆畅想美好未来
B.
努力保持心理健康
C.
模范遵守社会公德
D.
积极参加社会实践
【单选题】旅行社在( )情形下,违约责任可以减轻或免除。
A.
履行合同后发生不可抗力
B.
由于自身的原因造成违约
C.
自身和游客都有违约行为
D.
完全是导游过错对游客造成违约
【单选题】某块主板能够支持哪种类型的内存,这是由主板上的()决定的.
A.
北桥芯片
B.
CPU
C.
南桥芯片
D.
网卡芯片
【单选题】要在平滑曲线转折点和直线转折点之间进行转换,可以使用( )工具。
A.
删除锚点
B.
添加锚点
C.
自由钢笔
D.
转换点
【单选题】某块主板能够支持哪种类型的内存,这是由主板上的( )决定的.
A.
CPU
B.
北桥芯片
C.
南桥芯片
D.
网卡芯片
【单选题】两独立样本比较的秩和检验,为便于查临界值表,其检验统计量 T 通常取:
A.
例数较小的秩和
B.
例数较大的秩和
C.
较小的秩和
D.
较大的秩和
E.
任意一组数据的秩和
【单选题】旅行社在( )情形下,违约责任可以减轻或免除。
A.
履行合同后发生不可抗力
B.
自身和游客都有违约行为
C.
由于自身的原因造成违约
D.
完全是导游过错对游客造成违约
【单选题】旅行社在()情形下,违约责任可以减轻或兔除。
A.
履行合同后发生不可抗力
B.
身和游客都有违约行为
C.
由于自身的原因造成违约
D.
完全是导游过错对游客造成违约
【单选题】What is NOT stated about the product?
A.
Its design is patented.
B.
It is recommended by doctors.
C.
It allows air to pass through.
D.
It is available in different sizes.
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